JPH0766083B2 - Organic color filter - Google Patents

Description

The present invention relates to an organic color filter having an improved dyed layer.

[Conventional technology]

It has been known for a long time that a mixture of natural protein, particularly gelatin, glycerin, albumin or a partial hydrolyzate thereof and dichromate, exhibits photosensitivity. It is used. For example, it is widely used as a dyeing layer of a color separation organic color filter used in a color image pickup device by taking advantage of the dyeability of dyes.

As a method of manufacturing an organic color filter, when roughly classified,
The following two are listed.

A method in which a patterned resist is provided on the layer to be dyed, the exposed portion of the layer to be dyed is dyed to form the dyed layer, the resist is peeled off, and then the next dyed layer is similarly formed. (A method in which a single dyed layer is dyed separately into a plurality of dyed portions.) The dyed layer is exposed to a predetermined pattern, developed and dyed to form a dyed layer, and then a transparent dye resistant insulating layer And then forming a next dyed layer on it in the same manner.

The above method has a problem such as color bleeding at the boundary of each dyed portion, and the method is generally used.

Also, as a form of a color filter, a color filter is directly manufactured on a solid-state image sensor (on-chip type) A color filter is manufactured on a glass plate and is attached to a solid-state image sensor (bonding type).

In any of the conventional cases, as a dyed layer, a natural protein, particularly gelatin, griux or the like or a partial hydrolyzate thereof which is made to have photosensitivity with a dichromate or the like has been used.

[Problems to be solved by the invention]

Gelatin, griux, etc. are usually prepared by hydrolyzing beef bones or pork skin with alkali or acid, extracting with warm water and adjusting the pH to produce pH, so that alkali metal ions, alkaline earth metal ions as anions and halogen ions as anions are used. Contains. These metal ions cannot be completely removed by ordinary purification, and usually contain several hundred ppm or more of alkali metal ions, alkaline earth metal ions, and halogen ions. When an organic color filter is produced using gelatin, guille, etc. containing such metal ions or halogen ions and applied to a solid-state image sensor, solid-state imaging is gradually performed by alkali metal ions, halogen ions, etc. in the color filter. However, there is a drawback that the reliability of the solid-state image pickup device is significantly lowered, such as moving to an element portion and causing a malfunction.

[Means for solving problems]

The present inventors have conducted intensive studies in view of the above points, and as a result, found that the problem can be solved by using desalted and refined gelatin or grille or a partial hydrolyzate thereof. Completed the invention.

That is, the gist of the present invention is to provide an organic color filter having a dyeing layer formed by dyeing a layer to be dyed and a dye resistant insulating layer on a substrate,
An organic color filter is characterized in that the layer to be dyed contains a natural protein or a partial hydrolyzate thereof, which is desalted and purified by passing through a mixed bed of a cation exchange resin and an anion exchange resin as a main component.

Hereinafter, the present invention will be described in detail.

1 (a) to 1 (i) are explanatory views showing the manufacturing process of an example of the organic color filter of the present invention.

In the figure, 1 is a silicon wafer, 2 is a light detecting part, 3 is a scanning line, 4 is a light-shielding film, 5 is a protective film, 6 is a flattening layer, 7 is a mask, 8 is a dyed layer, and 8'is a dyed layer. , 9 is a dye-resistant insulating layer, 10 is a banding pad, 11 is a dyeing layer, and 12 is a surface layer.

There are two types of methods for mounting the organic color filter on the solid-state image pickup device, a direct attachment type and a bonding type, but the one shown in the figure is the direct attachment type.

In the case of a direct-mounting type color filter, an organic color filter is directly provided on the surface of the solid-state image pickup device, and the solid-state image pickup device which is the base of the organic color filter is, for example, a silicon wafer 1 as shown in FIG. The portion 2, the scanning line 3, the light-shielding film 4 and the like are provided, and the protective film 5 of phosphorus glass, quartz or the like is provided on the upper surface thereof.

The organic color filter of the present invention is formed on the upper surface of the solid-state image pickup device as described above, and will be described in the order of steps.

First, the flattening layer 6 is coated on the protective film 5 of the solid-state image sensor to a thickness of about 0.2 to 2.0 μm. For this flattening layer, it is preferable to use the same photosensitive resin as that used for the dye-resistant insulating layer 9 described later. By this layer, the surface of the light detecting portion is flattened, the dyed layer 8, the dye-resistant insulating layer 9 and the like are easily formed, and color stains and the like due to uneven thickness of the dyed layer 8 are reduced. To be done. Then, a predetermined bonding /
Process pad 10 etc.

To process the bonding pad 10 or the like, a mask 7 having a flattening layer made of a photosensitive resin or the like in a predetermined pattern, that is, a pattern in which a portion where the bonding pad 10 is formed, etc. is made light opaque. Is exposed to light, the photosensitive resin is cross-linked by light, and then developed with a developing solution, the unexposed portions corresponding to the bonding pad portions and the like are eluted to be processed {Fig. 1 ( C)}.

Next, the dyed layer of the present invention is formed by the following procedure.

First, desalting and refining are performed by using gelatin, griue, etc. or their partial hydrolyzate as an aqueous solution of 3 to 50%, preferably 5 to 40%. Desalination purification is carried out by passing through a mixed bed of cation exchange resin and anion exchange resin. In order to reduce the viscosity of gelatin, desalting is preferably carried out at 25 to 80 ° C, more preferably 30 to 60 ° C. Only small Preferably SV can raise the effect of desalting for high viscosity diffusion coefficient of the gelatin is small 10 hr ^-1 or less, more preferably not carried out at 5 hr ^-1 or less. Desalination degree is 10ppm or less for each of alkali metal and halogen (relative to solid content)
Is desirable. Photosensitivity is imparted by adding 5 to 50 wt% (to solid content) of ammonium dichromate, diazo resin and the like to the thus obtained aqueous solution of gelatin, griue and the like.

The water-soluble photosensitive composition thus obtained is applied to the surface of the flattening layer 6 by a method such as spin coating to form a dyed layer 8.

The layer to be dyed 8 is usually provided so as to have a thickness of 0.1 to 2 μm (FIG. 1 (d)).

Then, similarly to the processing of the flattening layer 6 described above, exposure and development are performed through a mask having a predetermined pattern.

Since the photosensitive composition is usually made to have a photosensitivity in the range of 440 to 380 nm, it is exposed by using a high pressure mercury lamp having a wavelength in such a region as a light source {Fig. 1 (e)}.

Then, it is developed with water to form a dyed layer 8 having a predetermined pattern, and dyed by a known method with a first color desalted and purified dye having a predetermined spectral characteristic to form a dyed layer 8 '{ FIG. 1 (f)}.

Then, the dye-resistant insulating layer 9 is covered.

The dye-resistant insulating layer 9 is made of polymethacrylic acid ester, polyglycidylmethacrylate, polyacrylic acid ester, cyclized rubber, or the like in view of dyeing resistance, adhesion to the substrate and the dyeing layer 8 ', transparency, and coating property. A copolymer of them and other components, or a combination of them with an aromatic bisazide or a diazonium salt as a cross-linking agent for imparting photosensitivity, a cellosolve such as ethyl cellosolve or methyl cellosolve, or xylene or the like. It is formed by coating an aromatic solvent. Exposure and development are performed in the same manner as in the case of the flattening layer 6 described above {FIG. 1 (g)}.

Then, the second dyed layer 11 is provided on the dye-resistant insulating layer 9 using the aqueous solution photosensitive composition of the present invention in the same manner as described above. As described above, since the organic color filter is used semi-permanently in contact with the solid-state image pickup device, a small amount of alkali metal or halogen ion contained as an impurity in the color filter moves to the solid-state image pickup device for a long time and the solid-state image pickup device of the element is not used. This is a cause of lowering the reliability, but in the case of the organic color filter of the present invention, the impurity level is kept sufficiently low, so that high reliability can be secured.

The second dyed layer thus obtained is exposed and developed in the same manner as described above to form a dyed layer having a predetermined pattern.
Then, the second dyed layer 11 is formed by dyeing with a second color dye having a predetermined spectral characteristic {FIG. 1 (h)}.

By repeating this operation, another dyeing layer may be formed through another dyeing resistant insulating layer.

As the dyeing layers 8'and 11, three types of three primary color systems of red, green and blue may be used, or three types of complementary color systems of cyan, green and yellow may be used. At this time, for example, the second yellow dyeing layer 11 may be formed so as to partially overlap with the first cyan dyeing layer 8 ', and the third color green color may be obtained at the overlapping portion. .

Usually, a surface layer 12 is provided on the uppermost dye layer for the purpose of flattening the surface or protecting the dye layer.

As the surface layer 12, a resin having strength, transparency, and adhesion to the intermediate layer and the dyeing layer is used, and an acrylic resin, a polyamide resin, or the like can be used. Moreover, you may use the polymer of the above-mentioned dyeing resistant insulating layer.

The surface layer is usually provided so as to have a film thickness of 0.1 to 2 μ {FIG. 1 (i)}.

Thus, an organic color filter can be obtained. Such an organic color filter can be advantageously used as various color image sensors.

The above description with reference to the drawings is for the case of a direct attachment type color filter. When the present invention is applied to a laminated type color filter, a layer to be dyed or the like may be formed on a glass substrate or the like to obtain a color filter, and the color filter may be mounted on a solid-state image sensor by laminating it.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 75:15:10 (molar ratio) copolymer of methyl methacrylate, methacrylic acid, and 2-hydroxyethyl methacrylate on a solid-state imaging device substrate (ηsp / C = 0.95dl / g at 30 ° C. in THF) And a solution of diazo resin (solvent: ethyl cellosolve / N-methylpyrrolidone = 8: 2 (volume ratio) mixed solvent) were spin-coated to a film thickness of 2 μm to form a flattening layer. This flattening layer was exposed through a mask having a predetermined bonding pad pattern at an energy amount of 300 millijure / cm ² and then developed with ethyl cellosolve for 2 minutes at room temperature to be transparent and the bonding pad portion was processed to be flat. A layer was obtained.

Then, on this flattening layer, gelatin-ammonium dichromate {10: 2, weight ratio, 16% aqueous solution of gelatin was used as a cation exchange resin (DIAION SK1B Mitsubishi Kasei Co., Ltd.) at 40 ° C.
And anion exchange resin (Diaion SA10A manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) mixed with SV = 3hr ^-1 for purification, and alkali metal ion and halogen ion less than 10ppm} aqueous solution film thickness Was spin-coated so that

The wettability with the flattening layer was sufficient, and a smooth dyed layer without film roughness was formed.

After this layer to be dyed is exposed with an energy amount of 200 mm / cm ² through a mask having a predetermined pattern,
It was developed with water (45 ° C., 1 minute). Then, after heating at 120 ° C for 15 minutes to harden the gelatin film, "Kayanol Yellow N5G" (manufactured by Nippon Kayaku Co., Ltd.) whose pH was adjusted to 4 with acetic acid
Then, a dyed layer was formed by dyeing with an approximately 0.1% aqueous solution of desalted and purified) at 75 ° C. for 1 minute.

Next, a photosensitive composition having the same composition as that of the planarizing layer is formed to a film thickness of 0.5.
It was coated so that it had a thickness of μ, and was exposed and developed in the same manner as in the case of the flattening layer to form a transparent dyeing resistant insulating layer having a bonding pad portion processed.

Then, a gelatin monochromate ammonium layer was formed on the dye-resistant insulating layer as described above, exposed and developed in the same manner as described above, and the pH was adjusted to 4 with acetic acid, "Diacron Turquisble GF". "(Manufactured by Mitsubishi Kasei Co., Ltd., desalted and purified) was dyed with an approximately 0.3% aqueous solution at 75 ° C for 1 minute to form a dyed layer.

Next, the same photosensitive composition as the flattening layer is applied as a protective film so as to have a film thickness of 0.5 μ, exposed, and developed to form a transparent surface layer having a bonding pad portion processed.
A solid-state color image sensor was manufactured.

[Advantages of the Invention] In the organic color filter of the present invention, since metal ions and halogen ions in the filter are completely removed, malfunction due to movement of metal ions and halogen ions to the image pickup device portion is prevented, and reliability is improved. Can be significantly improved.

[Brief description of drawings]

1 (a) to 1 (i) are explanatory views showing the manufacturing process of an example of the organic color filter of the present invention. In the figure, 1 is a silicon wafer, 5 is a protective film, 6 is a flattening layer, 8 is a dyed layer, 8'is a dyed layer, 9 is a dye resistant insulating layer,
11 is a dyed layer, and 12 is a surface layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideo Makishima 1000 No. 1, Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Chemical Industry Co., Ltd. (56) Reference JP-A-59-7318 (JP, A) Kaisho 58-155759 (JP, A)

Claims (4)

[Claims] 1. An organic color filter having a dyeing layer formed by dyeing a dyeing layer and a dye resistant insulating layer on a substrate, wherein the dyeing layer is a mixture of a cation exchange resin and an anion exchange resin. An organic color filter comprising, as a main component, a natural protein or a partial hydrolyzate thereof, which is desalted and purified by passing through a floor. 2. The content of alkali metal and halogen of the natural protein or its partial hydrolyzate is 10 ppm, respectively.
The organic color filter according to claim (1), characterized in that: 3. The organic color filter according to claim 1, wherein the natural protein is gelatin or mulberry. 4. The organic color filter according to any one of claims (1), (2) and (3), wherein the substrate is a solid-state image sensor. .