JPH0490501A - Production of light shielding film - Google Patents

Abstract

PURPOSE:To improve the accuracy of the black stripes and the light shueldability of the light shielding film by forming a negative type resist on regions where colored films are to be formed to coat these regions, then subjecting the resist to exposing and developing. CONSTITUTION:Photopolymers dispersed with red, green and blue pigments are successively applied on a glass substrate 1 and are then baked after drying and patterning by exposing. The negative resist consisting of fine powdery palladium, silver, or the alloy composed thereof is applied over the entire surface of the red R, green G and blue B is applied thereon and is dried; thereafter, the resist is exposed with UV light from the rear surface of the substrate and is developed. The resist film 2 having a catalyst function, then, remains in the pars exclusive of the red, green and blue. The substrate is immersed into an electroless plating liquid to form a nickel/phosphorus plating film 3 in the parts exclusive of the red, green and blue. The light shielding film consisting of the metal is effectively formed in the regions between the colored films in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for manufacturing a light-shielding film, and particularly to a method for manufacturing a light-shielding film used in color TVs using liquid crystals, solid-state image pickup tubes, and the like.

(B) Conventional technology Conventionally, in color liquid crystal displays, in order to improve the ability to block unnecessary light, areas other than picture elements of color filters (red, blue, and green colored films) formed on a substrate, i.e. The area between the colored films is filled with a light-blocking material. Specifically, methods have been adopted in which synthetic resin materials containing black pigments, black carbon, etc. are filled and formed using printing methods or photoresist methods, and metals are filled and formed using vapor deposition methods or electroless plating methods. These filling layers are called light-shielding films.

(c) Problems to be solved by the invention However, in these conventional printing methods, the positional accuracy of printed pixels is not high, so in order to completely block light, it is necessary to increase the line width of the light-shielding film. As a result, there was a problem that the effective pixel area became smaller and the image on the liquid crystal display became darker.

In addition, although the photoresist method has higher accuracy than the printing method, it cannot be filled in large quantities because it contains a photosensitive group as a material component, and black pigments and black carbon for light shielding inhibit photocuring. There was still room for improvement in terms of light-shielding properties.

In addition, in the vapor deposition method, metal Cr is usually used as a light shielding film, so
Although it has excellent light-shielding properties, it requires a complicated process to form a predetermined pattern, is regulated by the dimensions of the vacuum chamber, and has problems such as a small number of treatments.

On the other hand, in the electroless plating method, a layer of palladium alloy or silver alloy is first formed on the substrate by vapor deposition or sputtering, and then a predetermined pattern is printed on it using ink of one or more colors by printing. In this method, after forming a color filter with a color filter, the substrate is immersed in an electroless plating solution to form an electroless plating film in the area where there is no ink layer (area between colored films). Since there is a layer of palladium alloy or silver alloy between the colored film and the substrate, the transmittance of the color filter decreases, causing problems such as dark images.

As described above, light-shielding films produced by conventional printing methods, photoresist methods, metal vapor deposition methods, and electroless plating methods have problems with black stripe accuracy, light-shielding properties, complicated processes, and image brightness. I chewed it.

(d) Means and effect for solving the problem In order to solve the above problem, in the present invention, red,
After forming a large array of green and blue colored films at predetermined intervals and coating the colored film forming area with a negative resist containing fine powder of palladium, silver, or an alloy thereof, The negative resist is exposed and developed using a method of irradiating light having a wavelength to which the negative resist is sensitive, to form a residual resist film in the area between the colored films, and then this substrate is subjected to electroless plating. By attaching the resist film, a light-shielding metal film is formed on the cured resist film.

The present invention is a method of forming a light-shielding film by applying an electroless plating method. In particular, a colored film is first formed on a substrate, and this colored film is used as a kind of mask to inject palladium, silver, or an alloy thereof. The main feature of this invention is that a resist film for electroless plating containing fine powder of ) A large number of red, green, and blue colored films are arranged in a predetermined pixel pattern on a transparent substrate such as a substrate.

Here, as the red, green, and blue colored films, predetermined spectral characteristics (coloring) can be obtained, and ultraviolet 1 (300 to 40 Qnm)
Pigment-dispersed color filters or interference filters that absorb Pigment-dispersed color filters are produced by dispersing pigments and patterning photosensitive resin (for example, positive or negative ultraviolet curable resin such as acrylic, unsaturated polyester, or polyether acrylate) using photolithography. can be formed by
The interference filter is made of SiO* or T that has predetermined absorption characteristics.
It can be formed by patterning a multilayer film of i1t by a so-called lift-off method. Here, the pattern configuration of a known color filter can be adopted as the arrangement pattern and the interval between each colored film.

Next, a negative resist containing powdered palladium, palladium alloy, silver, or silver alloy is applied on top of the substrate using a spin coater or roll coater, and after drying, the photosensitive wavelength of the negative resist is applied from the back side of the substrate. Expose and develop using the light you have. Suitable examples of this negative resist include UV curable resins such as acrylic, unsaturated polyester, and polyether acrylate. A photosensitizer may be added as appropriate. This negative resist acts as a catalyst layer and base layer for electroless plating in the subsequent process.

The thickness of the negative resist layer is suitably 0.5 μm or less. If the lower limit film thickness Q is more than 5 uz, the thickness of the light-shielding film will increase unnecessarily, which is not practical.

The lower limit film thickness is t, which functions as a catalyst for electroless plating.
It is not particularly limited as long as it is within Q range.

Further, in order to exhibit a catalytic function, these layers do not need to be a uniform film, and it is sufficient that the metal powder is present at a certain density or higher.

The above-mentioned palladium and silver generally have mtb as a catalyst for electroless plating. Its function as a catalyst is
It includes not only silver and palladium alone, but also silver and palladium alloys, and alloys in which a certain proportion of silver or palladium is alloyed with other metals. Such alloys include, for example, balanum copper based, palladium-tin based, silver-tin based,
Examples include silver-copper alloys.

The content of palladium, palladium alloy, silver, or silver alloy added to the negative resist is suitably 5 to 300% by weight based on the solid content of the negative resist. If it is less than 5% by weight, it will not be effective as a catalyst for electroless plating, and if it exceeds 300% by weight, the adhesion will be poor. Moreover, the average particle diameter is approximately 01 to 05 μm, which is suitable.

As mentioned above, by exposing the negative resist from the back side of the substrate, the negative resist layer in the area between the colored films, especially the bottom part, is hardened, and by development, the resist film remains only in the area between the colored films. .

By immersing the resist film-formed substrate thus obtained in an electroless plating solution, a metal film is formed by plating on the parts other than the patterned red, green, and blue colored films.

The thickness of the metal film is suitably from 300 μl to 1 μl, but preferably from 1 μl to 1 μl. Film thickness is 50
If it is less than 0 Å, only 1% of Fugo's light will pass through and the light will not be completely blocked, which is not preferable. Further, a film having a diameter of lμ1 or more is not practical considering that the purpose is light shielding.

Through the above steps, a light shielding film for a color liquid crystal display or the like can be formed.

A detailed explanation will be given below using examples.

(E) Example Example■ A fourth spectral characteristic was applied on the glass substrate l shown in FIG.
A photopolymer in which red, green, and blue pigments are dispersed as shown in Figure A is applied sequentially (2 μl thick) using a spin code method.
), and after drying and exposure patterning, baking was performed at 120° C. for 10 minutes [see FIG. 2(b)].

Next, a negative resist (acrylic UV curing resin) containing 30vt% of finely powdered palladium with a particle size of 0.2μ or less was applied to the entire surface of the red R1 green G and blue B, and dried.
2(C)] and then added to the negative resist from the back side of the substrate at t:4. When exposed and developed [Figure 2 (d)] with UV light having the sensitive wavelength range of C-bis(diethylamino)penzophenono (Figure 3), a film with a thickness of 0.5 μm was formed in the areas outside the red, green, and blue regions. A resist film 2 having a catalytic function remained. [Figure 2(e):.

Next, as an electroless plating solution, the red,
By forming a nickel-phosphorus plating film 3 of about 0.4 .mu.s on the areas outside the green and blue patterns, a color filter element as shown in FIG. 1 having a light-shielding film of the present invention was obtained. The nickel-phosphorus plating film 3 was formed on the areas outside the red, green, and blue patterns, and the light transmittance of this light-shielding film portion was 0.1% or less, indicating that it had a sufficient function as a light-shielding film.

Example 2 51 formed on a glass substrate by lift-off method etc.
A red, green, and blue interference color filter whose spectral characteristics were optically designed as shown in FIG. 4B was formed by using multiple layers of 01 and Tide.

Next, 35% of finely powdered silver is applied to the entire surface of the red, green and front elements.
A nickel-phosphorus plating film, which was coated with the same negative resist as in Example containing wt% and dried, and then formed in the same manner as in Example I, was reliably formed on the areas outside of the red, green, and blue patterns, and was sufficiently It was found that it has the function of a light-shielding film.

Example 3 510 formed on a glass substrate by lift-off method etc.
2. By using multiple layers of TiOt, a red, green, and blue interference color filter is formed with optically designed spectral characteristics as shown in FIG. 4B.

Next, as an electroless plating solution, cobalt sulfate 0.1 mol/f2 sodium tartrate 0.2 o1/(sodium succinate
0.1mol/12 Sodium hypophosphite 0.151
1101/12 ammonium sulfate O, 1 mol/
A nickel-phosphorus plating film was formed in the same manner as in Example 1, except that 12PH9.0 (adjusted with sodium hydroxide) was used. This plating film was formed on the areas outside of the red, green, and blue areas, and was found to have a sufficient function as a light-shielding film.

(F) Effects of the Invention As shown in the above embodiments, according to the light-shielding film manufacturing method of the present invention, a metal light-shielding film can be selectively and efficiently formed in the region between colored films.

Therefore, the pixel area can be increased, and it is also possible to prevent the image from becoming dark, thus achieving the objective.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of a color filter element manufactured by the method of the present invention, FIG. 2 is an explanatory diagram showing the same manufacturing process sequentially, and FIG.
FIG. 4 is a graph showing the spectral characteristics of the green and blue colored films, and FIG. 4 is a graph showing the spectral sensitivity of the negative resist used in the examples. ...Glass substrate, ...Palladium-containing negative resist, 3 ...Nickel-phosphorus plating film.

Claims (1)

[Claims] 1. A large number of colored films of red, green, and blue are formed in an array at predetermined intervals on a transparent substrate, and palladium,
After forming a coating with a negative resist containing powder of silver or an alloy thereof, the negative resist is exposed and developed using a method of irradiating light having a wavelength to which the negative resist is sensitive from the back side of the substrate. A method for producing a light-shielding film, characterized in that a resist film is left in the region between the colored films, and then a light-shielding metal film is formed on the resist film by subjecting the substrate to electroless plating.