JP3083006U - Solid-state imaging device - Google Patents

Abstract

(57) [Problem] To provide a structure that can be assembled without using an adhesive so that an optical component is not adversely affected when an optical component such as a solid-state imaging device or a converging lens is mounted on a circuit board. SOLUTION: A circuit board 1 on which a solid-state image pickup device 3 is mounted, an inner case 4 holding a converging lens 6 and being engaged with the circuit board 1, an outer case 9 incorporated so as to cover the inner case 4, and these are combined. The solid state imaging device 3 and the center of the converging lens 6 are constituted by a holding bracket 10 for fixing the circuit board 1.
The packing 7 and the packing 8 are arranged between the outer case 9 and the converging lens 6 and between the outer case 9 and the circuit board 1 and the inner case 4 and the converging lens 6 are fixed. I do.

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small solid-state imaging device used for a mobile device such as a mobile phone and a digital camera, a video camera, and the like.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional solid-state imaging device. In this solid-state imaging device, a plurality of electronic components 2 and a solid-state imaging device 3 are mounted at predetermined positions on a circuit board 1, and a lower case 12 to which a glass 11 for IR / UV cut is attached forms the solid-state imaging device 3. The solid-state image sensor has a structure in which the upper case 13 to which the converging lens 6 is adhered is screwed into the opening of the lower case 12 to adjust the focus of the image and to prevent loosening. To prevent dust, the gap between the joints of the components is filled with an adhesive.

In such a solid-state imaging device, light incident from an opening 13 a of an upper case 13 is condensed by a converging lens 6 and focused on a light-receiving surface 3 a of the solid-state imaging device 3 to form a light-receiving device (see FIG. (Not shown) receives the light, converts it into an electric signal, converts it into an image signal by the electronic component 2 mounted on the circuit board 1, and outputs the image signal to the outside.

[0004]

[Problems to be Solved by the Invention] However, the conventional solid-state imaging device has the following disadvantages. That is, in the conventional solid-state imaging device, the circuit board 1 on which the solid-state imaging device is mounted and the lower case 12 are assembled, the converging lens 6 and the upper case 13 are assembled, and the space formed by the circuit board 1 and the converging lens 6 is sealed. Since the adhesive is used to prevent the screw portion of the upper case 13 from loosening, the light receiving surface 3a of the solid-state imaging device 3 and the surface of the converging lens 6 are stained with the adhesive during the operation, and the image quality is deteriorated. is there. In addition, since such adhesives are used to join the gangs, it is extremely uneconomical because it is not possible to regenerate defective products generated on the production line or to disassemble and reuse expensive members. In addition, as is well known, the curing process of the adhesive requires aging and heating in a batch-type drying furnace, and the stagnation in the process after the input of the work of assembling parts, etc. becomes long, and a large number of parts are stored or large work areas (Such as a clean room) and a product storage area.

In addition, a screw structure has been often used for adjusting the focal length of an image in an optical device because of its simple structure and easy handling, and it has been widely used in solid-state imaging devices. There is a limit to the demand for smaller and thinner solid-state imaging devices because there is no space for adopting the screw structure, and adjustment of the focal length of the image is screwed or loosened while judging the image quality with the sense of the operator. The complicated work that takes place in the solid-state imaging device occupies the largest number of man-hours in the assembly process, resulting in poor quality and productivity and high cost. It is an issue.

Accordingly, an object of the present invention is to adjust the focal length of a video without deteriorating the functions and characteristics of a conventional solid-state imaging device, using a thin, adhesive structure for an assembly structure or a closed structure. An object of the present invention is to provide a small-sized solid-state imaging device capable of eliminating work.

[0007]

Means for Solving the Problems Therefore, in order to achieve the above object, the present invention employs the following technical means. The solid-state imaging device of the present invention includes a circuit board having a solid-state imaging device mounted at a predetermined position, an inner case that holds a converging lens, and is engaged with the circuit board, and an outer case that is embedded so as to cover the inner case. And the mounting bracket for fixing them, the light receiving surface of the solid-state imaging device and the center of the converging lens are determined by engaging the positioning part of the circuit board and the positioning part of the inner case. Adjust the focal length of the image by inserting an appropriate spacer between them. In addition, an elastic packing or sealing material is disposed between the contact portion between the outer case and the convergent lens and between the contact portion between the outer case and the circuit board, and the inner case and the convergent lens are fixed, and the inner case and the convergent lens are fixed. Seal the space formed by the circuit board.

[0008]

Hereinafter, embodiments of the solid-state imaging device according to the present invention will be described with reference to the drawings. 1 and 2, a plurality of electronic components 2 and a solid-state imaging device 3 are mounted at predetermined positions on a circuit board 1 with a plurality of reference holes 1a (four locations in the present invention). A plurality of positioning bosses 4a (four places in the present invention) provided are engaged to bring the surface of the circuit board 1 and the bearing surface 4b of the inner case 4 into close contact with each other, so that the light receiving surface 3a of the solid-state imaging device 3 and the dragon of the inner case 4 The center position of the part 4c is matched. Next, the spacer 5, the converging lens 6 and the packing 7 are mounted on the seal part 4 c in a superimposed manner, and further, the outer case 9 in which the packing 8 is loaded on the seal part 9 a is put on the outside thereof, and the circuit board 1 is clamped by the holding bracket 10. Fix in the form. At this time, the packing 7 and the packing 8 are suppressed and deformed between the circuit board 1 and the outer case 9, and the inner case 4, the spacer 5, and the converging lens 6 are positioned and fixed while the center is determined. The light receiving surface 3a, the center of the converging lens 6 and the focal length of the image are determined, and a solid-state imaging device in which the solid-state imaging device 3 is sealed in the space formed by the inner case 4, the converging lens 6 and the circuit board 1 is constructed. Since the functions and characteristics of the present invention are the same as those of the conventional solid-state imaging device, the description is omitted.

The circuit board 1 shown in FIG. 2 is made of, for example, a hard plate-like epoxy resin, a flexible sheet lined with an epoxy resin, or a ceramic. ), A wire bonding pad (not shown), and a reference hole 1a penetrating therethrough.

As described above, the electronic components 2 and the solid-state imaging device 3 are mounted, and the center positions of the converging lens 6 and the light receiving surface 3a can be determined by engaging with the positioning boss 1a. To prevent the phenomenon, the surface is made dark with a matte color.

Since the circuit board 1 of the thin solid-state imaging device needs to have a thickness as small as possible, it is impossible to form the reference hole 1a with a closed hole, and it is inevitable to form the reference hole 1a as a through hole. A dust-proof problem occurs as a function of. Therefore, in the present invention, three dustproof parts are provided as shown in FIG. 4, that is, the fitting part of the reference hole 1a and the positioning boss 4a, the peripheral part of the reference hole 1a, and the inner case 4 are provided. At the surface contact portion between the bearing surface 4b and the flat plate portion 10c (shown in FIG. 8) of the holding metal member 10, the surface contact portion is tightly adhered by the narrow clearance of the fitting portion and the fixing force of the holding metal member 10, so that a good dustproof effect is obtained. Demonstrate. For this reason, for the purpose of preventing dust, the base hole 1a and the periphery of the hole of the circuit board 1 and the support portion 4b and the flat plate portion 10c are in close contact with each other due to obstacles such as scratches and dirt that hinder dust protection. If the conductive wiring pattern and the coating are not provided, the degree of freedom of patterning of the circuit board 1 is increased.

This is a reference for an assembly configuration in making the focal length of an image unadjustable. Further, as other forms of dust prevention of the reference hole 1a, the same effect can be obtained by attaching a plastic or a metal film to the relevant portion of the circuit board 1, filling the reference hole 1a with a sealing material, or the like.

Next, the inner case 4 shown in FIG. 5 is formed in a substantially cylindrical shape by injection-molding a synthetic resin such as a polycarbonate resin containing glass, and has a spacer 5 and a converging lens 6 at one inner end. And a seal part 4c for holding the packing 7 and supporting the spacer 5, and a rectangular space 4e for covering the solid-state imaging device 3 at the other end. (See FIG. 1) A light guide hole 4d in the form of a wider angle cone is provided. Outside the seal portion 4c and the light guide hole 4d, a circular outer peripheral portion 4f is formed concentrically with the seal portion 4c for engaging and positioning with the seal portion 9c (shown in FIG. 7) of the outer case 9, and the space portion 4e. Is a rectangular outer shell 4g, and a rectangular bearing surface 4b, which is in contact with the circuit board 1, is formed between the space 4e and the space 4e at right angles to the intaglio portion 4c. An embossed positioning boss 4a having a height slightly lower than the thickness of the circuit board 1 to be formed is arranged on a concentric circle of the intaglio portion 4c. The surface is matte dark to prevent flare of the image due to light reflection.

Next, the converging lens 6 shown in FIG. 6 is formed by molding a synthetic resin such as a colorless and transparent acrylic resin or a polycarbonate resin, and is fitted to the ink dragon part 4b concentrically with the convex lens part 6d. A flange 6a is provided, and a plane 6b and a plane 6c which are in contact with the spacer 5 and the packing 7 are parallel and arranged at right angles to the center of the lens. In the present invention, in order to reduce the thickness and cost, the surface of the converging lens 6 is subjected to vacuum deposition, ion plating, thin film coating, etc. for the purpose of anti-reflection, improvement of hardness, and IR / UV cut effect. It was used instead of the IR / UV cut glass conventionally used.

Next, an outer case 9 shown in FIG. 7 is made by injection-molding a synthetic resin such as a polycarbonate resin containing glass, for example. The outer case 9 has a rectangular shape approximately the same as the width of the circuit board 1 and a relative outer shape 9 g. A hooking portion 9e for hooking a hooking portion 10a (shown in FIG. 8) of the holding bracket 10 is provided on two side surfaces to hold a packing 8 and a circular opening 9b acting as a stop of the converging lens 6. A substantially square ink dragon portion 9a is arranged at both ends, and a circular ink dragon portion 9c that engages with the outer peripheral portion 4f of the inner case 4 and abuts on the packing 7 is arranged concentrically inside the opening 9b. The inner surface 9d of the seal dragon portion 9a does not interfere with the outer shell 4g of the inner case 4. When such an outer case 9 is put on the inner case 4, the seal part 9c is guided by the outer peripheral part 4f so that the center of the opening 9b and the center of the light receiving surface 3a coincide. The surface has a matte dark color to prevent flare of the image due to reflection.

It is desirable that the thickness of the opening 9b in the optical axis direction is as small as possible. As shown in FIG. 7, an inner slope having a wider angle than the angle of view Φ of the lens is provided on the converging lens 6 side from the opening 9b. 9e is provided, and the opposite slope 9f is wider than the angle α formed by the line segment connecting the lens center point Q of the converging lens 6 and the opening 9b and the center of the converging lens 6 to prevent image ghosting. Can be.

By the way, in an assembly which is not fixed by an adhesive as in the present invention, it is important to use the same material for the main structural parts, that is, the linear expansion of the respective parts due to the difference in the material. Since the coefficients are different, there is a difference in the dimensional change with the change in the environmental temperature, and a minute strain is generated at the fixed portion. However, even when the environmental temperature is restored thereafter, the distortion does not disappear and the hysteresis phenomenon that the environmental temperature changes to the opposite side and gradually recovers is possible. Even the occurrence of distortion may adversely affect optical performance over time. In view of such a case, the inner case 4 and the outer case 9 are made of the same material and the same grade.

Next, the holding fitting 10 shown in FIG. 2 is obtained by, for example, pulling a stainless steel plate for a spring. The shape of the holding fitting 10 is shown in a plan view of FIG. (2) shows a side view and will be described. In FIG. 8A, a flat plate portion 10 having a rectangular shape substantially the same size as the width of the circuit board 1 is provided, and a T-shaped hook that is hooked to the hook 9e at the center of two parallel sides on the outer periphery. A hook 10a is disposed, and the mountain is bent at the positions of MM and NN. Further, as a spring for pressing the circuit board 1 when the outer case 9 and the flat plate 10c are clamped and fixed. An operating elastic section 10b is provided in series with the hooking section 10a, and valley-folding is performed at the positions of XX and YY to form a fixing bracket 10 as shown in FIG. The operation of the holding bracket 10 is as follows.

[0008] As described in the above, the circuit board 1 in which the components are incorporated and locked, and the circuit board 1 side of the outer case 9 are inserted between the hooking portions 10a in comparison with the holding bracket 10, and the circuit board 1 and the flat plate 10c are inserted. The circuit board 1 is pressed against the outer case 9 by the spring force of the elastic portion 10b, and the elastic portion 10b is bent so that the elastic portion 10b is bent. The king 8 is crushed to secure and seal the components. Further, in the holding metal fitting 10 using the spring property disclosed in the present invention, the flexure of the elastic portion 10b is regulated by the circuit board 1 so that excessive deformation does not occur, and an excessive load is applied during the assembly work. Accidents such as damage or deformation of components can be prevented without being applied.

Next, non-adjustment of the focal length of an image will be described. As shown in FIG. 9, the focal length of the image is obtained by substituting the optical characteristics of the converging lens 6 for the distance F between the light receiving surface 3a of the solid-state imaging device 3 and the apex P of the converging lens 6. The focal length was adjusted by moving the vertex P closer or farther away from the light-receiving surface 3a with a screw and judging that the image was clear when the focus was in agreement. It was the fact that he was searching for it. Therefore, the present invention estimates the expected value of the interval F of the assembled solid-state imaging device by a statistical method, and when there is a significant difference from the reference value of the interval F in a state where the focus is in agreement. It is intended to adjust the focal length of an image by reflecting the difference size in the current component size. The conventional solid-state imaging device employs a configuration in which components are stacked and assembled on the basis of a circuit board, and an interval F is determined by the stacking height from the circuit board 1 to the vertex P of the converging lens 6 and the circuit board 1. It is determined by the difference in the stack height from the image to the light-receiving surface 3. Therefore, in order to adjust the focal length of the image, it is important that the components related to the stack have small dimensional variations and a small number of components. In the present invention, the components other than the solid-state imaging device 3 and the converging lens 6 are constituted by only one point of the inner case 4, and the structure is such that no adhesive is used for fixing the components. . As a result, the variation factors related to the interval F are the layer thickness N of the adhesive when the solid-state imaging device 3 is mounted on the circuit board 1 and the thickness S of the solid-state imaging device 3 and the thickness of the inner case 4 shown in FIG. The height H from the bearing surface 4b to the seal dragon part 4c and the lens height R of the converging lens 6 are extremely small compared to the conventional solid-state image pickup device due to the three parts and four factors. The difference between the expected value of the actual product and the height H of the inner case 4 can be combined to determine the focal length of the image and eliminate focus adjustment.

By the way, in recent years, mobile devices and the like have been reduced in size and weight, and there has been a demand for smaller and thinner solid-state imaging devices. However, by making the devices thinner, the required image quality is generally the same as before. Since the solid-state imaging device is almost the same as the conventional one, a solid-state imaging device having a convergent lens with a short focal length and a wide angle of view is required. However, the inherent characteristic of the lens is that as the focal length becomes shorter, the depth of focus becomes shallower, making it relatively difficult to adjust the focus of the image.

[0017] It is not sufficient to simply describe the height H of the inner case 4 described in the above. Therefore, the present invention is to adjust the focal length of an image by inserting a spacer 5 having an intended thickness T between the inner case 4 and the converging lens 6, thereby eliminating the focus adjustment during the assembly work. Is

Next, the spacer 5 shown in FIG. 1 and FIG. 2 is made of, for example, a synthetic resin or metal and has a rectangular ring shape in cross section, and is fitted to the seal part 4 c of the inner case 4. The outer surface of the inner case 4 and the flat surface that comes into contact with the seal part 4c of the inner case 4 and the converging lens 6 have a matte dark color to prevent a flare phenomenon due to light reflection. The thickness T is determined by ascertaining the process capability of each component lot before assembling, estimating the expected value and variance of the interval F 1, and calculating the difference between the reference value of the video focal length and the expected value of the interval F. If the difference is negative, the difference may be reduced, and if the difference is negative, the difference may be increased.

Next, the packing 7 and the packing 8 shown in FIGS. 1 and 2 are formed by molding a rubber-based synthetic resin, for example, and have a circular or rectangular cross section, and a planar shape having a circular sealing length of the sealing portion. The ring has a circular shape or a ring shape having the same projection shape as the sealed portion. The surface is matte black to prevent a flare phenomenon due to light reflection.

Next, a solid-state imaging device shown in FIG. 10 is another embodiment in which a package-enclosed solid-state imaging device 14 is mounted.

[0008] The solid-state imaging device described above has the same structure and operation.

[0022]

As described above, according to the first, fourth, and fifth aspects of the present invention, the components are mounted on the circuit board and fixed by the holding bracket, so that the solid-state imaging is achieved. The overall equipment will be thinner and the need for bonding work will be eliminated, which will reduce the number of work steps and reuse of parts, and will also reduce the retention and in-process inventory of components related to the curing of the adhesive. Can be.

According to the invention of claim 2, since positioning and guiding are performed by the component parts, the positioning accuracy of the assembly is improved, the assembly jig is not required, and the number of assembly steps is reduced. It is possible to reduce and prevent work errors.

Further, according to the invention of claim 3, focus adjustment of an image is eliminated, product quality is improved, work steps are reduced, and the solid-state imaging device can be made thin.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a solid-state imaging device according to the present invention.

FIG. 2 is a perspective view (1) and an exploded perspective view (2) showing an embodiment of the solid-state imaging device according to the present invention.

FIG. 3 is a cross-sectional view showing a conventional example of a solid-state imaging device.

4 is a detailed partial cross-sectional view of the solid-state imaging device shown in FIG.

FIG. 5 is a detailed sectional view of an inner case 4 of the solid-state imaging device shown in FIG.

FIG. 6 is a detailed sectional view of a converging lens 6 of the solid-state imaging device shown in FIG.

FIG. 7 is a detailed sectional view of an outer case 9 of the solid-state imaging device shown in FIG.

FIG. 8 is a developed plan view (1) and a side view (2) of the holding fitting 10 shown in FIG.

FIG. 9 is an explanatory diagram illustrating an operation of the solid-state imaging device according to the present invention.

FIG. 10 is an exploded perspective view showing another embodiment of the solid-state imaging device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board 2 Electronic component 3 Solid-state image sensor 4 Inner case 5 Spacer 6 Convergent lens 7 Packing 8 Packing 9 Outer case 10 Holding bracket

Claims (5)

[Utility model registration claims] 1. A circuit board on which a solid-state imaging device is mounted at a predetermined position, an inner case holding a converging lens and being engaged with the circuit board, an outer case incorporated so as to cover the inner case, and fixing these. A solid-state imaging device, comprising: 2. The solid-state imaging device according to claim 1, wherein the light-receiving surface of the solid-state imaging device and the center of the converging lens are determined in agreement with a positioning portion of the circuit board and a positioning portion of the inner case. 3. The image focus is determined by inserting a spacer between the inner case and the converging lens.
3. The solid-state imaging device according to item 1. 4. An elastic packing is mounted between a contact portion between the outer case and the convergent lens and between a contact portion between the outer case and the circuit board to fix the inner case and the convergent lens, and to fix the inner case and the convergent lens; 2. The solid-state imaging device according to claim 1, wherein a space formed by the circuit board is sealed. 5. A fixing member for fixing the inner case and the converging lens and converging the inner case and the converging lens by gluing an elastic sealing material between a contact portion between the outer case and the converging lens and a contact portion between the outer case and the circuit board. The solid-state imaging device according to claim 1, wherein a space formed by the lens and the circuit board is sealed.