U.S. patent application number 11/843821 was filed with the patent office on 2008-02-28 for solid-state imaging device, camera module, and camera-module manufacturing method.
This patent application is currently assigned to FUJIFILM Corporation. Invention is credited to Hiroshi Maeda, Kazuhiro Nishida, Shigehisa Shimizu.
Application Number | 20080049127 11/843821 |
Document ID | / |
Family ID | 32985658 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080049127 |
Kind Code |
A1 |
Maeda; Hiroshi ; et
al. |
February 28, 2008 |
SOLID-STATE IMAGING DEVICE, CAMERA MODULE, AND CAMERA-MODULE
MANUFACTURING METHOD
Abstract
A cover glass covers only light-receiving elements formed on a
semiconductor substrate of a solid-state imaging device. The other
area of the substrate except the light-receiving elements is
exposed. An FPC interposed between an optical unit and the
solid-state imaging device is formed with an opening for exposing
the cover glass and an assembly reference surface of the
solid-state imaging device. When the solid-state imaging device is
attached to the optical unit, the center of the light-receiving
elements is determined as a reference position. The optical unit is
directly attached to the assembly reference surface so as to make
the reference position coincide with a photographic optical axis of
the optical unit.
Inventors: |
Maeda; Hiroshi; (Kanagawa,
JP) ; Shimizu; Shigehisa; (Kanagawa, JP) ;
Nishida; Kazuhiro; (Kanagawa, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
FUJIFILM Corporation
|
Family ID: |
32985658 |
Appl. No.: |
11/843821 |
Filed: |
August 23, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10839231 |
May 6, 2004 |
|
|
|
11843821 |
Aug 23, 2007 |
|
|
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Current U.S.
Class: |
348/294 ;
257/E31.117; 257/E31.127; 348/E5.027; 348/E5.091 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 31/02325 20130101; H01L 2924/0002 20130101; H04N 5/2253
20130101; H01L 31/0203 20130101; H01L 27/14618 20130101; H04N
5/2257 20130101; H01L 27/14625 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
348/294 ;
348/E05.091 |
International
Class: |
H04N 5/335 20060101
H04N005/335 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2003 |
JP |
2003-130599 |
Claims
1. A manufacturing method for a camera module including a
solid-state imaging device in which light-receiving elements are
formed on a semiconductor substrate, and an optical unit having a
built-in photographic optical system for forming a subject image on
said light-receiving elements, said manufacturing method comprising
the steps of: obtaining image data by imaging said solid-state
imaging device with an electronic camera; determining a first
reference position of said solid-state imaging device from said
image data; carrying out positioning on a plane perpendicular to a
photographic optical axis of said optical unit so as to make said
first reference position coincide with a predetermined second
reference position of said optical unit; and fixing said
solid-state imaging device to said optical unit.
2. A manufacturing method for a camera module according to claim 1,
wherein said first reference position is located at the center of a
light-receiving area of said light-receiving elements.
3. A manufacturing method for a camera module according to claim 2,
wherein said second reference position is located at said
photographic optical axis of said optical unit.
4. A manufacturing method for a camera module according to claim 1,
wherein said solid-state imaging device comprising: a translucent
member attached to a first surface of the semiconductor substrate
on which said light-receiving elements are formed, said translucent
member covering only the light-receiving elements; an external
connection terminal formed on a second surface of said
semiconductor substrate, said second surface being opposite to said
first surface; and a wiring member for electrically connecting said
light-receiving element and said external connection terminal.
5. A manufacturing method for a camera module according to claim 4,
wherein said first surface of said semiconductor substrate is used
as an assembly reference plane when said solid-state imaging device
is fixed to said optical unit.
6. A manufacturing method for a camera module according to claim 5,
wherein said optical unit is directly attached to said first
surface.
7. A manufacturing method for a camera module according to claim 5,
wherein said translucent member has flatness being identical with
that of said semiconductor substrate.
8. A manufacturing method for a camera module according to claim 7,
wherein said optical unit is attached to said translucent member.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a solid-state imaging
device, a camera module and a manufacturing method for the camera
module, wherein a thickness in an optical-axis direction is thin
and it is possible to assemble the solid-state imaging device and
an optical unit with great accuracy.
[0003] 2. Description of the Related Art
[0004] A digital camera and a video camera employing a solid-state
imaging device are widely used. Further, it is also done to add a
photographing function to a personal computer and electronic
equipments of a cellular phone, an electronic notebook and so forth
by incorporating the solid-state imaging device and a memory
therein. In order to easily add the photographing function to the
electronic equipments except the digital camera, is provided a
unitized camera module in which the solid-state imaging device, an
optical unit and a circuit board are assembled in advance. The
optical unit has a built-in imaging optical system, and the circuit
board is provided with a control circuit.
[0005] The solid-state imaging device comprises a light-receiving
element and an external connection terminal, which are formed on a
semiconductor substrate made from silicon. In case the solid-state
imaging device is in a state that the light-receiving element is
not protected, namely in case the solid-state imaging device is a
bare chip, dust and dart adhere to the light-receiving element and
a trouble is caused. Therefore, in the conventional solid-state
imaging device, the bare chip is contained in a package formed from
ceramic and so forth. The solid-state imaging device and the
package are connected by wire bonding. A cover glass is attached to
an opening of the package to supply the solid-state imaging device
in a sealed state.
[0006] As to one of mounting manners for downsizing the solid-state
imaging device, there is a chip-size package (hereinafter,
abbreviated as CSP) structure wherein mounting the solid-state
imaging device is completed without using the package (see Japanese
Patent Application No. 2002-119262). The solid-state imaging device
of the CSP type is provided with a spacer, which is disposed on an
upper surface of the semiconductor substrate so as to surround the
light-receiving element. A cover glass is attached to the top of
the spacer to seal the light-receiving element.
[0007] In order to obtain a high-quality photographic picture by
effectively utilizing performance of the solid-state imaging
device, it is necessary to make a photographic optical axis of the
imaging optical system coincide with the center of a
light-receiving area of the solid-state imaging device. Further, it
is also necessary to make the light-receiving element of the
solid-state imaging device perpendicular to the photographic
optical axis of the imaging optical system. If the photographic
optical axis of the imaging optical system does not coincide with
the center of the light-receiving area of the solid-state imaging
device, shading and so forth occur due to a decline of a light
amount, deterioration of resolution, and unevenness of sensitivity.
Moreover, if the solid-state imaging device inclines relative to
the photographic optical axis, it is impossible to obtain a proper
image due to a condition of so-called "swing-and-tilt
photographing".
[0008] In a conventional way, image pickup is performed with the
solid-state imaging device during an assembly operation for the
purpose of assembling the solid-state imaging device and the
optical unit with great accuracy. A pickup image is viewed to carry
out an operation (aligning operation) for deciding relative
positions of the solid-state imaging device and the imaging optical
system. The aligning operation, however, takes a lot of time so
that it is caused to increase the cost and to deteriorate a yield
rate.
[0009] In order to accurately assemble the solid-state imaging
device and the optical unit without the above-mentioned aligning
operation, a plurality of positioning plates are attached to the
outside of the package of the solid-state imaging device described
in Japanese Patent Laid-Open Publication No. 05-102448. By using
the positioning plates, the solid-state imaging device is
positioned and fixed to the optical unit. Meanwhile, with respect
to the solid-state imaging device described in Japanese Patent
Laid-Open Publication No. 11-252416, an attachment reference plane
is accurately formed on the package. The attachment reference plane
abuts on a reference plane of the optical unit to carry out
positioning and fixing.
[0010] As to the solid-state imaging device sealed in the package,
positioning accuracy thereof relative to the optical unit is
affected by size accuracy of the package, assembly accuracy of the
solid-state imaging device and the package, and assembly accuracy
of the package and the optical unit. Therefore, even if the package
is attached to the optical unit with great accuracy, positional
accuracy of the solid-state imaging device and the optical unit is
not greatly improved. The aligning operation is still required to
carry out appropriate positioning.
[0011] The solid-state imaging device sealed in the package has a
broad external size (project area perpendicular to an optical-axis
direction) and a wide size in the optical-axis direction (thickness
size). Thus, the digital camera and the camera module, in which the
solid-state imaging device is incorporated, are prevented from
being downsized.
SUMMARY OF THE INVENTION
[0012] In view of the foregoing, it is a primary object of the
present invention to provide a solid-state imaging device whose
size is reduced.
[0013] It is a second object of the present invention to provide a
camera module whose size is reduced.
[0014] It is a third object of the present invention to provide a
camera-module producing method in which an aligning operation is
unnecessary at the time of assembling a solid-state imaging device
and an optical unit.
[0015] In order to achieve the above and other objects, the
solid-state imaging device according to the present invention
comprises light-receiving elements formed on a first surface of a
semiconductor substrate. A translucent member covers only the
light-receiving elements so as to expose the other area of the
semiconductor substrate except the light-receiving elements. An
external connection terminal is formed on a second surface of the
semiconductor substrate, which is opposite to the first surface
thereof. A wiring member electrically connects the light-receiving
element and the external connection terminal.
[0016] A planar accuracy of the semiconductor substrate is
extremely high. Thus, when the semiconductor substrate of the
solid-state imaging device is exposed, it is possible to utilize
the first surface of the semiconductor substrate as an assembly
reference plane at the time of combining the solid-state imaging
device and the optical unit during manufacture of a camera
module.
[0017] The optical unit is directly attached to the first surface
of the semiconductor substrate. In virtue of this, there is no
factor for deteriorating assembly accuracy of the first surface and
the optical unit so that it is possible to construct the camera
module with great accuracy. Similarly, the translucent member for
covering the light-receiving element is also processed with great
accuracy and is attached to the semiconductor substrate. Therefore,
even if the optical unit is attached to the translucent member,
equivalent accuracy may be obtained in comparison with the case in
that the optical unit is attached to the semiconductor
substrate.
[0018] A circuit board provided with a circuit for driving the
solid-state imaging device is disposed between the solid-state
imaging device and the optical unit. Alternatively, the circuit
board is attached to the opposite surface of the solid-state
imaging device on which the light-receiving element is not formed.
It is possible to properly select the attachment position of the
circuit board in accordance with forms and assembly positions of
the solid-state imaging device and the camera module. Further, the
circuit board may be folded so as to be disposed under the
solid-state imaging device. In this case, a project area is reduced
on a plane perpendicular to a photographic optical axis of the
optical unit. By the way, instead of the circuit board, electronic
components may be directly mounted on the solid-state imaging
device.
[0019] For attaching the solid-state imaging device to the optical
unit, are executed the steps of obtaining image data by imaging the
solid-state imaging device with an electronic camera, determining a
reference position of the solid-state imaging device from the image
data, carrying out positioning on a plane perpendicular to the
photographic optical axis so as to make the reference position of
the solid-state imaging device coincide with a predetermined
reference position of the optical unit, and fixing the solid-state
imaging device to the optical unit. It is possible to accurately
assemble the camera module without using an output image of the
solid-state imaging device such as performed in the conventional
way.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above objects and advantages of the present invention
will become apparent from the following detailed description of the
preferred embodiments of the invention when read in conjunction
with the accompanying drawings, in which:
[0021] FIG. 1 is a perspective view showing a camera module of a
first embodiment according to the present invention;
[0022] FIG. 2 is an exploded perspective view showing the camera
module of the first embodiment;
[0023] FIG. 3 is a partial section view showing the camera module
of the first embodiment;
[0024] FIG. 4 is a plan view of a solid-state imaging device used
in the first embodiment;
[0025] FIG. 5 is a partial section view showing a state in that FPC
is bent in the camera module of the first embodiment;
[0026] FIG. 6 is a flowchart showing a procedure for manufacturing
the camera module of the first embodiment;
[0027] FIG. 7 is an explanatory illustration showing a state in
that a reference position of the solid-state imaging device is
determined during the procedure for manufacturing the camera module
of the first embodiment;
[0028] FIG. 8 is an explanatory illustration showing a state in
that the solid-state imaging device is positioned and adhesive is
applied during the procedure for manufacturing the camera
module;
[0029] FIG. 9 is an explanatory illustration showing a state in
that the solid-state imaging device is attached to an optical unit
during the procedure for manufacturing the camera module;
[0030] FIG. 10 is partial section view showing a camera module of a
second embodiment according to the present invention;
[0031] FIG. 11 is a partial section view showing a camera module of
a third embodiment according to the present invention;
[0032] FIG. 12 is a partial section view showing a solid-state
imaging device used in the camera module of the third
embodiment;
[0033] FIG. 13 is a partial section view showing another
solid-state imaging device used in the camera module of the third
embodiment;
[0034] FIG. 14 is a partial section view showing a solid-state
imaging device used in a camera module of a fourth embodiment
according to the present invention;
[0035] FIG. 15 is a partial section view showing the camera module
of the fourth embodiment; and
[0036] FIG. 16 is a partial section view showing a camera module of
a fifth embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0037] FIG. 1 is a perspective view of a camera module according to
the present invention, and FIG. 2 is an exploded perspective view
thereof. FIG. 3 is a section view of a line A-B-C shown in FIG. 1.
In FIG. 3, a left side of a photographic optical axis E is a
section view in an X-direction, and a right side thereof is a
section view in a Y-direction. A camera module 2 comprises an
optical unit 4 containing an imaging lens 3, a solid-state imaging
device 5 disposed behind a photographic optical axis E of the
optical unit 4, and a flexible printed circuit board (FPC) 6
attached to the solid-state imaging device 5 between the optical
unit 4 and the solid-state imaging device 5. Incidentally, although
illustration is omitted in FIG. 1 for the purpose of avoiding
complication, sealing is performed by plastic 7 between the optical
unit 4 and the FPC 6 and between the solid-state imaging device 5
and the FPC 6.
[0038] The solid-state imaging device 5 employs a CCD, for
instance. The solid-state imaging device 5 has a CSP structure
without using a package, and light-receiving elements 9 are
provided on a semiconductor substrate 8 having a rectangular shape.
A frame-shaped spacer 10 is attached to a surface of the
semiconductor substrate 8, on which the light-receiving elements 9
are formed, by an adhesive or the like so as to surround the
light-receiving elements 9. On the spacer 10, a cover glass 11 is
disposed. The cover glass 11 is a translucent member for covering
the light-receiving elements 9.
[0039] FIG. 4 is a plan view of the solid-state imaging device 5.
Such as shown in FIG. 4, pair of edge portions oppositely arranged
on the upper surface of the semiconductor substrate 8 are terminal
areas 13 to be externally connected. Within the respective areas
13, are provided external connection terminals 14 for electrically
connecting the solid-state imaging device 5 and the FPC 6. The
external connection terminal 14 is provided with an Au bump and so
forth to mount the solid-state imaging device 5 on the FPC 6 in
Flip Chip (FC) mounting.
[0040] Another pair of edge portions, which are perpendicular to
the terminal area 13, are terminal non-forming areas 16 wherein
there is no terminal to be externally connected. There is nothing
on a surface 16a of the terminal non-forming area 16 so that the
surface 16a has accurate flatness of the time when the
semiconductor substrate 8 has been divided from a wafer. Thus, the
surface 16a of the terminal non-forming area 16 may be used as a
reference plane for assembly, without additional processing, when
the optical unit 4 and the solid-state imaging device 5 are
combined.
[0041] The optical unit 4 comprises a lens holder 18 and the
imaging lens 3 contained therein. The lens holder 18 is made from a
plastic, for example. A cylindrical lens barrel 18a for containing
the imaging lens 3 is integrally formed with a rectangular base 18b
located at a lower end of the lens barrel 18a. A lower surface of
the base 18b is formed with a pair of rectangular protrusions 19 to
be fixed to the reference surfaces 16a of the solid-state imaging
device 5 by an adhesive or the like.
[0042] The FPC 6 has a rectangular form. The solid-state imaging
device 5 is placed at one side of the FPC 6, and the other side of
which, an IC 22 for driving the solid-state imaging device 5 is
mounted. The IC 22 works as an analog front end circuit wherein H
driver (V driver), CDS, AGC, ADC and so forth are incorporated into
a single chip, for example. The side of the FPC 6 to which the
solid-state imaging device 5 is fixed is formed with an opening 23
having a size for exposing both of the cover glass 11 of the
solid-state imaging device 5 and the terminal non-forming areas
16a. The opening 23 is provided with a pair of opposite edge
portions 23a. A lower surface of the edge portion 23a is formed
with electrodes 24 to be connected to the external connection
terminals 14 of the solid-state imaging device 5.
[0043] The FPC 6 is disposed between the optical unit 4 and the
solid-state imaging device 5, but is not caught between them.
Therefore, a thickness of the FPC 6 and thicknesses of the IC 22
and so forth attached to the FPC 6 do not affect a measure of the
optical unit 4 and the solid-state imaging device 5 in a direction
of the optical axis E. Incidentally, such as shown in FIG. 5, when
the FPC 6 is bent so as to dispose the IC 22 under the solid-state
imaging device 5, it is possible to extremely reduce a project area
on a perpendicular plane to the direction of the optical axis E
even though a measure of the camera module 2 increases by a little
in the direction of the optical axis E. As to the circuit board,
the FPC is not exclusive. Plate-shaped boards of a popular
glass-epoxy board, a ceramic board and so forth may be used. The
plate-shaped board may be constituted of a plurality of board
members connected by jumper cables, and the board member may be
disposed under the solid-state imaging device 5 by bending the
jumper cable.
[0044] The camera module described in the above is manufactured
along a procedure of a flowchart shown in FIG. 6. First of all, the
FPC 6 is put from the upside of the solid-state imaging device 5 at
the first step. The cover glass 11 of the solid-state imaging
device 5 and the terminal non-forming areas 16 are exposed through
the opening 23 of the FPC 6. At this time, the external connection
terminal 14 of the solid-state imaging device 5 overlaps with the
electrode 24 so as to be electrically connected. In this way, the
solid-state imaging device 5 is FC-mounted on the FPC 6.
[0045] The optical unit 4 and the solid-state imaging device 5 are
set to an assembly apparatus for positioning and combining them. At
the next second step, a reference position of the solid-state
imaging device 5 is determined in the assembly apparatus. The
reference position is a center position of a light-receiving area
of the light-receiving elements 9, for example.
[0046] As shown in FIG. 7, the solid-state imaging device 5 mounted
on the FPC 6 is positioned and retained on an XYZ table 27, which
is movable in directions of X-axis, Y-axis and Z-axis. In the
drawing, the X-axis direction is a right-and-left direction, and
the Z-axis direction is an up-and-down direction. The Y-axis
direction is perpendicular to the X-axis direction. A well-known
electronic camera 28 of a TV camera, a digital camera and so forth
images the surface of the solid-state imaging device 5 on which the
light-receiving elements 9 are provided. Image data outputted from
the electronic camera 28 is inputted into an image processor 29
comprising a computer and so forth, and is processed to calculate
the center position of the light-receiving area of the
light-receiving elements 9. The calculated center position of the
light-receiving elements 9 is inputted into a system controller 30
for controlling the assembly apparatus.
[0047] As shown in FIG. 8, at the next third step, the system
controller 30 controls a well-known table moving mechanism 33,
which comprises a ball thread, a motor and so forth, to move the
XYZ table 27. Positioning is performed so as to make the center
position of the light-receiving area of the light-receiving
elements 9 coincide with the photographic optical axis E of the
imaging lens 3 of the optical unit 4 in the Z-axis direction.
[0048] When the optical unit 4 is manufactured, the photographic
optical axis E of the imaging lens 3 is determined, and the imaging
lens 3 is fitted into the lens barrel 18a so as to set the
photographic optical axis E to a predetermined position relative to
an outer shape of the lens holder 18. In virtue of this, by
retaining the lens holder 18 at a predetermined position with a
positioning member 34, the position of the photographic axis E may
be defined inside the assembly apparatus.
[0049] At the next fourth step, the solid-state imaging device 5 is
attached to the optical unit 4. Dispensers 36 for the adhesive are
disposed near the stop position of the stationed solid-state
imaging device 5. The dispenser 36 supplies and applies the
adhesive to the assembly reference surface 16a of the solid-state
imaging device 5.
[0050] After applying the adhesive, the table moving mechanism 33
is actuated to move the solid-state imaging device 5 in the Z-axis
direction so that the assembly reference surface 16a abuts on the
protrusion 19 such as shown in FIG. 9. The adhesive hardens after a
prescribed period to fasten the solid-state imaging device 5 to the
optical unit 4. At the next fifth step, plastic sealing is carried
out by injecting the melted plastic 7 between the optical unit 4
and the FPC 6, and further between the solid-state imaging device 5
and the FPC 6.
[0051] By the way, the adhesive may be applied to the protrusion 19
of the optical unit 4 in advance before setting the optical unit 4
and the solid-state imaging device 5 to the assembly apparatus. In
another way, the adhesive may be applied to a joint portion of the
optical unit 4 and the solid-state imaging device 5 after
positioning and combining them.
[0052] As described above, assembling is carried out so as to make
the photographic optical axis E of the imaging lens 3 coincide with
the center of the light-receiving elements of the solid-state
imaging device 5. Thus, deterioration of a light amount and
resolution, shading to be caused by unevenness of sensitivity, and
so forth are prevented from occurring. Moreover, since the assembly
reference surface 16a of the terminal non-forming area 16 of the
solid-state imaging device 5 has the accurate flatness, the
solid-state imaging device 5 is prevented from being attached to
the optical unit 4 in a slant state. Further, it is unnecessary to
perform an aligning operation in that positional adjustment is
carried out while confirming an output picture of the solid-state
imaging device 5. Thus, it is possible to extremely decrease
manufacture time and the cost of the camera module 2.
[0053] Another embodiment of the solid-state imaging device and the
camera module is described below. The respective section views of
the solid-state imaging device used in the following description
are taken along the X-direction shown in FIG. 1. With respect to
the respective section views of the camera module, a left side of
the photographic optical axis E is a section view in the
X-direction, and a right side thereof is a section view in the
Y-direction. By the way, a component being identical with that of
the above-described embodiment is denoted by the same reference
numeral, and description thereof is abbreviated.
[0054] FIG. 10 shows an embodiment wherein a camera module 43
employs a solid-state imaging device 41 of a bare-chip state in
that a light-receiving element 40 is not covered with a cover
glass. With respect to this solid-state imaging device 41, a
semiconductor substrate 42 has a broader upper surface to be used
for assembly with an optical unit 44. Thus, it is possible to
combine the solid-state imaging device 41 and the optical unit 44
with great accuracy. Incidentally, a cover glass 45 for covering
the light-receiving element 40 may be contained in the optical unit
44 for the purpose of protecting the light-receiving element
40.
[0055] In the above embodiments, the FPC 6 is disposed between the
solid-state imaging device and the optical unit. However, such as
shown in FIG. 11, an FPC 48 may be attached to a lower surface of a
solid-state imaging device 47. By doing so, the whole upper surface
of the solid-state imaging device 47 may be used for attachment to
an optical unit 57. Further, in this case, it is possible to reduce
a size of a camera module in the direction of the photographic
optical axis E by mounting the IC 56 on an upper surface of the FPC
48.
[0056] In this embodiment, it is preferable to form an external
connection terminal 49 in a lower surface of a semiconductor
substrate 50 of the solid-state imaging device 47 for the purpose
of electrically connecting the solid-state imaging device 47 and
the FPC 48 in an easy manner. In order to connect a light-receiving
element 52 to the external connection terminal 49 of the lower
surface, a through wiring 54 may be used such as illustrated in
FIG. 12 showing a section view of the solid-state imaging device
47. The through wiring 54 is formed such that conductive paste is
loaded in a through hole formed under an external connection
terminal 53 of the upper surface of the semiconductor substrate 50.
The external connection terminal 49 comprising an Au bump is formed
under the through wiring 54 so that the light-receiving element 52
and the external connection terminal 49 are electrically
connected.
[0057] Alternatively, as illustrated in FIG. 13 showing a section
view of a solid-state imaging device 60, a surface wiring may be
formed on a side surface of a semiconductor substrate 61 instead of
the through wiring. The surface wiring connects external connection
terminals 62 and 63 of an upper surface and a lower surface.
[0058] In the forgoing embodiments, the analog front end IC 22 is
mounted on the FPC. However, such as shown in FIG. 14, an IC 69 may
be mounted on a lower surface of a semiconductor substrate 68 of a
solid-state imaging device 67. In other words, the IC 69 being as
an electronic component may be mounted on the other surface of the
semiconductor substrate opposite to the surface on which the
light-receiving element is formed. In this case, such as shown in
FIG. 15, a project area of a camera module 73 including an optical
unit 71 and an FPC 72 may be extremely reduced on a plane being
perpendicular to the photographic optical axis E. Moreover, a
wiring distance between a light-receiving element 75 and the IC 69
becomes shorter by adopting a through wiring 74 so that it is
possible to fasten an operation of the solid-state imaging device
67. Incidentally, also in this embodiment, a surface wiring formed
on a side surface of the semiconductor substrate 68 may be used
instead of the through wiring.
[0059] In the forgoing embodiments, the assembly reference surface
is provided within the terminal non-forming area of the solid-state
imaging device to attach the optical unit. However, such as shown
in FIG. 16, an optical unit 80 may be attached to a cover glass 79
fixed to a semiconductor substrate 78 of a solid-state imaging
device 77. The cover glass 79 for the solid-state imaging device 77
having the CSP structure keeps flatness being identical with that
of a wafer, which is a base of the semiconductor substrate 78. When
the cover glass 79 is fixed to the semiconductor substrate 78, an
upper surface (assembly reference surface) of the semiconductor
substrate 78 is utilized as a reference plane so that the cover
glass 79 is prevented from being slantingly fixed. Thus, it is
possible to attach the optical unit 80 to the solid-state imaging
device 77 with equal accuracy in comparison with the case in that
the optical unit is attached to the semiconductor substrate.
[0060] In the first embodiment, the optical unit 4 is manufactured
so as to set the photographic optical axis E of the imaging lens 3
to the predetermined position. However, in accordance with a result
of determining the photographic optical axis E of the imaging lens
3, the solid-state imaging device 5 may be positioned when the
solid-state imaging device 5 is attached to the optical unit 4.
[0061] In the forgoing embodiments, the description is made under
the specific combinations regarding the position of the external
connection terminal, the wiring manner between the light-receiving
element and the external connection terminal, the attachment
position of the FPC relative to the solid-state imaging device, the
arrangements of the FPC in the flat state and in the bending state,
the attachment position of the IC, the attachment position of the
optical unit relative to the solid-state imaging device, the
procedure for manufacturing the solid-state imaging device and the
optical unit, and so forth. However, these combinations are not
limited to the above embodiments of the present invention. It is
possible to adopt proper combinations in accordance with usage
manners and so forth of the solid-state imaging device and the
camera module.
[0062] Further, the solid-state imaging device employed in the
camera module of the respective forgoing embodiments may be used,
as it is, in various electronic equipment of a digital camera and
so forth. The present invention is not limited to the camera
module, and may be also utilized for manufacturing the other
optical units.
[0063] Although the present invention has been fully described by
way of the preferred embodiments thereof with reference to the
accompanying drawings, various changes and modifications will be
apparent to those having skill in this field. Therefore, unless
otherwise these changes and modifications depart from the scope of
the present invention, they should be construed as included
therein.
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