U.S. patent number RE41,147 [Application Number 11/873,641] was granted by the patent office on 2010-02-23 for method and apparatus for pluggable fiber optic modules.
This patent grant is currently assigned to JDS Uniphase Corporation. Invention is credited to Edwin Dair, Wenbin Jiang, Ron Cheng Chuan Pang, Yong Peng Sim, Kee Sin Tan, Ronson K. Tan, Cheng Ping Wei.
United States Patent |
RE41,147 |
Pang , et al. |
February 23, 2010 |
Method and apparatus for pluggable fiber optic modules
Abstract
Pluggable fiber optic modules having a receive printed circuit
board and a transmit printed circuit board perpendicular with an
interface printed circuit board with an edge connection. The edge
connection of the interface printed circuit board to plug into and
out from an edge connector of a host printed circuit board. A
transmitter optoelectronic device is coupled to the transmit
printed circuit board. A receiver optoelectronic device is coupled
to the receive printed circuit board. The pluggable fiber optic
modules may further include a support base, a nose receptacle, and
an alignment plate.
Inventors: |
Pang; Ron Cheng Chuan
(Singapore, SG), Sim; Yong Peng (Singapore,
SG), Dair; Edwin (Los Angeles, CA), Jiang;
Wenbin (Thousand Oaks, CA), Wei; Cheng Ping (Gilbert,
AZ), Tan; Ronson K. (Singapore, SG), Tan; Kee
Sin (Singapore, SG) |
Assignee: |
JDS Uniphase Corporation
(Milpitas, CA)
|
Family
ID: |
27403356 |
Appl.
No.: |
11/873,641 |
Filed: |
October 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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09656779 |
Sep 7, 2000 |
6873800 |
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09321308 |
May 27, 1999 |
6901221 |
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60283046 |
Apr 10, 2001 |
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Reissue of: |
10118761 |
Apr 8, 2002 |
07116912 |
Oct 3, 2006 |
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Current U.S.
Class: |
398/139; 398/138;
385/92 |
Current CPC
Class: |
G02B
6/4214 (20130101); G02B 6/428 (20130101); G02B
6/4277 (20130101); G02B 6/4261 (20130101); G02B
6/4246 (20130101); G02B 6/4263 (20130101); G02B
6/4257 (20130101); G02B 6/4284 (20130101); G02B
6/424 (20130101); G02B 6/4201 (20130101); G02B
6/4253 (20130101); G02B 6/4292 (20130101) |
Current International
Class: |
H04B
10/00 (20060101) |
Field of
Search: |
;398/138-139
;385/88-94 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2 297 007 |
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Jul 1996 |
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GB |
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07-225327 |
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Aug 1995 |
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JP |
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07-225328 |
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Aug 1995 |
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JP |
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WO 95/12227 |
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May 1995 |
|
WO |
|
Other References
Naoaki Yamanaka, Optoelectronic Packaging, a Wiley-Interscience
Publication, Chapter Two, "Communication System Interconnection
Structure," pp. 11-23, 38-43. cited by examiner .
Shinichi Sasaki, "A Compact Optical Active Connector: An Optical
Interconnect Module with an Electrical Connector Interface," IEEE
Transactions on Advanced Packaging, vol. 22, No. 4, Nov. 1999. pp.
541-550. cited by examiner.
|
Primary Examiner: Bello; Agustin
Attorney, Agent or Firm: Pequignot; Mathew A. Pequignot +
Myers LLC
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This U.S. Non-Provisional Patent Application claims the benefit of
U.S. Provisional Patent Application No. 60/283,046 entitled "METHOD
AND APPARATUS FOR PLUGGABLE FIBER OPTIC MODULES", filed Apr. 10,
2001 by Ron Cheng Pang et al.
This U.S. Non-Provisional Patent Application also claims the
benefit of and is a continuation-in-part application of U.S.
application Ser. No. 09/321,308, entitled "METHOD AND APPARATUS FOR
VERTICAL PCB FIBER OPTIC MODULES", filed May 27, 1999 by inventors
Wenbin Jiang et al, and claims the benefit of and is a
continuation-in-part application of U.S. application Ser. No.
09/656,779, entitled "HOT PLUGGABLE OPTICAL TRANSCEIVER IN A SMALL
FORM PLUGGABLE PACKAGE", filed Sep. 7, 2000 now U.S. Pat. No.
6,873,800, by inventors Wei et al, which is incorporated herein by
reference, all of which are to be assigned to E2O Communications,
Inc.
Claims
What is claimed is:
1. A fiber optic module for coupling photons between optoelectronic
devices and optical fibers, the fiber optic module comprising: a
horizontal printed circuit board (PCB) arranged horizontally, the
horizontal printed circuit board having an edge connection to plug
into and out of an edge connector of a host system; a first
vertical printed circuit board (PCB) arranged at a perpendicular
angle with the horizontal printed circuit board, the first
optoelectronic device having terminals coupled to the first
vertical printed circuit board, the first vertical printed circuit
board electrically coupled to the horizontal printed circuit board
along a right side thereof; a second vertical printed circuit board
(PCB) arranged at a perpendicular angle with the horizontal printed
circuit board, the second optoelectronic device having terminals
coupled to the second vertical printed circuit board, the second
vertical printed circuit board electrically coupled to the
horizontal printed circuit board along a left side thereof parallel
to the first vertical printed circuit board; and a support base to
support the horizontal printed circuit board, the first vertical
printed circuit board, and the second vertical printed circuit
board; wherein the support base includes right and left slots to
support the sides of the first and second vertical printed circuit
boards, respectively; and wherein the horizontal printed circuit
board includes first and second cutouts enabling edges of the first
and second vertical printed circuit boards to be received in the
right and left slots, respectively.
2. The fiber optic module of claim 1 further comprising: a housing
coupled around the horizontal printed circuit board, the first
vertical printed circuit board, and the second vertical printed
circuit board.
3. The fiber optic module of claim 2 wherein, the housing is a
shielded housing to shield the horizontal printed circuit board,
the first vertical printed circuit board, and the second vertical
printed circuit board to reduce electromagnetic interference
(EMI).
4. The fiber optic module of claim 1 wherein the edge connection of
the horizontal printed circuit board has a plurality of pads to
couple to the edge connector of the host system; and wherein the
first vertical printed circuit board has one or more solder pads to
couple to one or more first solder pads of the horizontal printed
circuit board, and the second vertical printed circuit board has
one or more solder pads to couple to one or more second solder pads
of the horizontal printed circuit board.
5. The fiber optic module of claim 1, wherein the first vertical
printed circuit board further includes one or more first electrical
components coupled to the first optoelectronic device to control
the first optoelectronic device, and wherein the second vertical
printed circuit board further includes one or more second
electrical components coupled to the second optoelectronic device
to control the second optoelectronic device, and a backside ground
plane between the first and second electrical components to
minimize crosstalk therebetween.
6. The fiber optic module of claim 1 wherein, the horizontal
printed circuit board further includes a ground plane to reduce
electromagnetic fields generated by electrical components.
7. The fiber optic module of claim 1, wherein the first and second
vertical printed circuit boards each further include a ground plane
facing each other to reduce electromagnetic fields generated by
electrical components.
8. The fiber optic module of claim 1, further comprising: a first
optical block coupled to the first optoelectronic device, the first
optical block having a first opening to receive the first
optoelectronic device, and a first lens to couple photons between
the first optoelectronic device and an optical fiber; and a second
optical block coupled to the second optoelectronic device, the
second optical block having a second opening to receive the second
optoelectronic device, and a second lens to couple photons between
the second optoelectronic device and an optical fiber.
9. The optic fiber module of claim 8 further comprising: a nose
receptacle to receive an optical fiber connector and to hold an
optical fiber substantially fixed and aligned with an optical
opening of the optical block.
10. The fiber optic module of claim 9 wherein, the nose receptacle
is formed of metal or metalized plastic to reduce electromagnetic
interference.
11. The fiber optic module of claim 1 further comprising: an
optical block coupled to the first and second optoelectronic
devices, the optical block having first and second openings to
receive the first and second optoelectronic devices perpendicular
to the first and second printed circuit boards, respectively, a
first lens and a first reflector to couple photons between the
first optoelectronic device and a first optical fiber, and a second
lens and a second reflector to couple photons between the second
optoelectronic device and a second optical fiber.
12. The fiber optic module of claim 11, wherein the first lens of
the optical block to launch photons from the first optoelectronic
device along a first optical axis; wherein the second lens of the
optical block is a focusing lens to couple photons to the second
optoelectronic device along a second optical axis; wherein the
first and second optical axes are offset from each other to
minimize optical crosstalk therebetween.
13. The fiber optic module of claim 11 further comprising: a nose
receptacle to receive an optical fiber connector and to hold an
optical fiber substantially fixed and aligned with an optical
opening of the optical block.
14. The fiber optic module of claim 13 wherein, the nose receptacle
is formed of metal or metalized plastic to reduce electromagnetic
interference.
15. The fiber optic module of claim 13 further comprising: an
alignment plate coupled between the optical block and the nose
receptacle, the alignment plate to align one or more optical fibers
with the optical opening of the optical block.
16. The fiber optic module of claim 1, wherein the support base
includes one or more pillars to engage one or more respective
openings in the horizontal printed circuit board to deter movement
thereof when the fiber optic module is plugged into or unplugged
from the edge connector of the host system.
17. The fiber optic module of claim 1, further comprising: a
cover/housing coupled to the support base and the nose receptacle
around the horizontal printed circuit board, the first vertical
printed circuit board, and the second vertical printed circuit
board.
18. The fiber optic module of claim 17 wherein, the cover/housing
is a shielded cover/housing to shield the horizontal printed
circuit board, the first vertical printed circuit board, and the
second vertical printed circuit board to reduce electromagnetic
interference (EMI).
19. The fiber optic module of claim 17 further comprising: an
internal shield located under the cover/housing, over the
horizontal printed circuit board, and between the first vertical
printed circuit board and the second vertical printed circuit
board, the internal shield to shield and reduce electromagnetic
interference (EMI).
20. The fiber optic module of claim 1, wherein, the first
optoelectronic device is a photodetector.
21. The fiber optic module of claim 1, wherein, the second
optoelectronic device is an emitter.
22. The fiber optic module of claim 1, wherein the horizontal
printed circuit board has a plurality of pins to couple to a host
system; and wherein the first and second vertical printed circuit
boards have solder pads to couple to the horizontal printed circuit
board.
23. A fiber optic transceiver comprising: an interface printed
circuit board (PCB) having an edge connection to couple to and to
decouple from an edge connector of a host system; a receive printed
circuit board (PCB) perpendicularly coupled to the interface
printed circuit board along a right side thereof, the receive
printed circuit board having a receiving optoelectronic device
coupled perpendicularly thereto; a transmit printed circuit board
(PCB) perpendicularly coupled to the interface printed circuit
board along a left side thereof parallel to the receive printed
circuit board, the transmit printed circuit board having a
transmitting optoelectronic device coupled perpendicularly thereto;
and a support base to support the interface printed circuit board,
the receive printed circuit board, and the transmit printed circuit
board; wherein the support base includes right and left slots to
support the sides of the transmit and receive printed circuit
boards, respectively; and wherein the interface printed circuit
board includes first and second cutouts enabling edges of the
transmit and receive printed circuit boards to be received in the
right and left slots, respectively.
24. The fiber optic transceiver of claim 23 further comprising: an
optical block coupled to the transmitting optoelectronic device and
the receiving optoelectronic device, the optical block having a
first opening to receive the transmitting optoelectronic device
perpendicular to the transmit printed circuit board, a first lens
to couple photons from the transmitting optoelectronic device into
a first optical fiber, a first reflector for reflecting photons at
substantially a 90.degree. angle into the first optical fiber; a
second opening to receive the receiving optoelectronic device
perpendicular to the receive printed circuit board, a second lens
to couple photons from a second optical fiber into the receiving
optoelectronic device, and a second reflector for reflecting
photons at substantially a 90.degree. angle into the second optical
fiber.
25. The fiber optic transceiver of claim 24 further comprising: a
nose receptacle to receive an optical fiber connector and to hold
an optical fiber substantially fixed and aligned with an optical
opening of the optical block.
26. The fiber optic transceiver of claim 25 further comprising: an
alignment plate coupled between the optical block and the nose
receptacle, the alignment plate to align first and second optical
fibers with the optical opening of the optical block.
27. The fiber optic transceiver of claim 26 further comprising: a
cover/housing coupled to the support base and the nose receptacle
around the interface printed circuit board, the receive printed
circuit board, and the transmit printed circuit board.
28. The fiber optic transceiver of claim 27 wherein, the
cover/housing is a shielded cover/housing to shield the interface
printed circuit board, the receive printed circuit board, and the
transmit printed circuit board to reduce electromagnetic
interference (EMI).
29. The fiber optic transceiver of claim 28 wherein, the alignment
plate is formed of metal or metalized plastic to reduce
electromagnetic interference and the cover/housing has a tab to
electrically couple to the alignment plate.
30. The fiber optic transceiver of claim 29 wherein the support
base includes one or more pillars to engage one or more respective
openings in the interface printed circuit board to deter movement
thereof when the fiber optic transceiver is plugged into or
unplugged from the edge connector of the host system.
31. The fiber optic transceiver of claim 23, wherein the transmit
printed circuit board further includes one or more first electrical
components coupled to the transmitting optoelectronic device to
control the transmitting optoelectronic device, wherein the receive
vertical printed circuit board further includes one or more second
electrical components coupled to the receiving optoelectronic
device to control the receiving optoelectronic device, and wherein
at least one of the receive and transmit printed circuit boards
further includes a backside ground plane between the first and
second electrical components to minimize crosstalk
therebetween.
32. A fiber optic module comprising: a base having one or more
pillars; a first printed circuit board (PCB) having an edge
connection, at least one left solder pad, at least one right solder
pad, and one or more openings, the one or more openings to slide
over the one or more pillars and align the first printed circuit
board to the base; a second printed circuit board (PCB) having at
least one solder pad to couple perpendicularly to the at least one
left solder pad along a left side of the first printed circuit
board, the second printed circuit board having a first
optoelectronic device coupled thereto; a third printed circuit
board (PCB) having at least one solder pad to couple
perpendicularly to the at least one right solder pad along a right
side of the first printed circuit board parallel to the second
printed circuit board, the third printed circuit board having a
second optoelectronic device coupled thereto; an optical block
having openings to receive the first optoelectronic device and the
second optoelectronic device; a nose receptacle having a plug
opening to receive an optical fiber plug; and a cover coupled to
the base and the nose receptacle to cover and protect the optical
block and the first, second, and third printed circuit boards;
wherein the base includes right and left slots to support the sides
of the second and third printed circuit boards, respectively; and
wherein the first printed circuit board includes first and second
cutouts enabling edges of the second and third printed circuit
boards to be received in the right and left slots,
respectively.
33. The fiber optic module of claim 32 wherein the base couples to
the nose receptacle and includes a support tab to support an end of
the first printed circuit board and a support edge to support an
opposite end of the first printed circuit board.
34. The fiber optic module of claim 32 further comprising: an
alignment plate coupled between the optical block and the nose
receptacle, the alignment plate to align first and second optical
fibers with an optical opening of the optical block.
35. The fiber optic module of claim 34 wherein, the cover to shield
the first, second, and third printed circuit boards to reduce
electromagnetic interference (EMI).
36. The fiber optic module of claim 35 wherein, the cover is formed
of metalized plastic.
37. The fiber optic module of claim 35 wherein, the cover further
includes one or more fingers to couple to a cage of the host
system.
38. The fiber optic module of claim 35 wherein, the alignment plate
to shield and reduce electromagnetic interference (EMI), and the
cover has a tab to couple to the alignment plate.
39. The fiber optic module of claim 38 wherein, the alignment plate
is formed of metalized plastic.
40. The fiber optic module of claim 32, wherein the second printed
circuit board further includes one or more first electrical
components coupled to the first optoelectronic device to control
the first optoelectronic device, wherein the third vertical printed
circuit board further includes one or more second electrical
components coupled to the second optoelectronic device to control
the second optoelectronic device, and wherein at least one of the
second and third printed circuit boards further includes a backside
ground plane between the first and second electrical components to
minimize crosstalk therebetween.
41. The fiber optic module of claim 32, wherein the block includes:
a first opening to receive the first optoelectronic device
perpendicular to the second printed circuit board, a first lens to
couple photons from the first optoelectronic device into a first
optical fiber, a first reflector for reflecting photons at
substantially a 90.degree. angle into the first optical fiber; a
second opening to receive the second optoelectronic device
perpendicular to the third printed circuit board, a second lens to
couple photons from a second optical fiber into the second
optoelectronic device, and a second reflector for reflecting
photons at substantially a 90.degree. angle into the second optical
fiber.
Description
FIELD OF THE INVENTION
This invention relates to fiber optic modules.
BACKGROUND OF THE INVENTION
Fiber optic modules interface optical fibers to electronic
circuitry transducing communication by light or photons with
communication by electrical signals. A fiber optic module may be a
fiber optic receiver, transmitter or transceiver including both
receive and transmit functions. The fiber optic receiver,
transmitter and transceiver each have optical elements (OE) and
electrical elements (EE). The fiber optic transmitter OE includes
an emitter (such as a semiconductor LED or Laser) mounted in a
package and an optical coupling element for coupling light or
photons from the OE into the optical fiber. The type of
semiconductor laser (light amplification by stimulated emission of
radiation) may be a vertical cavity surface emitting laser (VCSEL).
The fiber optic receiver OE includes a photodetector (such as a
photodiode) mounted in a package and an optical coupling element
for coupling light or photons from the optical fiber into the
photodetector. The EE for each includes integrated circuits and
passive elements mounted on a substrate such as a printed circuit
board (PCB) or ceramic. The OE and EE are connected electrically at
the emitter and photodetector.
Because of the high transmission frequencies utilized in fiber
optic communication, crosstalk between receive and transmit signals
is of concern. Additionally, electromagnetic interference (EMI) is
of concern due to the high frequency of operation of the fiber
optic modules. In order to reduce EMI, shielding of the electrical
components is required which is usually accomplished by attaching a
metal shield to the substrate of the fiber optic module and
connecting it to ground. In order to avoid electronic crosstalk and
EMI, the fiber optic transceiver usually employs separate
components and separate shielding of fiber optic receiver and fiber
optic transmitter components. In order to avoid optical crosstalk
where light or photons can interfere between communication
channels, the fiber optic transceiver usually employs separate
optical elements for coupling light or photons into and out of the
optical fiber for fiber optic receiver and fiber optic transmitter.
Using separate optical elements requires additional components and
increases the costs of fiber optic transceivers. It is desirable to
reduce the component count of fiber optic transceivers such that
they are less expensive to manufacture.
The form factor or size of the fiber optic module is of concern.
Previously, the fiber optic transceiver, receiver, and transmitter
utilized horizontal boards or substrates which mounted parallel
with a system printed circuit board utilized significant footprint
or board space. The horizontal boards provided nearly zero optical
crosstalk and minimal electronic crosstalk when properly shielded.
However, the horizontal boards, parallel to the system printed
circuit board, required large spacing between optical fiber
connectors to make the connection to the optical fibers. While this
may have been satisfactory for early systems using minimal fiber
optic communication, the trend is towards greater usage of fiber
optic communication requiring improved connectivity and smaller
optical fiber connectors to more densely pack them on a system
printed circuit board. Thus, it is desirable to minimize the size
of system printed circuit boards (PCBs) and accordingly it is
desirable to reduce the footprint of the fiber optic module which
will attach to such system PCBs. Additionally, the desire for
tighter interconnect leads of fiber optic cables, restricts the
size of the OE's. For example, in the common implementation using
TO header and can, the header dimension of the interconnect lead is
normally 5.6 mm. In small form factor optical modules, such as the
MT family, the two optical fibers are separated by a distance of
only 0.75 mm. This severely restricts the method of coupling light
or photons from the OE into and out of fiber optic cables.
BRIEF DESCRIPTIONS OF THE DRAWINGS
FIG. 1 is a simplified top cutaway view of a first embodiment of
the invention.
FIG. 2 is an exploded view of the first embodiment of the
invention.
FIG. 3A is a cross-sectional view from the top of the optic block
for the first embodiment of the invention.
FIG. 3B is a front side perspective view from the left of the optic
block for the first embodiment of the invention.
FIG. 3C is a frontal view of the optic block for the first
embodiment of the invention.
FIG. 3D is a back side perspective view from the right of the optic
block for the first embodiment of the invention.
FIG. 3E is a back view of the optic block for the first embodiment
of the invention.
FIG. 3F is a right side view of the optic block for the first
embodiment of the invention.
FIG. 3G is a left side view of the optic block for the first
embodiment of the invention.
FIG. 3H is a cross-sectional view of the optic block for the first
embodiment of the invention.
FIG. 3I is a magnified cross-sectional view of the alignment post
of the optic block.
FIG. 4 is a simplified top cutaway view of another embodiment of
the invention.
FIG. 5A is an exploded view of the embodiment of the invention of
FIG. 4.
FIG. 5B is an exploded view of an alternate embodiment of the
invention of FIG. 4.
FIG. 5C is an exploded view of another alternate embodiment of the
invention of FIG. 4.
FIG. 5D is an exploded view of another alternate embodiment of the
invention of FIG. 4.
FIG. 6A is a cross-sectional view from the top of the optic block
for embodiments of the invention.
FIG. 6B is a front side view of the optic block for the embodiments
of the invention.
FIG. 6C is a back side view of the optic block for the embodiments
of the invention.
FIG. 6D is a top side view of the optic block for the embodiments
of the invention.
FIG. 7A is a top view of a manufacturing step of the invention.
FIG. 7B is a side view of a manufacturing step of the
invention.
FIG. 8A is an exploded view of another embodiment of the
invention.
FIG. 8B is perspective view of an alternate baseplate for
embodiments of the invention.
FIG. 8C is a rear cross sectional view of the assembled invention
illustrated in FIG. 8A.
FIG. 9A is an exploded view of another embodiment of the
invention.
FIG. 9B is a rear cross sectional view of the assembled invention
illustrated in FIG. 9A.
FIG. 9C illustrates an alternate embodiment of a single ground
plane for a printed circuit board.
FIG. 9D illustrates an alternate embodiment of a single ground
plane for a printed circuit board.
FIG. 9E illustrates an alternate embodiment of a ground plane
sandwiched between layers in a multilayer printed circuit
board.
FIG. 10A is an exploded view of another embodiment of the
invention.
FIG. 10B is a rear cross sectional view of the assembled invention
illustrated in FIG. 10A.
FIG. 11A is an exploded view of another embodiment of the
invention.
FIG. 11B is a rear cross sectional view of the assembled invention
illustrated in FIG. 11A.
FIG. 12A is an exploded view of another embodiment of the
invention.
FIG. 12B is a rear cross sectional view of the assembled invention
illustrated in FIG. 12A.
FIG. 13 illustrates a receive optical block and a transmit optical
block as an alternative to a single optical block.
FIG. 14A illustrates how the pin configuration of the fiber optic
modules can plug into a socket on a host printed circuit board.
FIG. 14B illustrates how a socket configuration of the fiber optic
modules can plug into a socket on a host printed circuit board.
FIG. 14C illustrates how a socket configuration of the fiber optic
modules can horizontally plug into a socket on a host printed
circuit board.
FIG. 15A illustrates a bottom perspective view of an alternate
embodiment of the shielded housing or cover and base of the
invention.
FIG. 15B illustrates a rear cross sectional view of the assembled
invention illustrated in FIG. 10A substituting the alternate
embodiment of the shielded housing or cover of FIG. 15A.
FIG. 15C illustrates a rear cross sectional view of the alternate
embodiment of the shielded housing or cover of FIG. 15A.
FIG. 15D illustrates a cross sectional view of another alternate
embodiment of the shielded housing or cover.
FIG. 15E illustrates a cross sectional view of another alternate
embodiment of the shielded housing or cover.
FIG. 15F illustrates a cross sectional view of another alternate
embodiment of the shielded housing or cover.
FIG. 15G illustrates a cross sectional view of another alternate
embodiment of the shielded housing or cover.
FIG. 16A illustrates a rear cross sectional view of an assembled
alternate embodiment of the invention.
FIG. 16B illustrates a rear cross sectional view of an assembled
alternate embodiment of the invention.
FIGS. 17A-17D illustrate exploded perspective views of an
embodiment of the invention.
FIGS. 18A-18D illustrate a perspective views of the embodiment of
the invention illustrated in FIGS. 17A-17D without the
cover/housing assembled thereto.
FIGS. 19A-19E are views of an exemplary cage assembly or module
receptacle for fiber optic modules.
FIG. 20 is a side view of an embodiment of a fiber optic module and
an exemplary host connector without the exemplary cage assembly of
FIGS. 19A-19E.
FIGS. 21A-21D are perspective views of an embodiment of a fiber
optic module and an exemplary host connector without the exemplary
cage assembly of FIGS. 19A-19E.
FIGS. 22A-22B are cross section views illustrating an embodiment of
a fiber optic module coupling to the exemplary host connector of
FIGS. 20, 21A-21D and the exemplary cage assembly of FIGS.
19A-19E.
FIGS. 23A-23C illustrate an example of how an electrical connection
between the interface printed circuit board of an embodiment of the
fiber optic module and the host connector of a host printed circuit
board is formed.
Like reference numbers and designations in the drawings indicate
like elements providing similar functionality.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following detailed description of the invention, numerous
specific details are set forth in order to provide a thorough
understanding of the invention. Note however that embodiments of
the invention may be practiced without these specific details. In
other instances well known methods, procedures, components, and
circuits have not been described in detail so as not to
unnecessarily obscure aspects of the embodiments of the
invention.
The embodiments of the invention include a method, apparatus and
system for vertical board construction of fiber optic transmitters,
receivers and transceivers. Briefly, fiber optic transmitter and
receiver electrical elements are implemented on at least two
separate printed circuit boards (PCBs) in a fiber optic module. The
separate boards are arranged within the fiber optic module to
reduce the footprint of the fiber optic module. In one embodiment,
bending light or photons through ninety degrees, the light
transmitter (a packaged type of emitter) and a light receiver (a
packaged type of photodetector) are each mounted substantially
perpendicular to the transmit and receive boards respectively such
that their active areas are nearly facing each other but offset. A
single optical block can be used to implement lenses and reflecting
surfaces to minimize manufacturing costs. In one embodiment, the
light receiver and light transmitter are mounted offset from each
other in the optical block in order to avoid optical cross talk. In
a second embodiment, the light transmitter (emitter) and the light
receiver (photodetector) are each mounted substantially parallel
with the transmit and receive boards respectively, the optical axis
of transmitter and receiver and the connection to the optical
fibers. The separate receive and transmit boards can be provided
with ground planes in order to minimize electrical cross talk.
Preferably the ground planes on the back sides of the printed
circuit boards face each other. A module outer shielded housing or
cover, manufactured out of metal or metal plated plastic, provides
further shielding for EMI. The separate boards may be extended to
support multiple channels or multiple parallel fibers such as in a
ribbon optical fiber cable. Manufacturing steps of the boards for
the fiber optic module are disclosed to provide reduced
manufacturing costs.
Referring now to FIG. 1, a simplified cutaway view of the first
embodiment of the invention is illustrated. FIG. 1 illustrates a
fiber optic module 100 coupling to a pair of fiber optic cables
101. Fiber optic module 100 includes an optical block 102 and an
electrical element 104. The optical block 102 may also be referred
to as a nose, an optical port, an alignment block, an optical
connector, an optical receptacle or receptacle. The optical block
102 can interface to an optical connector such as an LC, MT-RJ or
VF-45 optical connector. The electrical element 104 includes a
transmit printed circuit board (PCB) 106, a receive PCB 108, an
optional internal shield 109, a light transmitter 110, a light
receiver 111, and a shielded housing or cover 119. The light
transmitter 110 and light receiver 111 are optoelectronic devices
for communicating with optical fibers using light of various
wavelengths or photons. An optoelectronic device is a device which
can convert or transduce light or photons into an electrical signal
or an electrical signal into light or photons. The transmitter 110
is a packaged emitter, that converts an electrical signal into
emitting light or photons, such as a semiconductor laser or LED,
preferably packaged in a TO can. The receiver 111 is a packaged
photodetector, that detects or receives light or photons and
converts it into an electrical signal, such as a photo diode,
preferably package in a TO can. However other packages, housings or
covers, or optoelectronic devices for receiving and transmitting
light or photon may be used for the receiver 111 or transmitter
110.
Each of the optoelectronic devices, receiver 111 and transmitter
110, have terminals. In one embodiment, terminals of one or more
optoelectronic devices couple to thru-holes of the PCB 106 or PCB
108 or both. In another embodiment, terminals of one or more
optoelectronic devices couple to an edge connector of the PCB 106
or PCB 108 or both. In one embodiment, the transmit PCB 106
includes electrical components 112 (transmitter integrated circuit
(laser driver), resistors, capacitors and other passive or active
electrical components), pins 113, and a ground plane 114. The
electrical components 112 control the transmitter 110 and buffer
the data signal received from a system for transmission over an
optical fiber. In one embodiment, the receive PCB 108 includes
electrical components 116 (receiver integrated circuit
(transimpedance amplifier and post amplifier), resistors,
capacitors and other passive or active electrical components), pins
117, and a ground plane 118. The electrical components 116 control
the receiver 111 and buffer the data signal received from an
optical fiber. The ground planes 114 and 118 and the shielded
housing or cover 119 are coupled to ground. In another embodiment,
a pin header consisting of a dielectric medium that is molded over
a plurality of pins, is used to couple to through holes in the PCB
108 or PCB 106. The electrical components 116 and pins 117 are
sandwiched between the ground plane 118 and the shielding 119 to
shunt electromagnetic fields to ground and avoid crosstalk in the
receive PCB 108. Electrical components 112 and pins 113 are
sandwiched between the ground plane 114 and the shielded housing or
cover 119 to shunt electromagnetic fields generated by these
components to ground and avoid crosstalk in the transmit PCB 106.
Optional internal shielding 109 further provides additional
crosstalk protection between printed circuit boards. If ground
planes 114 and 118 are not used, then internal shielding 109 is
required to reduce the electromagnetic fields that may be
generated.
The optical block 102 includes lenses 120-123 and reflectors
124-125. Lenses 120-123 may be any collimating lenses including
aspheric lenses, ball lenses, and GRIN lenses. Lenses 121-123 may
be symmetric (circular symmetry) or asymmetric to provide optical
steering. Lens 123 is for collimating the light or photons
diverging from the transmitter 110 and lens 122 is for focussing
the collimated light or photons into an optical fiber. Lens 120 is
for collimating the light or photons diverging out from the end of
an optical fiber and lens 121 is for focusing the collimated light
or photons into the receiver 111. Reflectors 124-125 may be facets
formed in the optical block having angles to provide total internal
reflection between the optical block material and the atmosphere.
Preferably they are forty five degree angle facets. Alternatively,
they may be facets coated with a reflective surface or mirror
surface to reflect light or photons off the reflective coated
surface or facets having an optical grating surface to reflect
photons. The optical block 102 is preferably constructed of a
thermoplastic or polycarbonate which is clear to the desired
wavelengths of light or photons. The reflectors 124-125, lenses
120-123 and other elements of the optical block 102 described below
are preferably formed through injection molding of the desired
material.
Referring to FIG. 2; an exploded diagram of the fiber optic module
100 is illustrated and its assembly is described. Transmitter 110
is inserted into an opening 214 in the optical block 102. Receiver
111 is inserted into an opening 213 in optical block 102. An epoxy
is injected into top and bottom tacking holes 215 in order to hold
the transmitter 110 and receiver 111 in openings 214 and 213
respectively. An MT alignment plate 201 has optical block alignment
holes 216, an optical opening 217 and fiber optic connector
alignment pins 218 for alignment purposes. The optical block holes
216 couple to optical block alignment pins in the optical block
102, not illustrated in FIG. 2. The fiber optic connector alignment
pins 218 are for aligning optical fibers that couple to the fiber
optic module 100.
For coupling to a fiber optic connector, the fiber optic module 100
has a nose 202 and a nose shield 203. The nose 202 includes an
optical fiber opening 222 and a latch opening 223. The latch
opening 223 receives the optical fiber connector and holds the
optical fiber substantially fixed in place and aligned with the
optical opening 217 of the alignment plate 201. The nose shield 203
includes an opening 224 for insertion over the nose 202 and shield
tabs 225 for coupling to the ground plane of the package. The nose
shielding 203 further reduces EMI.
After assembling the nose pieces to the optical block 102, the
transmitter 110 and receiver 111 may be aligned to provide optimal
light or photon output and reception. Alignment of the transmitter
110 and receiver 111 in optical block 102 is performed by active
alignment where the receiver 111 and transmitter 110 are powered up
to detect and emit photons. The receiver 111 and transmitter 110
are properly aligned in the optical block 102 to provide maximum
photon detection from or coupling into fiber 101. The tacking holes
215 extend into the openings 213 and 214 such that epoxy may poured
in to hold the optoelectronic devices to the optical block. After
alignment is complete, the epoxy is UV cured and allowed to set
such that receiver 111 and transmitter 110 are substantially
coupled to the optical block 102.
After the epoxy has set, the receive PCB 108 and the transmit PCB
106 may be attached to the receiver 111 and transmitter 110
respectively. Receiver thruholes 232 in the receive PCB 108 are
aligned and slid over terminals 211 of the receiver 111. The
terminals 211 are then soldered to make an electrical connection on
the component side (opposite the side of the ground plane 118) of
the receive PCB 108. Transmitter thruholes 233 in the transmit PCB
106 are aligned and then slid over the terminals 210 of the
transmitter 110. The terminals 210 are then soldered to make an
electrical connection on the component side (opposite the side of
the ground plane 114) of transmit PCB 106. Ground planes 114 and
118 have sufficient material removed around the transmitter
thruholes 233 and the receiver thruholes 232 respectively to avoid
shorting the terminals of the transmitter 110 and receiver 111 to
ground.
After coupling the PCBs 108 and 106 to the receiver 111 and
transmitter 110 respectively, the assembly is inserted into the
shielded housing or cover 119. The optional internal shield 109 is
next assembled into the shielded housing or cover 119 between the
PCBs 106 and 108. The optional internal shield 109 has pin slots
230 to surround the pins 113 and 117 and avoid shorting
thereto.
The shielded housing or cover 119 includes clips or tabs 236 at
each corner for mating to a base 205. The base 205 includes PCB
slots 240, clip openings or slots 238 into which the clips or tabs
236 may be inserted, and base pin holes 242 into which the PCB pins
113 and 117 may be inserted. The base 205 includes a guide post 244
for mounting the fiber optic module into a system printed circuit
board. The bottom of the base mounts parallel to the printed
circuit board of the system such that when horizontal, the receive
PCB 108 and the transmit PCB 106 are vertical and substantially
perpendicular in reference to the printed circuit board of the
system and the base 205. Next in assembly, the base 205 has its
base pin holes 242 slid over the PCB pins 113 and 117, the printed
circuit boards 106 and 108 are guided to mate with the PCB slots
240, and the clips or tabs 236 of the shielded housing or cover 119
are guided into the clip openings or slots 238. The receive PCB
pins 113 and the transmit PCB pins 117 are vertical and
substantially perpendicular in reference to the printed circuit
board of the system and the base 205. After coupling the base 205
to the shielded housing or cover 119, the clips or tabs 236 are
bent, twisted, or otherwise changed in order to hold the base 205
in place. As an alternative to clips or tabs 236 and clip openings
or slots 238, the shielded housing or cover 119 may use plastic
clips, or a ridge, integrated into each side that couples to base
205 appropriately. The shielded housing or cover 119, which is
coupled to ground, encases the PCBs 106 and 108 to reduce the
electromagnetic fields generated by the electrical components
coupled thereto by shunting the electric fields to ground to reduce
electromagnetic interference (EMI).
Referring now to FIG. 3A, a cross-sectional view of the optical
block 102 for the first embodiment is illustrated. The transmitter
110, the receiver 111, and the MT alignment plate 201 are coupled
to the optical block 102. The light transmitter 110 includes an
emitter 302 for generation of light or photons in response to
electrical signals from the transmit PCB 106. The light receiver
111 includes a detector 304 to receive light or photons and
generate electrical signals in response to light or photons coupled
thereto. Light or photons emitted by the emitter 302 are coupled
into lens 123 and collimated onto the reflector 125 at an incident
angle I1 (angle with the perpendicular to reflector 125 surface)
preferably of substantially forty five degrees. Reflector 125
reflects the incident light or photons on a refraction angle R1
(angle with the perpendicular to reflector 125 surface) equivalent
to incident angle I1 preferably of substantially forty five
degrees. The reflected light or photons preferably travel
perpendicular to the incident light or photons towards the lens
122. Lens 122 focuses the light or photons from the emitter 302
into an aligned optical fiber through the optical port 217 in the
MT alignment plate 201. Thus, light or photons coupled or launched
into an optical fiber, defining a first optical axis, are
preferably substantially perpendicular to the light or photons
emitted and incident upon lens 123 from the emitter 302 of the
transmitter 110.
Light or photons, incident from a fiber optic cable coupled to the
fiber optic module 100, is received through the optical port 217 of
the MT alignment plate 201. Light or photons from the fiber optic
cable are aligned to be incident upon the lens 120. Lens 120
collimates the incident light or photons from a fiber optic cable
onto the reflector 124 at an incident angle I2 of preferably
substantially forty five degrees. Reflector 124 reflects incident
light or photons at a refractive angle R2 equivalent to incident
angle I2 of preferably substantially forty five degrees towards
lens 121. Lens 121 focuses the light or photons received from a
fiber optical cable onto the detector 304. Light or photons
incident from a fiber optic cable, defining a second optical axis,
are preferably substantially perpendicular to the light or photons
incident upon the detector 304.
FIG. 3B illustrates a frontal perspective view from the left side
of the optical block 102. The front side of the optical block 102
includes optical block alignment pins 316 and an optical output
opening 317. The optical block alignment pins 316 couple to the
alignment holes 216 of the alignment plate 201 such that the
optical output opening 317 is aligned with the optical port 217 in
the alignment plate 201. FIG. 3C illustrates the front side of the
optical block 102. The optical output opening 317 is indicated.
FIG. 3D is a back side perspective view from the right of the
optical block 102. The back side of the optical block 102 includes
a cavity 322 that is used to form the shape of the reflective
surfaces 124-125 during manufacturing of the optical block 102.
FIG. 3E is a back view of the optic block illustrating the opening
into the cavity 322.
FIG. 3F illustrates the right side of the optical block 102 which
has the opening 214 to mate with the type of housing of the
transmitter 110. The lens 123 can be viewed near the center of the
opening 214. FIG. 3G illustrates the left side of the optical block
102. which has the opening 213 to mate with the type of housing of
the receiver 111. The lens 121 can be viewed near the center of the
opening 213. Comparing FIGS. 3F and 3G, the offset between openings
213 and 214 to avoid optical crosstalk is visible. In the preferred
embodiment, receiver 111 is closer to the optical opening 317 in
order to minimize the loss of incoming received optical power.
However, the position of receiver 111 and transmitter 110 can be
interchanged. FIG. 3H is a cross-sectional view of the optical
block 102 illustrating the relative position of the optical block
alignment posts 316. The area 324 surrounding the alignment post
316 is magnified in FIG. 3I. FIG. 3I provides a magnified
cross-sectional view of the alignment post 316.
FIG. 4 illustrates another embodiment of the invention. To couple
to the optical fibers 101, a fiber optic module 400 includes an
optical block 402 and electrical elements 404. The optical block
402 may also be referred to as a nose, an optical port, an
alignment block, an optical connector, an optical receptacle or
receptacle. The optical block 402 can interface to an optical
connector such as an LC, MT-RJ or VF-45 optical connector.
Electrical elements 404 include transmitter PCB 106, receiver PCB
108, light receiver 111, light transmitter 110, and a shielded
housing or cover 419. Shielded housing or cover 419 may be narrower
than shielded housing or cover 119 due to receiver 111 and
transmitter 110 being parallel with the PCBs 108 and 106. The
optical or alignment block 402 may include lens 423 and lens 421
for coupling light or photons into and out of the fiber optic cable
101. Alternatively the lens 423 and 421 may be coupled to the
receiver 111 and transmitter 110. Lens 423 and 421 may be spherical
lenses or each may be a pair of aspheric lenses on the same optical
axis. Light or photons emitted by the transmitter 110 are collected
and focused by lens 423 into a transmit fiber optic cable. Light or
photons on a receive fiber optic cable are collected and focused by
lens 421 into the receiver 111. In this manner, fiber optic module
400 preferably keeps light or photons substantially in parallel and
does not have to reflect the light or photons to couple it with
receiver 111 or transmitter 110.
FIG. 5A illustrates an exploded diagram of the fiber optic module
400. Fiber optic module 400 is assembled similar to fiber optic
module 100 as previously described with reference to FIG. 2.
However, optical or alignment block 402 differs from optical block
102. Receiver 111 and transmitter 110 are inserted into openings
513 and 514 respectively in the optical or alignment block 402. The
receiver and transmitter may be held in place by a press fit or
glued in place. To glue in place, an epoxy or glue is injected in
top and bottom tacking holes 515 of the optical or alignment block
402 while the receiver 111 and transmitter 110 are tested and
aligned to substantially couple light or photons into and out of
fiber optic cables. After the epoxy is set and the receiver and
transmitter are substantially fixed in the optical block 102, the
transmit PCB 106 and the receive PCB 108 are coupled respectively
to the transmitter 110 and the receiver 111. The terminals 511 and
510 of the receiver 111 and the transmitter 110 respectively are
soldered directly onto the PCB. The high frequency pins associated
with the receiver 111 and transmitter 110 are preferably soldered
on the component side of the printed circuit boards in order to
provide proper shielding. The alignment plate 201, the nose 202 and
the nose shielding 203 are unnecessary in this embodiment of the
invention. Fiber ferrules are utilized instead for alignment
between the optical or alignment block 402 and the optical fibers
101.
Referring now to FIG. 5B, an exploded view of a fiber optic module
400' is illustrated. Fiber optic module 400' is assembled similar
to fiber optic module 400 as previously described with reference to
FIG. 5A but a different base 205' is utilized. The base 205'
differs from base 205 in that it has a pair of guide rails 540 to
hold the PCBs 106 and 108 in place and a pair of cutouts or open
slots 542 for the pins 113 and 117 to extend through. In this
manner, the PCBs 106 and 108 may slide into place onto the base
205'.
Referring now to FIG. 5C, an exploded view of a fiber optic module
400'' is illustrated. Fiber optic module 400'' is assembled similar
to fiber optic module 400 as previously described with reference to
FIG. 5A but a different base 205'' is utilized. The base 205''
differs from base 205 in that it has pairs of mounting brackets
540' to hold the PCBs 106 and 108 in place and a pair of openings
542' for the pins 113 and 117 to extend through.
The PCB slots 240, guide rails 540 or brackets 540' can be replaced
by slots, brackets or guide rails of the optical block 402 to align
the PCBs thereto. Additionally, it is to be understood that
alternate bases may be formed by combining the elements of the
bases 205, 205', and 205'' in different ways. For example, refer to
FIG. 5D. FIG. 5D illustrates an exploded view of a fiber optic
module 400'''. Fiber optic module 400''' is assembled similar to
fiber optic module 400 as previously described with reference to
FIG. 5A but a different base 205''' is utilized and a slightly
different optical block 502 is utilized. The base 205''' differs
from base 205 in that there are no slots 240 and that there are a
pair of cutouts or open slots 542 for the pins 113 and 117 to
extend through. The optical block 502 differs from the optical
block 402 in that a pair of slots 525 are provided to align the
PCBs 106 and 108 with the optical block.
Referring now to FIG. 6A, a cross-sectional view of the optical or
alignment block 402 for the second embodiment is illustrated. The
transmitter 110 and the receiver 111 are coupled to the optical or
alignment block 402. The transmitter 110 includes an emitter 302
for generation of light or photons. The receiver 111 includes a
detector 304 to receive light or photons. Light or photons emitted
by the emitter 302 are coupled into lens 423, collected and focused
into the optical fiber through the optical port 417A. Light or
photons, incident from a fiber optic cable coupled to the fiber
optic module 400, is received through the optical port 417B.
Photons from the fiber optic cable are incident upon the lens 421.
Lens 421 collects and focuses the incident light or photons from
the fiber optic cable onto the detector 304 of the receiver 111. In
order to keep the optical fibers 101 in alignment with the optical
or alignment block 402, a pair of fiber ferrules 421 are provided.
The fiber ferrules 421 are inserted into the optical ports 417A and
417B.
FIG. 6B illustrates the front side of the optical or alignment
block 402. The front side of the optical or alignment block 402
includes optical output ports 417A and 417B. In FIG. 6B, the lens
421 is visible through the optical output port 417B and lens 423 is
visible through the optical output port 417A. FIG. 6C is an
illustration of the back side of the optical or alignment block
402. In FIG. 6C, the lens 421 is visible through opening 513 and
lens 423 is visible through opening 514. FIG. 6D illustrates the
top side of the optical or alignment block 402 which has the
tacking holes 515 coupling to the openings 513 and 514. Epoxy may
be inserted into the top and bottom tacking holes 515 to hold the
transmitter 110 and receiver 111 in position in the optical or
alignment block 402.
Referring now to FIGS. 7A-7B, final steps of the assembly of
printed circuit boards 106 and 108 are illustrated. Transmit PCB
106 and receive PCB 108 are assembled as one unit on one printed
circuit board 700 with a center score 702 defining a boundary line
between transmit and receive components. After all components have
been attached and assembled onto the unitary PCB 700, the PCB 700
is flexed along the score 702 such that the transmit PCB 106 and
the receive PCB 108 may be separated. Transmit PCB 106 and the
receive PCB 108 may thereafter be assembled as part of the fiber
optic module 100 and the fiber optic module 400. The transmit PCB
106 and the receive PCB 108 may each be approximately 6.5 mm in
height excluding pins 113 and 117.
Referring now to FIG. 8A, another embodiment of the invention is
illustrated. FIG. 8A illustrates an exploded view of a fiber optic
module 800. The fiber optic module 800 includes an upper transmit
PCB 106U, a lower transmit PCB 106L, an upper receive PCB 108U, a
lower receive PCB 108L, the transmitter 110, the receiver 111, the
optical block 402, the shielded housing or cover 419, a first and
second PCB interconnect pin headers 827, a first terminal pin
header 823 for the transmitter, a second terminal pin header 817
for the receiver, and a baseplate 805.
The transmitter 110 is a transmit optical subassembly (Tx OSA) that
includes a VCSEL or other semiconductor device that transduces
electrical signals into photons or a light output. The receiver 111
is a receive optical subassembly (Rx OSA) including a PIN diode or
other device that converts photons or light input into electrical
signals. The Tx OSA and Rx OSA are attached to physically separated
transmit and receive electrical subassemblies (ESA's). In one
embodiment, the transmit ESA includes an upper and lower transmit
PCBs 106U and 106L with components 116 mounted thereto. In one
embodiment, the receive ESA includes an upper and lower receive
PCBs 108U and 108L with components 112 mounted thereto.
The lower transmit PCB 106L and the upper transmit PCB 106U provide
similar functionality to that of the transmit PCB 106 and include
components 112. The lower receive PCB 108L and the upper receive
PCB 108U provide similar functionality to that of the receive PCB
108 and include components 116. The upper and lower transmit PCBs
106U and 106L are parallel to each other in a horizontal plane and
parallel with the optical axis of the transmitter 110. The upper
and lower receive PCBs 108U and 108L are parallel to each other in
a horizontal plane and parallel with the optical axis of the
receiver 111. This configuration of parallel horizontal boards for
each of the transmit and receive capability can be referred to as
dual-stack horizontal modular PCBs.
The first and second pin interconnect headers 827 include the
conductive signal pins 837 molded into a non-conductive medium. The
first and second pin interconnect headers 827 are used to
interconnect lower and upper PCB's. The first pin header 827
provides signal interconnection between the upper and lower
transmit PCBs 106U and 106L. The first pin header 827 provides
signal interconnection between the upper and lower transmit PCBs
106U and 106L. The second pin header 827 provides signal
interconnection between the upper and lower receive PCBs 108U and
108L. The second pin header 827 has pins 837 that couple into upper
through-holes 847U in the upper receive PCB 108U and lower through
holes 847L in the lower receive PCB 108L. The first pin header 827
similarly has pins 837 that couple into upper and lower
throughholes in the upper and lower transmit PCBs 106U and 106L
respectively.
The first and second terminal pin headers 817 and 813 include
conductive signal pins molded into a non-conductive medium. The
first and second terminal pin headers 817 and 813 are used to route
electrical signals to and from the fiber optic module 800 to a host
system. The first terminal pin header 813 has pins 113 that couple
to through holes 842 in the lower transmit PCB 106L. Similarly, the
second terminal pin header 817 has pins 117 that couple to through
holes 842 in the lower receive PCB 108L.
The transmitter 110 couples to the upper transmit PCB 106U in one
embodiment. The terminals 810 of the transmitter 110 couple to the
upper transmit PCB 106U in one embodiment. Using a straddle mount,
one or more terminals couple to upper edge traces 820U on a top
side of the upper transmit PCB 106U and one or more terminals
couple to lower edge traces 820L on a back side of the upper
transmit PCB 106U. In a straddle mount, the optoelectronic device
(i.e. the transmitter 110 or the receiver 111) has its optical axis
nearly in-line and parallel with a plane of the printed circuit
board. In an alternate embodiment, the terminals 810 may couple to
the lower transmit PCB 106U. In another alternate embodiment, the
terminals 810 may couple between the upper and lower receive PCBs
so that one or more couple to the upper PCB and one or more couple
to the lower PCB. In yet another alternate embodiment using a
through hole mount, the terminals 810 may couple into holes of the
upper or lower transmit PCBs or both upper and lower transmit PCBs.
In a through hole mount, the optoelectronic device (i.e. the
transmitter 110 or the receiver 111) has its optical axis nearly
parallel with a plane of the printed circuit board.
The receiver 111 couples to the upper receive PCB 108U in one
embodiment. The terminals 811 of the receiver 111 couple to the
upper receive PCB 108U in one embodiment. Using a straddle mount,
one or more terminals couple to upper edge traces 821U on a top
side of the upper receive PCB 108U and one or more terminals couple
to lower edge traces 821L on a back side of the upper receive PCB
108U. In an alternate embodiment, the terminals 811 may couple to
the lower receive PCB 108U. In another terminal embodiment, the
terminals 811 may couple between the upper and lower receive PCBs
so that one or more couple to the upper PCB and one or more couple
to the lower PCB. In yet another alternate embodiment, the
terminals 811 may couple into holes of the upper or lower receive
PCBs or both upper and lower receive PCBs.
Included with the fiber optic module 800 is a baseplate 805. The
baseplate 805 may include an inner septum 815 that divides the
transceiver and receiver into two separate cavities, for EMI and
electrical isolation of the transmitter from the receiver or
between channels. The baseplate 805 acts like a chassis or frame to
provide support for the shielded housing or cover 419 and the
receiver and transmit subassemblies. The baseplate 805 may include
an inner septum 815, one or more openings 242 to receive the pins
113 and 117, and one or more clip openings or slots 238 to receive
the clips or tabs 236. The baseplate 805 in one embodiment is
plastic in other embodiments that baseplate may be metal or a
metalized plastic to provide shielding. The inner septum 815
provides separation between the transmitter and the receiver or
between channels.
Referring now to FIG. 8B, an alternate baseplate 805' is
illustrated. Baseplate 805' differs from baseplate 805 in that it
includes slots 842 for pins 113 and 117. Baseplate 805' may
similarly include clip openings or slots 238 and the inner septum
815.
Referring now to FIG. 8C, a rear cross sectional view of the
assembled fiber optic module 800 is illustrated. The baseplate 805
with the inner septum 815 can divide the fiber optic module 800
into two separate cavities. The separate cavities can improve EMI
and electrical isolation of the transmitter from the receiver. The
receiver 111 couples to the upper receive PCB 108U with its
terminals 811 using a straddle mount in one embodiment. The
transmitter 111 couples to the upper transmit PCB 106U with its
terminals 810 using a straddle mount in one embodiment.
In FIG. 8C, the upper and lower transmit PCBs 106U and 106L are
parallel to each other in a horizontal plane and parallel with the
optical axis of the transmitter 110. The upper and lower receive
PCBs 108U and 108L are parallel to each other in a horizontal plane
and parallel with the optical axis of the receiver 111. This
configuration of parallel horizontal boards for each channel can be
referred to as dual-stack horizontal modular PCBs. The dual stacked
horizontal PCB's allow an increase in component surface mounting
area for a given volume. Both sides of the upper and lower transmit
and receive PCB's can be utilized to mount electronic components.
This increased surface area can provide increased functionality in
a fiber optic module by allowing additional components such as
integrated circuits and passive components such as filters,
capacitors, and inductors to be utilized.
Referring now to FIG. 9A, another embodiment of the invention is
illustrated. FIG. 9A illustrates an exploded view of a fiber optic
module 900. The fiber optic module 900 utilizes a motherboard which
is common to daughtercards PCBs which are substantially
perpendicular to the motherboard. Assuming the motherboard is
horizontal, the daughtercard PCBs are substantially vertical to the
motherboard and can be also be referred to as vertical PCBs. The
substantially vertical PCB's couple to the common motherboard.
The fiber optic module 900 includes a vertical transmit PCB 106'
and a vertical receive PCB 108' in parallel coupled to a horizontal
motherboard PCB 905. The motherboard PCB 905 can separate ground
and power planes between receiver and transmitter channels in order
to maximize isolation and minimize cross talk. The vertical
transmit PCB and the vertical receive PCB may have traces soldered
to traces of the motherboard for electrical connectivity or
otherwise include pins that plugged into holes or sockets of the
motherboard to ease replacement or to expand the number of transmit
or receive channels with additional transmit PCBs or receive PCBs.
Alternatively, the electrical connection between the vertical
transmit PCB and the vertical receive PCB and motherboard PCB may
be made with electrical connectors in lieu of solder joints. The
mother board PCB includes Input/Output Pins (I/O Pins) or an I/O
socket connector to couple to holes or a socket of a host system
PCB to interface with a host system.
In order to further minimize the form factor of the fiber optic
module 900, the vertical transmit PCB and the vertical receive PCB
provides mounting surfaces for components on both the left and
right side surfaces (or front and back surfaces). Additionally, a
top surface of the motherboard PCB 905 may also be used to mount
components or circuits for increased electrical functionality such
as a clock/data recovery (CDR) function and minimize the form
factor of the fiber optic module.
To minimize EMI and crosstalk between the vertical transmit PCB and
the vertical receive PCB, an inner shield similar to the shield 109
may be used. Alternatively, one or both of the vertical transmit
PCB and the vertical receive PCB may have a ground plane on of its
left or right side surfaces (sometimes referred to as a backside
ground plane).
The vertical PCBs 106' and 108' are similar to PCBs 106 and 108 but
for the coupling to the horizontal motherboard PCB 905. The
vertical PCBs 106' and 108' have signal traces soldered to signal
traces of the horizontal motherboard PCB 905 which can also
mechanically support the vertical PCBs 106' and 108'. Solder joints
917R couple the receive PCB 108' to the horizontal motherboard PCB
905. Solder joints 917T couple the transmit PCB 106' to the
horizontal motherboard PCB 905 (see FIG. 9B). The fiber optic
module 900 can be referred to as having vertical PCB's with a
horizontal motherboard PCB.
The horizontal motherboard PCB 905 includes input/output (I/O) pins
113 and 117 to couple to a host system and wire traces to route
power, ground and signals between the pins 113 and 117 and the
vertical PCBs 106' and 108'.
The fiber optic module 900 further includes the transmitter 110,
the receiver 111, the optical block 402, and the shielded housing
or cover 419. The shielded housing or cover 419 has clips or tabs
236 that couple into clip openings or slots 238 in the motherboard
PCB 905. The clips or tabs 236 can be held in place in the slots by
a friction fit or glued in place or they may extend through the
motherboard PCB 905 and be turned and or bent to couple the
shielded housing or cover 419 and the motherboard PCB 905 together.
Alternatively, the clips or tabs 236 of the shielded housing or
cover 419 can wrap around the motherboard PCB 905 to couple them
together.
The transmitter 110 couples into the opening 514 of the optical
block 402. The receiver 111 couples into the opening 513 of the
optical block. They are held in place by either a friction fit or a
glue such as an epoxy.
The transmitter 110 couples to the transmit PCB 106'. The terminals
810 of the transmitter 110 couple to the transmit PCB 106'. In one
embodiment using a straddle mount, one or more terminals 810 couple
to left edge traces 920L on a left side and one or more terminals
810 couple to right edge traces 920R on a right side of the
transmit PCB 106'. In alternate embodiment, the terminals 810 may
couple to one side of the transmit PCB 106'. In yet another
alternate embodiment, the terminals 810 may couple into holes of
the transmit PCB 106'.
The receiver 111 couples to the receive PCB 108'. The terminals 811
of the receiver 111 couple to the receive PCB 108'. Using a
straddle mount, one or more terminals 811 couple to left edge
traces 921L on a left side and one or more terminals 811 couple to
right edge traces 921R on a right side of the receive PCB 108'. In
an alternate embodiment, the terminals 811 may couple to one side
of the receive PCB 108'. In yet another alternate embodiment, the
terminals 811 may couple into holes of the receive PCB 108'.
Referring now to FIG. 9B, a rear cross-sectional view of the
assembled fiber optic module 900 is illustrated. Traces 920 on the
motherboard PCB route signals to components on the motherboard PCB,
the I/O pins 113 and 117, and the solder joints 917R and 917T. A
ground plane 118 can be coupled to a side the vertical receive PCB
108' or a ground plane 114 can be coupled to a side of the vertical
transmit PCB 106' or both. Referring to FIG. 9C, the vertical
transmit PCB 106' includes the ground plane 114 and the vertical
receive PCB 108' is without a ground plane to allow room for added
components 116 on each side; Referring to FIG. 9D, the vertical
receive PCB 108' includes the ground plane 118 and the vertical
transmit PCB 106' is without a ground plane to allow room for added
components 112 on each side. An optional inner shield 109 can also
be used for further isolation between channels to reduce cross-talk
and EMI as illustrated in FIG. 9B. In any case, the ground plane
114 and 118 will have cutouts for traces to coupled to the
terminals 810 and 811 and may have additional cutouts for
components 112 or 116 as the case may be. Referring now to FIG. 9E,
the ground plane 118 or the ground plane 114 may be alternatively
sandwiched between layers of either the vertical receive PCB 108'
or the vertical transmit PCB 106' or both as a part of a multilayer
PCB as illustrated by FIG. 9C. This can allow for further
components 116 and 112 to be added to both sides of the vertical
receive PCB 108' and the vertical transmit PCB 106'.
Referring now to FIG. 10A, another embodiment of the invention is
illustrated. FIG. 10A illustrates an exploded view of a fiber optic
module 1000. The fiber optic module 1000 has angled PCBs with
respect to a horizontal or vertical axis of the fiber optic module
1000. The length of the PCBs remain parallel to the optical axis of
the receiver 111 and transmitter 110. By angling the PCBs with the
horizontal or vertical axis, the PCBs may be made smaller to fit a
smaller form factor or alternatively the surface area can be
increased. That is the available PCB surface area for mounting
components can be increased for a given volume by angling the PCBs.
The increased surface area can give the final assembled fiber optic
module increased functionality by allowing components such as
integrated circuits and passive components such as filters,
capacitors, and inductors to be added. More room can also be
provided in the fiber optic module 1000 for mounting larger
components by angling the PCBs.
The fiber optic module 1000 includes an angled transmit PCB 106'',
an angled receive PCB 108'', the transmitter 110, the receiver 111,
an optical block 402', the shielded housing or cover 419, a first
terminal pin header 1027T for the transmitter, a second terminal
pin header 1027R for the receiver, and the baseplate 805 or
805'.
The angled transmit PCB 106'' and the angled receive PCB 108'' are
arranged within the fiber optic module at an angle with respect to
the horizontal axis thereof as defined by a line normal to both
receiver and transmitter optical axes. The angled transmit PCB
106'' and the angled receive PCB 108'' are held in place having a
width that is on an angle with respect to a horizontal or vertical
axis of the fiber optic module 1000. The length of the angled
transmit PCB 106'' and the angled receive PCB 108'' are parallel to
the optical axis of the receiver 111 and transmitter 110. The
angled transmit PCB 106'' includes components 116 and left and
right edge traces 921L and 921R. The first terminal pin header
1027T has pins 117 that couple to holes of the angled transmit PCB
106'' on one end. The angled receive PCB 108'' includes components
112 and left and right edge traces 920L and 920R. The second
terminal pin header 1027R has pins 113 that couple to holes of the
angled receive PCB 108'' on one end.
The transmitter 110 is a transmit optical subassembly (Tx OSA) that
includes a VCSEL or other semiconductor device that transduces
electrical signals into photons or a light output. The receiver 111
is a receive optical subassembly (Rx OSA) including a PIN diode or
other device that converts photons or light input into electrical
signals. The Tx OSA and Rx OSA are attached to physically separated
transmit and receive electrical subassemblies (ESA's). In one
embodiment, the transmit ESA includes the angled transmit PCB 106''
with components 116 and the first terminal pin header 1027T mounted
thereto. In one embodiment, the receive ESA includes the angled
receive PCB 108'' with components 112 and the second terminal pin
header 1027R mounted thereto.
The optical block 402' is similar to the optical block 402 but has
some modifications to accommodate the angled transmit PCB 106'' and
the angled receive PCB 108''. The optical block 402' includes
openings 513' and 514' to receive the receiver 111 and transmitter
110 respectively and angled slots 1015 to receive the angled
transmit PCB 106'' and the angled receive PCB 108''. The angled
slots 1015 can provide a friction fit with the angled transmit PCB
106'' and the angled receive PCB 108'' or glue or epoxy can be used
to couple them together. The angled slots 1015 can also serve to
tack the receiver 111 and transmitter 110 in place within the
optical block 402'.
The transmitter 110 couples into the opening 514' of the optical
block 402'. The receiver 111 couples into the opening 513' of the
optical block 402'. They can be held in place by either a friction
fit or a glue such as an epoxy.
The transmitter 110 also couples to the transmit PCB 106''. The
terminals 810 of the transmitter 110 couple to the transmit PCB
106'' in one embodiment. Using a straddle mount, one or more
terminals 810 couple to left edge traces 920L on a left side and
one or more terminals 810 couple to right edge traces 920R on a
right side of the transmit PCB 106''. In an alternate embodiment,
the terminals 810 may couple to one side of the transmit PCB 106''.
In yet another alternate embodiment, the terminals 810 may couple
into holes of the transmit PCB 106''.
The receiver 111 also couples to the receive PCB 108''. The
terminals 811 of the receiver 111 couple to the receive PCB 108''.
Using a straddle mount, one or more terminals 811 couple to left
edge traces 921L on a left side and one or more terminals 811
couple to right edge traces 921R on a right side of the receive PCB
108''. In an alternate embodiment, the terminals 811 may couple to
one side of the receive PCB 108''. In yet another alternate
embodiment, the terminals 811 may couple into holes of the receive
PCB 108''.
Referring now to FIG. 10B, a rear cross-sectional view of the
assembled fiber optic module 1000 is illustrated. The first
terminal pin header 1027T is coupled to the angled transmit PCB
1027T so that pins 117 are vertical with the reference axis. The
second terminal pin header 1027R is coupled to the angled receive
PCB 108'' so that pins 113 are vertical with the reference axis. A
ground plane 118 can be coupled to a side the angled receive PCB
108'' or a ground plane 114 can be coupled to a side of the angled
transmit PCB 106'' or both similar to previously described with
reference to the vertical boards and FIGS. 9B-9E. The shield
housing or cover 419 couples to the base or baseplate 805 or 805'
around the printed circuit boards. Depending upon the width of the
printed circuit boards 106' and 108' and the width of the fiber
optic module 1000, the angles .theta..sub.1 and .theta..sub.2 which
the printed boards make with the base or baseplate 805 or 805' can
vary between zero and ninety degrees.
Referring now to FIG. 11A, another embodiment of the invention is
illustrated. FIG. 11A illustrates an exploded view of a fiber optic
module 1100. The fiber optic module 1100 has parallel angled or
slanted PCBs with respect to a horizontal or vertical axis of the
fiber optic module 1100. The length of the PCBs remain parallel to
the optical axis of the receiver 111 and transmitter 110. By
parallel angling the PCBs with the horizontal or vertical axis, the
PCBs may be made smaller to fit a smaller form factor or
alternatively the surface area can be increased. That is the
available PCB surface area for mounting components can be increased
for a given volume by angling the PCBs. The increased surface area
can give the final assembled fiber optic module increased
functionality by allowing components such as integrated circuits
and passive components such as filters, capacitors, and inductors
to be added. More room can also be provided in the fiber optic
module 1100 for mounting larger components by angling the PCBs in
parallel together.
The fiber optic module 1100 includes an angled transmit PCB 106''',
an angled receive PCB 108''', the transmitter 110, the receiver
111, an optical block 402'', the shielded housing or cover 419, a
first terminal pin header 1027T for the transmitter, a second
terminal pin header 1027R for the receiver, and a baseplate
805''.
The angled transmit PCB 106''' and the angled receive PCB 108'''
are arranged in parallel and at an angle with respect to a
horizontal datum plane that passes through and is normal to
receiver and transmitter optical axes. The angled transmit PCB
106''' and the angled receive PCB 108''' are slanted in parallel to
the right but can be easily arranged so as to slant in parallel to
the left. The angled transmit PCB 106''' and the angled receive PCB
108''' are held in place having a width that is on an angle with
respect to a horizontal or vertical axis of the fiber optic module
1100. The length of the angled transmit PCB 106''' and the angled
receive PCB 108''' are parallel to the optical axis of the receiver
111 and transmitter 110. The angled transmit PCB 106''' includes
components 116 and left and right edge traces 921L and 921R. The
first terminal pin header 1027T has pins 117 that couple to holes
of the angled transmit PCB 106''' on one end. The angled receive
PCB 108''' includes components 112 and left and right edge traces
920L and 920R. The second terminal pin header 1027R' has pins 113
that couple to holes of the angled receive PCB 108''' on one
end.
The transmitter 110 is a transmit optical subassembly (Tx OSA) that
includes a VCSEL or other semiconductor device that transduces
electrical signals into photons or a light output. The receiver 111
is a receive optical subassembly (Rx OSA) including a PIN diode or
other device that converts photons or light input into electrical
signals. The Tx OSA and Rx OSA are attached to physically separated
transmit and receive electrical subassemblies (ESA's). In one
embodiment, the transmit ESA includes the angled transmit PCB
106''' with components 116 and the first terminal pin header 1027T
mounted thereto. In one embodiment, the receive ESA includes the
angled receive PCB 108''' with components 112 and the second
terminal pin header 1027R' mounted thereto.
The baseplate 805'' is similar to the baseplate 805 and 805' but
has angled inner septum 815' to be angled in parallel with the
angled transmit PCB 106''' and the angled receive PCB 108'''. The
baseplates 805, 805', 805'' in one embodiment may be a dielectric
to isolate components and insulate them from one another. In
another embodiment, baseplates 805, 805', 805'' may be an
insulator. In another embodiment, baseplates 805, 805', 805'' may
have their septum 815 or 815' metalized so as to provide EMI and
crosstalk shielding. Alternatively, a metal shield my be placed on
top of the septum 815 or 815' such as shield 109.
The optical block 402'' is similar to the optical block 402 but has
some modifications to accommodate the angled transmit PCB 106'''
and the angled receive PCB 108'''. The optical block 402'' includes
openings 513'' and 514'' to receive the receiver 111 and
transmitter 110 respectively and angled slots 1115 to receive the
angled transmit PCB 106''' and the angled receive PCB 108'''. The
angled slots 1115 can provide a friction fit with the angled
transmit PCB 106''' and the angled receive PCB 108''' or glue or
epoxy can be used to couple them together. The angled slots 1115
can also serve to tack the receiver 111 and transmitter 110 in
place within the optical block 402''.
The transmitter 110 couples into the opening 514'' of the optical
block 402''. The receiver 111 couples into the opening 513'' of the
optical block 402''. They can be held in place by either a friction
fit or a glue such as an epoxy.
The transmitter 110 also couples to the transmit PCB 106'''. The
terminals 810 of the transmitter 110 couple to the transmit PCB
106''' in one embodiment. Using a straddle mount, one or more
terminals 810 couple to left edge traces 920L on a left side and
one or more terminals 810 couple to right edge traces 920R on a
right side of the transmit PCB 106'''. In an alternate embodiment,
the terminals 810 may couple to one side of the transmit PCB
106'''. In yet another alternate embodiment, the terminals 810 may
couple into holes of the transmit PCB 106'''.
The receiver 111 also couples to the receive PCB 108'''. The
terminals 811 of the receiver 111 couple to the receive PCB 108'''.
Using a straddle mount, one or more terminals 811 couple to left
edge traces 921L on a left side and one or more terminals 811
couple to right edge traces 921R on a right side of the receive PCB
108'''. In an alternate embodiment, the terminals 811 may couple to
one side of the receive PCB 108'''. In yet another alternate
embodiment, the terminals 811 may couple into holes of the receive
PCB 108'''.
Referring now to FIG. 11B, a rear cross-sectional view of the
assembled fiber optic module 1100 is illustrated. The angled
receive PCB 108''' and the angled transmit PCB 106''' of the fiber
optic module 1100 are angled in parallel together with respect to a
horizontal or vertical axis thereof. The first terminal pin header
1027T' is coupled to the angled transmit PCB 1027T' so that pins
117 are vertical with the reference axis. The second terminal pin
header 1027R' is coupled to the angled receive PCB 108''' so that
pins 113 are vertical with the reference axis. A ground plane 118
can be coupled to a side the angled receive PCB 108''' or a ground
plane 114 can be coupled to a side of the angled transmit PCB
106''' or both similar to previously described with reference to
the vertical boards and FIGS. 9B-9E. The shield housing or cover
419 couples to the baseplate 805'' around the printed circuit
boards. Depending upon the width of the printed circuit boards
106''' and 108''' and the width of the fiber optic module 1100, the
angles .theta..sub.3 and .theta..sub.4 which the printed boards
make with the base or baseplate 805'' and the angle .theta..sub.5
which the septum 815' makes with the base or baseplate 805'' can
vary between zero and ninety degrees.
Referring now to FIG. 12A, another embodiment of the invention is
illustrated. FIG. 12A illustrates an exploded view of a fiber optic
module 1200. The fiber optic module 1200 has angled or slanted PCBs
with respect to a horizontal or vertical axis of the fiber optic
module 1200. The PCBs are angled or slanted away at top edges to
form a V configuration of PCB orientation. The length of the PCBs
remain parallel to the optical axis of the receiver 111 and
transmitter 110. By angling the PCBs with the horizontal or
vertical axis, the PCBs may be made smaller to fit a smaller form
factor or alternatively the surface area can be increased. That is
the available PCB surface area for mounting components can be
increased for a given volume by angling the PCBs. The increased
surface area can give the final assembled fiber optic module
increased functionality by allowing components such as integrated
circuits and passive components such as filters, capacitors, and
inductors to be added. More room can also be provided in the fiber
optic module 1200 for mounting larger components by angling the
PCBs.
The fiber optic module 1200 includes an angled transmit PCB
106'''', an angled receive PCB 108'''', the transmitter 110, the
receiver 111, an optical block 402''', the shielded housing or
cover 419, a first terminal pin header 1027T'' for the transmitter,
a second terminal pin header 1027R'' for the receiver, and the
baseplate 805 or 805'.
The angled transmit PCB 106'''' and the angled receive PCB 108''''
are arranged at an angle with respect to the horizontal axis of the
fiber optic module as defined by a line normal to both receiver and
transmitter optical axes. The angled transmit PCB 106'''' and the
angled receive PCB 108'''' slant away from each other to form the V
configuration. The angled transmit PCB 106'''' and the angled
receive PCB 108'''' are held in place having a width that is on an
angle with respect to a horizontal or vertical axis of the fiber
optic module 1200. The length of the angled transmit PCB 106''''
and the angled receive PCB 108'''' are parallel to the optical axis
of the receiver 111 and transmitter 110. The angled transmit PCB
106'''' includes components 116 and left and right edge traces 921L
and 921R. The first terminal pin header 1027T'' has pins 117 that
couple to holes of the angled transmit PCB 106'''' on one end. The
angled receive PCB 108'''' includes components 112 and left and
right edge traces 920L and 920R. The second terminal pin header
1027R'' has pins 113 that couple to holes of the angled receive PCB
108'''' on one end.
The transmitter 110 is a transmit optical subassembly (Tx OSA) that
includes a VCSEL or other semiconductor device that transduces
electrical signals into photons or a light output. The receiver 111
is a receive optical subassembly (Rx OSA) including a PIN diode or
other device that converts photons or light input into electrical
signals. The Tx OSA and Rx OSA are attached to physically separated
transmit and receive electrical subassemblies (ESA's). In one
embodiment, the transmit ESA includes the angled transmit PCB
106'''' with components 116 and the first terminal pin header
1027T'' mounted thereto. In one embodiment, the receive ESA
includes the angled receive PCB 108'''' with components 112 and the
second terminal pin header 1027R'' mounted thereto.
The optical block 402''' is similar to the optical block 402 but
has some modifications to accommodate the angled transmit PCB
106'''' and the angled receive PCB 108''''. The optical block
402''' includes openings 513''' and 514''' to receive the receiver
111 and transmitter 110 respectively and angled slots 1215 to
receive the angled transmit PCB 106'''' and the angled receive PCB
108''''. The angled slots 1215 can provide a friction fit with the
angled transmit PCB 106'''' and the angled receive PCB 108'''' or
glue or epoxy can be used to couple them together. The angled slots
1215 can also serve to tack the receiver 111 and transmitter 110 in
place within the optical block 402'''.
The transmitter 110 couples into the opening 514''' of the optical
block 402'''. The receiver 111 couples into the opening 513''' of
the optical block 402'''. They can be held in place by either a
friction fit or a glue such as an epoxy.
The transmitter 110 also couples to the transmit PCB 106''''. The
terminals 810 of the transmitter 110 couple to the transmit PCB
106'''' in one embodiment. Using a straddle mount, one or more
terminals 810 couple to left edge traces 920L on a left side and
one or more terminals 810 couple to right edge traces 920R on a
right side of the transmit PCB 106''''. In an alternate embodiment,
the terminals 810 may couple to one side of the transmit PCB
106''''. In yet another alternate embodiment, the terminals 810 may
couple into holes of the transmit PCB 106''''.
The receiver 111 also couples to the receive PCB 108''''. The
terminals 811 of the receiver 111 couple to the receive PCB
108''''. Using a straddle mount, one or more terminals 811 couple
to left edge traces 921L on a left side and one or more terminals
811 couple to right edge traces 921R on a right side of the receive
PCB 108''''. In an alternate embodiment, the terminals 811 may
couple to one side of the receive PCB 108''''. In yet another
alternate embodiment, the terminals 811 may couple into holes of
the receive PCB 108''''.
Referring now to FIG. 12B, a rear cross-sectional view of the
assembled fiber optic module 1200 is illustrated. The angled
receive PCB 108'''' and the angled transmit PCB 106'''' of the
fiber optic module 1200 are angled away from each other with
respect to a horizontal or vertical axis thereof. The first
terminal pin header 1027T'' is coupled to the angled transmit PCB
1027T'' so that pins 117 are vertical with the reference axis. The
second terminal pin header 1027R'' is coupled to the angled receive
PCB 108'''' so that pins 113 are vertical with the reference axis.
A ground plane 118 can be coupled to a side the angled receive PCB
108'''' or a ground plane 114 can be coupled to a side of the
angled transmit PCB 106'''' or both similar to previously described
with reference to the vertical boards and FIGS. 9B-9E. The shield
housing or cover 419 couples to the baseplate 805 or 805' around
the printed circuit boards. Depending upon the width of the printed
circuit boards 106'''' and 108'''' and the width of the fiber optic
module 1200, the angles .theta..sub.6 and .theta..sub.7 which the
printed boards make with the base or baseplate 805 or 805' can vary
between zero and ninety degrees.
While symmetrical angles for the printed circuit boards have been
illustrated, combinations can be utilized to form alternate
embodiments. For example, one of the printed circuit boards may be
arranged on an angle with the base so as to slant while the other
printed circuit board may be arranged perpendicular to the base.
FIG. 16A illustrates a fiber optic module 1600 with such an
arrangement for an alternate embodiment of the invention.
Referring now to FIG. 13, a receiver optical block 402R and a
transmitter optical block 402T are illustrated as an alternative to
the optical block 402 or 402'. Previously the fiber optic modules
were described and illustrate using a single optical block 402 or
402'. However, the optical blocks 402R and 402T can provide similar
functionality to the single optical block 402 or 402'. The receiver
optical block 402R couples to the receiver 111 while the transmit
optical block 402T couples to the transmitter 110. The receiver 111
and transmitter 110 can be press fit into the openings 513 and 514
or alternatively a glue or epoxy can inserted into the tacking
holes to couple them together. Each optical receiver optical block
402R and transmit optical block 402T provides alignment to an
optical fiber and may include a lens. If one more receiver channels
are desired, one or more receiver optical blocks 402R can be
utilized. If one or more transmit channels are desired, one or more
transmit optical blocks 402T can be utilized.
While pins 113 and 117 of the fiber optic modules (100, 400, 800,
900, 1000, 1100, or 1200) facilitate soldering to a host printed
circuit board, they can also be plugged into a socket 1402 on a
host printed circuit board 1404 as illustrated in FIG. 14A.
Alternatively, the pins 113 and 117 can each be replaced with one
or more sockets 1406R and 1406T coupled to the printed circuit
boards on the bottom edge or back edge. In the case of sockets
1406R and 1406T on the bottom edges of the printed circuit boards,
the fiber optic module (100, 400, 800, 900, 1000, 1100, or 1200)
plugs vertically or downward on sockets 1408R and 1408T for example
of the host printed circuit board 1404' as illustrated by FIG. 14B.
In the case of a socket or sockets 1416R and 1416T on the back edge
of the printed circuit boards, the fiber optic module (100, 400,
800, 900, 1000, 1100, or 1200) plugs horizontally or inward into a
socket or sockets 1418R and 1418T of the host printed circuit board
1404''.
Referring now FIG. 15A, an alternate embodiment of a shielded
housing or cover 1519 and an alternate base 1505. The shielded
housing or cover 1519 includes a center inner septum 1515
incorporated as part of the housing or cover to isolate a transmit
channel from a receive channel or one channel from another channel.
The center inner septum 1515 splits the fiber optic module into a
left side and a right side as does the other septums described
herein. The housing or cover 1519 further includes a back side
1521, a left side 1522, a right side 1523 and clips or tabs 236. A
front side 1524 of the housing or cover 1519 is open to couple to
the optical block 402 and/or a nose.
The alternate base 1505 has no septum and may include clip openings
or slots 238. Alternately, a base is without the clip openings or
slots 238 such that the clips or tabs 236 of the housing or cover
are bent over and around the base.
Referring now to FIG. 15B, a cross sectional view of a fiber optic
module 1000' utilizing the alternate embodiment of the shielded
housing or cover 1519 and base 1505 is illustrated. The fiber optic
module 1000' is similar to fiber optic module 1000 as described
with reference to FIGS. 10A-10B but for the alternate shielded
housing or cover 1519 and the alternate base 1505.
Referring now to FIG. 15C, a cross sectional view of the alternate
embodiment of the shielded housing or cover 1519 is illustrated.
The shielded housing or cover 1519 is a monolithic or integrated
shielded housing or cover incorporating the septum 1515. The
shielded housing or cover 1519 can be formed of a metal, a plastic
or other solid material. The shielded housing or cover 1519 if made
of metal, can be formed by forging, stamping or machining. Lower
costs methods to fabricate the shielded housing or cover 1519
include injection, transfer, or blow molding the shape out of
plastic. The plastic can then be plated, painted or otherwise
coated with a conductive material, if conductivity is desired.
Likewise a metal part can be overcoated with a non-conductive
material if conductivity is not desired.
Referring now to FIG. 15D and FIG. 15E, the septum can be angled as
well to accommodate parallel angled PCB boards as illustrated by
the septum 1515' of the shielded housing or cover 1519' and the
septum 1515'' of the shielded housing or cover 1519''.
Referring now to FIG. 15F, the septum can be formed separately from
the housing or cover and coupled thereto. The shielded housing or
cover 1519''' includes a septum 1515''' which is formed separately
and coupled together. The septum 1515''' can be coupled to the
outer housing by using fusion techniques such as soldering,
welding, or melting. FIG. 15F illustrates the fuse links 1530
(solder, weld, etc) coupling the septum 1515''' to the outer
housing of the shielded housing or cover 1519'''.
Referring now to FIG. 15G, the septum can be formed separately from
the housing or cover and coupled thereto by alternate means. FIG.
15G illustrates the shielded housing or cover 1519'''' including a
septum 1515'''' which is formed separately and coupled together.
The outer cover of the shielded housing or cover 1519'''' includes
a groove 1532 and the septum 1515'''' includes a tongue 1534 to
form a tongue and groove system. A glue, adhesive or epoxy 1535 is
applied between the tongue and groove system which may be
conductive or non-conductive to couple the outer housing and the
septum 1515'''' together to form the shielded housing or cover
1519''''.
The fiber optic modules previously described with reference to
FIGS. 8A-15G were illustrated with the optoelectronic devices
(transmitter 110 and receiver 111) having its terminals coupled to
the printed circuit boards using a straddle mount. However, one or
all of the optoelectronic devices may have their terminals coupled
to the printed circuit boards using a through hole mount. In a
straddle mount, the optoelectronic device (i.e. the transmitter 110
or the receiver 111) has its optical axis nearly in-line and
parallel with a plane of the printed circuit board. In a through
hole mount, the optoelectronic device (i.e. the transmitter 110 or
the receiver 111) has its optical axis nearly parallel with a plane
of the printed circuit board.
Referring now to FIG. 16A, a rear cross-section of a fiber optic
module 1600 is illustrated having a first optoelectronic device
with its terminals coupled to a first printed circuit board in a
straddle mount configuration and a second optoelectronic device
with its terminals coupled to a second printed circuit board in a
through hole mount configuration. Alternatively, both the first
optoelectronic device the second optoelectronic device may have
their terminals coupled to their respective printed circuit boards
in a through hole mount configuration as illustrated by the rear
cross-section of fiber optic module 1602 of FIG. 16B.
Referring now to FIGS. 17A-17D, exploded perspective views of a
pluggable fiber optic module 1700 are illustrated. In one
embodiment, the pluggable fiber optic module 1700 is an MTRJ-SFP
pluggable fiber optic module. As illustrated in FIG. 17A, the
pluggable fiber optic module 1700 may include a cover/housing 1702,
an interface printed circuit board (PCB) 1704, a support base 1706,
a transmit printed circuit board (PCB) 1708, a receive printed
circuit board (PCB) 1710, the optical block 102, the transmitter
110, the receiver 111, an alignment plate 201', a nose receptacle
202', and an actuator 1714.
The details of the optical block 102, the transmitter 110, the
receiver 111 were previously described and will not be repeated
here for reasons of brevity.
The cover/housing 1702 may have one or more top, left, and right
side electromagnetic interference (EMI) fingers 1720T, 1720L, 1720R
extending outward from a top surface, left surface and right
surface thereof, respectively. The cover/housing 1702 may further
have one or more right and left side openings 1721R, 1721L, 1722R,
1722L, 1723R, 1723L in the top surface, the left surface, and the
right surface thereof. The cover/housing 1702 may further have a
contact tab 1726 extending inward from the top surface.
The right and left side openings 1721R, 1721L, 1722R, 1722L may
interface to right and left tabs 1741R, 1741L, 1742R, 1742L in the
support base 1704 to couple the cover/housing 102 to a subassembly
of the fiber optic module 1700. The right and left side openings
1723R, 1723L may interface to right and left tabs (right tab 1782R
only shown in the Figures with left tab 1782L being a mirror image
thereof) in the nose receptacle 202' to further the cover/housing
102 to the subassembly of the fiber optic module 1700. If the
cover/housing 102 is conductive, the contact tab 1726 may
electrically couple to an edge of the alignment plate 201', if its
conductive. Alternatively, the contact tab 1726 may extend and
electrically couple to both the alignment plate 201' and the nose
receptacle 202' if both are conductive.
The cover/housing 1702, alignment plate 201', and nose receptacle
202' may be formed of a metal or a plastic. In the case of plastic,
the plastic may be metalized to form of a metalized plastic in
order to be conductive and provide static (ESD), EMI, or RF
shielding through a ground connection which may be made through the
one or more fingers 1720T, 1720L, 1720R (one or more fingers 1720L
are not shown in the figures but being a mirror image of the one or
more fingers 1720R). In a preferred embodiment, the cover/housing
1702 is formed of stainless steel.
The interface PCB 1704 may also be referred to as a horizontal
printed circuit board. The interface PCB 1704 may include one or
more openings 1734 to slide over one or more alignment pillars 1740
in the support base 1706. The interface PCB 1704 may further
include an edge connection 1730 formed by traces on the surface of
the interface PCB 1704; left and right side solder pads 1732L,
1732R; and one or more integrated circuits (ICs) 1736 or other
electrical components. The edge connection 1730 of the interface
PCB 1704 may also be referred to as an edge connector, a plug, an
interface slot, or a connector tongue. The left and right side
solder pads 1732L, 1732R are for forming an electrical connection
with the transmit PCB 1708 and the receive PCB 1710 by means of one
or more solder joints. In the preferred embodiment, each solder
joint is a ninety degree castellation solder joint. The interface
PCB 1704 may further include left and right cutouts 1738L, 1738R
which may allow respective edges of the transmit PCB 1708 and the
receive PCB 1710 to slide into respective left and right slots
1743L, 1743R in the support base 1706. The edge connection 1730 of
the interface PCB 1704, allows the fiber optic module 1700 to be
plugged into and out of an edge connector of a host printed circuit
board. The edge connection 1730, as discussed further below, may
allow for the hot pluggability of the fiber optic module 1700 into
a powered up host printed circuit board.
The support base 1706 may include the one or more alignment pillars
1740; the left and right tabs 1741R, 1741L, 1742R, 1742L (left tab
1741L is not shown in the figures but being a mirror image of the
right tab 1741R); the left and right slots 1743L, 1743R; a support
edge 1744; and a support tab 1746. The left slot 1743L is for
receiving an edge of the transmit PCB 1708 in the preferred
embodiment. The right slot 1743R is for receiving an edge of the
receive PCB 1710 in the preferred embodiment. In an alternate
embodiment, the receive PCB and transmit PCB can swap sides along
with swapping sides of the transmitter 110 and receiver 111 and the
optical components (i.e. lenses, etc.) within the optical block
102.
As previously discussed, the interface PCB 1704 may include one or
more openings 1734 to slide over the one or more alignment pillars
1740 in the support base 1706. An epoxy or glue can be deposited
around the pillars 1740 and on the surface of the interface PCB
1704 near the openings 1734 in order to hold interface PCB 1704 and
the support base 1706 coupled together. When the edge connection
1730 of the interface PCB 1704 is plugged into and out of an edge
connector of a host PCB, the pillars 1740 deter movement of the
interface PCB 1704 with respect to the fiber optic module 1700. The
support edge 1744 of the support base 1706 provides support to the
interface PCB 1704 nearer the edge connection 1730. The support tab
1746 provides support to the interface PCB 1704 near an end
opposite to the end having the edge connection 1730.
As previously discussed, the right and left tabs 1741R, 1741L,
1742R, 1742L in the support base 1704 couple into the right and
left side openings 1721R, 1721L, 1722R, 1722L in the cover/housing
102 to couple the cover/housing 102 and the support base 1704
together. In the preferred embodiment, the tabs are shaped as a
ramp or a wedge as illustrated so that the edges of the
cover/housing 102 can easily slide over the tabs. However, when the
tabs are engaged into the openings, it is difficult to release the
cover/housing 102 and disassemble it from the fiber optic module
1700.
The receive PCB 1710 may also be referred to as a vertical printed
circuit board and is a receiver electrical subassembly. The receive
PCB 1710 includes one or more solder pads 1752, one or more
integrated circuits (ICs) 1754 or other electrical components, and
one or more thruholes 1756. The receive PCB 1710 may also include a
ground plane or a portion thereof on one side or the other to
provide EMI/RF shielding. The receive PCB 1710 may also a cutout
area 1758 in the circuit board to electrically couple the one or
more solder pads 1752 to the interface PCB and allow the edge of
the transmit PCB to slide into a slot in the support base 1706. The
one or more thruholes 1756 in the receive PCB 1710 are similar to
the thruholes 1756 in the receive PCB 1710 are similar to the
thruholes 232 in the receive PCB 108 illustrated in FIG. 2 and
discussed previously. The one or more thruholes 1756 in the receive
PCB 1710 are aligned and then slid over the terminals 211 of the
receiver 111. The terminals 211 are then soldered to the receive
PCB 1710 to make an electrical connection thereto. The one or more
solder pads 1752 may be electrically coupled to the receiver 111
and/or the one or more integrated circuits (ICs) 1754 or other
electrical components thereon through traces of the receiver PCB
1710. As previously discussed, the right side solder pads 1732R of
the interface PCB 1704 form an electrical connection with the
solder pads 1752 of the receive PCB 1710 by means of one or more
solder joints. In the preferred embodiment, each solder joint is a
ninety degree castellation solder joint.
The transmit PCB 1708 may also be referred to as a vertical printed
circuit board and is a transmitter electrical subassembly. The
transmit PCB 1708 includes one or more solder pad 1762, one or more
integrated circuits (ICs) 1764 or other electrical components, and
one or more thruholes 1766. The transmit PCB 1708 may also include
a ground plane or a portion thereof on one side or the other to
provide EMI/RF shielding. The transmit PCB 1708 may also a cutout
area 1768 in the circuit board to electrically couple the one or
more solder pads 1762 to the interface PCB and allow the edge of
the transmit PCB to slide into a slot in the support base 1706. The
one or more thruholes 1766 in the transmit PCB 1708 are similar to
the thruholes 233 in the transmit PCB 106 illustrated in FIG. 2 and
discussed previously. The one or more thruholes 1766 in the
transmit PCB 1708 are aligned and then slid over the terminals 210
of the transmitter 110. The terminals 210 are then soldered to the
transmit PCB 1708 to make an electrical connection thereto. The one
or more solder pads 1762 may be electrically coupled to the
transmitter 110 and/or the one or more integrated circuits (ICs)
1764 or other electrical components thereon through traces of the
transmit PCB 1708. As previously discussed, the left side solder
pads 1732L of the interface PCB 1704 form an electrical connection
with the solder pads 1762 of the transmit PCB 1708 by means of one
or more solder joints. In the preferred embodiment, each solder
joint is a ninety degree castellation solder joint.
With the transmitter 110 coupled to the transmit PCB 1708 and the
receiver 111 coupled to the receive PCB 1710, the transmitter 110
can be inserted into the opening 213 of the optical block 102 and
the receiver 111 can be inserted into the opening 214 of the
optical block 102. As discussed previously, the transmitter 110 and
the receiver 111 can be aligned and coupled to the optical block
102 within the openings 213 and 214, respectively.
The alignment plate 201' may also be referred to as an EMI block
and functions somewhat similar to the alignment plate 201.
Alignment plate 201' may have some similar features and may have
some different features as the alignment plate 201 in order to
accommodate the same or different fiber optic plugs and fiber optic
cables. The alignment plate 201' has the optical block alignment
holes 216 and an optical opening 217' to allow light to pass
through similar to the alignment plate 201. The alignment plate
201' may or may not have the fiber optic connector alignment pins
218 depending upon the type of fiber optic plug is being used. The
optical block holes 216 couple to optical block alignment pins in
the optical block 102, not illustrated in FIG. 2. The fiber optic
connector alignment pins 218 are for aligning optical fibers that
couple to the fiber optic module 100. The alignment plate 201' may
further have openings 1770 to align with pins in the nose
receptacle 202' in order to couple to the nose receptacle 202'. The
alignment plate 201' may be formed of plastic, metal or a metalized
plastic. If formed of metal or metalized plastic, the alignment
plate 201' may be electrically grounded through the cover/housing
1702 or otherwise to reduce EMI or RF interference.
For coupling to a fiber optic connector, the fiber optic module
1700 has the nose receptacle 202'. The nose receptacle 202' may
include the plug opening 222' and the latch opening 223 to couple
to a fiber optic connector or plug of an optical fiber. The optical
fiber may be one or more optical fibers to provide unidirectional,
bidirectional, or multidirectional communication. The latch opening
223 can receive a latch of the optical fiber connector and hold the
fiber optic connector of the optical fiber coupled thereto. The
optical fiber plug opening 222' receives an optical fiber plug and
aligns the optical fibers with the optical opening 217 of the
alignment plate 201'. The nose receptacle 202' may be formed of
plastic, metal or metalized plastic. If formed of metal or
metalized plastic, the nose receptacle 202' may be electrically
grounded through the cover/housing 1702 or otherwise to further
reduce EMI or RF interference.
The nose receptacle 202' may further include the right and left
tabs (right tab 1782R only shown in the Figures with left tab 1782L
being a mirror image thereof) to interface with the right and left
side openings 1723R, 1723L of the cover/housing 102. The nose
receptacle 202' may further include right and left slots (right
slot 1783R only shown in the Figures with left slot 1783L being a
mirror image thereof) to allow a portion of the support base 1706
including the right and left side tabs 1742R, 1742L to slide
therein. In this manner, the right and left side tabs 1742R, 1742L
may be supported in place by the nose receptacle 202' when the
cover/housing 1702 is engaged therewith.
As illustrated in FIG. 17A, the nose receptacle 202' may further
include an opening 1784 having a pair of tangs or ridges 1786 on
opposite side thereof to slideably interface with the actuator
1714. In a preferred embodiment, the actuator 1714 is an SFP
actuator. The nose receptacle 202' may further include a center
region in the opening 1784 over which a portion of the actuator
1714 may slide.
The actuator 1714 includes one or more ramps or wedges (a pair of
which are illustrated) 1792, slot or grooves 1794 on each side
having an opening at one end and a closure at an opposite end. The
slots or grooves 1794 in the actuator 1714 slideably engage the
ridges or tangs 1786 in the nose receptacle 202'.
As illustrated in FIG. 17B, the nose receptacle 202' may further
include a pair of pins 1780 and a support slot 1781 for engaging
with the alignment plate 201'. The pair of pins 1780 can slide into
the openings 1770 in the alignment plate 201'. The support slot
1781 may be unshaped to accept and hold the alignment plate 201' in
place with the nose receptacle 202'.
As illustrated in FIGS. 17C and 17D, the nose receptacle 202' may
further include a hook or boss 1785 and the center region 1787. The
hook or boss 1785 interfaces to a latch of a cage or host
receptacle as described further below. A portion of the actuator
1714 may slide over the center region 1787 in the opening 1784.
The actuator 1714 includes the one or more ramps or wedges (a pair
of which are illustrated) 1792 for releasing the hook or boss 1785
from a latch and freeing the fiber optic module from 1700 a cage or
host receptacle. The center region 1787 can provide slideable
support to the actuator 1714 to allow it to push out on the latch
while the ridges or tangs 1786 can provide slideable guidance in
movement thereof.
The nose receptacle 202' may further include a nose grip at its
sides. In one embodiment, the nose grip includes vertical ribs
located at the sides near the opening 222'. The nose grip can serve
to provide additional gripable surface area during the withdrawal
process of the fiber optic module 1700. The one or more vertical
ribs deters slippage during handling. The nose grip may be an
integrated part of the nose receptacle 202' and can be formed of
similar materials.
Additionally, the fiber optic module 1700 may optionally include an
internal shield, such as the optional internal shield 109
illustrated in FIGS. 1-2 and previously described above, located
between the receive PCB 1710 and the transmit PCB 1708 and the
interface PCB 1704. The internal shield may be coupled to a ground
trace or ground plane of one of the receive PCB 1710, the transmit
PCB 1708 and the interface PCB 1704 or alternatively, it may be
coupled to the cover/housing 1702. In any case, the optional
internal shield needs to formed so as to not short to any
integrated circuit, other electrical component, wire or trace of
the printed circuit boards.
Additionally, the fiber optic module 1700 may optionally include
pull-action delatching, push button release, pull-lever release, or
other delatching or release mechanisms as described in application
Ser. No. 09/896,695, titled "METHOD AND APPARATUS FOR PUSH BUTTON
RELEASE FIBER OPTIC MODULES", filed Jun. 28, 2001; application Ser.
No. 09/939,403, titled "DE-LATCHING MECHANISMS FOR FIBER OPTIC
MODULES", filed Aug. 23, 2001; application Ser. No. 09/939,413,
titled "PULL-ACTION DE-LATCHING MECHANISMS FOR FIBER OPTIC
MODULES", filed Aug. 23, 2001; and application Ser. No. 10/056,394,
titled "METHOD AND APPARATUS FOR PULL-LEVER RELEASE FOR FIBER OPTIC
MODULES", filed Jan. 24, 2002, all of which are incorporated herein
by reference and are to be assigned to E2O Communications, Inc.
Referring now to FIGS. 18A-18D, perspective views of a partially
assembled pluggable fiber optic module 1700 are illustrated with
the cover/housing 1702 being disassembled therefrom. The
transmitter 110 and receiver 111 are coupled into respective
openings in the optical block 102. The pins 211 of the receiver 111
are coupled to the receive PCB 1710. The pins 210 of the
transmitter are coupled to the transmit PCB 1708. The cutout 1758
of the receive PCB 1710 and the cutout 1738R of the interface PCB
allow the respective solder pads 1752 and solder pads 1732R align
up together. The solder pads 1752 of the receive PCB 1710 are
electrically coupled to the right side solder pads 1732R of the
interface PCB 1704 by means of one or more solder joints 1802R. The
cutout 1768 of the transmit PCB 1708 and the cutout 1738L of the
interface PCB allow the respective solder pads 1762 and solder pads
1732L align up together. The solder pads 1762 of the transmit PCB
1708 are electrically coupled to the left side solder pads 1732L of
the interface PCB 1704 by means of one or more solder joints 1802L
(The one or more solder joints 1802L are not shown in the figures
but are a mirror image of the one or more solder joints 1802R). In
the preferred embodiment, the one or more solder joints are ninety
degree castellation solder joints. This subassembly is then
assembled to the support base 1706.
The openings 1734 of the interface PCB 1704 are slid over the
pillars 1740 of the support base 1706. The respective edges of the
transmit PCB 1708 and the receive PCB 1710 slide into the slot
1743L and the slot 1743R. The interface PCB 1704 rests for is
support on the support edge 1744 and the support tab 1746. A wax,
epoxy, or glue may be dripped onto the pillars 1740 to couple the
support base 1706 and the interface PCB 1704 together with the rest
of the subassembly.
The alignment plate 201' is coupled to the optical block 102. The
alignment holes 216 of the alignment plate 201' are slid over the
alignment pins 316 in the optical block 102. In an alternate
embodiment, the alignment plate 201' may first couple to the nose
receptacle 202' before coupling to the optical block 102.
The actuator 1714 is coupled to the nose receptacle 202'. The slots
or grooves 1794 in the actuator 1714 are mated with the ridges or
tangs 1786 of the nose receptacle 202'. The actuator 1714 may slide
back and forth in the opening 1784 in the nose receptacle 202'.
The nose receptacle 202' is coupled to the alignment plate 201' and
the support base 1706. The openings 1770 in the alignment plate
201' are slid over the pins 1780 of the nose receptacle 202'. The
extended portion of the support base 1706 including the right and
left side tabs 1742R, 1742L, slides into respective right and left
slots (right slot 1783R only shown in the Figures with left slot
1783L being a mirror image thereof) of the nose receptacle
202'.
The cover/housing 1702 is coupled to the nose receptacle 202' and
the support base 1706. The sides of the cover/housing 1702 are slid
over the sides of the subassembly so that the openings 1721R,
1722R, 1723R, 1712L, 1722L, and 1723L may align with the respective
tabs 1741R, 1742R, 1782R, 1741L, 1742L, and 1782L of the support
base 1706 and the nose receptacle 202'. The edge of the sides of
the cover/housing 1702 slide over the tabs 1741R, 1742R, 1782R,
1741L, 1742L, and 1782L. The tabs 1741R, 1742R, 1782R, 1741L,
1742L, and 1782L engage the respective openings 1721R, 1722R,
1723R, 1712L, 1722L, and 1723L in the cover/housing 1702. In one
embodiment, the tabs snap in place into the openings of the
cover/housing. In this manner, the sides of cover/housing 1702
couple to the sides of the support base 1706 and the nose
receptacle 202'. The contact tab 1726 of the cover/housing 1702 may
contact a surface of the alignment plate 201' or a surface of both
the alignment plate 201' and nose receptacle 202'. The completed
assembly of the fiber optic module 1700 with the cover/housing 1702
coupled in place is illustrated in FIG. 20 and FIGS. 21A-21D.
Referring now to FIGS. 19A-19E, views of an exemplary cage assembly
or module receptacle 1900 for fiber optic modules is illustrated.
That is a fiber optic module, such as fiber optic module 1700, is
inserted into the cage assembly or module receptacle 1900. In FIG.
19B, the latch 1902 is illustrated in a bottom view of the module
receptacle 1900. The latch 1902 includes a catch 1905 that mates
with the hook or boss 1785 of the fiber optic module 1700. As
illustrated in the cross sectional view of FIG. 19C and the
exploded cross-sectional view of FIG. 19D, the latch 1902 is flexed
downward in order to release the fiber optic module. The one or
more ramps 1792 of the actuator 1714 of the fiber optic module 1700
flexes the latch 1902 downward when the fiber optic module is
pushed in or a force is exerted on a delatching or other release
mechanism operating in conjunction with the actuator. The one or
more ramps 1792 of the actuator 1714 meets a lip 1908 of the latch
1902 which is bent on an angle and then flexes the latch 1902
outward so that the catch 1905 is released from the hook or boss
1785. The cage assembly or module receptacle 1900 may include one
or more pins 1910 to mechanically and/or electrically couple to a
host printed circuit board 1912. The pins 1910 may couple to a
ground trace or a ground plane so that static charges, EMI, and RF
interference may be dissipated through to ground or a negative
power supply.
Referring now to FIG. 20, a side view of an embodiment of a fiber
optic module 1700 to couple to a host system 2000 is illustrated.
The host system 2000 may include the host printed circuit board
1912, an exemplary host connector 2002 coupled to the host printed
circuit board 1912, and the exemplary cage assembly or module
receptacle 1900 coupled to the host printed circuit board 1912. The
host system 2000 may be networking equipment, computer equipment,
or other equipment desiring data communication using an optical
fiber.
The cage assembly or module receptacle 1900 may extend through an
opening 2004 in a plate or bezel 2006 of the host system 2000 as
illustrated in FIG. 20, remain flush with the plate or bezel 2006,
or be recessed from the plate or bezel 2006. The plate or bezel
2006 may be formed of metal or plastic. If formed of plastic, the
plastic may be metalized to make the plate or bezel 2006
conductive. The cage assembly or module receptacle 1900 may include
external grounding fingers to couple to a surface of the plate or
bezel 2006 or within the opening 2004 of the plate or bezel 2006 so
as to ground thereto. Alternatively, the cage assembly or module
receptacle 1900 may be insulated from the plate or bezel 2006 so as
to electrically isolate each from the other.
The exemplary host connector 2002 is for coupling to an edge
connection of a printed circuit board, such as the edge connection
1730 of the interface PCB 1704 in the pluggable fiber optic module
1700. The host connector 2002 may also be referred to as an edge
connector. The edge connector 2002 is located inside the perimeter
of the cage assembly or module receptacle 1900 nearer its back
end.
The edge connector 2002 may include one or more alignment posts
2014 to interface with one or more openings in the host printed
circuit board 1912. The edge connector 2002 further includes one or
more external pins 2016 on either or both sides to couple to
electrical traces of the host printed circuit board 1912. As will
be discussed further below, the edge connector 2002 further
includes one or more internal pins to couple to the edge connection
1730 of the interface PCB 1704 of the pluggable fiber optic module
1700. The one or more external pins 2016 are electrically coupled
to one or more internal pins of the edge connector 2002 in order to
electrically couple the fiber optic module 1700 to the host printed
circuit board 1912.
To couple, insert, or plug the fiber optic module 1700 into the
host system 2000, the edge connector 1730 of the fiber optic module
1700 is first inserted into an open end of the cage assembly or
module receptacle 1900. The fiber optic module 1700 is further
inserted into the cage assembly or module receptacle 1900 so that
the one or more top, left, and right side electromagnetic
interference (EMI) fingers 1720T, 1720L, 1720R extending outward
from the top surface, left surface and right surface are inserted
into the open end of the cage assembly or module receptacle 1900.
The one or more top, left, and right side electromagnetic
interference (EMI) fingers 1720T, 1720L, 1720R of the fiber optic
module 1700 slidingly couple to the top, left, or right side inner
surfaces of the cage assembly or module receptacle 1900. In this
manner, static charges may be grounded out to the cage assembly or
module receptacle 1900 before the fiber optic module 1700 couples
to the edge connector 2002. The fiber optic module 1700 is further
inserted into the cage assembly or module receptacle 1900 so that
the edge connection 1730 finally couples to the edge connector 2002
of the host system 2000 and the opening 1905 in the latch 1902
engages with the boss 1785. To decouple, remove or unplug the fiber
optic module 1700 from the host system 2000, the fiber optic module
may be pushed further inward to cause the ramps 1792 of the
actuator 1714 to push out on the latch 1902, disengaging the
opening 1905 from the boss 1785 and pulling out on the fiber optic
module 1700. Alternatively, the methods and apparatus described in
application Ser. Nos. 09/896,695; 09/939,403; 09/939,413; and
10/056,394 referred to above may be used to decouple, remove or
unplug the fiber optic module 1700 from the host system 2000.
Referring now to FIGS. 21A-21D, perspective views of the fiber
optic module 1700 and the exemplary edge connector 2002 are
illustrated. FIGS. 21A-21D better illustrate some aspects of the
edge connector 2002. The edge connection 1730 of the interface PCB
1704 is inserted into the opening 2018 of the edge connector 2002
to couple thereto. As discussed previously, the pins 2016 of the
edge connector 2002 are for coupling to conductive traces on a host
printed circuit board. The alignment pins 2014 of the edge
connector 2002 assure that the pins 2016 properly line up to couple
to the traces of the host printed circuit board. The pins 2016 may
be soldered to the host printed circuit board. The edge connection
1730 includes one or more pads 2100A on one side and one or more
pads 2100B on an opposite side of the interface PCB 1704. The one
or more pads 2100A and 2100B on the interface PCB 1704 are to
couple to internal pins of the edge connector 2002 when inserted
into the opening 2018. The size of the edge connector 2002 is such
that the sides of cover/housing 1702 of the fiber optic module 1700
may fit over and partially cover the edge connector 2002. That is,
the cover/housing 1702 of the fiber optic module 1700 may receive
the edge connector 2002 so that the edge connection 1730 may couple
thereto.
With the tabs 1741R, 1742R, 1782R, 1741L, 1742L, and 1782L engaged
with the respective openings 1721R, 1722R, 1723R, 1712L, 1722L, and
1723L in the cover/housing 1702, the cover/housing 1702 is deterred
from being decoupled from the fiber optic module 1200 during the
sliding engagement between the one or more top, left, and right
side electromagnetic interference (EMI) fingers 1720T, 1720L, 1720R
of the fiber optic module 1700 and the top, left, or right side
inner surfaces of the cage assembly or module receptacle 1900.
Referring now to FIG. 22A, a cross sectional view of the fiber
optic module 1700 coupled to the edge connector 2002 is
illustrated. The cross section view of the fiber optic module 1700
illustrates more clearly how the support tab 1746 and the support
edge 1744 of the support base 1744 supports the interface PCB 1704.
It also further illustrates how the one or more openings 1734 slide
over the one or more pillars 1740 and keep the interface PCB 1704
from moving when plugged into and pulled out from the edge
connector 2002. A portion of the sides of the cover/housing 1702 of
the fiber optic module 1700 fit over and partially cover the edge
connector 2002. The edge connection 1730 of the interface PCB 1704
is coupled into the edge connector 2002 through the opening
2018.
Referring now to FIG. 22B, a cross sectional view of the fiber
optic module 1700 coupled to the host system 2000 is illustrated.
The host system 2000 includes the edge connector 2002 and the cage
assembly 1900 coupled to the host printed circuit board 1912. The
fiber optic module 1700 is illustrated as being fully inserted into
the cage assembly 1900 so that its edge connection 1730 is coupled
into the edge connector 2002 through the opening 2018. The pins
2016 of the edge connector 2002 are coupled to traces 2202 on the
host printed circuit board 1912. The alignment pins 2104 are
coupled into openings or holes in the host printed circuit board
1912. The one or more top side electromagnetic interference (EMI)
fingers 1720T of the fiber optic module 1700 is coupled to the top
inner surface of the cage assembly or module receptacle 1900.
Referring now to FIGS. 23A-23C, an example of forming the
electrical connection between interface PCB of the fiber optic
module 1700 and the edge connector of the host system is
illustrated. As illustrated in FIGS. 23A-23C, the edge connection
1730 includes the one or more pads 2100A on one side 1704A and the
one or more pads 2100B on an opposite side 1704B of the interface
PCB 1704. The edge connector 2002 includes one or more internal
pins 2302A on one side and one or more internal pins 2302B on an
opposite side of the opening 2018. The one or more pads 2100A of
the edge connection 1730 slidingly couple to respective ones of the
one or more internal pins 2302A of the edge connector 2002. Contact
is made between the pads 2100A and the pins 2302A such that an
electrical connection is formed. The one or more pads 2100B of the
edge connection 1730 slidingly couple to respective ones of the one
or more internal pins 2302B of the edge connector 2002. Contact is
made between the pads 2100B and the pins 2302B such that an
electrical connection is formed.
Referring now to FIG. 23C, a side view of the edge connection 1730
is illustrated. In FIG. 23C, a side view of one of the one or more
pads 2300A and one of the one or more pads 2300B on opposite sides
of the interface PCB 1704 are more clearly illustrated. A side view
of one of the one or more internal pins 2302A and one of the one or
more internal pins 2302B of the edge connector 2002 is also
illustrated in FIG. 23C. The one or more internal pins 2302A and
2302B are coupled to the external pins 2016 of the edge connector
2002. With the external pins 2016 coupled to the host printed
circuit board 1912, the internal pins 2302A and 2302B are coupled
to the host printed circuit board 1912 as well. A number of the one
or more pads 2100A and/or 2100B can be staggered from the edge of
the edge connection 1730 as illustrated in FIGS. 23A-23C in order
that ground may be provided first and power may be provided
secondly, prior to making connections for signal or data lines. In
this case, the interface PCB 1704 and the fiber optic module 1700
may be hot-pluggable into the edge connector 2002 and the host
system 2000. That is, power can be maintained to the host printed
circuit board 1912 while the fiber optic module 1700 is plugged
into or out of the cage assembly 1900 and the edge connector
2002.
The previous detailed description describes fiber optic modules as
including a receiver and transmitter. However, one of ordinary
skill can see that a fiber optic module may be a receiver only or a
transmitter only such that only one board type is used.
Additionally, the previous detailed description described one
receive channel and one transmit channel. However, the invention
may be extended to a plurality of channels in parallel which can be
all transmit channels, all receive channels or both receive and
transmit channels into multiple fiber optic cables.
The preferred embodiments of the invention are thus described.
While the invention has been described in particular embodiments,
the invention should not be construed as limited by such
embodiments, but rather construed according to the claims that
follow below.
* * * * *