JP4187481B2 - Solid-state image device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid-state imaging device using a solid-state imaging device.
[0002]
[Prior art]
In this type of conventional apparatus, a solid-state imaging device is electrically connected to the surface of a hard camera circuit board. A lens assembly that holds a lens or the like is disposed at a position where the solid-state image sensor can capture an image. Peripheral circuit elements such as an image processing element of a solid-state image sensor are mounted on the back surface of the camera circuit board. A drive circuit for driving the solid-state imaging device is formed on the camera circuit board, and the circuit patterns on the front surface and the back surface are electrically connected through the through holes. A flexible printed circuit board (FPC) is used to electrically connect the circuit pattern to the circuit on the main body side, and a connection terminal for electrically connecting the FPC is provided on the back surface of the end portion of the circuit board for the camera. The FPC is bent and used, and since the electrical connection between the camera circuit board and the FPC is easily peeled off or the FPC circuit pattern is easily disconnected, the FPC is attached to the hard camera circuit board. It has been considered that a solid-state imaging device or the like is directly mounted on the FPC so that it is not necessary to electrically connect the two.
[0003]
An example thereof is shown in FIGS. 3 and 4, in which an opening 10 a is provided in the FPC 10, and the opening 10 a is disposed between the imaging surface 20 a and the lens assembly 30 on the back side of the FPC 10. The solid-state imaging device 20 is mounted via a bump electrode 20b that electrically connects the FPC 20 and the FPC 10. A lens assembly 30 is arranged on the front side of the FPC 10 so that a subject image is formed on the imaging surface 20a. Here, since the FPC 10 is a soft material and bends in a state where the solid-state imaging device 20 is mounted, the lens assembly 30 cannot be fixed to the FPC 10 as it is, and is at a position on the FPC 10 where the lens assembly 30 is fixed. It is necessary to interpose a rigid reinforcing plate 40 for improving the rigidity of the FPC 10.
[0004]
[Problems to be solved by the invention]
In such a conventional configuration, since it is necessary to provide the hard reinforcing plate 40 on the FPC 10, there is a limit to miniaturization by the thickness of the reinforcing plate 40. In addition, since the reinforcing plate 40 is used, the number of parts is increased, and the number of manufacturing steps is increased, resulting in complicated manufacturing operations.
[0005]
Therefore, the present invention provides a thin solid-state imaging device by preventing the FPC from being bent at the mounting portion of the lens assembly without using a reinforcing plate.
[0006]
[Means for Solving the Problems]
The solid-state imaging device of the present invention includes a solid-state imaging device and a lens assembly that holds a lens for forming a subject image on the solid-state imaging device. The lens assembly is disposed such that an end surface thereof is in contact with one surface of the flexible printed circuit board, and the solid-state image sensor is disposed between the solid-state image sensor and the lens assembly. It arrange | positions at the other surface of the said flexible printed circuit board so that the opening provided in may be located. Between the solid-state imaging device and the flexible printed circuit board, a reinforcing bump electrode that mechanically connects the two is provided at a position facing the end surface of the lens assembly . According to such a configuration, since the reinforcing bump electrode for mechanically connecting the solid-state imaging device and the flexible printed circuit board is provided on the other surface of the flexible printed circuit board, a reinforcing plate is not used as in the past. In addition, it is possible to prevent the flexible printed circuit board from being bent at the mounting portion of the lens assembly, and to provide a thin solid-state imaging device.
[0007]
Further, since the end face is rectangular and the reinforcing bump electrode is provided corresponding to each corner of the end face, by providing the reinforcing bump electrode only at a position corresponding to each corner, It is possible to efficiently prevent the flexible printed circuit board from being bent at the mounting portion of the lens assembly.
[0008]
Further, since the reinforcing bump electrodes are arranged along the circumferential direction of the end face so as to correspond to the end face and the entire circumference thereof, the flexible printed circuit board at the mounting portion of the lens assembly Can be reliably and efficiently prevented.
[0009]
In addition, between the solid-state imaging device and the flexible printed circuit board, a connection bump electrode that electrically connects the two is along the circumferential direction of the end face so as to correspond to the end face and the entire circumference thereof. Since the reinforcing bump electrodes are provided between the connecting bump electrodes, in addition to the reinforcing bump electrodes, for electrical connection between the solid-state imaging device and the flexible printed circuit board. With this connection bump electrode, it is possible to more reliably and efficiently prevent the flexible printed circuit board from being bent at the mounting portion of the lens assembly.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0011]
As shown in FIG. 1, a flexible printed circuit board 1 is used as a camera circuit board. An opening 1 a is formed in a flexible printed circuit board (hereinafter referred to as FPC) 1. The solid-state imaging device 2 having the imaging surface 2a formed on the front surface is mounted on the back side of the FPC 1 so that the opening 1a is disposed between the imaging surface 2a and a lens assembly 3 described later. The lens assembly 3 is arranged at a position where a subject image can be formed on the image pickup surface 2a of the solid-state image pickup device 2 on the surface side across the surface.
[0012]
The lens assembly 3 is formed by fitting the first lens barrel 31 to the second lens barrel 32, and an optical member such as a lens 4 is held in the first lens barrel 31. A filter 5 is attached in the second lens barrel 32. The lens assembly 3 is fixed by bonding or the like such that the rectangular end surface 3a of the second lens barrel 32 is brought into contact with the surface of the FPC 1 around the opening 1a. The first lens barrel 31 is provided so as to be able to advance and retreat toward the solid-state imaging device 2 with respect to the second lens barrel 32. The lens 4 and the filter 5 are adjusted by adjusting the distance between the lens 4 and the imaging surface 2a. Focusing is enabled so that a subject image is formed on the imaging surface 2a of the solid-state imaging device 2 by the light that has passed. The shape of the end surface 3a is not limited to a quadrangle, and may be a polygon or a circle, for example.
[0013]
A circuit pattern (not shown) for signal transmission such as the solid-state imaging device 2 is formed on the FPC 1, and the solid-state imaging device 2 is mounted on the circuit pattern by a flip chip method. Here, as shown in FIG. 2, between the solid-state imaging device 2 and the FPC 1, the connection bump electrodes 6 that electrically connect the two correspond to each side of the end surface 3 a of the lens assembly 3. Are arranged in line. That is, the connection bump electrodes 6 are arranged along the circumferential direction of the end surface 3a so that the FPC 1 is sandwiched between the connection bump electrode 6 and the end surface 3a.
[0014]
Further, between the solid-state image pickup device 2 and the FPC 1, a dedicated reinforcing bump electrode 7 is provided between the solid-state image pickup device 2 and the FPC 1, which is mechanically connected to each other, that is, to reinforce the fixation of both. It is provided at each corner between the connecting bump electrodes 6 and 6 so as to correspond to each corner of 3a. That is, the reinforcing bump electrode 7 is provided so that the FPC 1 is sandwiched between the reinforcing bump electrode 7 and the end face 3a.
[0015]
When assembling the solid-state imaging device, an opening 1a is formed in the FPC 1, the lens assembly 3 is located on the front surface side of the FPC 1, and the rear surface of the FPC 1 is opposed to the end surface 3a of the lens assembly 3 with the opening 1a as the center. Further, the solid-state imaging device 2 formed by aligning the connecting bump electrode 6 and the reinforcing bump electrode 7 and aligned so that the imaging surface 2a faces the opening 1a is interposed through the bump electrodes 6 and 7. When mounted on the FPC 1, the solid-state imaging device of the present invention is completed.
[0016]
In the solid-state imaging device assembled in this way, the FPC 1 and the solid-state imaging device 2 are mechanically connected to the back surface of the FPC 1 so as to correspond to the end surface 3a of the lens assembly 3 that is in contact with the front surface of the FPC 1. Since the reinforcing bump electrode 7 is provided, the FPC 1 is sandwiched between the reinforcing bump electrode 7 and the end surface 3a, and the FPC 1 is not bent at the mounting position of the lens assembly 3. Therefore, the solid-state image pickup device 2 is not peeled off or the circuit pattern of the FPC 1 is disconnected at this mounting position, and the quality of the solid-state image pickup device is stabilized. Furthermore, the tilt of the lens assembly 3 and the image sensor 2 can be prevented, and the mechanical connection strength between the solid-state image sensor and the FPC 1 can be improved.
[0017]
Further, the reinforcing bump electrode 7 can be provided at the same time as the connecting bump electrode 6 in the manufacturing process of the connecting bump electrode 6, and the manufacturing process is not complicated.
[0018]
Further, the shape of the end face 3a of the lens assembly 3 is a quadrangle, and the reinforcing bump electrode 7 is provided corresponding to each corner of the end face 3a, so that the reinforcing bump electrode 7 corresponds to the corner. By providing only at the position, it is possible to prevent the deflection of the FPC 1 at the mounting portion of the lens assembly 3 with high efficiency.
[0019]
Further, in addition to the reinforcing bump electrode 7, a connection bump electrode 6 for electrical connection between the circuit pattern of the FPC 1 and the solid-state imaging device 2 is also formed on the end surface 3a so as to correspond to the entire end surface 3a. Since they are arranged along the circumferential direction, the connecting bump electrode 6 and the reinforcing bump electrode 7 can more reliably and efficiently prevent the bending of the FPC 1 at the mounting portion of the lens assembly 3.
[0020]
In this embodiment, the connection bump electrode 6 is provided corresponding to each side of the end surface 3a of the lens assembly 3, but the arrangement position of the connection bump electrode 6 is not limited to this and can be changed as appropriate. It is.
[0021]
In this embodiment, the reinforcing bump electrode 7 is provided at the corner between the connecting bump electrodes 6 and 6 arranged vertically and horizontally along the circumferential direction of the end face 3a so as to face the end face 3a. However, the present invention is not limited to the corner portion, and may be provided between any of the adjacent connection bump electrodes 6 and 6.
[0022]
【The invention's effect】
In the present invention, the lens assembly is disposed with its end face in contact with one side of the FPC, and a reinforcing bump electrode for mechanically connecting the FPC and the solid-state imaging device is provided on the other side of the FPC. Therefore, it is possible to prevent bending of the FPC at the mounting portion of the lens assembly without using a reinforcing plate, and to provide a thin solid-state imaging device. Further, the tilt of the lens assembly can be prevented and the mechanical connection strength between the solid-state imaging device and the FPC can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a cross-sectional view showing a conventional configuration.
4 is a plan view of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flexible printed circuit board 1a Opening 2 Solid-state image sensor 3 Lens assembly 3a End surface 6 Bump electrode for connection 7 Bump electrode for reinforcement (reinforcement member)

Claims (4)

A solid-state image sensor, and a lens assembly that holds a lens for forming a subject image on the solid-state image sensor;
The lens assembly is disposed with its end face in contact with one surface of the flexible printed circuit board,
The solid-state image sensor is disposed on the other surface of the flexible printed circuit board so that an opening provided in the flexible printed circuit board is positioned between the solid-state image sensor and the lens assembly.
Between the solid-state imaging device and the flexible printed circuit board, a reinforcing bump electrode that mechanically connects both is provided at a position facing the end surface of the lens assembly. apparatus.   The solid-state imaging device according to claim 1, wherein the end surface has a rectangular shape, and the reinforcing bump electrode is provided corresponding to each corner of the end surface.   2. The solid-state imaging device according to claim 1, wherein the reinforcing bump electrodes are arranged along the circumferential direction of the end face so as to correspond to the end face and the entire circumference thereof.   4. The bump electrode for connection for electrically connecting the solid-state imaging device and the flexible printed circuit board according to any one of claims 1 to 3 so as to correspond to the end surface and the entire circumference thereof. The solid-state imaging device is characterized in that the reinforcing bump electrodes are arranged between the connection bump electrodes.

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