JPH0466680A - Method for etching metal sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method of etching a metal plate.

[Conventional technology]

Color filters for liquid crystal displays are currently being actively manufactured using printing techniques such as intaglio offset printing. In order to manufacture filters using printing methods in this way, a printing plate is required in which many fine striped grooves are repeatedly formed.Currently, these grooves are mainly carved by etching. .

[Problem to be solved by the invention]

When the resist 2 is left in a desired pattern on the surface of the metal plate 1 and, for example, the window-like exposed portion 11 is etched to form the image groove 12, the metal plate 1 is left on the surface that will come into contact with the etching solution. Since etching is performed vertically, etching progresses simultaneously in the width direction as well as in the thickness direction, so that the etching also extends to the lower side covered by the resist 2. Therefore, as the etching progresses, the width of the image groove 12 increases, and for this reason, it is formed shallower on both sides. It is difficult to print highly accurate lines from such shaped line grooves, and ink unevenness occurs in the width direction, making it possible to produce only color filters with shading. There was a problem. For this reason,
There has been a strong desire to develop an etching method that can form grooves with as little increase in width as possible and with as uniform a depth as possible.

[Means to solve the problem]

The present invention was made to solve the problems of the prior art described above, and a ferric chloride solution with a concentration exceeding 47'Be' is heated at 60°C on the surface of a metal plate on which a resist remains in a pattern. 2 from a distance shorter than 15c+s at a temperature exceeding
The present invention provides a method for etching a metal plate characterized by spraying at a pressure exceeding Kgf/cm2.

[Effect]

Compared to conventional etching methods, the etching method of the present invention sprays the etching liquid at a high concentration and high temperature from a short distance under high pressure, so that etching progresses more in the thickness direction than in the width direction. Therefore, the image groove does not increase in diameter in the width direction, but is formed deep in the thickness direction.

[Examples and comparative examples]

Next, the present invention will be explained in detail in connection with a comparative example. A stainless steel plate with a thickness of 100B is used as the metal plate 1, and a suitable resist (for example, casein) 2 is coated on one side of the plate.
A film is uniformly coated with a thickness of 0 gM, and a mask is exposed using a well-known photolithography method, for example, the exposed area is
A window-like exposed portion 11 was formed in the center of the metal plate 1 by removing the metal plate 1 to a width of 01111 mm. The metal plate 1 is placed horizontally with the window-like exposed portion 11 facing upward, and the etching solution ferric chloride solution 3 is sprayed from above under the conditions shown in Table 1 to form the window-like shape of the metal plate 1. Exposed part 1
The shapes of the drawing grooves 12 with a depth of 50 g formed corresponding to No. 1 were compared. Table 1 The quality of etching is determined not by comparing the depth, width, etc. of the print grooves, but by comparing the window-like exposed portion 11 as shown in Figure 4.
The width of WIN is 01, and the depth of the drawing groove 12 actually engraved is 01.
When the width is W2, etch factors E and F defined by the following equations were determined and compared using these values as parameters. As can be seen from the definitions, the larger the etch factors E and F, the better from the viewpoint of processing accuracy. W2 Wt R As is clear from FIG. 1 showing the comparison results, experiment numbers 15 and 16 of the present invention have the etch factor E of the other experiment numbers.
, higher than F. Therefore, it can be seen that etching progressed more effectively in the depth direction than in the width direction. This is the cross-sectional shape (
This is also clear from the comparison of the cross-sectional shape of the image line groove 12 obtained in Experiment No. 1 (FIG. 2b). As described above, according to the etching method of the present invention, even when forming the image line groove 12 of the same depth as the conventional etching method, the increase in the groove width is small, so that the window-like exposed portion 11 is formed in advance to an appropriate width. If formed in advance, the groove width will not expand significantly beyond this width, so the accuracy of the groove width can be improved. In addition, since the depth of both sides of the image groove 12 is significantly reduced compared to the previous technology, the width accuracy is high when used for printing color filters, etc. A line with stable shading in the direction is easily formed. Note that the present invention is not limited to the above embodiments, and the metal plate 1 may be made of brass, nickel,
Iron/nickel alloy, stainless steel such as 5US-304,
It may be made of cupronickel, etc., and the material of the resist 2 does not matter as long as it can expose only the part to be etched with the desired precision, and the shape, size, and number of resists to be exposed can be changed. etc., are not limited either. Further, as for the method of spraying the ferric chloride solution, any method may be used as long as it can spray the exposed surface of the metal plate 1 at a pressure similar to -.

【Effect of the invention】

As explained above, compared to conventional etching methods, the metal plate etching method of the present invention, in which the etching solution is sprayed at a high concentration and high temperature from a short distance under high pressure, allows etching to proceed more in the thickness direction than in the width direction. Therefore, the drawing groove does not expand so much in the width direction, but is formed deep in the thickness direction. Therefore, it is an extremely effective etching method for manufacturing printing plates such as color filters for liquid crystal display devices, since image grooves with a shape that is not nearly shallow on both sides are etched with high precision.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the experimental results of the example of the present invention and a comparative example, FIGS. 2a and 2b are diagrams showing the cross-sectional shape of the drawing groove according to experiment numbers 16 and 1, respectively, and FIG. 3 is an illustration of the etching pattern. FIG. 4 is an explanatory diagram showing the procedure, and FIG. 4 is an explanatory diagram showing an example of shape cane measurement. 1... Metal plate 11... Window-like exposed portion 12... Image groove 2... Resist 3... Ferric chloride liquid

Claims (1)

[Claims] A ferric chloride solution with a concentration exceeding 47'Be' is applied to the surface of the metal plate on which the resist remains in a pattern at a temperature exceeding 60°C from a distance shorter than 15 cm at a rate of 2 Kgf/cm.
A method for etching a metal plate, characterized by spraying at a pressure exceeding ^2.