| 摘要 |
PURPOSE:To improve the reproducibility of patterning by adding specified amounts of an alkali citrate and boric acid basing on the amount of solid casein to inhibit a coated photosensitive film from causing a dark reaction and a residual reaction. CONSTITUTION:To a photosensitive casein soln. contg. an alkali dichromate as a sensitizer are added 1-15wt% alkali citrate and 15-45wt% boric acid basing on the amount of the solid casein. When sodium citrate is used as the alkali citrate, it is added by 2-15wt%, and when ammonium citrate is used, it is added by 1- 11wt%. When ammonium dichromate is used as the alkali dichromate, it is contained by 4-18wt% basing on the amount of the solid casein. The alkali citrate and boric acid contribute chiefly toward inhibiting a dark reaction and a residual reaction, respectively. The boric acid contributes toward regulating the activity of the alkali dichromate sensitizer and the concn. of acidic chromate ions, and it is useful to maintain the photosensitivity during exposure. The photosensitivity is increased, so the patterning exposure time can be shortened, and the dimensional stability of a film and the reproducibility of processing are improved. |
