JPS6316528A - Manufacture of black matrix phosphor screen - Google Patents

Abstract

PURPOSE:To attempt to uniformalize a paint film of light absorptive material laid on the curved part of a face panel by causing a photoresist after development to react with a substance to insolubirize polyvinyl alcohol so as to insolubirize the photoresist. CONSTITUTION:A photoresist 2 composed of PVA(polyvinyl alcohol) and dichromate is applied to the inner periphery of a cleaned face panel 1 and after drying it, a shadow mask 4 is attached to a panel pin 3 to expose the specified position of the photoresist 2 by means of a high pressure mercury lamp or the like. Then, the shadow mask 4 is detached, and developed by spraying it with deionized water to display a an exposed and hardened photoresist 6. Following this, a substance to insolubirize PVA is injected onto the inner surface of the face panel 1 to cause it to react with a substance to insolubirize PVA of the photoresist 6 so as to insolubirize the surface thereof. Then, light absorptive material 8 is applied to the inner surface of the face plate 1 and after drying it, the photoresist 6 and the light absorptive material 8 on the photo-resist 6 are removed by causing a reaction between the photoresist 6 and an oxiding agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a method for manufacturing a black matrix type phosphor screen used in a color cathode ray tube. More specifically, the present invention relates to a method of manufacturing a black matrix type phosphor screen in which the periphery of the light-emitting pixels of the phosphor screen is covered with a black light-absorbing material.

[Prior Art] A black matrix type phosphor screen has conventionally been manufactured by the process shown in FIG. That is, the inner surface of the face panel (1) is cleaned and coated with polyvinyl alcohol (P).
A negative type photoresist (2) containing VA) and dichromate as main components is applied to the inner surface of the face panel (1) and then dried.

Next, a shadow mask (4) is attached to the panel bin (3) provided on the face panel (1), and ultraviolet light (5) is irradiated from a predetermined light source to coat the photoresist (2).
expose a predetermined position. Next, shadow mask (4
) is removed and developed by spraying with deionized water to melt and remove the unexposed areas (7). Next, a black light-absorbing material (8) such as a graphite suspension is applied to the inner surface of the face panel (1) and dried. Next, an oxidizing agent such as a hydrogen peroxide solution that decomposes the photoresist (6) that has been photocured is injected into the inner surface of the face panel (1) and allowed to react. High pressure deionized water is then sprayed to remove the decomposed photoresist and the black light-absorbing material (8) above it. In this way, the black matrix is completed.

Thereafter, a green light emitting pixel 01), a blue light emitting pixel az and a red light emitting pixel are sequentially formed by a photo printing method to complete a black matrix type phosphor screen (2).

[Problems to be Solved by the Invention] In this conventional method for manufacturing a black matrix type phosphor screen, as shown in FIG. Materials (8
) is warped (8a), or a part of the light-absorbing material (8) is missing (8b), and the light emitted in the cathode ray tube leaks from these parts, and the curved part (
A so-called push-through type television set in which 1a) is exposed has problems such as serious screen defects.

As a result of a detailed investigation into the above-mentioned problem, the inventor of the present invention found that there was no defect in the coating film itself of the light-absorbing material (8), and that it was caused by the reaction between the photoresist and the oxidizing agent (8a) shown in FIG.
, (8b). In other words, the spray of deionized water during the photoresist development process not only dissolves and removes the unexposed areas (swords), but also partially dissolves the photoresist (6) that has been photocured and removes the curved areas of the face panel (1). (1a), and the photoresist present in the curved portion (1a) reacts with the oxidizing agent during the treatment process with the oxidizing agent, causing the above-mentioned problem.

The present invention solves the above problems and provides a uniform coating of the light-absorbing material (8) on the curved portion (1a) of the face panel,
The purpose of the present invention is to develop a novel method for manufacturing a black matrix type phosphor screen that can provide a high quality black matrix type phosphor screen with no screen defects.

[Means for Solving the Problem] The present invention chemically insolubilizes the surface of the photoresist in order to prevent the elution of the photoresist (6) that has been photocured. The photoresist (6) is insolubilized by reacting with a substance that insolubilizes polyvinyl alcohol.

That is, the present invention applies a photoresist made of polyvinyl alcohol and dichromate to the inner surface of the face panel, dries it, exposes a predetermined position of the photoresist, develops it, and then reacts the photoresist with a substance that insolubilizes the polyvinyl alcohol. The present invention relates to a method for manufacturing a black matrix type phosphor screen, which further comprises applying a light-absorbing material to the inner surface of a face panel, drying it, and removing the photoresist and the light-absorbing material on the photoresist.

[Function] Due to the treatment with a substance that insolubilizes polyvinyl alcohol in the present invention, even if the photoresist that has been photocured once swells during the development process with deionized water, the surface will be chemically insolubilized so that it will not re-elute. As a result, there is no photoresist in the curved portion of the face panel, which is no longer affected by the oxidizing agent.

[Example] Next, an example of the present invention will be described based on FIGS. 1 and 2. FIG. 1 is a flowchart showing the steps of this embodiment, and FIG. 2 is a sectional view schematically showing the manufacturing steps of this embodiment.

First, a photoresist (2) made of polyvinyl alcohol (hereinafter referred to as PVA) and dichromate is applied to the inner surface of the cleaned face panel (1). As the face panel (1), those conventionally used in color cathode ray tubes can be used. Examples of dichromates include ammonium dichromate, sodium dichromate, etc., and photoresists made of PVA and dichromates include PVA 1 to 5% (wt%, same hereinafter), dichromate, etc. A composition consisting of 0.1-0.5% acid salt and the balance deionized water can be used. As a coating method, a spin coating method or the like can be used.

After drying the applied photoresist (2), apply a shadow mask (2) to the panel bin (3) of the face panel (1).
4) and remove the photoresist (a) from the predetermined light source position.
A predetermined position is exposed using a high-pressure mercury lamp or the like. Exposure conditions vary depending on the composition of the photoresist, the type of exposure apparatus, etc., and are adjusted as appropriate.

Next, the shadow mask (4) was removed, the photoresist (6) was developed by spraying deionized water, and the photoresist (6) was photocured.
). Next, a substance that makes PVA insoluble is injected into the inner surface of the face panel (1) and the photoresist (
6) is reacted with a substance that insolubilizes PVA to insolubilize the surface of the photoresist (6).

Examples of substances that insolubilize PVA include boric acid aqueous solution, tannin aqueous solution, and ammonium molybdate aqueous solution. For example, when using a boric acid aqueous solution,
Preferably, the concentration is 0.05 to 0.5%. Further, the temperature of the boric acid aqueous solution is preferably 15 to 30°C, and the reaction time is preferably 5 to 20 seconds.

Next, the light-absorbing material (8) is applied to the inner surface of the face panel (1) and dried, and then the photo-resist (6) and the light-absorbing material (8) on the photo-resist (6) are coated with the photo-resist ( A black matrix ω) is obtained by reacting 6) with an oxidizing agent and removing it.

As light absorbing materials, graphite suspension,
Carbon black etc. can be used. As a coating method, a spin coating method or the like can be used. As the oxidizing agent, hydrogen peroxide, periodate, etc. can be used. For example, when hydrogen peroxide is used as the removal method, 5-20% hydrogen peroxide at 20-50°C is applied to the face panel. A preferred method is to inject the material into the inner surface of (1), react for 20 seconds to 1 minute, and then spray deionized water.

Next, a green light-emitting pixel (Il+), a blue light-emitting pixel 0, and a red light-emitting pixel 0 are sequentially formed by a photographic printing method to produce a black matrix type phosphor screen (2).

EXAMPLES The present invention will be explained in more detail below using Examples, but the present invention is not limited to these Examples.

Example 1 First, a photoresist (2) consisting of 1% polyvinyl alcohol and 0.1% ammonium dichromate was applied to the cleaned face panel (1) on the inner surface of the face panel (1) to a thickness of 2 μm in a dry field. It was dissolved in deionized water and applied by spin coating, followed by drying.

Next, a shadow mask (4) was installed in the panel bin (3) of the face panel (1), and a predetermined position of the photoresist (2) was exposed to light from a predetermined light source position using a high-pressure mercury lamp.

Next, the shadow mask was removed, and deionized water was sprayed and developed to reveal the exposed areas. Next, 0 at 30℃
．． The photoresist (6), which was photocured by injecting a 5% aqueous boric acid solution into the inner surface of the face panel (1), was reacted with the aqueous boric acid solution to insolubilize the photoresist (6).

Next, the graphite suspension (8) was applied to the inner surface of the face panel (1) and dried at 30°C.
5% hydrogen peroxide solution was injected into the inner surface of the face panel and allowed to react for 1 minute, and then sprayed with deionized water to form a photoresist (6) and a film of graphite suspension (a light-absorbing material) on the photoresist (6). (8)) was removed.

The graphite suspension film on the curved part of the obtained face panel (1) is normal and as shown in Figure 4 (
Defects such as 8a) and (8b) did not occur at all.

Next, a green light-emitting pixel 01), a blue light-emitting pixel 02) and a red light-emitting pixel 0 were sequentially formed by a photographic printing method to produce a black matrix type phosphor screen (2).

In the above example, a boric acid aqueous solution was used alone to insolubilize the photoresist, but it may also be used together with a surfactant that has a rinsing effect to give the effect of rinsing off the eluted photoresist. In exactly the same way (
The effect of preventing defects such as 8a) and (8b) can be improved.

[Effects of the Invention] As described above, according to the manufacturing method of the present invention, defects do not occur in the light-absorbing material film on the curved portion of the face panel, so even in a television set where this portion is exposed, there are no defects on the screen. This has the effect of being able to provide a high-quality black matrix type phosphor screen with no blemishes.

[Brief explanation of the drawing]

FIG. 1 is a flow chart showing the steps of an embodiment of the present invention, and FIG. 2 is a sectional view schematically showing the manufacturing steps of the present invention. FIG. 3 is a sectional view schematically showing the manufacturing process of a conventional black matrix type phosphor screen, and FIG. 4 is a sectional view showing defects in the conventional black matrix type phosphor screen. (Main symbols of the drawing) (1): Face panel (z: Photoresist (4): Shadow mask (8): Light-absorbing material agent

Claims (2)

[Claims] (1) Apply a photoresist made of polyvinyl alcohol and dichromate to the inner surface of the face panel, dry it, expose a predetermined position of the photoresist, develop it, and then react the photoresist with a substance that makes polyvinyl alcohol insoluble. A method for producing a black matrix type phosphor screen, which further comprises applying a light-absorbing material to the inner surface of a face panel, drying it, and removing the photoresist and the light-absorbing material on the photoresist. (2) The manufacturing method according to claim (1), wherein the substance that insolubilizes polyvinyl alcohol is an aqueous boric acid solution, an aqueous tannin solution, or an aqueous ammonium molybdate solution.