U.S. patent application number 10/198982 was filed with the patent office on 2003-11-06 for chip on board package for optical mice and lens cover for the same.
This patent application is currently assigned to Samsung Electro-Mechanics Co., Ltd. Invention is credited to Kim, Tae Jun, Song, Yoo Sun.
Application Number | 20030205800 10/198982 |
Document ID | / |
Family ID | 29267934 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030205800 |
Kind Code |
A1 |
Kim, Tae Jun ; et
al. |
November 6, 2003 |
CHIP ON BOARD PACKAGE FOR OPTICAL MICE AND LENS COVER FOR THE
SAME
Abstract
Disclosed herein is a chip on board lead package for optical
mice and lens cover for the same. A semiconductor chip on board
package for optical mice has a board, a semiconductor chip, at
least one circuit pattern, at least one bonding wire, and a lens
cover. The board has top and bottom surfaces, and a pair of via
holes. The semiconductor chip is attached to a center portion on
the top surface of the board and provided with a plurality of
electrode terminals. The circuit pattern is formed on the top
surface of the board. The bonding wire electrically connects the
electrode terminals of the semiconductor chip with the circuit
pattern. The lens cover encloses the top surface of the board and
has a lens disposed on the same axis as that of the semiconductor
chip, a plurality of electrode pins formed at positions of the lens
cover corresponding to the positions of the via holes in the board
to be integrated with the lens cover, and an opening formed in a
center portion within the lens cover.
Inventors: |
Kim, Tae Jun; (Suwon,
KR) ; Song, Yoo Sun; (Seoul, KR) |
Correspondence
Address: |
LOWE HAUPTMAN GOPSTEIN GILMAN & BERNER, LLP
Suite 310
1700 Diagonal Road
Alexandria
VA
22314
US
|
Assignee: |
Samsung Electro-Mechanics Co.,
Ltd
|
Family ID: |
29267934 |
Appl. No.: |
10/198982 |
Filed: |
July 22, 2002 |
Current U.S.
Class: |
257/684 ;
257/697; 257/698 |
Current CPC
Class: |
H01L 2224/73265
20130101; H01L 2224/45144 20130101; H01L 2224/48227 20130101; G06F
3/0317 20130101; H01L 2224/48091 20130101; H01L 2224/32225
20130101; H01L 2224/48091 20130101; H01L 2924/00014 20130101; H01L
2224/73265 20130101; H01L 2224/32225 20130101; H01L 2224/48227
20130101; H01L 2924/00 20130101; H01L 2224/45144 20130101; H01L
2924/00 20130101 |
Class at
Publication: |
257/684 ;
257/697; 257/698 |
International
Class: |
H01L 023/06 |
Foreign Application Data
Date |
Code |
Application Number |
May 6, 2002 |
KR |
2002-24663 |
Claims
What is claimed is:
1. A semiconductor chip on board package for optical mice,
comprising: a board having top and bottom surfaces, and a pair of
via holes formed along opposite side surfaces of the board to pass
through the top and bottom surfaces; a semiconductor chip attached
to a center portion on the top surface of the board and provided
with a plurality of electrode terminals formed therein; at least
one circuit pattern formed on the top surface of the board to be
extended from the position to which the semiconductor chip of the
board is attached, to positions in which the via holes are formed;
at least one bonding wire for electrically connecting the electrode
terminals of the semiconductor chip with the circuit pattern; and a
lens cover for enclosing the top surface of the board, the lens
cover having a lens disposed on the same axis as that of the
semiconductor chip, a pair of electrode pins formed at positions of
the lens cover corresponding to the positions of the pair of via
holes in the board to be integrated with the lens cover, and an
opening formed in a center portion within the lens cover for
accommodating the semiconductor chip therein, wherein one end of
each of the electrode pins of the lens cover is protruded
downwardly from the bottom surface of the board through each via
hole when the lens cover is combined with the board, and the
electrode pins are bonded to the via holes of the board with
solder, thus enabling the electrode pins to be electrically
connected to the circuit pattern of the board.
2. The semiconductor chip on board package for optical mice
according to claim 1, wherein the electrode pins and the lens cover
are integrated into one body by injection molding.
3. The semiconductor chip on board package for optical mice
according to claim 1, wherein the lens cover is designed such that
its center portion is formed to be protruded relative to other
portions of the lens cover, thus allowing the lens and the
semiconductor chip to be spaced apart from each other.
4. The semiconductor chip on board package for optical mice
according to claim 3, wherein the electrode pins are formed such
that the other end of each electrode pin is protruded to be higher
than the protruded center portion of the lens cover.
5. A semiconductor chip on board package for optical mice,
comprising: a board having top and bottom surfaces, and a plurality
of via holes formed along opposite longer side surfaces of the
board to pass through the top and bottom surfaces; a semiconductor
chip arranged between the opposite via holes on the top surface of
the board and provided with a plurality of electrode terminals
formed therein; at least one circuit pattern formed on the top
surface of the board to be extended from the position to which the
semiconductor chip of the board is attached, to positions in which
the via holes are formed; at least one bonding wire for
electrically connecting the electrode terminals of the
semiconductor chip with the circuit pattern; and a lens cover for
enclosing the top surface of the board, the lens cover having a
lens disposed on the same axis as that of the semiconductor chip, a
plurality of electrode pins formed at positions of the lens cover
corresponding to the positions of the via holes in the board to be
integrated with the lens cover, and an opening formed in a center
portion within the lens cover so as to prevent interference with
the semiconductor chip, wherein one end of each of the electrode
pins of the lens cover is protruded downwardly from the bottom
surface of the board through each via hole when the lens cover is
combined with the board, and the electrode pins are bonded to the
via holes of the board with solder, thus enabling the electrode
pins to be electrically connected to the circuit pattern of the
board.
6. The semiconductor chip on board package for optical mice
according to claim 5, wherein the electrode pins and the lens cover
are integrated into one body by injection molding.
7. The semiconductor chip on board package for optical mice
according to claim 5, wherein the lens cover has a fixing
protrusion disposed between opposite electrode pins and formed to
be protruded downwardly from the bottom surface of the lens cover,
and the board has a fixing hole formed on its top surface such that
the fixing protrusion can be inserted thereinto.
8. The semiconductor chip on board package for optical mice
according to claim 5, wherein the lens cover is designed such that
a portion at which the lens is disposed is formed to be protruded
relative to other portions of the lens cover, thus allowing the
lens and the semiconductor chip to be spaced apart from each
other.
9. The semiconductor chip on board package for optical mice
according to claim 8, wherein the electrode pins are formed such
that a first end of each electrode pin is protruded to be higher
than the protruded center portion of the lens cover.
10. The semiconductor chip on board package for optical mice
according to claim 5, wherein the lens cover is designed such that
its opposite shorter sides are opened so as to prevent the opposite
shorter sides of the lens cover from coming in contact with
opposite shorter side surfaces of the board.
11. A lens cover used for a chip on board package for optical mice,
the lens cover enclosing a board, in which a semiconductor chip
having a plurality of electrode terminals formed therein is
attached to a top surface of the board, a plurality of via holes
are formed along opposite longer side surfaces of the board to pass
through the top and bottom surfaces, at least one circuit pattern
is formed on the top surface of the board to be extended from the
position to which the semiconductor chip is attached, to positions
in which the via holes are formed, and the electrode terminals of
the semiconductor chip are electrically connected to the circuit
pattern by wire bonding, wherein: the lens cover encloses the top
surface of the board and has a lens disposed on the same axis as
that of the semiconductor chip, a plurality of electrode pins
formed at positions of the lens cover corresponding to the
positions of the via holes in the board to be integrated with the
lens cover, and an opening formed in a center portion within the
lens cover so as to prevent interference with the semiconductor
chip, and one end of each of the electrode pins of the lens cover
is protruded downwardly from the bottom surface of the board
through each via hole when the lens cover is combined with the
board, and the electrode pins are bonded to the via holes of the
board with solder, thus enabling the electrode pins to be
electrically connected to the circuit pattern of the board.
12. The lens cover according to claim 11, wherein the lens cover
has a fixing protrusion disposed between opposite electrode pins
and formed to be protruded downwardly from the bottom surface of
the lens cover, and the board has a fixing hole formed on its top
surface such that the fixing protrusion is inserted into the fixing
hole.
13. The lens cover according to claim 11, wherein the lens cover is
designed such that a portion at which the lens is disposed is
formed to be protruded relative to other portions of the lens
cover, thus allowing the lens and the semiconductor chip to be
spaced apart from each other.
14. The lens cover according to claim 13, wherein the electrode
pins are formed such that a first end of each electrode pin is
protruded to be higher than the protruded center portion of the
lens cover.
15. The lens cover according to claim 11, wherein the lens cover is
designed such that its opposite shorter sides are opened so as to
prevent the opposite shorter sides of the lens cover from coming in
contact with opposite shorter side surfaces of the board.
16. The lens cover according to claim 11, wherein the electrode
pins and the lens cover are integrated into one body by injection
molding.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a chip on board
package for optical mice and lens cover for the same, and more
particularly to a chip on board package for optical mice and lens
cover for the same, in which a semiconductor chip of a package for
optical mice is connected to circuit patterns on a board, and the
circuit patterns are connected to a plurality of pins functioning
as lead frames.
[0003] 2. Description of the Prior Art
[0004] Generally, in semiconductor packages used for optical mice,
a construction using lead frames is popularly used, which is
depicted in FIG. 1. Referring to FIG. 1, a semiconductor chip 102
is attached to a die paddle 101. The die paddle 101 is electrically
connected to lead frames 105 using fine gold wires 103. In this
case, the fine gold wires 103 are bonding wires. The die paddle 101
and some portion of each lead frame 105 are molded by epoxy molding
compound 106, thus allowing their positions to be fixed. Then, a
cavity 108 in which both the semiconductor chip 102 and the fine
gold wires 103 are accommodated is enclosed with a cover 107. As
described above, after the cavity 108 is enclosed, the lead frames
105 are adjusted to be mounted to a set (not shown) so as to form
external terminals. In order to mount such a semiconductor package
using lead frames to the set, via holes are formed in the set, and
then leads are inserted into the via holes and soldered.
[0005] However, the package using lead frames is problematic in
that it requires high initial investment cost so as to develop and
produce lead frames, and molds must be managed continuously.
Further, if lead frames in use must be changed, the same investment
cost as that for previously used lead frames is inevitably
required, thus preventing new products from being developed.
[0006] In order to overcome such problems, there is proposed a chip
on board (COB) package not using lead frames as a typical
semiconductor chip package. Such a COB semiconductor chip package
is popularly used for supplementing disadvantages of the
semiconductor chip package using lead frames. FIG. 2 shows a
conventional COB package. Referring to FIG. 2, a semiconductor chip
202 is mounted on a board 201, and circuit patterns 204 are formed
around the semiconductor chip 202 on the board 201. The circuit
patterns 204 are extended to the bottom of the board 201 via the
side surfaces of the board 201, thus enabling terminals 205 to be
formed. Circuit patterns 204 are electrically connected to
terminals of the semiconductor chip 202 by fine gold wires 203. In
order to protect the semiconductor chip 202 and the fine gold wires
203, they are molded using epoxy resin. When the COB package is
mounted on a set, the terminals 205 formed beneath the board 201
are directly attached to the set through a soldering process, etc.
Since the COB package does not use lead frames, it does not require
high initial investment cost, it can cope with variations in
products, and can decrease development time of new products.
[0007] However, there is difficulty in using the COB package as a
semiconductor chip package for optical mice. That is, in order to
allow light recognized by an optical mouse to reach a semiconductor
chip through a lens, focus must be controlled by adjusting the
height of the lens when the semiconductor chip is mounted on a set.
However, if the conventional COB package is used, a board is
directly mounted on the set, so the height of the package cannot be
adjusted.
[0008] Further, as a mouse is used for various purposes, there are
required mouse devices having various and complicated functions,
compared with a conventional mouse. For this reason, the number of
terminals of a semiconductor chip package is increasing compared
with a conventional semiconductor chip package. Therefore, there is
needed a new package product in which more terminals than those of
a conventional package product can be formed.
[0009] Consequently, there is required a package for optical mice,
which can be used as a lead frame package if necessary, having not
only advantages of the COB package that initial investment cost is
low, a development time of a product is short and application to
development of various products is possible, but also advantages of
the lead frame package that the focus of light can be controlled
through a lens if the lead frame package is used for optical mice
and additional terminals can be easily formed.
SUMMARY OF THE INVENTION
[0010] Accordingly, the present invention has been made keeping in
mind the above problems occurring in the prior art, and an object
of the present invention is to provide a semiconductor chip on
board package for optical mice and lens cover for the same, which
can simplify and facilitate a manufacturing process of a chip on
board package, reduce initial investment cost thereof, reduce a
development time thereof, and can easily cope with variations in
products, by using a lens cover integrated with electrode pins.
[0011] Another object of the present invention is to provide a
semiconductor chip on board package for optical mice and lens cover
for the same, which can be used as a lead frame package when a
semiconductor package is mounted on a set, and can have more
terminals than those of a conventional chip on board package.
[0012] A further object of the present invention is to provide a
semiconductor chip on board package for optical mice and lens cover
for the same, in which central axes of both a lens and a
semiconductor chip can easily correspond to each other when a board
and a lens cover are assembled, and the lens cover has opened sides
so as to combine several not-cut boards with lens covers, thus
improving productivity of a semiconductor chip on board
package.
[0013] In order to accomplish the above object, the present
invention provides a semiconductor chip on board package for
optical mice, comprising a board having top and bottom surfaces,
and a pair of via holes formed along opposite side surfaces of the
board to pass through the top and bottom surfaces; a semiconductor
chip attached to a center portion on the top surface of the board
and provided with a plurality of electrode terminals formed
therein; at least one circuit pattern formed on the top surface of
the board to be extended from the position to which the
semiconductor chip of the board is attached, to positions in which
the via holes are formed; at least one bonding wire for
electrically connecting the electrode terminals of the
semiconductor chip with the circuit pattern; and a lens cover for
enclosing the top surface of the board, the lens cover having a
lens disposed on the same axis as that of the semiconductor chip, a
pair of electrode pins formed at positions of the lens cover
corresponding to the positions of the pair of via holes in the
board to be integrated with the lens cover, and an opening formed
in a center portion within the lens cover for accommodating the
semiconductor chip therein, wherein one end of each of the
electrode pins of the lens cover is protruded downwardly from the
bottom surface of the board through each via hole when the lens
cover is combined with the board, and the electrode pins are bonded
to the via holes of the board with solder, thus enabling the
electrode pins to be electrically connected to the circuit pattern
of the board.
[0014] Further, the present invention provides a semiconductor chip
on board package for optical mice, comprising a board having top
and bottom surfaces, and a plurality of via holes formed along
opposite longer side surfaces of the board to pass through the top
and bottom surfaces; a semiconductor chip arranged between the
opposite via holes on the top surface of the board and provided
with a plurality of electrode terminals formed therein; at least
one circuit pattern formed on the top surface of the board to be
extended from the position to which the semiconductor chip of the
board is attached, to positions in which the via holes are formed;
at least one bonding wire for electrically connecting the electrode
terminals of the semiconductor chip with the circuit pattern; and a
lens cover for enclosing the top surface of the board, the lens
cover having a lens disposed on the same axis as that of the
semiconductor chip, a plurality of electrode pins formed at
positions of the lens cover corresponding to the positions of the
via holes in the board to be integrated with the lens cover, and an
opening formed in a center portion within the lens cover so as to
prevent interference with the semiconductor chip, wherein one end
of each of the electrode pins of the lens cover is protruded
downwardly from the bottom surface of the board through each via
hole when the lens cover is combined with the board, and the
electrode pins are bonded to the via holes of the board with
solder, thus enabling the electrode pins to be electrically
connected to the circuit pattern of the board.
[0015] Further, the present invention provides a lens cover used
for a chip on board package for optical mice, the lens cover
enclosing a board, in which a semiconductor chip having a plurality
of electrode terminals formed therein is attached to a top surface
of the board, a plurality of via holes are formed along opposite
longer side surfaces of the board to pass through the top and
bottom surfaces, at least one circuit pattern is formed on the top
surface of the board to be extended from the position to which the
semiconductor chip is attached, to positions in which the via holes
are formed, and the electrode terminals of the semiconductor chip
are electrically connected to the circuit pattern by wire bonding,
wherein the lens cover encloses the top surface of the board and
has a lens disposed on the same axis as that of the semiconductor
chip, a plurality of electrode pins formed at positions of the lens
cover corresponding to the positions of the via holes in the board
to be integrated with the lens cover, and an opening formed in a
center portion within the lens cover so as to prevent interference
with the semiconductor chip, and one end of each of the electrode
pins of the lens cover is protruded downwardly from the bottom
surface of the board through each via hole when the lens cover is
combined with the board, and the electrode pins are bonded to the
via holes of the board with solder, thus enabling the electrode
pins to be electrically connected to the circuit pattern of the
board.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0017] FIG. 1 is a sectional view of a conventional optical mouse
package using lead frames;
[0018] FIG. 2 is a sectional view of a typical semiconductor chip
on board package;
[0019] FIGS. 3A to 3C are views showing the construction and
assembly sequence of parts of a chip on board package for optical
mice according to a preferred embodiment of the present
invention;
[0020] FIG. 4 is a perspective view of another chip on board
package for optical mice according to another preferred embodiment
of the present invention;
[0021] FIGS. 5A to 5C are views showing the construction and
assembly sequence of parts of the chip on board package of FIG. 4;
and
[0022] FIG. 6 is a perspective view of a further chip on board
package for optical mice according to a further preferred
embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Hereinafter, embodiments of the present invention will be
described in detail with reference to the attached drawings.
[0024] FIGS. 3A to 3C are views showing the construction and
assembly sequence of parts of a chip on board package for optical
mice according to a preferred embodiment of the present
invention.
[0025] FIG. 3A shows a lens cover 1 according to a preferred
embodiment of the present invention. Electrode pins 2 functioning
as lead frames are formed to be integrated with the lens cover 1
such that the electrode pins 2 are positioned along opposite side
surfaces of the lens cover 1. In this case, the pins 2 are
protruded from the lens cover 1 upwardly and downwardly by a
predetermined length. Further, a lens 11 for receiving light is
disposed at a center portion of the lens cover 1. A protrusion 12
being more protruded than other portions of the lens cover 1 is
formed at the portion to which the lens 11 is disposed. Further, an
opening 13 to accommodate a semiconductor chip mounted on a board
as described later is formed in a center portion within the lens
cover 1.
[0026] FIG. 3B shows a board 7 combined with the lens cover 1. The
board 7 has top and bottom surfaces, wherein a semiconductor chip 5
is mounted on the center portion of the top surface of the board 7.
The semiconductor chip 5 has a plurality of electrode terminals
formed therein. In the board 7, via holes 6 are formed to allow the
electrode pins 2 of the lens cover 1 to be inserted into the holes
6. In the preferred embodiment, the via holes 6 are positioned
along an arbitrary side surface of the board 7 and its opposite
side surface, and formed to pass through the top and bottom
surfaces of the board 7.
[0027] Further, on the top surface of the board 7, circuit patterns
3 are formed to be extended from the position of the semiconductor
chip 5 to the via holes 6. The semiconductor chip 5 is electrically
connected to the circuit patterns 3 by fine gold wires, that is,
bonding wires 4. Therefore, the semiconductor chip 5 forms
electrical connections with the circuit patterns 3 on the top
surface of the board 7 as in a conventional COB package.
[0028] The board 7 and the lens cover 1 formed by the above process
are combined with each other as shown in FIG. 3C. The lens cover 1
is formed to cover the top surface of the board 7. The lens 11 is
disposed on the same axis as that of the semiconductor chip 5, thus
enabling inputted light to reach the semiconductor chip 5 through
the lens 11. Therefore, the electrode pins 2 and the via holes 6
must be adjusted in their formation positions such that the lens 11
and the semiconductor chip 5 are disposed on the same axis. The
lens cover 1 encloses the top surface of the board 7 while being in
contact with top surface of the board 7. The lens cover 1 and the
board 7 are adhered to each other using an adhesive applied at
their contact portions. Simultaneously, the electrode pins 2 pass
through the via holes 6 to be protruded downwardly. In this case,
the electrode pins 2 are bonded to the via holes 6 with solder 8,
and are electrically connected to the circuit patterns 3 on the top
surface of the board 7.
[0029] Therefore, the electrode pins 2 function as lead frames of
the combined semiconductor chip package for optical mice. Further,
the semiconductor chip 6 within the package is mounted on the board
7 according to a typical chip on board method.
[0030] In the above embodiment, the via holes 6 formed on the board
7 are disposed along opposite side surfaces of the board 7. The
pins 2 and the lens cover 1 are integrated into one body through
injection molding. The injection molding is compared with molding
of a typical lead frame package. The lens cover 1 of the present
invention uses straight pins, and the structure of the pins is
simple, so the molding can be easily performed, and complicated
molding is not required. Further, one end of each of the electrode
pins 2 passes through each via hole 6 of the board 7 and protrudes
downwardly from the bottom surface of the board 7, while the other
end thereof is protruded upwardly from the top surface of the board
7 to be higher than the protrusion 12 formed on the center portion
of the lens cover 1. Therefore, the arrangement of input/output
(I/O) terminals of the semiconductor chip package and leads can be
freely designed. Further, the chip on board package of this
invention can be applied to various products.
[0031] FIG. 4 is a perspective view of another semiconductor chip
on board package for optical mice according to another preferred
embodiment of the present invention. In this embodiment, a
plurality of pins 22 are arranged along opposite longer side
surfaces of a lens cover 21 in a longitudinal direction of the lens
cover 21. FIGS. 5A to 5C are views showing the construction and
assembly sequence of parts of the chip on board package of FIG.
4.
[0032] Referring to FIG. 4 and FIG. 5A, a protrusion 32 to which a
lens 31 is attached is formed on the lens cover 21 as in the above
embodiment of the present invention. However, the embodiment of
FIG. 4 is different from the above embodiment of FIGS. 3A to 3C in
that the protrusion 32 is formed in not the center portion of the
cover 21, but a portion offset from the center. The lens cover 21
is formed to be integrated with a plurality of electrode pins 22. A
plurality of electrode pins 22 are arranged along opposite side
surfaces in a longitudinal direction of the lens cover 21 at
regular intervals. The pins 22 are protruded from the cover 21
upwardly and downwardly by a predetermined height, and preferably
protruded to be higher than the protrusion 32. Further, the pins 22
are protruded downwardly while passing through via holes of a board
described later. An opening 33 to accommodate a semiconductor chip
mounted on the board described later is formed in a center portion
within the lens cover 21.
[0033] FIG. 5B shows a board 27 combined with the lens cover 21.
The board 27 has top and bottom surfaces, wherein a semiconductor
chip 25 is mounted at a portion offset from a center on the top
surface of the board 27. The semiconductor chip 25 has a plurality
of electrode terminals formed therein. In the board 27, a plurality
of via holes 26, into which the electrode pins 22 of the lens cover
21 are inserted, are formed. In this preferred embodiment, the via
holes 26 are oppositely arranged in the longitudinal direction of
the board 27, positioned along opposite longitudinal side surfaces,
and formed to pass through the top and bottom surfaces of the board
27. Preferably, in order to protect the semiconductor chips 5 and
25 respectively mounted on the boards 7 and 27 of FIG. 3B and FIG.
5B and wires 4 and 24 connected thereto, a wall (not shown) with a
predetermined height is formed around a position, on which each
semiconductor chip is mounted, with resin. Then, the wall is filled
with transparent resin, thus enabling each semiconductor chip and
wires to be protected by the transparent resin. Therefore, the wall
serves to contain the transparent resin so as to allow the
transparent resin to cover only the semiconductor chip and
wires.
[0034] Further, circuit patterns 23 are formed on the top surface
of the board 27 to be extended from the position of the
semiconductor chip 25 to the via holes 26. The semiconductor chip
25 is electrically connected to the circuit patterns 23 by fine
gold wires, that is, bonding wires 24.
[0035] The board 27 and the lens cover 21 formed by the above
process are combined with each other as shown in FIG. 5C. The lens
cover 21 encloses the top surface and each side surface of the
board 27. The lens 31 is disposed on the same axis as that of the
semiconductor chip 25, thus enabling inputted light to reach the
semiconductor chip 25 through the lens 31. As described above, in
order to adjust both the lens 31 and the semiconductor chip 25 such
that both are positioned on the same axis, a fixing hole 36 and a
fixing protrusion 37 are formed in the board 27 and the lens cover
21, respectively. The fixing protrusion 35 is formed to be
protruded from the cover 21 downwardly, while being spaced apart
from the center of the protrusion 32 in the lens cover 21 by a
predetermined spaced distance 37. In this case, the fixing
protrusion 35 is cylindrically formed. Further, the fixing hole 36
corresponding to the fixing protrusion 35 of the lens cover 21 is
formed in the board 27 so as to allow the fixing protrusion 35 to
be inserted into the fixing hole 36. Therefore, a centering process
between the lens and the semiconductor chip is simplified by
inserting the fixing protrusion 35 into the fixing hole 36, thereby
simplifying an entire manufacturing process of the semiconductor
chip on board package.
[0036] The lens cover 21 encloses the board 27 while being in
contact with the top surface and each side surface of the board 27.
The lens cover 21 and the board 27 are adhered to each other using
an adhesive applied at their contact portions. Simultaneously, the
electrode pins 22 pass through the via holes 26 to be protruded
downwardly. In this case, the electrode pins 22 are bonded to the
via holes 26 with solder, and are electrically connected to the
circuit patterns 23 on the top surface of the board 27, the same as
the embodiment of FIGS. 3A to 3C.
[0037] In the preferred embodiment, the holes 26 formed on the
board 27 are oppositely arranged in a longitudinal direction of the
board 27, formed along opposite longer side surfaces of the board
27 and arranged at regular intervals. The pins 22 and the lens
cover 21 are integrated into one body through injection molding. In
this case, the number of pins 22 arranged in the cover 21 is the
same as that of the via holes 26. In the construction of this
embodiment of the present invention, it is possible to produce a
package having more than 24 pins, compared with a conventional
package typically having 13 pins. Therefore, the chip on board
package of the present invention is advantageous in that it can
easily increase the number of terminals due to enlargement of
functions of a mouse.
[0038] FIG. 6 shows a modified embodiment of the lens cover of FIG.
5A. As shown in FIG. 6, two shorter sides of all sides of a lens
cover 41 are opened. Therefore, the lens cover 41 is combined with
a board 27, while being in contact with only the top surface and
two longer side surfaces of the board 27. Accordingly, even if
there is an error in the size of the board 27, or there is
variation in length of the board 27 in a manufacturing process, a
phenomenon that the lens cover 41 is not perfectly fitted to the
board 27 can be prevented. Further, it is possible to carry out a
process for obtaining a package by producing several boards at a
time, combining the several not-cut boards with lens covers, and
then cutting the boards individually. This process is advantageous
in that it can simplify and facilitate a manufacturing process of a
chip on board package, compared with a conventional process for
first cutting respective boards, and combining respective boards
with respective lens covers, thus improving productivity of a
semiconductor chip on board package.
[0039] As described above, the present invention provides a
semiconductor chip on board package for optical mice and lens cover
for the same, which can simplify and facilitate a manufacturing
process of a chip on board package, can reduce initial investment
cost thereof, can reduce a development time thereof, and can cope
with variations in products, by using a lens cover integrated with
electrode pins, and without using a construction in which a
semiconductor chip is directly connected to lead frames.
[0040] Further, the present invention can provide a semiconductor
chip on board package for optical mice and lens cover for the same,
which can be used as a lead frame package when the chip on board
package is mounted on a set, and can have more terminals than those
of a conventional semiconductor chip package.
[0041] Moreover, the present invention is advantageous in that
central axes of both a lens and a semiconductor chip can easily
correspond to each other when a board and a lens cover are
assembled, and the lens cover has opened sides so as to combine
several not-cut boards with lens covers, thus improving
productivity of a semiconductor chip on board package.
[0042] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
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