Patent ID: 7129011

Claim:
A heat resistant negative working photosensitive composition that comprises (a) one or more polybenzoxazole precursor polymers (I): wherein x is an integer from about 10 to about 1000, y is an integer from 0 to about 900 and (x+y) is about less then 1000; Ar 1 is selected from the group consisting of a tetravalent aromatic group, a tetravalent heterocyclic group, or mixtures thereof; Ar 2 is selected from the group consisting a divalent aromatic, a divalent heterocyclic, a divalent alicyclic, or a divalent aliphatic group that may contain silicon; Ar 3 is selected from the group consisting a divalent aromatic group, a divalent aliphatic group, a divalent heterocyclic group, or mixtures thereof; Ar 4 is selected from the group consisting Ar 1 (OH) 2 or Ar 2 ; G is H or an organic group having a group attached directly to the terminal NH of the polymer and wherein said group attached directly to the terminal NH of the polymer is selected from the group consisting of a carbonyl, a carbonyloxy and a sulfonyl group; (b) one or more photo-active compounds which release acid upon irradiation (PAGs); (c) one or more latent crosslinkers, each of which contains at least two ˜N—(CH 2 OR) n units where n=1 or 2, and R is a linear or branched C 1 –C 8 alkyl group; (d) at least one solvent, and (e) at least one dissolution rate modifier to increase the dissolution rate with the proviso that when the latent crosslinker is highly reactive, the dissolution rate modifier does not contain carboxylic acid groups.