JPS59228755A - Solid state image sensor - Google Patents

Abstract

PURPOSE:To enable to accurately separate colors by filling a transparent substance having the same refractive index as that a color filter layer between a solid state image sensing element for photographing in color and a window member of a package. CONSTITUTION:A recess 31 is formed on the upper surface of an IC package 30. The recess 31 becomes a vessel 33 of a solid state image sensing element 32, which contains a photoreceiving surface formed with a color filter layer 34 toward opening side of the vessel 33. A transparent substance 35 is filled in the vessel 33 which contains the element 32, and the recess 31 is sealed by a sealing 36 to become a transparent window member. The substrate 35 has similar refractive index to the layer 34. Thus, even if irregular surface exists on the surface of the layer 34, the irregular surface is buried with the substrate 35. Accordingly, an input light is not refracted on the surface of the layer 34. The boundary to an air layer is flat only on the surface of the glass 36. Accordingly, a lens effect is not produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a solid-state imaging device for color imaging in which a color filter layer is formed on a light-receiving surface.

[Technical background of the invention and its problems]

Recently, television cameras using solid-state imaging devices such as CCD type and MOS type have been put into practical use. In particular, with regard to general color video cameras, efforts are being made to develop so-called single-chip video cameras that effectively use a single solid-state image sensor, similar to conventional single-tube video cameras. . This type of single-chip video camera basically provides a color filter corresponding to each pixel on the light-receiving surface of the solid-state image sensor, and uses frequency separation or phase separation from the output to extract the color signal. After each is extracted, a color television signal is obtained.

That is, as shown in the color filter configuration example in FIG. 1, for example, a Ye (yellow) filter 2 and a Cy (cyan) filter 3 are arranged in a predetermined manner corresponding to a plurality of pixels 1 formed on the light receiving surface of a solid-state image sensor. They are arranged according to a rule, and after combining and reading out each pixel signal between two adjacent lines, they are frequency-separated to separate and reproduce each color signal.

By the way, such color filters are generally formed by dyeing a glass substrate, and are attached to the light receiving surface of the solid-state image sensor in alignment with the light receiving surface.

For this reason, there is a problem that misalignment between the Ye filter 2 or the Cy filter 3 and the pixel is likely to occur, and the productivity is poor.

Therefore, recently, a solid-state image sensor (COD in this example) has been proposed in which the above-mentioned problem is solved by forming a color filter layer directly on the light-receiving surface of the solid-state image sensor, as shown in FIG. ing.

That is, the COD includes, for example, a charge storage section 14 and a charge transfer section 15 made up of an N layer forming a pixel on a P-type silicon substrate 11.
and a channel stopper 16, and furthermore, an electrode 1 made of polysilicon is formed on the P-type silicon substrate 11.
7° 18 is formed using the entire StO□ film 19, the portion other than the charge storage portion 14f is covered with a light shielding layer 2θ made of aluminum or the like, and the surface thereof is further covered with a smoothing layer 21 made of glass or the like. It has become.

On the smoothing layer 21 of such a COD, a Ye dyeing layer 23 and a Cy dyeing layer 24 are laminated via an intermediate layer 25 in correspondence with the pixels.

However, with such a structure, the smoothing layer 21
Even though the surface of the CCD has been smoothed by the method, there are still irregularities of about 3 μm.

Moreover, since each dyeing layer 23, 24 is provided corresponding to a specific pixel, there is a difference in thickness between the area where the dyeing layer 23, 24 is provided and other areas, and the surface is uneven. Become. As a result, a different so-called lens effect occurs at each pixel position, resulting in a problem that the effective light-receiving area of each pixel varies. This causes a problem in that the color component ratio of the signal obtained from each pixel changes, making it impossible to effectively perform color separation.

In other words, the color reproducibility is poor.

[Purpose of the invention]

The present invention has been made in view of these problems, and its purpose is to prevent the lens effect that occurs in a solid-state image sensor on which a color filter layer is formed, to perform accurate color separation, and to improve color reproducibility. An object of the present invention is to provide a solid-state imaging device with excellent productivity and high productivity.

[Summary of the invention]

The present invention provides a structure in which a color filter layer is formed on a light-receiving surface of a solid-state image sensor for color imaging, and a transparent window member of a cage that accommodates the solid-state image sensor. It is characterized by being filled with a transparent material having the same refractive index.

〔Effect of the invention〕

According to the present invention, an engineering CA in which a solid-state image sensor is housed
? Since the sealed space in the cage is filled with a transparent material having the same refractive index as the color filter layer, the unevenness on the surface of the color filter layer is completely filled with the transparent material. Therefore, the refraction that conventionally occurs at the interface between the color filter layer and the air is eliminated, making it possible to prevent the problematic lens effect.

As a result, the effective light-receiving area of each pixel can be made constant, accurate color separation can be performed, and a solid-state imaging device with good color reproducibility can be provided.

[Embodiments of the invention]

The details of the present invention will be explained below based on the illustrated embodiments.

3 and 4 are diagrams showing a solid-state imaging device according to an embodiment of the present invention. In the figure, 30 is an IC package, and a recess 31 is formed in the center of the upper surface of the IC package 30. This recessed portion 31 serves as a housing portion 33 for a solid-state image sensor (for example, C0D) Jj.
The element 32 is housed with the light-receiving surface side on which the color filter layer 34 is formed facing toward the opening side of the housing section 33 . Therefore, the transparent material 3 is placed in the storage section 33 in which the element 32 is stored.
5 is filled and becomes a transparent window member.
6, the recess 31 is sealed. Transparent substance 3 above
5 has the same refractive index as the color filter layer 34. Therefore, if the color filter layer 34 is made of acrylic resin, the transparent material 35 used is a material whose refractive index is about 1.5. Ideally, the transparent material 35 is preferably an acrylic resin. However, in this case, if the melting point of the transparent material 35 is made lower than the melting point of the color filter layer 34, there is a high possibility that the color filter layer 34 will melt when the transparent material 35 is filled, which is not practical. Therefore, the transparent substance 35
For example, liquid oil with a refractive index of about 1.5 may be used, such as oil in which objects to be observed are immersed during microscopic observation. This oil is filled into the storage section 33 to prevent air bubbles from entering, and the storage section 33 is sealed liquid-tightly by the sealing glass 36.

Note that 37 in the figure is a lead pin for electrically connecting the solid-state imaging device to an external element;
The end portion of the housing portion 33 side of the storage portion 1 is connected to the solid-state image sensor 32 by a bonding wire 38 .

Thus, in the device of this embodiment, even if there are irregularities on the surface of the color film layer 34, the irregularities can be removed by removing the irregularities from the color filter layer 3.
Since the color filter layer 34 is filled with a transparent material 35 having the same refractive index as the color filter layer 34, the input light is not refracted on the surface of the color filter layer 34. The interface with the air layer is only the surface of the sealing glass 360, which is flat.

Therefore, no lens effect occurs.

As a result, the effective light-receiving area of each pixel becomes approximately equal, making it possible to provide a solid-state imaging device that can perform accurate color separation, that is, has excellent color reproducibility.

Furthermore, in this case, the liquid transparent substance 35 functions as a cooling medium for the heat generated by the solid-state imaging device, so that the cooling effect of the device is also improved. Therefore, it exhibits great effects such as suppressing dark current and increasing device density.

It goes without saying that the present invention can also be applied to MOS type devices related to CCD type devices.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of color arrangement of color filters in a single-chip color video camera, FIG. 2 is a cross-sectional view of a COD on which a color filter layer is formed, and FIG. 3 is a solid-state imaging device according to an embodiment of the present invention. FIG. 4, which is a perspective view of the appearance of the device, is a sectional view taken along the line A-A in FIG. 3 and viewed from the direction of the arrow. 1...Pixel, 2...Ye filter, 3...C
y filter, 11... P-type silicon substrate, 23.
...Ye staining layer, 24...Cχ staining layer, 30...I
c package, 32... Solid-state image sensor, 33... Storage section, 34... Color filter layer, 35... Transparent substance, 36... Sealing glass. Applicant's agent Patent attorney Rin Ushiki Hiko Figures 1, 2, 3, and 4

Claims (2)

[Claims] (1) A solid-state image sensor for color imaging formed by forming a color filter layer on a light-receiving surface, and a package that houses the solid-state image sensor with a transparent window member facing the color filter layer of the solid-state image sensor. and a transparent substance having the same refractive index as that of the color filter layer, which is filled between the transparent window member of the package and the color filter layer of the solid-state image sensor. . (2) The solid-state imaging device according to claim 1, wherein the transparent substance is a liquid substance that is filled and sealed in the package.