Abstract
The authors have prepared high-sensitive photopolymerizable materials for laser scanning exposure, which consist of alkaline soluble polymer, multifunctional monomer (pentaerythritol triacrylate), organic peroxide ( 3, 3', 4, 4'- tetrakis (t-butyldioxycarbonyl) benzophenone) and sensitizing dye such as ketocoumarins and coumarins. The dry film type photoresist was prepared by coating the material on a base film in ca. 40μm thickness and the sensitivity to visible laser and patterning characteristics were measured. The highest sensitivity to 488 nm line of argon laser was obtained when ketocoumarin was used as the sensitizer. The sensitivity was 25μJ/cm for the layer with 1μm thickness and 10mJ/cm2 for the layer with 40μm thickness. The test pattern image was formed by a laser scanning system under the following conditwn: laser power at the material; 0.5-0.8W, beam diameter; 25μm, wavelength; 488 nm, scanning speed; 9.8m/s. 25μm line and space was resolved for 40μm thick resist layer on a copper plate after development with 1wt% aqueous solution of sodium metasilicate.
