U.S. patent application number 09/826480 was filed with the patent office on 2003-04-10 for small format optical subassembly.
Invention is credited to Dwarkin, Robert M., Gilliland, Patrick B., Jines, Carlos.
Application Number | 20030067951 09/826480 |
Document ID | / |
Family ID | 46204080 |
Filed Date | 2003-04-10 |
United States Patent
Application |
20030067951 |
Kind Code |
A1 |
Gilliland, Patrick B. ; et
al. |
April 10, 2003 |
SMALL FORMAT OPTICAL SUBASSEMBLY
Abstract
A small format optoelectronic package or device includes a
non-electrically conductive substrate partially covered by an
electrically conductive can. The electrically conductive can has a
transparent element affixed to an aperture of the electrically
conductive can. The electrically conductive can encloses and
hermetically seals an edge emitting optical diode, a reflecting
mirror, a monitor diode, and conductors between the electrically
conductive can and the non-electrically conductive substrate. The
non-electrically conductive substrate has three through-holes
formed through a thickness of the non-electrically conductive
substrate. The three through-holes are filled with an electrically
conductive material so as to form three electrically conductive
vias. Additionally, a surface of the non-electrically conductive
substrate is organized into three regions. The first and third
regions have the electrically conductive plating material applied
thereto.
Inventors: |
Gilliland, Patrick B.;
(Chicago, IL) ; Jines, Carlos; (Forest Park,
IL) ; Dwarkin, Robert M.; (Chicago, IL) |
Correspondence
Address: |
David L. Newman
Stratos Lightwave, Inc.
7444 West Wilson Avenue
Chicago
IL
60706
US
|
Family ID: |
46204080 |
Appl. No.: |
09/826480 |
Filed: |
April 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09826480 |
Apr 5, 2001 |
|
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09545087 |
Apr 7, 2000 |
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6331992 |
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Current U.S.
Class: |
372/36 |
Current CPC
Class: |
H01L 2224/48091
20130101; H01S 5/02255 20210101; H01S 5/02325 20210101; H01S 5/0683
20130101; H01L 2224/48091 20130101; H01L 2924/00014 20130101 |
Class at
Publication: |
372/36 |
International
Class: |
H01S 003/04 |
Claims
What is claimed is:
1. A device comprising: a non-electrically conductive substrate
having a first surface and a second surface, the first surface
separated from the second surface by a thickness of the
non-electrically conductive substrate, the first surface having a
first region, a second region, and a third region, the first region
having a first through-hole extending through the thickness, the
second region having a second through-hole extending through the
thickness and a third through-hole extending through the thickness,
the first region being separated from the third region by the
second region; an electrically conductive plating substantially
covering both the first region and the third region of the first
surface; an electrically conductive material substantially filling
the first through-hole so as to form a first electrically
conductive via, the electrically conductive material substantially
filling the second through-hole so as to form a second electrically
conductive via, and the electrically conductive material
substantially filling the third through-hole so as to form a third
electrically conductive via, and the electrically conductive
plating substantially covering the first region being electrically
connected to the electrically conductive material substantially
filling the first through-hole; an edge emitting optical diode
having a first lead and a second lead, the first lead of the edge
emitting optical diode electrically connected to the electrically
conductive plating of the first region, the first lead of the edge
emitting optical diode electrically connected to the first
electrically conductive via, the second lead of the edge emitting
optical diode electrically connected to the second electrically
conductive via, the edge emitting optical diode having a first
optical axis, and the edge emitting optical diode being capable of
emitting an optical signal along the first optical axis; a
reflecting mirror mounted to the non-electrically conductive
substrate, the reflecting mirror having a reflective surface; a
monitor diode having a third lead and a fourth lead, the third lead
of the monitor diode electrically connected to the electrically
conductive plating of the first region, the third lead of the
monitor diode electrically connected to the first electrically
conductive via, the fourth lead of the monitor diode electrically
connected to the third electrically conductive via; an electrically
conductive can having a first aperture and a second aperture; and a
transparent element mounted on and sealed to the first aperture of
the electrically conductive can, and wherein the second aperture of
the electrically conductive can is mounted on and sealed to the
electrically conductive plating adhered to the third region of the
non-electrically conductive substrate so as to seal the monitor
diode, the reflecting mirror, and the edge emitting optical diode
from an ambient atmosphere, and wherein the reflective surface of
the reflecting mirror intersects the first optical axis of the edge
emitting optical diode so as to reflect the optical signal of the
edge emitting optical diode from the first optical axis to a second
optical axis, and wherein the second optical axis passes through
the transparent element.
2. The device according to claim 1 wherein the second aperture of
the electrically conductive can is mounted on and sealed to the
electrically conductive plating adhered to the third region of the
non-electrically conductive substrate so as to hermetically seal
the monitor diode, the reflecting mirror, and the edge emitting
optical diode from the ambient atmosphere.
3. The device according to claim 1 wherein the first through-hole
has a longitudinal axis, and wherein the longitudinal axis of the
first through-hole passes through at least one of the edge emitting
optical diode and the monitor diode.
4. The device according to claim 1 wherein the electrically
conductive can has a height, and wherein the height of the
electrically conductive can is substantially equal or less than
0.040 inches.
5. The device according to claim 1 wherein the reflecting surface
of the reflecting mirror has a curved shape.
6. The device according to claim 1 wherein the second optical axis
is substantially perpendicular to the first optical axis.
7. The device according to claim 1 wherein the edge emitting
optical diode is a Fabry-Perot device.
8. The device according to claim 1 wherein the reflecting mirror is
a plane reflecting mirror.
9. The device according to claim 1 wherein the reflecting mirror is
a concave, cylindrical reflecting mirror.
10. The device according to claim 1 wherein the non-electrically
conductive substrate has a rectangular shape.
11. The device according to claim 1 wherein the transparent
element, the electrically conductive can, and the non-electrically
conductive substrate form a space separate from the ambient
atmosphere and is substantially filled with an inert gas.
12. The device according to claim 1 wherein the electrically
conductive can has a substantially rectangular shape.
13. The device according to claim 1, further comprising a holder
mounted to the second surface of the non-electrically conductive
surface.
14. The device according to claim 1, further comprising a first
conductor electrically connecting the second lead of the edge
emitting optical diode to the second electrically conductive
via.
15. The device according to claim 14, further comprising a second
conductor electrically connecting the second lead of the monitor
diode to the third electrically conductive via.
16. The device according to claim 15 wherein the first conductor is
made of a gold material.
17. The device according to claim 16 wherein the second conductor
is made of a gold material.
18. The device according to claim 17 wherein the non-electrically
conductive substrate is made of a ceramic material.
19. The device according to claim 18 wherein the electrically
conductive plating is made of a solidified molten mixture of silver
and glass, and wherein the electrically conductive material is made
of the solidified molten mixture of silver and glass.
20. The device according to claim 19, further comprising a flex
connector mounted on the second surface of the non-electrically
conductive substrate, the flex connector having a first via,
wherein the second trace is electrically connected to the second
via, and wherein the third trace is electrically connected to the
third via.
21. A device comprising: a non-electrically conductive substrate
having a first surface and a second surface, the first surface
separated from the second surface by a thickness of the
non-electrically conductive substrate, the first surface having a
first region, a second region, and a third region, the first region
having a first through-hole extending through the thickness, the
second region having a second through-hole extending through the
thickness, the first region being separated from the third region
by the second region; an electrically conductive plating
substantially covering both the first region and the third region
of the first surface; an electrically conductive material
substantially filling the first through-hole so as to form a first
electrically conductive via, and the electrically conductive
material substantially filling the second through-hole so as to
form a second electrically conductive via, and the electrically
conductive plating substantially covering the first region being
electrically connected to the electrically conductive material
substantially filling the first through-hole; an edge emitting
optical diode having a first lead and a second lead, the first lead
of the edge emitting optical diode electrically connected to the
electrically conductive plating of the first region, the first lead
of the edge emitting optical diode electrically connected to the
first electrically conductive via, the second lead of the edge
emitting optical diode electrically connected to the second
electrically conductive via, the edge emitting optical diode having
a first optical axis, and the edge emitting diode being capable of
emitting an optical signal along the first optical axis; a
reflecting mirror mounted to the non-electrically conductive
substrate, the reflecting mirror having a reflective surface; an
electrically conductive can having a first aperture and a second
aperture; and a transparent element mounted on and sealed to the
first aperture of the electrically conductive can, and wherein the
second aperture of the electrically conductive can is mounted on
and sealed to the electrically conductive plating adhered to the
third region of the non-electrically conductive substrate so as to
seal the edge emitting optical diode and the reflecting mirror from
an ambient atmosphere, and wherein the reflective surface of the
reflecting mirror intersects the first optical axis of the edge
emitting optical diode so as to reflect the optical signal of the
edge emitting optical diode from the first optical axis to a second
optical axis, and wherein the second optical axis passes through
the transparent element.
22. The device according to claim 21 wherein the second aperture of
the electrically conductive can is mounted on and sealed to the
electrically conductive plating adhered to the third region of the
non-electrically conductive substrate so as to hermetically seal
the reflecting mirror and the edge emitting optical diode from the
ambient atmosphere.
23. The device according to claim 21 wherein the first through-hole
has a longitudinal axis, and wherein the longitudinal axis of the
first through-hole passes through the edge emitting optical
diode.
24. The device according to claim 21 wherein the electrically
conductive can has a height, and wherein the height of the
electrically conductive can is substantially equal or less than
0.040 inches.
25. The device according to claim 21 wherein the reflecting surface
of the reflecting mirror has a curved shape.
26. The device according to claim 21 wherein the second optical
axis is substantially perpendicular to the first optical axis.
27. The device according to claim 21 wherein the edge emitting
optical diode is a Fabry-Perot device.
28. The device according to claim 21 wherein the reflecting mirror
is a plane reflecting mirror.
29. The device according to claim 21 wherein the reflecting mirror
is a concave, cylindrical reflecting mirror.
30. The device according to claim 21 wherein the non-electrically
conductive substrate has a rectangular shape.
31. The device according to claim 21 wherein the transparent
element, the electrically conductive can, and the non-electrically
conductive substrate form a space separate from the ambient
atmosphere and is substantially filled with an inert gas.
32. The device according to claim 21 wherein the electrically
conductive can has a rectangular shape.
33. An apparatus comprising: a first non-electrically conductive
substrate having a first surface and a second surface, the first
surface separated from the second surface by a thickness of the
first non-electrically conductive substrate, the first surface
having a first region, a second region, and a third region, the
first region having a first through-hole extending through the
thickness, the second region having a second through-hole extending
through the thickness and a third through-hole extending through
the thickness, the first region being separated from the third
region by the second region; an electrically conductive plating
substantially covering both the first region and the third region
of the first surface; an electrically conductive material
substantially filling the first through-hole so as to form a first
electrically conductive via, the electrically conductive material
substantially filling the second through-hole so as to form a
second electrically conductive via, and the electrically conductive
material substantially filling the third through-hole so as to form
a third electrically conductive via, and the electrically
conductive plating substantially covering the first region being
electrically connected to the electrically conductive material
substantially filling the first through-hole; a first edge emitting
optical diode having a first lead and a second lead, the first lead
of the first edge emitting optical diode electrically connected to
the electrically conductive plating of the first region, the first
lead of the first edge emitting optical diode electrically
connected to the first electrically conductive via, the second lead
of the first edge emitting optical diode electrically connected to
the second electrically conductive via, the first edge emitting
optical diode having a first optical axis, and the first edge
emitting optical diode being capable of emitting a first optical
signal along the first optical axis; a first reflecting mirror
mounted to the first non-electrically conductive substrate, the
reflecting mirror having a first reflective surface; a first
monitor diode having a third lead and a fourth lead, the third lead
of the first monitor diode electrically connected to the
electrically conductive plating of the first region, the third lead
of the first monitor diode electrically connected to the first
electrically conductive via, the fourth lead of the first monitor
diode electrically connected to the third electrically conductive
via; a first electrically conductive can having a first aperture
and a second aperture; a first transparent element mounted on and
sealed to the first aperture of the first electrically conductive
can, and wherein the second aperture of the first electrically
conductive can is mounted on and sealed to the electrically
conductive plating adhered to the third region of the
non-electrically conductive substrate so as to hermetically seal
the first monitor diode, the first reflecting mirror, and the first
edge emitting optical diode from an ambient atmosphere, and wherein
the first through-hole has a longitudinal axis, and wherein the
longitudinal axis of the first through-hole passes through at least
one of the first edge emitting optical diode and the first monitor
diode, and wherein the first reflective surface of the first
reflecting mirror intersects the first optical axis of the first
edge emitting optical diode so as to reflect the first optical
signal of the first edge emitting optical diode from the first
optical axis to a third optical axis; a second non-electrically
conductive substrate having a third surface and a fourth surface,
the third surface separated from the fourth surface by a thickness
of the second non-electrically conductive substrate, the third
surface having a fourth region, a fifth region, and a sixth region,
the fourth region having a fourth through-hole extending through
the thickness, the fifth region having a fifth through-hole
extending through the thickness and a sixth through-hole extending
through the thickness; the electrically conductive plating
substantially covering both the fourth region and the sixth region
of the third surface; the electrically conductive material
substantially filling the fourth through-hole so as to form a
fourth electrically conductive via, the electrically conductive
material substantially filling the fifth through-hole so as to form
a fifth electrically conductive via, and the electrically
conductive material substantially filling the sixth through-hole so
as to form a sixth electrically conductive via, and the
electrically conductive plating substantially covering the fourth
region being electrically connected to the electrically conductive
material substantially filling the fourth through-hole; a second
edge emitting optical diode having a fifth lead and a sixth lead,
the fifth lead of the second edge emitting optical diode
electrically connected to the electrically conductive plating of
the fourth region, the fifth lead of the second edge emitting
optical diode electrically connected to the fourth electrically
conductive via, the sixth lead of the second edge emitting optical
diode electrically connected to the fifth electrically conductive
via, the second edge emitting optical diode has a second optical
axis, and the second edge emitting optical diode being capable of
emitting a second optical signal along the second optical axis; a
second reflecting mirror mounted to the second non-electrically
conductive substrate, the second reflecting mirror having a second
reflective surface; a second monitor diode having a seventh lead
and an eighth lead, the seventh lead of the second monitor diode
electrically connected to the electrically conductive plating of
the fourth region, the seventh lead of the second monitor diode
electrically connected to the fourth electrically conductive via,
the eighth lead of the second monitor diode electrically connected
to the sixth electrically conductive via; a second electrically
conductive can having a third aperture and a fourth aperture; and a
second transparent element mount on and sealed to the third
aperture of the second electrically conductive can, and wherein the
fourth aperture of the second electrically conductive can is
mounted on and sealed to the electrically conductive plating
adhered to the sixth region of the second non-electrically
conductive substrate so as to hermetically seal the second monitor
diode, the second reflecting mirror, and the second edge emitting
optical diode from an ambient atmosphere, and wherein the fourth
through-hole has a longitudinal axis, and wherein the longitudinal
axis of the fourth through-hole passes through at least one of the
second edge emitting optical diode and the second monitor diode,
and wherein the second reflective surface of the second reflecting
mirror intersects the second optical axis of the second edge
emitting optical diode so as to reflect the second optical signal
of the second edge emitting optical diode from the second optical
axis to a fourth optical axis, and wherein the first
non-electrically conductive substrate and the second
non-electrically conductive substrate are positioned on a plane,
and wherein the third optical axis is substantially parallel to the
fourth optical axis, and wherein the third optical axis is
separated from the fourth optical axis by a distance of 3.25
millimeters or less.
34. The apparatus according to claim 33 wherein the first
non-electrically conductive substrate has a rectangular shape, and
wherein the second non-electrically conductive substrate has a
rectangular shape.
35. The apparatus according to claim 34 wherein the first
electrically conductive can has a rectangular shape, and wherein
the second electrically conductive can has a rectangular shape.
36. The apparatus according to claim 33 wherein the third optical
axis is substantially perpendicular to the fourth optical axis.
37. The apparatus according to claim 36 wherein the first optical
axis is substantially perpendicular to the second optical axis.
38. The apparatus according to claim 33 wherein the first edge
emitting optical diode is a Fabry-Perot device.
39. The apparatus according to claim 38 wherein the second edge
emitting optical diode is a Fabry-Perot device.
40. The apparatus according to claim 33 wherein the first
reflecting mirror is a plane reflecting mirror.
41. The apparatus according to claim 40 wherein the second
reflecting mirror is a plane reflecting mirror.
42. The apparatus according to claim 33 wherein the first
reflecting mirror is a concave, cylindrical reflecting mirror.
43. The apparatus according to claim 42 wherein the second
reflecting mirror is a concave, cylindrical reflecting mirror.
44. The apparatus according to claim 33 wherein the first
transparent element, the first electrically conductive can, and the
first non-electrically conductive substrate form a space separate
from the ambient atmosphere and is substantially filled with an
inert gas.
45. A device comprising: a non-electrically conductive substrate
having a first surface and a second surface, the first surface
separated from the second surface by a thickness of the
non-electrically conductive substrate, the first surface having a
first region, a second region, and a third region, the first region
having a first through-hole extending through the thickness, the
second region having a second through-hole extending through the
thickness, the first region being separated from the third region
by the second region; an electrically conductive plating
substantially covering both the first region and the third region
of the first surface; an electrically conductive material
substantially filling the first through-hole so as to form a first
electrically conductive via, the electrically conductive material
substantially filling the second through-hole so as to form a
second electrically conductive via, and the electrically conductive
plating substantially covering the first region being electrically
connected to the electrically conductive material substantially
filling the first through-hole; an edge emitting optical diode
having a first lead and a second lead, the first lead of the edge
emitting optical diode electrically connected to the electrically
conductive plating of the first region, the first lead of the edge
emitting optical diode electrically connected to the first
electrically conductive via, the second lead of the edge emitting
optical diode electrically connected to the second electrically
conductive via; a reflecting mirror mounted to the non-electrically
conductive substrate; an electrically conductive can having a first
aperture and a second aperture; and a transparent element mounted
on and hermetically sealed to the first aperture of the
electrically conductive can, and wherein the second aperture of the
electrically conductive can is mounted on and sealed to the
electrically conductive plating adhered to the third region of the
non-electrically conductive substrate so as to hermetically seal
the edge emitting optical diode and the reflecting mirror from an
ambient atmosphere.
46. The device according to claim 45 wherein the first electrically
conductive via has a surface being substantially coplanar with the
first surface of the non-electrically conductive substrate, and
wherein the second electrically conductive via has a surface being
substantially coplanar with the first surface of the
non-electrically conductive substrate.
47. The device according to claim 45, further comprising a holder
mounted to the non-electrically conductive substrate.
48. The device according to claim 45, further comprising a flex
connector mounted on the second surface of the non-electrically
conductive substrate, the flex connector having a first trace, and
a second trace, wherein the first trace is electrically connected
to the first via, and wherein the second trace is electrically
connected to the second via.
49. The device according to claim 47 wherein the holder is made of
a non-magnetic material.
50. The device according to claim 45 wherein the electrically
conductive can is made of a non-magnetic material.
51. The device according to claim 45 wherein the edge emitting
optical diode is a Fabry-Perot device.
52. The device according to claim 45 wherein the reflecting mirror
is a plane reflecting mirror.
53. The device according to claim 45 wherein the reflecting mirror
is a concave, cylindrical reflecting mirror.
54. The device according to claim 45 wherein the non-electrically
conductive substrate has a rectangular shape.
55. The device according to claim 45 wherein the transparent
element, the electrically conductive can, and the non-electrically
conductive substrate form a space separate from the ambient
atmosphere and is substantially filled with an inert gas.
56. The device according to claim 55 wherein the electrically
conductive can has a rectangular shape.
57. A device comprising: a non-electrically conductive substrate
having a first region and a second region, the first region having
a first through-hole, and the first region having a second
through-hole; an electrically conductive plating substantially
covering the second region; an electrically conductive material
substantially filling the first through-hole so as to form a first
electrically conductive via, and the electrically conductive
material substantially filling the second through-hole so as to
form a second electrically conductive via; an edge emitting optical
diode having a first lead and a second lead, the first lead of the
edge emitting optical diode electrically connected to the first
electrically conductive via, and the second lead of the edge
emitting optical diode electrically connected to the second
electrically conductive via; a reflecting mirror mounted to the
non-electrically conductive substrate; an electrically conductive
can having a first aperture and a second aperture; and a
transparent element mounted on and hermetically sealed to the first
aperture of the electrically conductive can, and wherein the second
aperture of the electrically conductive can is mounted on and
sealed to the electrically conductive plating adhered to the second
region of the non-electrically conductive substrate so as to
hermetically seal the optical diode and the reflecting mirror from
an ambient atmosphere.
58. The device according to claim 57 wherein the edge emitting
optical diode is a Fabry-Perot device.
59. The device according to claim 57 wherein the reflecting mirror
is a plane reflecting mirror.
60. The device according to claim 57 wherein the reflecting mirror
is a concave, cylindrical reflecting mirror.
61. The device according to claim 57 wherein the non-electrically
conductive substrate has a rectangular shape.
Description
RELATED U.S. APPLICATION DATA
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 09/545,087, filed Apr. 7, 2000, which is
hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention pertains to optoelectronic devices or
optical subassemblies. The invention more particularly concerns a
small format optoelectronic package.
[0004] 2. Discussion of the Background
[0005] Optoelectronic devices such as optical transceivers are
known in the art and include active optical devices or diode
packages. Common diode packages include LED packages such as a
TO-46 package or a 5.6 mm TO style laser diode package such as an
RLD-85PC diode package by Rohm, Incorporated. These diode packages
or TO cans typically include a metallic housing having a laser
diode or LED for transmitting data and a photo diode for performing
power-monitoring, metal contact leads exiting from the diodes for
connection to a power source and a cover glass opposed to the
diode, through which the energy is transmitted. Discussion of the
power-monitoring and feedback control of the laser diode by the
photo diode is presented in U.S. Pat. Nos. 5,812,582 and 5,815,623.
U.S. Pat. Nos. 5,812,582 and 5,815,623 are hereby incorporated
herein by reference. The TO can is hermetically sealed. Often,
optics housings are metallic so as to provide ruggedness, ease of
machining complicated shapes, and to enhance shielding of
electromagnetic fields.
[0006] Smaller optoelectronic packages allow the devices into which
the optoelectronic packages are placed to become smaller. Smaller
optoelectronic packages allow for a higher density of data
transmission in a given space. Currently, there is a great demand
for smaller optoelectronic packages.
[0007] FIG. 8 is a partial cross-sectional pictorial view of an
optoelectronic package 200. The optoelectronic package 200 includes
a base element 212, posts 206, 208, 210, extending through the base
element 212 and secured thereto with solidified molten glass 214, a
monitor diode 204 mounted on the base element 212, an optical
emitting element 202 mounted on the monitor diode 204, a can 218
and lens 216 enclosing the monitor diode 204 and the optical
emitting element 202. In an effort to reduce space, the optical
emitting element 202 is mounted on top of the monitor diode 204.
Electrically conductive posts 206, 208, 210 extend through
through-holes in the electrically conductive base element 212. The
posts 206, 208, 210 are electrically insulated from the base
element 212 by solidified molten glass 214 which also attaches the
posts 206, 208, 210 to the base element 212. The posts 206, 208,
210 are large as compared to the other components and require a
large area for their mounting and placement.
[0008] At minimum, the diameter across the base element 212 is
approximately 3.8 millimeters, as incorporated on the SLT2160-LN
series of transmitter optical sub-assemblies manufactured by
Sumitomo Electric Industries, Ltd. Thus, if two of these devices
are placed side-by-side, on the same plane, the distance between
the optical axes is, hypothetically, at best, 3.8 millimeters.
However, typically, the optical axes are separated by 6.25
millimeters, due to packaging constraints as in typical LC duplex
transceivers such as Methode Electronics, Inc.'s, part number
MLC-25-4-X-TL which is described in the data sheet entitled,
"MLC-25-4-X-TL Optical Gigabit Ethernet--+3.3V Small Form Factor
(SFF) Transceiver--1.25 GBaud."
[0009] Therefore, there is a need in the industry for a small
format optoelectronic package that has a small diameter and is easy
to manufacture. Furthermore, there is a need for an optoelectronic
package that can be placed adjacent to another optoelectronic
package.
SUMMARY OF THE INVENTION
[0010] Therefore, it is an object of the present invention to
provide a small format optoelectronic device.
[0011] It is still another object of the invention to provide a
small format optoelectronic device which is hermetically sealed and
economical to manufacture.
[0012] Yet another object of the invention is to provide a small
format optoelectronic device which is able to be placed adjacent to
another small format optoelectronic device.
[0013] It is a further object of the invention to provide a small
format optoelectronic device which is easy to install, and provides
for more efficient utilization of the limited surface area by
incorporating rectangular geometry.
[0014] In one form of the invention, the small format
optoelectronic package or device includes a non-electrically
conductive substrate partially covered by an electrically
conductive can. The electrically conductive can has a transparent
element affixed to an aperture of the electrically conductive can.
The electrically conductive can encloses and hermetically seals an
edge emitting optical diode, a reflecting mirror, a monitor diode,
and conductors between the electrically conductive can and the
non-electrically conductive substrate. The non-electrically
conductive substrate has three through-holes formed through a
thickness of the non-electrically conductive substrate. The three
through-holes are filled with an electrically conductive material
so as to form three electrically conductive vias. When co-fired
with the substrate, the electrically conductive vias form a
hermetic seal. Additionally, a surface of the non-electrically
conductive substrate is organized into three regions. The first and
third regions have the electrically conductive plating material
applied thereto. The first through-hole protrudes through the first
region. The second and third through-holes protrude through the
second region. The first via is electrically connected to the
electrically conductive plating material adhered to the first
region. The edge emitting optical diode and the monitor diode both
have leads which are mounted on the electrically conductive plating
of the first region. A first conductor electrically connects
another lead of the edge emitting optical diode to the second via,
and a second conductor electrically connects another lead of the
monitor diode to the third via. The edge emitting optical diode
emits an optical signal along a first optical axis. The reflecting
mirror intersects the first optical axis and reflects the optical
signal from the first optical axis to a second optical axis.
[0015] In another form of the invention, two of the small format
optoelectronic packages discussed above are placed on the same
plane. The optical axis of one package is parallel to the optical
axis of the other package. Also, the optical axis of one package is
separated from the optical axis of the other package by less than
3.25 millimeters.
[0016] Thus, the device of the invention is superior to existing
optoelectronic devices. The small format optoelectronic package of
the invention eliminates the use of large and bulky components, and
replaces them with smaller components through use of a unique
combination of materials and arrangement of the materials. Thus,
the device of the invention is smaller than the prior art
device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] A more complete appreciation of the invention and many of
the attendant advantages thereof will be readily obtained as the
same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, wherein:
[0018] FIG. 1 is a perspective view of an optoelectronic
package;
[0019] FIG. 2 is an exploded perspective view of the optoelectronic
package of FIG. 1;
[0020] FIG. 3 is a perspective view of the monitor diode, optical
diode, base substrate, holder, and flex connector of the
optoelectronic package of FIG. 1;
[0021] FIG. 4 is a perspective view of a second embodiment of the
optoelectronic package;
[0022] FIG. 5 is an exploded perspective view of the optoelectronic
package of FIG. 4;
[0023] FIG. 6 is a perspective view of the monitor diode, optical
diode, base substrate, and flex connector of the optoelectronic
package of FIG. 4;
[0024] FIG. 7 is a perspective view of two optoelectronic packages
positioned side-by-side on a planar surface;
[0025] FIG. 8 is a partial cross-sectional perspective view of a
related optoelectronic package
[0026] FIG. 9 is a perspective view of an embodiment of the
invention where the optical diode of FIGS. 1-7 is replaced with an
edge emitting optical diode and a plane reflecting mirror;
[0027] FIG. 10 is the perspective view of the device shown in FIG.
9 with the addition of optical axes and an optical signal
schematically shown;
[0028] FIG. 11 is a side view of an edge emitting optical
diode;
[0029] FIG. 12 is a plan view of a projection of the optical signal
emanating from the edge emitting optical diode;
[0030] FIG. 13 is a side view of an edge emitting optical diode and
a plane reflecting mirror;
[0031] FIG. 14 is a plan view of a projection of the optical signal
reflected by the plane reflecting mirror;
[0032] FIG. 15 is a side view of a vertical cavity surface emitting
laser;
[0033] FIG. 16 is a plan view of a projection of the optical signal
emanating from the vertical cavity surface emitting laser;
[0034] FIG. 17 is a side view of a device similar to the device
shown in FIG. 9 where the plane reflecting mirror of FIG. 9 is
replaced with a concave, cylindrical reflecting mirror; and
[0035] FIG. 18 is the perspective view of the device shown in FIG.
17 with the addition of optical axes and an optical signal
schematically shown therein.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0036] Referring now to the drawings, wherein like reference
numerals designate identical or corresponding parts throughout the
several views, and more particularly to FIGS. 920 thereof, is a
small format optoelectronic package or device having an edge
emitting optical diode 300 and a reflecting mirror 360, 410 taking
the place of the optical diode 80 displayed in FIGS. 1-7. However,
a small format optoelectronic package or device 10, 110 as shown in
FIGS. 1-7 is discussed first since the embodiments disclosed in
FIGS. 9-20 depend on the disclosure of the devices 10, 110.
[0037] FIG. 1 is a perspective view of the optoelectronic package
10 which shows a transparent element 20 mounted in an electrically
conductive can 30, where the electrically conductive can 30 is
mounted on and sealed to an electrically conductive plating adhered
to a non-electrically conductive substrate. The device 10 can be
attached to a housing of another structure by way of the holder
50.
[0038] The holder 50 is mounted to the non-electrically conductive
substrate 40. The holder 50 has a width dimension W. A flex
connector 60 is attached to a second side of the non-electrically
conductive substrate 40.
[0039] FIG. 2 is an exploded perspective view of the optoelectronic
package 10 of FIG. 1. The electrically conductive can 30 has a
first aperture 32 and a second aperture 34. The transparent element
20 is mounted on and sealed to the first aperture 32 of the
electrically conductive can 30 by means known in the art. One means
includes using glass frit powder packed around the transparent
element 20 while it is in the first aperture 32 of the electrically
conductive can 30 and then firing the assembly so as to cause the
glass frit powder to flow and to bond and to hermetically seal the
transparent element 20 in the first aperture 32. Another means
includes molding or flowing molten glass into the first aperture 32
and letting the molten glass solidify, thus forming the transparent
element 20. The non-electrically conductive substrate 40 has a
first surface 47 and a second surface 48 separated by a thickness
as identified along edge 49, the thickness is between 0.008 inches
and 0.025 inches. The first surface 47 is divided into 3 regions.
The first region 43 is bound by line 3. The second region 42 is
bound by lines 3 and 4. The third region 41 is bound by lines 4 and
5. The regions include a first region 43, a second region 42, and a
third region 41. The first region 43 is separated from the third
region 41 by the second region 42.
[0040] The non-electrically conductive substrate 40 includes three
through-holes. The three through-holes include the first
through-hole 44, a second through-hole 46, and a third through-hole
45. Each through-hole has a diameter of approximately 0.010 inches.
An electrically conductive plating or coating is adhered to the
first surface 47 of the non-electrically conductive substrate 40 in
the first region 43 and in the third region 41. The plating
typically has a thickness of 0.003 inches. Furthermore, the
electrically conductive material, which can be the same as the
plating material, substantially fills the first through-hole 44,
the second through-hole 46, and the third through-hole 45, so as to
form first, second, and third conductive vias 44a, 46a, and 45a,
respectively. Each electrically conductive via is substantially
co-planar with the surfaces 47, 48 of the non-electrically
conductive substrate 40. Specifically, the vias do not
substantially protrude into the space defined by the transparent
element 20, the electrically conductive can 30, and the
non-electrically conductive substrate 40, so as to enable surface
mounting of components directly on top of the vias. The first
conductive via is electrically connected to the electrically
conductive plating of the first region 43. The optical diode 80 has
a first lead 82 and a second lead 84. The optical emitting diode 80
has an optical axis 86 along which optical energy is transmitted.
The second lead 84 of the optical diode 80 is electrically
connected to an electrically conductive plating of the first region
43 and mounted thereto by way of electrically conductive epoxy (not
shown). The monitor diode 70 has a first lead 74 and a second lead
72. The first lead 74 of the monitor diode 70 is electrically
connected to the electrically conductive plating of the first
region 43. The monitor diode 70 is mounted to the electrically
conductive plating of the first region 43 by way of electrically
conductive epoxy (not shown). A longitudinal axis of the first
through-hole 44 passes through the monitor diode 70. However, the
optical diode 70 can be placed over the first through-hole 44
instead of the monitor diode 80.
[0041] To attach the holder 50 to the non-electrically conductive
substrate 40, a portion of the second surface 48 has the
electrically conductive plating adhered thereto and to which the
holder 50 is either brazed or soldered. Alternatively, glass frit
powder can be placed between the holder 50 and the non-electrically
conductive substrate 40 and then the assembly is fired so as to
bond the holder 50 to the non-electrically conductive
substrate.
[0042] The electrically conductive can 30 is then mounted on and
sealed to the third region 41 of the non-electrically conductive
substrate 40. The electrically conductive can 30 is soldered to
electrically conductive plating adhered to the third region 41. The
optical emitting diode 80 and monitor diode 70 are hermetically
sealed and protected from atmospheric and environmental
contaminants. Preferably, the sealed-off region is filled with a
dry inert gas. Examples of the inert gas include nitrogen and
argon. In another embodiment, the sealed-off region is in a vacuum.
The holder 50 has a first surface 51 and a concave portion 52. The
first surface 51 is soldered to electrically conductive plating
adhered to the non-electrically conductive substrate. The flex
connector 60 has three conductive traces, which includes a first
conductive trace 64, a second conductive trace 62, and a third
conductive trace 63. The flex connector 60 may be formed of a
polyimide film, such a material is marketed under the trade name,
KAPTON, which is sold by E. I. Du Pont de Nemours and Company. The
conductive traces 62, 63, and 64 transmit electrical data and power
signals to the diodes 70, 80. The flex connector 60 passes through
the concave portion 52 of the holder 50 and each of the conductive
traces electrically connects with respective electrically
conductive vias. That is, the first conductive trace 64
electrically connects to conductive via 44a, electrically
conductive trace 62 electrically connects to electrically
conductive via 46a, and electrically conductive trace 63
electrically connects to electrically conductive via 45a.
[0043] FIG. 3 is a perspective view of the monitor diode 70, the
optical diode 80, the non-electrically conductive substrate 40, the
holder 50, and the flex connector 60 of the small format
optoelectronic package 10 of FIG. 1. FIG. 3 shows the optical diode
80 and the monitor diode 70 mounted to the first region 43 of the
non-electrically conductive substrate 40. FIG. 3 further shows the
optical axis 86 of the optical diode 80. A first conductor 90, for
example, a wire bond, electrically connects the first lead 82 of
the optical diode 80 to the electrically conductive material
filling the second through-hole 46 or to a metallized region
surrounding the via. A second conductor 100 electrically connects
the second lead 72 of the monitor diode 70 to the electrically
conductive material filling the third through-hole 45 or to a
metallized region surrounding the via.
[0044] The holder 50 needs to be solderable and weldable, as well
as having a coefficient of thermal expansion which generally is the
same as the coefficient of thermal expansion of the
non-electrically conductive substrate 40 which is a ceramic
material. Such materials include FeNi and FeNiCo. Specifically, a
material having twenty-nine percent Ni, seventeen percent Co, and
the balance Fe trades under the name KOVAR, the name is owned by
Carpenter Technology Corporation. The flex connector 60 has a base
substrate made of a flexible insulating material such as KAPTON and
on which electrically conductive traces are laid. Non-electrically
conductive substrate 40 is made of a ceramic material such as
alumina, AlN or BeO. The electrically conductive plating material
is typically made of a mixture of glass, palladium, and silver
which is mixed together, applied to the ceramic material, and
heated to a molten state and allowed to solidify. The glass
component of the mixture fuses with the base ceramic material of
the non-electrically conductive substrate 40. The palladium/silver
component of the mixture provides for the electrical conductivity
of the plating. The electrically conductive can 30 is typically
made of an alloy, such as KOVAR, which has a coefficient of thermal
expansion which generally is the same as the coefficient of thermal
expansion for both the non-electrically conductive substrate 40
which is ceramic and the transparent element 20 which is glass. The
electrically conductive can 30 is attached to the electrically
conductive plating material adhered to the third region 41 of the
non-electrically conductive substrate 40 in order to form a
hermetic barrier. The electrically conductive can 30 is attached to
the non-electrically conductive substrate 40, preferably, by a
soldering process or by a brazing process. The transparent element
20 is made of glass or sapphire. The conductors 90, 100 are
substantially made of gold and are affixed to the vias 45a, 46a and
to the leads 72, 82 by way of a gold bond technique where the gold
conductor touches the lead, which is held at a temperature above
ambient, or via and is vibrated. An exposed surface of the vias may
have a secondary plating of gold to enhance wire bond adhesion. The
vibrations and the elevated temperature cause the gold conductor to
adhere to the lead.
[0045] The unique combination of materials and arrangement of
components allows the width dimension W to be 3.25 millimeters or
less. The optical axis 86 is positioned mid-way along the width
dimension W. As compared to the device 200 of the related art shown
in FIG. 8, the device 10 of FIG. 1 is compact. The non-electrically
conductive substrate 40 has electrically conductive vias 44a, 45a,
and 46a, and electrically conductive regions 41 and 43, which forms
an unique electrical circuit arrangement based on geometry and
material selection. The non-electrically conductive substrate 40
also has a unique shape which is rectangular or square. The shape
and materials of construction allow two or more of the devices 10
to be placed together, and eliminate the wasted area present on the
device 200 of FIG. 8.
[0046] The structure of the small format optoelectronic package or
device 10 allows for two of the devices 10, 10 to be placed on the
same plane 2 adjacent to each other, as shown in FIG. 7. In such an
arrangement, the optical axis 86 of each device 10 are separated by
a distance, W2. The distance, W2, is 3.25 millimeters or less.
[0047] FIGS. 4-6 show a second embodiment of the small format
optoelectronic package or device 110. The device 110 includes many
of the same components as does the device 10. The device 110
includes the optical diode 80, the monitor diode 70, the
non-electrically conductive substrate 40, the flex connector 60,
the electrically conductive can 30, and first and second conductors
90, 100. Since the listed components are the same as previously
discussed in regard to device 10 they are not discussed further in
the discussion of the embodiment of device 110.
[0048] A transparent element 120 is mounted on and sealed to the
first aperture 32 of the electrically conductive can 30. A holder
150 has an aperture 151 and a surface 152. The aperture 151
receives the transparent element 120. The surface 152 of the holder
150 is brazed or welded to the electrically conductive can 30. The
device 110 can be mounted within another housing by way of the
holder 150 from a location of the electrically conductive can 30
which is different than the device 10. The materials of
construction are similar to those discussed in regard to the device
10.
[0049] The devices 10, 110 work well, especially when the optical
diode 80 is a vertical cavity surface emitting laser. Vertical
cavity surface emitting laser which emit an optical signal at a
frequency of approximately 850 nm are readily available. Vertical
cavity surface emitting lasers which emit an optical signal at a
frequency of approximately 1310 nm are not readily available. The
market place is asking for small format optical subassemblies which
operate at 1310 nm.
[0050] However, edge emitting optical diodes such as Fabry-Perot
device are readily available in a wavelength in the range of 1310
nm. The drawback to an edge emitting optical diode is that the
diode emits its signal out of its edge or side and not at its top
surface as does a vertical cavity surface emitting laser.
[0051] The problem of providing a 1310 nm optical subassembly is
solved by the embodiment shown in FIG. 9. FIG. 9 is a perspective
side view of an edge emitting optical diode 300, a plane reflecting
mirror 360, a monitor diode 70, and a non-electrically conductive
substrate 40. The solution to the described problem replaces the
optical diode 80 of the device 10, as shown in FIGS. 2 and 3, with
the edge emitting optical diode 300 and the plane reflecting mirror
360. All other aspects of the invention are the same as the device
10 and as such are not discussed further. The edge emitting optical
diode 300 is mounted to the non-electrically conductive substrate
40 in the same way as is the optical diode 80. The plane reflecting
mirror 360 can be mounted to the non-electrically conductive
substrate 40 by way of an adhesive or by fusing with a glass frit
powder or other suitable material. The plane reflecting mirror 360
may be conductive or non-electrically conductive and can be mounted
to non-conductive or conductive portions of the non-electrically
conductive substrate 40.
[0052] The plane reflecting mirror 360 has a surface 362 which is
used to reflect the optical signal emanating from the edge emitting
optical diode 300 out of the small format optical subassembly
through its transparent element 20 (see FIGS. 1 and 2). Therefore,
the combination of the edge emitting optical diode 300 and the
plane reflecting mirror 360 can act as a substitute for the optical
diode 80 and is the first embodiment of the invention.
[0053] FIG. 10 is the perspective view of FIG. 9 showing a first
optical axis 310 and a second optical axis 320. An optical signal
emanates from the edge emitting optical diode 300 and travels along
the first optical axis 310. The reflective surface 362 of the plane
reflecting mirror 360 is positioned so as to intersect the first
optical axis 310. Once the optical signal reaches the reflective
surface 362, the optical signal is reflected and travels along the
second optical axis 320. A schematic representation of the
reflected optical signal 330 is shown in FIG. 10.
[0054] FIG. 11 is a side view of the edge emitting optical diode
300 mounted to the non-electrically conductive substrate 40. FIG.
11 further shows the optical axis 310 and a display surface 392 of
a display device 390 such as a wall. The display surface 392 and
display device 390 are used merely to convey an idea of the shape
of the optical signal. The optical signal of the edge emitting
optical diode 300 is projected on the display surface 392. FIG. 12
is a plan view of a portion of the display surface 392 taken along
line 12-12 of FIG. 11 which shows the projection 340 of the optical
signal thereon. The projection 340 has a shape which is
approximately similar to an ellipse.
[0055] FIG. 13 is a side view of the edge emitting optical diode
300, the plane reflecting mirror 360, and a display surface 398 of
a display device 396. The display surface 398 and display device
396 are used merely to convey an idea of the shape of the optical
signal. The first optical axis 310 is shown along with the second
optical axis 320. The reflected optical signal travels along the
second optical axis 320 and is projected on the display surface
398. FIG. 14 is a plan view of a portion of the display surface 398
taken along line 14-14 of FIG. 13 which shows the projection 341 of
the optical signal thereon. The projection 341 has a shape which is
approximately similar to an ellipse.
[0056] As a comparison, FIG. 15 is a side view of the optical diode
80, such as a vertical cavity surface emitting laser, which
provides an optical signal which travels along the optical axis 86.
The optical signal is projected on display surface 402 of the
display device 400. The display surface 402 and display device 400
are used merely to convey an idea of the shape of the optical
signal. FIG. 16 is a plan view of the display surface 402 taken
along line 16-16 of FIG. 15 which shows the projection 401 of the
optical signal thereon. The projection 401 has a shape which is
approximately similar to a circle.
[0057] Since the circularly shaped projection 401 of the vertical
cavity surface emitting laser is more similar to the
cross-sectional shape of an optical fiber, more of the optical
signal enters the optical fiber than does the elliptically shaped
projection 341 of the edge emitting optical diode 300. In order to
increase the efficiency of the first embodiment of the invention,
it is desired to alter the projected shape of the optical signal of
the edge emitting optical diode 300.
[0058] FIG. 17 is a perspective view of a second embodiment of the
invention. The embodiment shown in FIG. 17 is similar to the
embodiment shown in FIG. 9 except for one difference, the plane
reflecting mirror 360 as shown in FIG. 9 is replaced with a
concave, cylindrical reflecting mirror 410. The concave,
cylindrical reflecting mirror 410 has a reflective surface 412
which reflects the optical signal of the edge emitting optical
diode 300.
[0059] FIG. 18 is the perspective view of the arrangement shown in
FIG. 17 showing a first optical axis 420 and a second optical axis
440. An optical signal emanates from the edge emitting optical
diode 300 and travels along the first optical axis 420. The
reflective surface 412 of the concave, cylindrical reflecting
mirror 410 is positioned so as to intersect the first optical axis
420. Once the optical signal reaches the reflective surface 412,
the optical signal is reflected and travels along the second
optical axis 440. A schematic representation of the reflected
optical signal 450 is shown.
[0060] FIG. 19 is a side view of the edge emitting optical diode
300, the concave, cylindrical mirror 410, and a display surface 462
of a display device 460. The display surface 462 and display device
460 are used merely to convey an idea of the shape of the optical
signal. FIG. 20 is a plan view of a portion of the display surface
462 taken along line 20-20 of FIG. 19 which shows the projection
461 of the optical signal thereon. The projection 461 has a shape
which is approximately similar to a circle. Therefore, the second
embodiment of the invention is more efficient in regard to the
coupling of available power present into an optical fiber. The
concave, cylindrical mirror 410 has a radius along one orthogonal
and an infinite radius along another orthogonal axis which provides
an essentially flat or linear dimension. Thus, the optical signal
is condensed along the major axis of the ellipse due to the
curvature of the reflective surface 412 and the width of the
optical signal along the minor axis of the ellipse is essentially
unchanged. Other curved mirror surfaces such as parabolic,
exponential, or et cetera, may be utilized to condense the
elliptical beam along an axis.
[0061] The invention can also be used in a device similar to that
described above where the package does not include a monitor diode
and its associated conductor.
[0062] In another embodiment, the holder and the electrically
conductive can are made of a non-magnetic material.
[0063] In still yet another embodiment, a laser driver circuit, a
PIN diode amplifier, or other signal conditioning electronic
components are placed within the space defined by the
non-electrically conductive substrate, the transparent element, and
the electrically conductive can.
[0064] In yet another embodiment, as shown in FIG. 1, the
electrically conductive can has a height, CH. Preferably, the
electrically conductive can height, CH, is nominally equal to 0.030
inches. However, the electrically conductive can height may be
substantially equal to 0.040 inches. The electrically conductive
can height, CH, is measured as the furthest point of the
electrically conductive can 30 from the non-electrically conductive
substrate 40 measured along a line perpendicular to the surface of
the non-electrically conductive substrate 40.
[0065] Obviously, numerous modifications and variations of the
present invention are possible in light of the above teachings. For
example, the optical diode may be a detector photo diode or a laser
such as a vertical cavity surface emitting laser (VCSEL) or a light
emitting diode. Therefore, the present invention may provide a
transmitting optical subassembly (TOSA) or a receiving optical
subassembly (ROSA). It is therefore to be understood that within
the scope of the appended claims, the invention may be practiced
otherwise than as specifically described herein.
* * * * *