| 摘要 |
PURPOSE:To improve working efficiency and to lower a cost in production by protecting a one-sided surface of a metallic plate by the use of the first impervious protective layer and the second pervious protective layer formed on the first layer and easily peeling/removing these protective layers. CONSTITUTION:A surface side, on which small apertures 14 are formed in advance by etching, is covered with the first impervious protective layer 20 and the second pervious protective layer 21 formed on the first layer. Since this second protective layer 21 is hard, the first protective layer 20 comparatively weak in mechanical friction can be much protected. Because the first protective layer 20 can be easily peeled and because the second protective layer 21 sticked on the first layer has a pervious property, these protective layers 20 and 21 can be easily peeled/removed after a finish of etching. Therefore, working efficiency can be improved and a cost in production of a shadow mask can be lowered.
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