U.S. patent application number 11/686748 was filed with the patent office on 2007-07-19 for overmolded optical package.
This patent application is currently assigned to ADVANCED SEMICONDUCTOR ENGINEERING, INC.. Invention is credited to Bernd Karl APPELT, William Tze-You CHEN.
Application Number | 20070166866 11/686748 |
Document ID | / |
Family ID | 34393387 |
Filed Date | 2007-07-19 |
United States Patent
Application |
20070166866 |
Kind Code |
A1 |
APPELT; Bernd Karl ; et
al. |
July 19, 2007 |
OVERMOLDED OPTICAL PACKAGE
Abstract
An optical semiconductor package includes a substrate, a chip, a
plurality of bonding wires, a window, a supporter, and an
encapsulant. The chip is disposed on the substrate and has an
optical element. The bonding wires are used for electrically
connecting the chip to the substrate. The window is supported on
the supporter and positioned over the optical element of the chip.
The encapsulant is overmolded on the substrate for fixing the
window and encapsulating the chip and the bonding wires.
Inventors: |
APPELT; Bernd Karl;
(Sunnyvale, CA) ; CHEN; William Tze-You;
(Endicott, NY) |
Correspondence
Address: |
LOWE HAUPTMAN BERNER, LLP
1700 DIAGONAL ROAD
SUITE 300
ALEXANDRIA
VA
22314
US
|
Assignee: |
ADVANCED SEMICONDUCTOR ENGINEERING,
INC.
26, Chin 3rd Road Nantze Export Processing Zone
Kaohsiung
TW
|
Family ID: |
34393387 |
Appl. No.: |
11/686748 |
Filed: |
March 15, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10667605 |
Sep 23, 2003 |
7199438 |
|
|
11686748 |
Mar 15, 2007 |
|
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|
Current U.S.
Class: |
438/64 ;
257/E23.092; 257/E31.117; 257/E31.127 |
Current CPC
Class: |
H01L 2924/00014
20130101; H01L 2924/181 20130101; H01L 2924/00014 20130101; H01L
31/0203 20130101; H01L 2924/181 20130101; H01L 2924/00014 20130101;
H01L 24/48 20130101; H01L 2924/1815 20130101; H01L 2224/48227
20130101; H01L 2224/45099 20130101; H01L 31/02325 20130101; H01L
2924/00012 20130101; H01L 2224/45015 20130101; H01L 23/4334
20130101; H01L 2924/207 20130101 |
Class at
Publication: |
438/064 |
International
Class: |
H01L 21/00 20060101
H01L021/00 |
Claims
1. A method for manufacturing an optical semiconductor package,
comprising the following steps of: providing a substrate; mounting
a chip having an optical element on the substrate; bonding a
plurality of bonding wires to the chip and the substrate for
electrically connecting the chip to the substrate; providing a
supporter; disposing a window on the supporter; mounting the
supporter on the substrate; positioning the window corresponding to
the optical element of the chip; and forming an encapsulant on the
substrate for fixing the window and encapsulating the chip and the
bonding wires.
2. The method as claimed in claim 1, wherein the encapsulant
forming step further comprises the following step of: overmolding
the encapsulant.
3. The method as claimed in claim 1, further comprising the
following step of: joining the window and the supporter
together.
4. The method as claimed in claim 1, wherein the window is a
lens.
5. A method for manufacturing an optical semiconductor package,
comprising the following steps of: providing a substrate; mounting
a chip having an optical element on the substrate; bonding a
plurality of bonding wires to the chip and the substrate for
electrically connecting the chip to the substrate; mounting a
window on the optical element of the chip; and forming an
encapsulant on the substrate for fixing the window and
encapsulating the chip and the bonding wires.
6. The method as claimed in claim 5, wherein the encapsulant
forming step further comprises the following step of: overmolding
the encapsulant.
7. The method as claimed in claim 5, wherein the window is a
lens.
8. The method as claimed in claim 5, wherein the window mounting
step further comprises the following step of: providing an adhesive
for mounting the window on the optical element of the chip.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 10/667,605, filed Sep. 23, 2003, the disclosure of which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an optical semiconductor
package, and more particularly, to an optical package which is
manufactured by the overmolding process.
[0004] 2. Description of the Related Art
[0005] Referring to FIG. 1, it depicts a typically optical package
10 in prior art. The optical package 10 comprises a carrier or a
substrate 12 and a chip 20 mounded on the substrate 12. The
substrate 12 has a sidewall 16 which surrounds the substrate 12. A
transparent lid 32 is mounted on the sidewall 16 by an adhesive 34
so as to form a hermetic cavity 30 and transmit the light
interacting with the chip 20. The chip 20 has optical elements 22,
such as optical sensors or imaging sensors, and is disposed in the
cavity 30. The chip 20 is electrically connected to a plurality of
bonding pads 18 of the substrate 12 by a plurality of bonding wires
26. The bonding pads 18 on the upper surface of the substrate 12
are electrically connected to the solder pads 14 on the bottom
surface thereof through traces or vias 19. Because of the
requirements of the manufacturing process, the substrate 12 is
typically made of caramel, i.e., the substrate 12 is a kind of
ceramic substrate. Furthermore, the bonding pads 18 and the solder
pads 14 are disposed on the upper surface and the bottom surface of
the substrate 12, respectively, so the substrate 12 is a multilayer
structure.
[0006] However, the multilayer ceramic substrate 12 has long
delivery lead times and is substantially expensive. The bonding
wires 26 are connected to the bonding pads 18 and the chip 20 which
are recessed in the cavity 30, so the cavity 30 or the space
surrounded by the sidewall 16 has to be large enough that the wire
bond tool (not shown) can gain access to the bonding pads 18 and
the chip 20. Therefore, the cost of the substrate 12 is further
increased. The ceramic substrate 12 is supplied typically as single
units or small arrays and hence is assembled in single units or
small arrays, rather than large matrix arrays, so the assembly cost
of the package 10 is further increased.
[0007] Accordingly, there exists a need for an optical package
which can use a planar substrate and be mass-produced to reduce the
manufacturing cost of the optical package.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an
optical package with a planar substrate for mass-producing and
reducing the manufacturing cost.
[0009] In order to achieve the above object, the present invention
provides an optical semiconductor package comprising a substrate, a
chip, a plurality of bonding wires, a window, a supporter, and an
encapsulant. The chip is disposed on the substrate and has an
optical element. The bonding wires are used for electrically
connecting the chip to the substrate. The window is supported on
the supporter and positioned over the optical element of the chip.
The encapsulant is overmolded on the substrate for fixing the
window and encapsulating the chip and the bonding wires.
[0010] Accordingly, the substrate of the optical semiconductor
package does not have to be provided with a cavity for receiving
the chip, so the substrate can be substantially planar and be an
organic laminate or ceramic substrate such that the cost of the
substrate is substantially reduced. Furthermore, according to the
manufacturing processes of the present invention, the substrate in
matrix array can be utilized for mass production and the cost of
the optical semiconductor package can be further reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other objects, advantages, and novel features of the
invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawing.
[0012] FIG. 1 is a schematic cross-sectional view of an optical
package in the prior art.
[0013] FIG. 2 is a schematic cross-sectional view of an optical
package according to an embodiment of the present invention.
[0014] FIG. 3 is a schematic cross-sectional view of an optical
package according to another embodiment of the present
invention.
[0015] FIG. 4 is a schematic cross-sectional view of an optical
package according to a further embodiment of the present
invention.
[0016] FIG. 5 is a schematic cross-sectional view of an optical
package according to a still further embodiment of the present
invention.
[0017] FIG. 6 is a schematic cross-sectional view of an optical
package according to yet another embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to FIG. 2, it depicts an optical package 100
according to an embodiment of the present invention. The optical
semiconductor package 100 comprises a carrier or substrate 112
which is substantially planar and a chip 120 mounted on the
substrate 112. The substrate 112 can be either an organic laminate
or a ceramic substrate. The chip 120 has optical elements 122, such
as optical sensors or imaging sensors, and is electrically
connected to a plurality of bonding pads 118 of the substrate 112
by a plurality of bonding wires 126. The substrate 112 is further
provided with solder balls 114 electrically connected to the
bonding pads 118 for being electrically connected to an external
printing circuit board (not shown).
[0019] A supporter 140 is disposed on the substrate 112 and is
provided with a shoulder 144 for supporting and holding a window
142. Then, an encapsulant 130 is formed by overmolding or insert
molding process and the window 142 is kept in place. The window 142
is typically positioned above the optical elements 122 of the chip
120 for receiving or transmitting the light interacting with the
optical elements 122. The encapsulant 130 is transparent plastic,
such as acrylate, nylon, polycarbonate, and the like. The supporter
140 can be made of thermal conductive material for serving as a
heat sink. Alternatively, the supporter 140 can be made of any
plastic, such as PPS, Polycarbonate, LCP and the like, for reducing
the cost.
[0020] The dimensions of the window 142 are designed such that the
window 142 does not interfere with the bonding wires 126. The
dimensions and shape of the supporter 140 depend on the height of
the apexes of the bonding wires 126, the dimensions of the chip
120, and dimensions of the substrate 112. The space or gap between
the window 142 and the optical elements 122 of the chip 120 is
optimized for overmolding and for light transmission. That is, the
gap needs to be large enough to allow the encapsulant 130 to be
filled without disturbing the bonding wires 126 or the optical
elements 122 and the gap needs to be small enough to permit
sufficient transmission of light to ensure adequate operation of
the optical sensor.
[0021] The material of the window 142 depends on the optical
requirements. For example, the material of the window 142 can be
glass for the light at the wavelength above 320 nm, or quartz for
ultraviolet (UV) light. The window 142 also can be made of
optically transparent plastic, such as acrylate, nylon,
polycarbonate, and the like.
[0022] For high volume applications, the supporter 140 and the
window 142 can be made integrally and made of plastic, such as
acrylate, nylon, polycarbonate, and the like.
[0023] Now referring to FIG. 3, it depicts an optical semiconductor
package 200 according to another embodiment of the present
invention. The optical semiconductor package 200 is similar to the
optical semiconductor package 100, and the identical elements are
designated with the similar reference numerals. The optical
semiconductor package 200 further comprises two paired snapping
elements including a groove 244 and a protrusion 248 which are
disposed on the supporter 240 and the window 242, respectively. The
protrusion 248 of the window 242 is snapped with or held in the
groove 244 of the supporter 240 so as to securely fix the window
242 on the supporter 240 and keep the window 242 in place during
the overmolding process. Further, the paired snapping elements,
i.e. the groove 244 and the protrusion 248, are cooperated with
each other to seal the junction of the supporter 240 and the window
242 and further prevent the encapsulant 230 from flushing over the
window 242 during the overmolding process. Besides, since the
window 242 and the supporter 240 are joined together, the window
242 and the supporter 240 can be handled more easily.
[0024] Now referring to FIG. 4, it depicts an optical semiconductor
package 300 according to further another embodiment of the present
invention. The optical semiconductor package 300 is similar to the
optical semiconductor package 100, and the identical elements are
designated with the similar reference numerals. The optical
semiconductor package 300 further comprises a lens 342 in place of
the window 142 of the optical semiconductor package 100. The lens
342 is used for focusing the light on to the optical elements 322
of the chip 320 and thus increasing the intensity of the light,
thereby increasing the sensitivity of the optical semiconductor
package 300.
[0025] Now referring to FIG. 5, it depicts an optical semiconductor
package 400 according to still another embodiment of the present
invention. The optical semiconductor package 400 is similar to the
optical semiconductor package 100, and the identical elements are
designated with the similar reference numerals. The optical
semiconductor package 400 further comprises a window 442 directly
disposed or mounted on the optical element 422 of the chip 420 by
an adhesive 440.
[0026] The adhesive 440 is a thin layer for retaining the high
optical transmission to the chip, and can be made of a material
which is of high optical transmission, such as acrylate. It will be
apparent to those skilled in the art that the encapsulant 430 of
the optical semiconductor package 400 can be made of an opaque
material because the encapsulant 430 does not cover the optical
elements 422 of the chip 420. The window 442 is further provided
with a plurality of mold locks or ledges 444 for securing the
window 442 in the encapsulant 430.
[0027] Now referring to FIG. 6, it depicts an optical semiconductor
package 500 according to still another embodiment of the present
invention. The optical semiconductor package 500 is similar to the
optical semiconductor package 200, and the identical elements are
designated with the similar reference numerals. The optical
semiconductor package 500 is provided with a supporter 540 which is
hermetically disposed on the substrate 512 to form a cavity 550.
The encapsulant 530 encapsulates the supporter 540 so as to fix the
supporter 540 on the substrate 512. The chip 520 and the bonding
wires 526 are positioned in the cavity 550. The window 542 is
hermetically disposed on the supporter 540 for transmitting light
into and out of the cavity 550. As indicated in the foregoing
description, the substrate of the optical semiconductor package
according to the present invention is not required to have a cavity
for receiving the chip, so the substrate can be substantially
planar and be an organic laminate or ceramic substrate such that
the cost of the substrate is substantially reduced. Furthermore,
according to the manufacturing processes of the present invention,
the substrate in matrix array can be utilized for mass production
and the cost of the optical semiconductor package can be further
reduced.
[0028] While the foregoing description and drawings represent the
preferred embodiments of the present invention, it will be
understood that various additions, modifications and substitutions
may be made therein without departing from the spirit and scope of
the principles of the present invention as defined in the
accompanying claims. One skilled in the art will appreciate that
the invention may be used with many modifications of form,
structure, arrangement, proportions, materials, elements, and
components and otherwise, used in the practice of the invention,
which are particularly adapted to specific environments and
operative requirements without departing from the principles of the
present invention. The presently disclosed embodiments are
therefore to be considered in all respects as illustrative and not
restrictive, the scope of the invention being indicated by the
appended claims and their legal equivalents, and not limited to the
foregoing description.
* * * * *