| 摘要 |
<p>PURPOSE: A method for forming a solder resist layer is provided to enough harden a film formed from a photosensitive composition from the surface to a core by compensating defects while showing advantages of a laser light of long wavelength compared with a laser light of short wavelength. CONSTITUTION: A method for forming a solder resist layer of a printed circuit board comprises the steps of: applying a photosensitive composition to a printed circuit board, and evaporating and drying the coating film; forming a pattern latent image irradiated from plural laser lights by irradiating laser lights with different wavelength to the dried film; developing the pattern latent image with an alkali solution; and heating and curing the developed material. The photosensitive composition comprises (A) a carboxylic acid-containing resin, (B) a photopolymerization initiator and (C) pigment.</p> |
