JPH0677451A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To provide a solid state image pickup device which is free from damages even if its cover is made of resin. CONSTITUTION:A solid-state image pickup element 2 is mounted on the approximately central part of a base 3, the solid-state image pickup element 2 is connected to leads 31 with bonding wires 32 and a resin cover 5 is put onto the base 3 so as to have the solid-state image pickup element 2, the bonding wires 32 and the connection parts of the leads 31 provided inside a recess 5a which is formed in the lower surface of the cover 5 to form a solid state image pickup device 1. Protrusions 6 are provided on the surface of the cover 5 except on the part corresponding to the effective picture element 21 of the solid-state image pickup element 2. Further, a surface treatment for light shielding is applied to the surfaces of the protrusions 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device such as a CCD area sensor or a linear sensor provided with a resin lid.

[0002]

2. Description of the Related Art A solid-state image pickup device of this type uses a so-called hollow package in which a solid-state image pickup element is mounted on a base made of ceramics or the like and hermetically sealed by a lid made of glass or resin. is there. In the hollow package, a predetermined space is formed between the lid and the base, and the solid-state image sensor, the bonding wire, etc. are arranged in a sealed state in this space. For this reason, the structure has a low hygroscopic property, and also has a structure in which dust from the outside does not easily adhere to the solid-state imaging device. In order to manufacture a solid-state image pickup device using a hollow package, first, a solid-state image pickup element is mounted using silver paste or the like on a substantially central portion of a ceramic base. Then, the solid-state imaging device and the lead are wired by a bonding wire, and a glass lid is mounted on the base via a frame having a predetermined height. When a lid made of resin is used, the lid is mounted on the base so that the solid-state image sensor, the leads and the bonding wires are arranged in the recess provided on the lower surface side of the lid. This attachment is performed by applying a low-temperature resin sealer, an ultraviolet curing adhesive, or the like on the joint surface between the base, the frame and the lid, and mounting it on the base, and pressing the lid from the surface side of the lid to fix it. . A metal weight is used when the low-temperature resin sealer is used, and a quartz glass weight is used when the ultraviolet curing adhesive is used. In recent years, in order to improve the workability of hollow packages, reduce the weight, and reduce the cost, more and more products use a resin base or lid.

Further, the conventional lid is made of a transparent resin in order to transmit the light incident on the solid-state image pickup element. FIG. 13A is a cross-sectional explanatory view of the lid 11 which is entirely transparent. In addition, as a conventional lid, as shown in FIG. 13 (B), in order to prevent the incidence of light from an oblique direction, an uneven surface 12 having a pear-skin texture is formed on the upper surface other than the central portion to make it opaque. Things are known.

[0004]

However, when a lid made of resin is used, the surface of the lid is scratched by pressing a weight made of metal or glass when the lid is attached. The surface of the lid is processed to have high flatness for transmitting light, and if the surface is scratched, the characteristics of the solid-state imaging device will be deteriorated. In particular, a solid-state imaging device using a lid made of resin is suitable for mass production, and thus a serious problem is a decrease in yield due to scratches on the surface of the lid.

As shown in FIG. 13B, the lid 11
When the pear-skin textured concavo-convex surface 12 is formed on the upper surface other than the central portion of the above, since the concavo-convex surface 12 makes it opaque, it is possible to prevent the incidence of light from an oblique direction. However, as shown in FIG. 14, when a strong incident light enters the transparent portion in the center of the lid, the light reflected by the bonding wire 13 is reflected by the lid 11.
Is reflected by the inner wall surface of the
There was a problem of flare.

Further, as described above, in order to make the lid transparent, the metal forming the lid must first be cut out by electric discharge machining and then mirror-polished, which requires an expensive die. In addition, when the lid is made of a polyolefin resin that has high light transmittance, low birefringence, and extremely low hygroscopicity and transparency, the material is soft, so damage is likely to occur due to the device or jig during sealing. It is easy for scratches to occur during product distribution and mounting. Due to this scratch, the quality of the product was often deteriorated.

The problem to be solved by the present invention lies in what kind of means should be taken to obtain a solid-state image pickup device which is not damaged even if a lid made of resin is used.
Further, another problem is what kind of means should be taken to reduce flare caused by the bonding wire.

[0008]

According to a first aspect of the invention of the present application, a solid-state image pickup device is mounted in a substantially central portion of a base, and the solid-state image pickup device and a relay are connected by a bonding wire to form a resin. In a solid-state imaging device in which this lid is mounted on a base in a state where a solid-state imaging device, a bonding wire, and a connecting portion of leads are arranged in a concave portion provided on the lower surface of a lid made of
The configuration is such that a convex portion is provided on the lid surface other than the portion corresponding to the effective pixels of the solid-state image sensor.

The invention according to claim 2 of this application is characterized in that the convex portions are provided in a bank shape on opposite sides of the lid. Further, the invention according to claim 3 is configured such that the convex portion is provided in a substantially central portion of each side of the lid in a projecting shape. Further, in the invention according to claim 4, the convex portion is composed of three protrusions, and the protrusion is arranged so that the solid-state imaging device is located at a substantially central portion of a triangle having these three protrusions as vertices. The arrangement is done. Furthermore, the invention according to claim 5 is
The surface of the convex portion is subjected to a surface treatment for shading. According to a sixth aspect of the present invention, the convex portion is a lid
The structure is provided in the shape of a protrusion in the corner.

According to a seventh aspect of the present invention, the solid-state image pickup device is mounted substantially in the center of the base, and the leads provided on the base and the solid-state image pickup device are connected by bonding wires, and the lid is provided with the lid. In the solid-state imaging device in which the solid-state imaging device is covered with a base and sealed, the lid has a light-transmitting region in the central portion for transmitting incident light to an effective pixel region of the solid-state imaging device, and sealing The surface facing the defined space is an opaque diffuse reflection surface excluding the central portion.

The invention according to claim 8 is characterized in that the lid is made of a polyolefin resin. In addition, claim 9
In the invention described above, the irregular reflection surface is a pear-like textured surface, and the surface of the light transmission region is a mirror surface. Further, the invention according to claim 10 is characterized in that the lid is a resin molded product injection-molded using a mold.

[0012]

In the inventions according to claims 1 to 6 of this application, since the convex portion is provided on the lid surface other than the portion corresponding to the effective pixels, when the weight is pressed from the front surface side of the lid, The ridge and the convex portion come into contact with each other.

That is, the weight does not directly contact the portion corresponding to the effective pixel on the lid surface, and the convex portions are evenly arranged on the lid surface, so that the lid can be pressed with equal pressure.

Further, by performing a surface treatment for light shielding on the surface of the convex portion, unnecessary light entering the solid-state image pickup device from a position other than above the effective pixel can be blocked, so that image disturbance such as flare can be suppressed. become.

In the invention according to claim 7 and claim 8 of this application, among the surfaces (inner side surfaces) of the lid facing the sealed space, the surface excluding the light transmission region in the central portion is a diffuse reflection surface. Has become. Therefore, when the light entering from the light transmitting area is reflected by the bonding wire and is incident on the irregular reflection surface,
Since it is diffusely reflected, it has an effect of suppressing strong light from entering the effective pixel region of the solid-state image sensor.

According to a ninth aspect of the present invention, since the light transmission region of the lid made of polyolefin resin has a high light transmittance and a small birefringence, the incident efficiency of light to the effective pixel region of the solid-state image pickup device is high. Become. Further, since the polyolefin resin has extremely low hygroscopicity and moisture permeability, it has an action of preventing characteristic deterioration of the solid-state imaging device sealed with the lid due to water. Also, if the surface other than the light-transmitting area in the center of the lid is made to be a diffuse reflection surface, especially a rough surface with a pear-skin texture, it will be scratched by handling during the production of the lid and by assembly equipment, jigs, etc. during the manufacturing process of the solid-state imaging device. Even if this occurs, it becomes inconspicuous and the yield can be improved.

According to the tenth aspect of the invention, the light transmission region and the irregular reflection surface can be easily formed by injection molding.

Particularly, the surface of the mold corresponding to the irregular reflection surface is
Usually, since the surface formed by electric discharge machining, which is a cutting process of a mold, is a pear-like textured surface as it is, only the portion corresponding to the light transmitting region needs to be mirror-polished and can be easily manufactured.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the solid-state image pickup device according to the present invention will be described below with reference to the embodiments shown in the drawings.

(Embodiment 1) FIG. 1 is a sectional view for explaining a solid-state image pickup device of Embodiment 1, and FIG. 2 is a perspective view thereof.

The solid-state image pickup device 1 includes a solid-state image pickup device 2 such as a CCD or a linear sensor mounted on a substantially central portion of a base 3.
Is a hollow package which is placed in the recess 5a of the resin lid 5 and hermetically sealed. Effective pixels 21 are formed on the upper surface of the solid-state image sensor 2 and convert light from the outside into electric signals. Further, a lead 31 for obtaining an electrical connection to the outside is arranged around the solid-state image sensor 2, and the lead 31 and the solid-state image sensor 2 are wired by a bonding wire 32. The lid 5 is mounted on the base 3 in a state where the solid-state imaging device 2, the leads 31, and the bonding wires 32 are arranged in the recess 5 a of the lid 5.

The lid 5 is made of, for example, a transparent polyolefin resin and its surface is processed to have a high degree of flatness. On the surface of the lid 5 other than the portion corresponding to the effective pixels 21, for example, bank-shaped convex portions 6 are provided on opposite sides of the lid 5. The height of the convex portion 6 may be about 0.1 mm, and when the weight is pressed from the surface side of the lid 5, a slight gap is formed between the weight and the surface of the lid 5. Good.

Next, a method of manufacturing the solid-state image pickup device 1 will be described with reference to the sectional views of FIGS.

First, as shown in FIG. 3, the solid-state image pickup device 2 is mounted on the base 3 having the lead 31 arranged at a predetermined position in a substantially central portion thereof using silver paste or the like. Then, the solid-state image sensor 2 and the leads 31 arranged around the solid-state image sensor 2 and the bonding wires 32 are used for wiring.

Next, the lower surface of the lid 5 is coated with an adhesive 7 such as a low temperature resin sealer or an ultraviolet curing adhesive, and the lid 5 is mounted on the base 3. As a result, the solid-state image sensor 2, the lead 31 and the bonding wire 32 are arranged in the recess 5 a of the lid 5.

Then, as shown in FIG. 4, a weight 8 is mounted on the surface side of the lid 5 and pressed. At this time, since the lower surface of the weight 8 contacts the convex portion 6 provided on the surface of the lid 5, a gap is formed between the weight 8 and the surface of the lid 5. Therefore, the load of the weight 8 is transmitted to the lid 5 via the convex portion 6, and the base 3 and the lid 5 are brought into close contact with each other without the weight 8 coming into contact with the surface of the lid 5.
For example, when an ultraviolet curing adhesive is used as the adhesive 7, a quartz glass weight 8 is used, and ultraviolet rays are irradiated from above the weight 8 in a pressed state. As a result, the ultraviolet rays pass through the quartz glass weight 8 and are applied to the adhesive 7 to be cured.

(Second Embodiment) Next, a second embodiment of the present invention will be described.

First, in the solid-state image pickup device 1 as shown in the perspective view of FIG. 5, the convex portions 6 are provided in a bank shape on the opposite short sides of the lid 5, which adversely affects the image of the solid-state image pickup element 2. It is formed to a size that does not reach

If necessary, a bank-shaped convex portion 6 may be provided on all four sides of the lid 5.

(Embodiment 3) In the present embodiment, as shown in the perspective view of FIG. 6, a projecting portion 6 is provided at a substantially central portion of each side of the lid 5.

With such arrangement of the convex portions 6, when the weight 8 shown in FIG. 4 is pressed from the surface side of the lid 5, the contact surface between the lower surface of the lid 5 and the base 3 can be evenly loaded. .

(Embodiment 4) In this embodiment, as shown in the perspective view of FIG. 7, a protrusion 5 having a projecting shape is provided at four corners of a lid 5, and the solid-state image pickup device 1 and Similarly, an even load can be applied to the contact surface between the lower surface of the lid 5 and the base 3.

(Embodiment 5) In the present embodiment, as shown in the plan view of FIG. 8, the convex portion 6 is composed of three protrusions, and a triangle having these three protrusions as vertices. The solid-state image pickup device 2 is arranged substantially at the center.

As a result, the area of the convex portion 6 can be reduced, so that the convex portion 6 does not interfere with the light pickup of the solid-state image pickup element 2 and a uniform load is applied to the lid 5. be able to.

(Embodiment 6) In the present embodiment, as shown in the perspective view of FIG. 9, a convex portion 6 is provided on the upper surface of the lid 5 except the portion corresponding to the effective pixel of the solid-state image pickup device 2. is there.

Therefore, the surface of the lid 5 corresponding to the most important effective pixel is easily protected. Further, the surface of the convex portion 6 may be subjected to a surface treatment for shading. For example, a black paint is applied to the surface of the convex portion 6, or the surface of the convex portion 6 is formed in a pear-skin texture. As a typical example of this, FIG.
In the solid-state imaging device 1 shown in the perspective view 0, the convex portion 6 is provided on the entire surface of the solid-state imaging element 2 except for the surface of the lid 5 corresponding to the effective pixel 21, and the entire surface of the convex portion 6 has a pear surface. -Like surface treatment is applied.

As a result, the lid 5 corresponding to the effective pixel 21
Since it is possible to block unnecessary light or strong light that enters the solid-state image sensor 2 from other than the surface, it is possible to suppress adverse effects on the image such as flare.

The various lids 5 used in the solid-state image pickup device 1 can be easily formed by using a mold having a shape corresponding to each shape.

(Embodiment 7) FIG. 11 is a sectional view of the lid 5 in the present embodiment, and FIG. 2 is a sectional view of the essential portions of the solid-state imaging device of the present embodiment.

In the present embodiment, as shown in FIG. 11, the central portion of the lid 5 corresponding to the effective pixel area of the solid-state image pickup element 2 is a light transmitting area 5b having front and back surfaces formed by mirror surfaces. The entire surface other than the light transmitting area 5b is made into a finely textured surface 5c having a pear-skin texture. The lid 5 is formed by injection molding a polyolefin resin using a mold. In this die, only the portion corresponding to the light transmitting region 5a needs to be mirror-finished, and the other portions can have a pear-like textured surface in a state where the die is cut by electric discharge machining.

When such a lid 5 is bonded to the base 3,
As shown in FIG. 12, even if the strong light entering from the light transmitting region 5b is reflected by the bonding wire 32 and enters the inner wall of the lid 5, the strong light is dispersed by the irregular reflection surface 5c. Therefore, strong reflected light does not enter the effective pixel area of the solid-state image sensor 2, and flare can be prevented from occurring. Further, since the lower end surface of the lid 5 is also formed with irregularities, the adhesive is well compatible with and airtightness is improved.

In this embodiment, the entire surface other than the light transmission area in the center of the lid is the diffuse reflection surface 5b, but at least the inner surface of the lid 5 facing the sealing space (excluding the light transmission area) is a diffuse reflection surface. If so, the flare prevention effect can be obtained.

Although each embodiment of the present invention has been described above, the present invention is not limited to this, and various design changes can be made within the scope of the gist of the configuration. For example,
In each of the above embodiments, the present invention is applied to the container-shaped lid,
Other shaped lids may be used.

In each of the above embodiments, the lid is made of polyolefin resin, but other materials may be used.

[0045]

As described above, according to the inventions described in claims 1 to 6 of this application, the following effects are obtained.

That is, since the convex portion is provided on the surface of the lid, even if the lid made of resin is used, the surface of the lid is not damaged by the weight pressed from the surface side of the lid. . Therefore, the characteristics of the solid-state imaging device can be prevented from being deteriorated, and the yield of the solid-state imaging device can be improved because the resin lid that can be mass-produced is used. Moreover, by performing a surface treatment for light shielding on the surface of the convex portion, it is possible to positively improve the adverse effect on the image.

Further, according to the invention described in claims 7 and 8 of this application, there is an effect of reducing flare caused by the bonding wire.

Further, according to the invention of claim 9 of this application, in addition to the above effects, the yield and quality are improved by using a polyolefin resin having good optical characteristics and extremely low hygroscopicity and moisture permeability. Has the effect of

Further, according to the invention of claim 10 of this application, since only the mold surface corresponding to the light transmitting region in the center of the lid needs to be mirror-finished, a low-cost mold can be used. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a first embodiment.

FIG. 2 is a perspective view illustrating the first embodiment.

FIG. 3 is a cross-sectional view illustrating attachment of a lid.

FIG. 4 is a cross-sectional view illustrating pressing by weight.

FIG. 5 is a perspective view illustrating a second embodiment.

FIG. 6 is a perspective view illustrating a third embodiment.

FIG. 7 is a perspective view illustrating a fourth embodiment.

FIG. 8 is a plan view illustrating a fifth embodiment.

FIG. 9 is a perspective view illustrating a sixth embodiment.

FIG. 10 is a perspective view illustrating a modified example of the sixth embodiment.

FIG. 11 is a sectional view showing a lid of the seventh embodiment.

FIG. 12 is a cross-sectional view of a main part of the seventh embodiment.

13A and 13B are cross-sectional views showing a conventional lid.

FIG. 14 is a sectional view of a main part of a conventional solid-state imaging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Solid-state imaging device 2 ... Solid-state imaging device 3 ... Base 5 ... Lid 5a ... Recess 5b ... Light transmission area 5c ... Diffuse reflection surface 6 ... Convex part 21 ... Effective pixel 31 ... Lead 32 ... Bonding wire

Claims (10)

[Claims] 1. A base having a solid-state image sensor mounted in a substantially central portion and connecting a lead and the solid-state image sensor with a bonding wire, and the solid-state image sensor in a recess formed in a lower surface. A solid-state imaging device comprising a resin lid placed on the base in a state where the bonding wire and the connection portion of the lead are arranged, which corresponds to an effective pixel of the solid-state imaging device on the lid surface. A solid-state imaging device, wherein a convex portion is provided in a portion other than a portion to be formed. 2. The solid-state imaging device according to claim 1, wherein the convex portions are provided in a bank shape on opposite sides of the lid. 3. The solid-state imaging device according to claim 1, wherein the convex portion is provided in a substantially central portion of each side of the lid in a protrusion shape. 4. The protrusion comprises three protrusions,
2. The solid-state imaging device according to claim 1, wherein the three protrusions are arranged in a state where the solid-state image pickup element is located at a substantially central portion of a triangle having the individual protrusions as apexes. 5. The solid-state imaging device according to claim 1, wherein a surface treatment for light shielding is applied to a surface of the convex portion. 6. The solid-state imaging device according to claim 1, wherein the protrusions are provided in four corners of the lid in a projecting shape. 7. A solid-state image sensor is mounted on the base substantially at the center,
And in the solid-state imaging device in which the lead provided in the base and the solid-state image sensor are connected by a bonding wire, and the lid is covered to seal the solid-state image sensor, the lid is the solid state. A light transmission region for transmitting incident light to an effective pixel region of the image pickup device is provided in a central portion, and a surface facing the sealed space is an opaque diffuse reflection surface except for the central portion. Solid-state imaging device. 8. The solid-state imaging device according to claim 7, wherein the irregular reflection surface is a pear-skin textured uneven surface, and the surface of the light transmission region is a mirror surface. 9. The solid-state imaging device according to claim 7, wherein the lid is made of polyolefin resin. 10. The solid-state imaging device according to claim 7, 8 or 9, wherein the lid is a resin molded product injection-molded using a mold.