JPH01172581A - Manufacture of shadow mask - Google Patents

Abstract

PURPOSE:To obtain a shadow mask in which respective breadths of etching overhangs are uniformized in both of the upper and lower positions by providing an etching-resisting film having roundish corners on a metal sheet and then carrying out etching. CONSTITUTION:Photosensitive resin is uniformly applied to a metal sheet and then a masking plate on which a graphic pattern is drawn and in which numerous pit patterns having roundish corners, respectively, are provided is laid on the above sheet to undergo exposure. Then, in a state where an etching-resisting film shape 1 of the above-mentioned patterns is provided, etching is carried out. By this method, isotropic etching is performed and etching can be uniformly applied as illustrated. Accordingly, an etched shape 2 in which etching is uniformly carried out by the same breadth in the right and left directions can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of manufacturing a shadow mask used in various display devices such as CRTs and color televisions.

<Prior art> Conventional etching patterns for shadow masks include Japanese Patent Publication No. 51-9264, Japanese Patent Publication No. 48-42017, Japanese Patent Publication No. 60-11418. There are Japanese special public works such as Showa 5L12986, but all of these have square corners, as shown in Figure 5. On the other hand, the Japanese Patent Publication No. 60-11419 has an acute angle shape. Furthermore, in Japanese Utility Model Publication No. 58-34675, a hole-shaped pattern is partially provided, but the arcs are not rounded at the edges, but rather protrude from the sides.

<Problems to be Solved by the Invention> However, in an etching-resistant coating having an etching pattern as described above, etching from the corner portions is slower than other portions at first, but once the etching progresses to a certain extent, it reverses. The etching speed is faster than other parts. Therefore, even if the etching-resistant coating 1 has a rectangular shape as shown in FIG. 3, the etching rate is faster at the upper and lower ends, so that it protrudes to the left and right. Therefore, the etching shape 2 becomes a cocoon shape as shown in FIG. 6, and the efficiency as a shadow mask becomes poor.
In addition, the etching cut-off time was important, and uniform production was the key.

Measures to Solve the Problem> In order to solve the above problem, the corner-shaped etching pattern that causes over-etching is eliminated, and the edges are rounded and etched.

Depending on the etching characteristics, if the etching is strongly isotropic, the edges should be slightly rounded, but if the etching is not very isotropic, then the edges should be slightly rounded. It is necessary to round the edges until the hole pattern forms a semicircle at the top and bottom.

<Function> If the shape of the etching-resistant film is rounded at the edges, the side etching direction will be only in one direction, and the etching will proceed at approximately the same speed. Therefore, the etching protrusion to the left and right has the same width in both the upper and lower positions, and the production of the shadow mask is stabilized.

<Example 1> Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partial plan view showing one embodiment of the present invention.

After uniformly coating a photosensitive resin on a metal plate, a mask plate with a pattern drawn on it is applied and exposed. This mask plate is provided with numerous hole patterns with rounded edges. Etching-resistant coating shape with such a pattern
If etching is performed in a state where the etching is provided, it will be isotropically etched, and as shown in FIG. 2, side etching will be uniformly performed.

Therefore, in the left-right direction, the etched upward shape 2 is uniformly etched in the same width direction.

<Example 2> FIG. 3 shows another anti-etching coating shape 2 in which the hole pattern forms a semicircle at the top and bottom.

Even with this, the etching upward shape 2 is as shown in Fig. 4.
Etching is done uniformly in the same width direction in both left and right directions.

<Effects of the Invention> According to the present invention, the engraving protrusion to the left and right has the same width regardless of whether it is in the upper or lower position. This allows for uniform etching in both the vertical and horizontal directions, which is useful for manufacturing and designing shadow masks. I can maintain my degree.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a plan view showing an embodiment of the present invention.
4 is a plan view showing another embodiment; FIG. 4 is a plan view of the notching shape; FIG. 5 is a plan view showing a conventional example; FIG. 6 is a plan view of the notching shape. 1...Etching-resistant film shape. 2...When etched up shape Applicant: Toppan Printing Co., Ltd. Representative: Kazuo Suzuki Figure 1 Figure 2 Figure 3 Figure 5

Claims (1)

[Claims] 1) A method for producing a shadow mask, which comprises providing an etching-resistant film having a hole pattern with rounded corners on a metal plate and etching the film. 2) The method for manufacturing a shadow mask according to claim 1, wherein the hole pattern has a semicircular shape at the top and bottom.