Photosensitive composition and pattern forming process using same

A process for forming a pattern of a powder coating layer which comprises:

• a step of coating a substrate with a photosensitive composition comprising (a) at least one salt of a diazonium compound of the formula:
• ##STR8## wherein R.sub.1 and R.sub.2 are independently --H, --CH.sub.3, --OCH.sub.3 or ##STR9## but R.sub.1 and R.sub.2 cannot be ##STR10## at the same time;
• and R.sub.3 and R.sub.4 are independently a straight-chain lower alkyl group, and (b) at least one salt of an aromatic diazonium compound having no --OH group directly bonding to a benzene ring, to form a thin coating layer on said substrate, the amount of the diazonium compound salt (a) in said photosensitive composition being 1 to 60% by weight based on the total weight of the diazonium compound salts (a) and (b);
• a step of imagewisely exposing said thin coating layer to light to make the exposed portions of the film sticky;
• and
• a step of contacting phosphor powder particles with the exposed thin coating layer to adhere the powder particles to the exposed portions.