JP2011199511A - Solid-state imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable solid-state imaging device that prevents the occurrence of peeling in an bonding and joining part, even in high density mounting.SOLUTION: The solid-state imaging device includes: a first substrate 100 which constitutes a lens holder to which a lens is fixed; and a second substrate 200 which includes a connection R2 to be mechanically connected with the first substrate 100 and a substrate mount R1 which mounts a stereoscopic circuit forming substrate to which a solid-state image sensor 502 is mounted; wherein the second substrate 200 is constituted by connecting the connection R2 with the substrate mount R1 via a flexible wiring part. By this configuration, the flexible wiring part R3 acts as a shock absorbing material, it is prevented that external force to be generated in mechanical connection is transmitted to the substrate mount R1, and the substrate mount R1 is certainly supported.

Description

  The present invention relates to a solid-state imaging device, and more particularly to a small-sized solid-state imaging device formed using a solid-state imaging device such as a surveillance camera, a medical camera, an in-vehicle camera, and an information communication terminal camera.

  In recent years, the demand for small cameras for mobile phones, in-vehicle components, etc. has been rapidly increasing. This type of small camera uses a solid-state imaging device that outputs an image input as an electrical signal by an optical system such as a lens by a solid-state imaging device. With the downsizing and high performance of this image pickup apparatus, the camera has become smaller and the use in various fields has increased, expanding the market as a video input apparatus. In a conventional image pickup apparatus using a semiconductor image pickup device, components such as an LSI on which a lens, a semiconductor image pickup device, a driving circuit thereof, a signal processing circuit, and the like are mounted are respectively formed in a housing or a structure and combined.

  The mounting structure by such a combination is formed by mounting each element on a printed circuit board on a flat plate. However, the demand for further thinning of individual devices is increasing year by year due to the demand for further thinning of cellular phones and the like. In order to meet this demand, attempts have been made to obtain a thinner imaging device by using a flexible wiring board or by directly mounting an IC on a translucent member by flip-chip mounting.

  For example, Patent Document 1 proposes an image sensor mounted on a flexible wiring board. In the structure of Patent Document 1, the flexible wiring board on which the imaging element is mounted is sandwiched between the optical element holding part and the main holding member.

JP 2005-72736 A

However, in the solid-state imaging device disclosed in Patent Document 1, it is necessary to mount a lens unit. However, in the above configuration, there is a problem in that it is difficult to adjust the optical axis and the strength of the device itself cannot be secured. It was.
In particular, the increase in the number of parts accompanying an increase in function and the high-density mounting accompanying the miniaturization have a limit in the number of board layers when trying to cope with only a flexible wiring board.
Further, when the flexible substrate is mounted on the camera body, it is easy to fasten the screw. However, when the screw is to be fastened to the camera body, there is a problem that an external force is applied to the bonding / joining portion and peeling easily occurs.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solid-state imaging device with high reliability without causing separation at an adhesive / joint portion even in high-density mounting.

A solid-state imaging device according to the present invention includes a first circuit board that forms a lens holder to which a lens is fixed, a connection part that is mechanically connected to the first circuit board, and a three-dimensional circuit formation board on which a solid-state imaging device is mounted. And a second substrate having a substrate mounting portion to be mounted. The second substrate is characterized in that the connection portion and the substrate mounting portion are connected via a flexible wiring portion.
With this configuration, the flexible wiring portion acts as a cushioning material, and it is possible to prevent external force generated during mechanical connection from being transmitted to the connecting portion, and the substrate mounting portion can be reliably supported.

In the solid-state imaging device according to the present invention, the connection portion includes a first through hole that penetrates from the first surface of the second substrate to the second surface, and a screw that is inserted into the through hole. It is characterized by that.
With this configuration, mechanical connection is efficiently performed by screwing, but it is possible to prevent external force generated during mechanical connection from being transmitted to the bonding / joining portion, and to reliably support the board mounting portion. .

In the solid-state imaging device according to the present invention, the flexible wiring portion has a frame shape.
With this configuration, since the connection portion is completely separated from the substrate mounting portion, the substrate mounting portion can be reliably protected from external force by the frame-shaped flexible wiring portion.

According to the present invention, in the solid-state imaging device, the flexible wiring portion is provided around the first through hole of the connection portion.
With this configuration, since the buffering effect is provided around the first through hole that receives a mechanical shock, the substrate mounting portion can be protected from external force while increasing the mechanical strength.

According to the present invention, in the solid-state imaging device, the substrate mounting portion of the second substrate is mounted with a third substrate on which the solid-state imaging element and the translucent member are mounted.
With this configuration, the optical axes of the solid-state imaging device and the lens can be easily aligned. Here, the lens is mounted on the first substrate constituting the lens holder.

In the solid-state imaging device according to the present invention, the first substrate is configured by a first cylindrical body, and has a second through hole that matches the first through hole at the first end. A holding portion that extends inward in the vicinity of the second end, and the holding portion includes a first flat portion for mounting the lens on the outer surface and a third substrate on the inner surface. A second flat part to be supported is provided.
With this configuration, it is possible to provide a solid-state imaging device that is easy to position and highly reliable while maintaining mechanical strength.

According to the present invention, in the solid-state imaging device, the third substrate is configured by a second cylindrical body housed in the first cylindrical body, and the first end portion is on the second substrate. A second flat surface portion is mounted and extends inward in the vicinity of the second end portion, and has a first flat surface portion for mounting the translucent member on the outer surface, and supports the solid-state imaging device on the inner surface. It has a flat surface portion and a protruding portion.
With this configuration, it is possible to provide a solid-state imaging device that is easy to position and highly reliable while maintaining mechanical strength.

In the solid-state imaging device according to the present invention, the third substrate is supported by a cylindrical body that protrudes from the holding portion toward the third substrate.
With this configuration, it is possible to provide a solid-state imaging device that is smaller, has high mechanical strength, and is highly reliable.

Thus, by using the solid-state imaging device of the present invention, it is possible to cope with high-density mounting. Moreover, since the external force generated at the time of screwing is not transmitted to the bonding / connecting portion, high reliability can be realized.
Furthermore, since it is directly screwed to the cover member to which the lens is fixed, the optical axis can be easily adjusted, the strength of the apparatus can be ensured, and the electrical terminal for the automatic focusing mechanism can be connected. . As a result, an excellent solid-state imaging device capable of easily manufacturing a small and thin solid-state imaging device can be provided.

Sectional drawing of the solid-state imaging device of Embodiment 1 The principal part expanded sectional view of the solid-state imaging device of Embodiment 1 Top view of the solid-state imaging device according to Embodiment 1 Upper surface explanatory drawing of the solid-state imaging device of Embodiment 2 Sectional drawing of the solid-state imaging device of Embodiment 3

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
A solid-state imaging device according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of the solid-state imaging device according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of the main part of the second substrate, and FIG. 3 is a top view of the second substrate.
In this solid-state imaging device, a first substrate 100 constituting a lens holder to which a lens is fixed and a second substrate 200 on which a solid-state imaging element 502 is mounted are mechanically connected. The second substrate 200 has a stress absorbing portion made of a flexible wiring portion R3. That is, the second substrate 200 having a multilayer wiring structure is characterized in that the substrate mounting portion R1 is connected to the connection portion R2 via the frame-like flexible wiring portion R3 as shown in the plan view of FIG. And The connecting portion R2 is mechanically connected to the first substrate 100 by a screw 300. The board mounting portion R1 is an area for mounting the third board 500, which is a three-dimensional circuit forming board on which the solid-state image sensor 502 is mounted. The first substrate 100 and the third substrate 500 are configured by resinous three-dimensional wiring substrates, and the second substrate 200 is configured by a multilayer wiring substrate.

Here, in the second substrate 200, the substrate mounting portion R1 and the connection portion R2 are formed of a rigid substrate. This rigid substrate has six wiring conductor layers 220. Between the wiring conductor layers 220, a polyimide film 230 and a prepreg 240 are formed and have rigidity. The flexible wiring portion R3 is composed of two wiring conductor layers 220 and a polyimide film 230 that covers and covers the surfaces of the wiring conductor layers 220, and maintains flexibility.
With this configuration, the flexible wiring portion R3 acts as a cushioning material, and it is possible to prevent an external force generated during mechanical connection from being transmitted to the connection portion R2, and the substrate mounting portion R1 can be reliably supported.

The connecting portion R2 includes a first through hole 201 that penetrates from the first surface 200A of the second substrate 200 to the second surface 200B, and a screw 300 that is inserted into the first through hole 201. Is done.
With this configuration, the mechanical connection is efficiently performed by screwing, but it is possible to prevent external force generated during the mechanical connection from being transmitted to the connection portion, and it is possible to reliably support the board mounting portion.

In addition, on the substrate mounting portion R1 of the second substrate 200, a third substrate 500 made of a three-dimensional circuit substrate on which the solid-state imaging element 502 and the translucent member 503 are mounted is mounted.
Further, the first substrate 100 is configured by a first cylindrical body 130, and has a second through hole 101 that matches the first through hole 201 in the first end portion 100 </ b> A, and has a second end. A holding portion 110 extending inward in the vicinity of the portion 100B. The holding portion 110 includes a first flat portion 120A for mounting a lens on the outer surface 100o, and a third substrate on the inner surface 100i. The second flat portion 120 </ b> B that supports 500 is provided. Here, the first cylindrical body 130 is formed of a cylindrical body, but a rectangular cylindrical body such as a square cylinder may be used.

  The third substrate 500 includes a second cylindrical body 530 accommodated in the first cylindrical body 130, the first end portion 500A is mounted on the second substrate 200, and the second cylindrical body 530 is mounted. A protrusion 511 extending inward is provided near the end 500B. The projecting portion 511 includes a first flat surface portion 511B for mounting the translucent member 503 on the outer surface, and a second flat surface portion 511A for supporting the solid-state imaging device 502 on the inner surface. ing. The second cylindrical body 530 is a cylindrical body, but a square cylindrical body such as a square cylinder may be used.

  Further, the third substrate 500 is supported by a cylindrical support portion 140 protruding from the holding portion 110 toward the third substrate 500 side. Moreover, although the support part 140 is comprised with a cylindrical body, you may use square-shaped cylindrical bodies, such as a square cylinder. And when this support part 140 is comprised with a cylindrical body, it is also possible to adjust an optical axis by rotating this cylindrical body.

  As shown in FIG. 1, the three-dimensional wiring board constituting the third substrate 500 has a solid-state imaging element 502 mounted on a third substrate body 501 and insulative sealing resin (not shown). The insulating sealing resin surrounds the metal bumps (not shown) of the solid-state imaging element 502 without leaking to the imaging region, and ensures the adhesion strength.

  The third substrate 500 on which the solid-state image sensor 502 is mounted and a solder ball or the like is attached is solder-mounted on the wiring pattern of the second substrate, and the strength is reinforced by an underfill (not shown). A chip component (not shown) is solder-mounted around the third substrate 500 and connected in an electrical circuit manner.

  In this state, the first substrate 100 as a lens housing in which the lens unit 400 is installed is set on the second substrate from above. Then, the screw 300 connects the first through hole of the second substrate 200 to the second through hole of the first substrate. The first substrate 100 may be formed with a reference protrusion for fitting into the reference hole, and an electrode terminal for an automatic focus adjustment mechanism may be drawn around the surface of the reference protrusion. The reference protrusion is formed with the optical axis of the lens unit 400 as a reference.

  In this way, the first substrate 100 as the lens housing is integrated with the third substrate on which the solid-state imaging element 502 is mounted, thereby completing the solid-state imaging device. As described above, by inserting and fitting the reference protrusion into the reference hole, it is possible to simplify the optical axis adjustment of the solid-state imaging device and the lens. Further, electrical connection between the inner wall of the reference hole and the electrode terminal on the surface of the reference protrusion may be performed simultaneously.

  By adopting such a structure, the first substrate 100 constituting the lens holder is fixed to the second substrate 200, whereas the second substrate has a flexible wiring portion as a stress absorbing portion. Therefore, even when screwing, it can be firmly fixed without fear of breakage due to strain. Also, the optical axis can be adjusted easily. Furthermore, the electrode terminal of the automatic focus adjustment mechanism can be easily performed by inserting and fitting the lens casing without separately taking out and soldering.

That is, by implementing the present invention, it is possible to obtain a solid-state imaging device having favorable imaging characteristics, high strength, and high electrical connection reliability.
Note that the translucent member 503 may be an optical filter film or an antireflection film. In that case, the optical characteristics can be further improved.

  In the above embodiment, an example using a multilayer wiring board has been described. However, the present invention is not limited to a multilayer wiring board, and may be a single-layer wiring board.

Further, as the thickness of the solid-state image pickup device chip continues to be reduced, it is desirable to use a light-shielding substrate as the third substrate having a cavity portion in order to prevent light from wrapping around from the back surface. Therefore, it is desirable to use a light-shielding resin such as an epoxy resin. Further, a ceramic substrate, a glass substrate on which a light-shielding film is formed, and the like are also applicable.
As the substrate structure, an upper layer substrate having a through hole may be laminated on a lower layer substrate on which a wiring pattern is formed, and it is also effective to form a cavity part by cutting or etching.

(Embodiment 2)
FIG. 4 is a top view of the solid-state imaging device according to the second embodiment.
In the first embodiment, the flexible wiring portion is formed so as to surround the board mounting portion R1 of the second substrate. However, in the present embodiment, the flexible wiring portion R3 is the first through hole of the connecting portion R2. It is provided in the vicinity of
Since it has such a structure, the strength can be further increased.

(Embodiment 3)
FIG. 5 is a cross-sectional view of the solid-state imaging device according to the third embodiment.
In the first embodiment, the third substrate is configured by a three-dimensional circuit substrate, but the third substrate may or may not have a different shape. That is, in the present embodiment, the translucent member 503 is mounted on the back surface side of the holding unit 110 protruding inside the cylindrical portion of the first substrate 100 and the second translucent member 503 is opposed to the second translucent member 503. The solid-state image sensor 502 may be mounted directly on the substrate 200. Thereby, the third substrate 500 becomes unnecessary.
Note that both the first substrate and the third substrate can be omitted if unnecessary. Also, with respect to the second substrate, the substrate connection portion and the connection portion are made rigid by the prepreg, but may be formed of a multilayer ceramic substrate, and the stress buffering portion therebetween may be formed of a flexible wiring portion. Moreover, in order to give rigidity about a board | substrate connection part and a connection part, you may make it make copper foil with a large board thickness, and make a flexible wiring part flexible.

  The solid-state imaging device of the present invention has an effect that the manufacturing method is simple and highly accurate, and the strength of the device can be secured. As a result, a small and thin excellent solid-state imaging device can be provided, which is highly useful in industry and is a useful invention.

100 First substrate 110 Holding portion 120A First flat portion 120B Second flat portion 130 Cylindrical body 140 Support portion 200 Second substrate 300 Screw 400 Lens unit 500 Third substrate 500A First end portion 500B First Two end portions 501 Third substrate body 502 Solid-state imaging device 503 Translucent member 511A Second flat surface portion 511B First flat surface portion 530 Second cylindrical body R1 Substrate mounting portion R2 Connection portion R3 Flexible wiring portion

Claims (8)

A first substrate constituting a lens holder to which the lens is fixed;
A substrate mounting portion for mounting a three-dimensional circuit forming substrate mounted with a solid-state imaging device; and a second substrate having a connection portion mechanically connected to the first substrate;
The second substrate is a solid-state imaging device in which the connection portion and the substrate mounting portion are connected via a flexible wiring portion. The solid-state imaging device according to claim 1,
The connection portion includes a first through hole penetrating from the first surface of the second substrate to the second surface;
A solid-state imaging device comprising a screw inserted into the through hole. The solid-state imaging device according to claim 1 or 2,
The flexible wiring section is a solid-state imaging device having a frame shape. The solid-state imaging device according to claim 1 or 2,
The flexible wiring portion is a solid-state imaging device provided around the first through hole of the connection portion. The solid-state imaging device according to claim 1,
A solid-state imaging device in which a third substrate on which a solid-state imaging element and a translucent member are mounted is mounted on the substrate mounting portion of the second substrate. The solid-state imaging device according to claim 5,
The first substrate is composed of a first cylindrical body,
Having a second through hole at the first end that matches the first through hole;
A holding portion extending inwardly in the vicinity of the second end;
The holding unit includes a first flat part for mounting a lens on an outer surface and a second flat part for supporting the third substrate on an inner surface. The solid-state imaging device according to claim 6,
The third substrate is composed of a second cylindrical body housed in the first cylindrical body,
A first end is mounted on the second substrate;
A first flat surface portion extending inward in the vicinity of the second end portion and mounting a translucent member on the outer surface;
A solid-state image pickup device including a protruding portion having a second flat surface portion that supports the solid-state image pickup element on an inner surface. The solid-state imaging device according to claim 7,
The solid-state imaging device, wherein the third substrate is positioned via a cylindrical support portion that protrudes from the holding portion toward the third substrate.

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