JPS6133633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive liquid coating method, and more particularly to a method for coating and forming a uniform photosensitive film of a desired thickness on at least one main surface of a long metal plate for a shadow mask mounted on a color picture tube. It is related to. For example, a shadow mask installed in a color picture tube is usually manufactured using photolithography. To do this, a uniform photoresist film of a desired thickness is coated on at least one principal surface of a long metal plate for a shadow mask, exposed to light through a dot-shaped or rectangular negative pattern, and then developed and etched. A method is used to form a shadow mask having regularly arranged dot-shaped or rectangular openings. Next, a conventional photosensitive liquid coating method will be explained with reference to FIG. After that, the photosensitive liquids 9 and 10, which have been poured into tanks 7 and 8 whose bottom surfaces are provided with elastic plates 5 and 6, are drawn up vertically by a first roller 4 provided in the water 3. The photosensitive liquid is guided through the second roller 11 to the drying process, and in such a photosensitive liquid coating device, rubber is usually used for the elastic plates 5 and 6 that regulate the thickness of the photosensitive film. Therefore, there are various drawbacks as follows. That is, (1) the thickness of the photosensitive film applied to both sides of the metal plate 1 is determined mostly by the correlation between the viscosity of the photosensitive liquid and the elasticity of the rubber; Even if a photosensitive liquid is used, the photosensitive film becomes thick, and when the elasticity of the elastic plates 5 and 6 is constant, the thickness of the photosensitive film changes depending on the viscosity of the photosensitive liquid. (2) If the elastic plates 5 and 6 are damaged, the photosensitive liquid may leak or streaks may form on the photosensitive film, degrading the quality of the photosensitive film, and ultimately causing damage to the openings of the shadow mask. Affects shape and size. (3) Since the elastic plates 5 and 6 must be replaced frequently, there are problems in terms of workability and economy. (4) Smuts and the like adhere to the photosensitive film, degrading the quality of the photosensitive film. The present invention has been made in view of the various drawbacks of the conventional art, and an object of the present invention is to provide a method for easily forming a photoresist film having a predetermined thickness on at least one principal surface of a long metal plate. Next, one embodiment of the present invention will be explained with reference to FIGS. 2 to 5. That is, after the long metal plate 21 that has been subjected to a degreasing process, a pickling process, and a water washing process (not shown) is introduced into the photosensitive liquid 23 poured into the tank 22 by the first roller 24, the first roller 24 and roller 2
In this case, a pair of cylindrical rollers 25, 2 are drawn out in the photosensitive liquid 23 near the liquid surface 29 of the photosensitive liquid 23.
6 is provided and the metal plate 21 is pulled up, a photosensitive liquid having a certain thickness is applied to both sides of the metal plate 21, and this photosensitive liquid is kept constant by the next pair of grooved rollers 27 and 28 . thickness. The grooved rollers 27 and 28 are located at the liquid level 2 of the photosensitive liquid 23.
9 may be brought into contact with the elongated metal plate 21 after the photosensitive liquid is applied thereto, or the elongated metal plate 21 may be brought into contact with the elongated metal plate 21 so that the coating film is evenly distributed while applying the photosensitive liquid. The contact position may be above the liquid level 29. In the latter case grooved rollers
Almost half of the particles 27 and 28 are in the photosensitive liquid 23. To explain further, this grooved roller 2
The shapes of the metal plates 7 and 28 are, for example, as shown in FIGS. is pulled up while being held between the protruding tops, but in this case, the grooved roller 2
Due to the shapes of 7 and 28 , a somewhat striped photosensitive liquid is applied, which passes through a drying chamber 35 to the second roller 25.
By reaching this point, it became possible to form a photosensitive film of uniform thickness on the main surface of the metal plate due to the surface tension of the photosensitive liquid, and all of the above-mentioned conventional drawbacks could be eliminated. Further, by changing the depths 30, 33 of the grooves of the grooved rollers 27 , 28 , the thickness of the photoresist film produced can be adjusted to an appropriate thickness. Regarding the thickness of the photoresist coated on the metal plate for a shadow mask, a thick one is more effective than a thin one in terms of resistance to etching liquid in the subsequent etching process, but a thick one is more effective in terms of resolution of the photoresist. In order to satisfy the conflicting characteristic that a thinner material is more effective, the main surface of the metal plate 21 that tends to affect resolution, for example, forming a small opening on the electron gun side of a color picture tube, is When it is desired to apply a thin photoresist film and to apply a thicker photoresist film to another surface, that is, a surface with a large amount of etching such as the fluorescent surface side, the grooves of the grooved roller 27 used on the fluorescent surface side are used. depth of 30
0.72mm, pitch 31 1.10mm, width of protruding top 32
When the photosensitive liquid is applied with 0.13mm, the thickness of the photosensitive film is approximately 5μ according to the graph in Figure 5, and
Groove depth 3 of the grooved roller 28 used on the electron gun side
3 is 0.58 mm, the pitch 34 is 0.90 mm, and the width 35 of the protruding top is 0.13 mm.
From the graph in the figure, the thickness of the photoresist film can be approximately 4 microns. The above-mentioned film thickness is determined by the pulling speed of the metal plate 21 of 2.2
m/min, from grooved rollers 27 , 28 to forced drying chamber 3
Distance from the liquid level 29 to the center of the grooved rollers 27 and 28 is 50 mm, Distance from the liquid level 29 to the cylindrical roller in the liquid is 30 mm, Photosensitive liquid temperature
This was conducted for a specific gravity of 1.0285 at 20℃.
Even if the conditions were changed, it was possible to achieve approximately this film thickness. The above embodiment is based on the principle of the present invention, and the cylindrical rollers 25 and 26 are omitted, and the grooved roller 2 is used.
It goes without saying that various modifications can be made, such as changing the shapes of rollers 7 and 28 , using only one of them, or providing blades for stirring the photosensitive liquid on the first roller 24, etc., and the industrial value of the present invention is It is extremely large.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of a conventional photosensitive liquid coating method, FIG. 2 is an explanatory cross-sectional view of an embodiment of the photosensitive liquid coating method of the present invention, and FIGS. 3 and 4 show groove depths of different depths. FIG. 5 is a partially enlarged side view of a grooved roller having a grooved surface, and is a curve diagram showing the relationship between groove depth and film thickness. 1, 21... Metal plate, 9, 10, 23... Photosensitive liquid, 27 , 28 ... Grooved roller, 30, 33...
groove depth.

Claims (1)

[Scope of Claims] 1. When introducing a long metal plate that has undergone the degreasing, pickling, and cleaning steps into a photosensitive liquid and leading it out in a substantially vertical direction, the long metal plate is placed on the surface of the photosensitive liquid. A grooved roller is brought into contact with both main surfaces or one main surface of the shaku metal plate,
A photosensitive liquid coating method characterized in that the amount of photosensitive liquid applied to the metal plate is regulated to form a uniform photosensitive film. 2. By changing the depth of each groove of a pair of grooved rollers that come into contact with both main surfaces of the metal plate, a photoresist film having a uniform thickness with different thicknesses is formed on both main surfaces of the metal plate. A photosensitive liquid coating method according to claim 1, characterized in that: