JPH037106B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a concavo-convex substrate, and more specifically, to a method for manufacturing a concavo-convex substrate, and more specifically, to form various concavo-convex patterns different from a pattern of a shadow mask on a substrate for forming a phosphor screen from a single shadow mask pattern. Regarding the method.

A concavo-convex substrate having a concavo-convex surface with fine pitches arranged two-dimensionally regularly is used to grow a phosphor on the concavo-convex surface. For example, in Philips Research Report, Vol. 29, pp. 353-362 (1974), a checkered pattern consisting of square irregularities of 10 to 50 μm on a side is formed on a copper plate, and a cesium iodide phosphor is placed on top of this. A method for growing the film to a thickness of several tens to hundreds of μm is disclosed.

In general, an optical printing method is preferably used to form a concavo-convex pattern on the surface of a substrate such as a metal such as copper or a glass plate. This optical printing method is
For example, after cleaning the surface of the substrate, applying a negative (or positive) photoresist film to the surface,
Next, a shadow mask having a light-transmitting part and a light-blocking part is placed on the photoresist film, and the photoresist film is exposed by shining light thereon, thereby transferring the pattern of the shadow mask onto the photoresist film. do. Next, the unexposed portions of the photoresist are removed using a developer to expose the underlying portions of the substrate, and after drying the substrate, an etching solution erodes the exposed portions of the substrate to form recesses. Finally, by peeling off the photoresist in the exposed area, an uneven surface having the same pattern as the shadow mask pattern is formed on the substrate.

Normally, in this process, the shadow mask is coated with a photoresist, for example, in order to make the uneven pattern on the substrate the same as the pattern of the shadow mask used and to form sharp boundaries between the depressions and protrusions on the substrate. A method of exposure is carried out in which the light diffraction effect, which causes the above-mentioned problems, is prevented by bringing the film into close contact with the film.

However, considering the relationship with the wavelength of light,
It is difficult to create a shadow mask with a line width of 2 μm or less and a pitch of 5 μm or less.

On the other hand, in the case of forming a fluorescent surface on a substrate, the pattern of the uneven pattern that spreads two-dimensionally is more important than the sharpness of the interface between the depressions and protrusions on the uneven surface of the substrate. be.

As a result of repeated research into the formation of various uneven patterns that spread two-dimensionally on a substrate, the inventors developed a shadow mask with an opening pattern having regular pitches of 5 to 20 μm perpendicular to each other on a photoresist film. The present invention was completed based on the discovery that various patterns different from the patterns of the shadow mask are formed on the substrate when the substrate is exposed to light after being maintained at a distance of 5 to 80 μm without being in close contact with each other.

An object of the method of the present invention is to provide a method for manufacturing a concavo-convex substrate in which various concavo-convex patterns different from the pattern of the shadow mask are formed on a substrate for forming a phosphor screen using one shadow mask.

That is, in the method of the present invention, a photoresist coated on the surface of a substrate is exposed through a shadow mask having a regular pattern, and then the photoresist is developed to create a resist image. In the method for manufacturing a concavo-convex substrate for forming a phosphor screen, the pattern of the shadow mask is an aperture pattern having a regular pitch of 5 to 20 μm in a direction perpendicular to each other; Further, by maintaining the distance between the shadow mask and the photoresist at 5 to 80 μm, a pattern different from the pattern of the shadow mask is exposed on the photoresist. The phosphor screen here includes CRT, thin film phosphor screen, etc.

In the method of the present invention, one example of the shadow mask used is as shown in FIG.
A regular aperture consisting of a checkered pattern with a pitch of 5 to 20 μm, consisting of a 10 μm square area that does not pass light (blacked out area in the figure) and a 2.5 to 10 μm side that allows light to pass (unfilled area in the figure). There's a pattern.

In the shadow mask, if the pitch exceeds 20 μm (one side of the square exceeds 10 μm), the pattern projected onto the photoresist upon exposure will simply be a blurred array of squares, and if the pitch is less than 5 μm (square (less than 2.5 μm on one side) is meaningless considering that the pattern formed on the substrate will be utilized through optical observation.

The shadow mask according to the present invention is not limited to the above-described checkerboard pattern, but may have an opening pattern having a regular pitch of 5 to 20 μm perpendicular to each other, and the shape of the openings is not limited to square. A similar effect can be obtained even if the shape is triangular, hexagonal, etc.

Using the shadow mask, the surface of the substrate coated with photoresist is exposed. One of the methods
An example is shown in Figure 2. In FIG. 2, reference numeral 1 denotes a substrate, and a photoresist 2 is coated on the surface of the substrate. 3 is a shadow mask according to the present invention,
The shadow mask 3 and the photoresist 2 are held at a constant distance 4 without being brought into close contact with each other. In the method of the present invention, the photoresist is exposed in such a state by irradiating parallel light rays 5 from a light source.

At this time, by setting the interval 4 in the range of 5 to 80 μm, various patterns different from the checkered pattern of the shadow mask 3 are projected onto the photoresist 2. When the distance 4 exceeds 80 μm,
The patterns projected onto the photoresist become indistinguishable due to mutual diffraction, resulting in nearly uniform illumination. Furthermore, if the interval 4 is less than 5 μm, the pattern of the shadow mask is only projected slightly blurred.

As mentioned above, the reason why a pattern different from the pattern of the shadow mask 3 can be obtained on the photoresist 2 when the distance 4 is between 5 and 80 μm is probably due to light interference. By providing unevenness to the phosphor screen, it is possible to increase the brightness and adhesive strength to the substrate compared to a flat phosphor screen, but according to the present invention, a pattern different from the pattern of the shadow mask can be provided on the photoresist, and by extension, on the phosphor screen. This makes it possible to obtain a phosphor screen with a complex or fine pattern according to design needs from a shadow mask with a simple pattern that can be obtained without complex or fine processing. Furthermore, by adjusting the spacing, a single shadow mask can be used to create a plurality of patterns of phosphor screens, contributing to rationalization of the process.

In the method of the present invention, the photoresist pattern formed as described above is developed in a conventional manner and then etched to obtain a textured substrate having a regular pattern of depressions and depressions on its surface.

The present invention will be explained below based on examples.

Example A bis-allyldiazide-based photosensitizer (negative photoresist) was applied on a quartz substrate with a smooth surface by a conventional method.
was applied.

The shadow mask used had a regular checkered pattern as shown in Fig. 1, which had square openings (pitch 10 μm) with sides of 5 μm.

As shown in FIG. 2, while maintaining the distance between the photoresist and the shadow mask, the photoresist was exposed to light from an ultra-high pressure mercury lamp and developed using xylene. Figure 3 shows the patterns formed on the photoresist when the spacing was changed to 8 μm, 30 μm, and 40 μm with an exposure time of 2 to 10 seconds.
It is shown in FIGS. 4 and 5. FIG. 6 shows a pattern when the exposure time is 60 seconds and the spacing is 8 μm.
In FIGS. 3 to 6, white areas are non-exposed areas, and black areas are exposed areas.

As is clear from FIGS. 1 and 3 to 6, even if the shadow masks have the same pattern,
It has been found that when exposure is performed while changing the distance between the photoresist and the photoresist, various patterns that are completely different from the pattern of the shadow mask are formed on the photoresist.

The one in Figure 4 was developed with xylene (developer) to remove the unexposed area, and after drying, hydrogen fluoride 6
%, ammonium 40% ammonium fluoride solution (etching solution) for 5 minutes. Finally, when the exposed areas (black areas) were removed with a mixture of hydrogen peroxide and sulfuric acid (mixing ratio 1:3), the white areas are grooves (concave areas) and the black areas are square plateaus (convex areas) on the uneven substrate. was gotten.

Magnification of 4200 from diagonally above the uneven pattern on the board
When photographed at double magnification, the ditch and square plateau mentioned above were clearly observed.

In addition, when a positive type photoresist was used as the photoresist, it was confirmed that the above-mentioned groove was formed as a bank and the square plateau was formed as a square basin.

[Brief explanation of the drawing]

FIG. 1 is an example of a shadow mask used in the method of the present invention, and FIG. 2 is a conceptual diagram for explaining exposure in the method of the present invention. 3 to 6 conceptually show patterns obtained on photoresist by the method of the present invention from the pattern of FIG. 1. 1...Substrate, 2...Photoresist, 3...Shadow mask, 4...Spacing, 5...Light.

Claims (1)

[Claims] 1. Photoresist applied to the surface of the substrate,
After exposure through a shadow mask having a regular pattern, the photoresist is developed to create a resist image, and the substrate is further etched to form a regular uneven pattern on the substrate. In the method for manufacturing a textured substrate for
It is characterized by an aperture pattern having a regular pitch of 20 μm, and by maintaining a distance between the shadow mask and the photoresist at 5 to 80 μm, a pattern different from the pattern of the shadow mask is exposed on the photoresist. A method for manufacturing an uneven substrate for forming a phosphor screen.