The present invention relates to a polyimide adhesive composition having a polyimide
derived from an aromatic dianhydride and a diamine component, where the diamine
component is preferably about 50 to 90 mole % of an aliphatic diamine and about
10 to 50 mole % of an aromatic diamine. In one embodiment, the aliphatic diamine
has the structural formula H2N—R—NH2 wherein
R is hydrocarbon from C4 to C16 and the polyimide adhesive
has a glass transition temperature in the range of from 150 C. to 200 C.
The present invention also relates to compositions comprising the polyimide adhesive
of the present invention, including polyimide metal-clad laminate useful as flexible
circuit when metal traces are formed out of the metal used in flexible, rigid,
or flex-rigid circuit applications.