1. Field of the Invention
The present invention relates generally to low temperature (less than about 225° C.) polyimide based adhesive compositions suitable for electronics applications, such as bonding films to form: multilayer flexible circuits, rigid-flex circuits, chip scale packaging or the like. The compositions of the present invention comprise an aliphatic-aromatic polyimide component, having advantageous thermal resistance, z-axis coefficient of thermal expansion (CTE) and modulus properties.
2. Discussion of Related Art
U.S. Pat. No. 5,922,167 to Rosenfeld is directed to polyimide adhesive compositions, having bonding temperatures taught to be in a range of about 250° C. to 450° C.
The present invention relates to prior research disclosed in U.S. Pat. No. 5,298,331, to Kanakarajan, et al. for polyimide adhesives with bonding temperatures in a range of about 250° C. to 275° C. The methods of manufacture and use described in the Kanakarajan patent are also applicable to the polyimide adhesives of the present invention, and therefore the Kanakarajan et al. patent is hereby incorporated by reference into this specification for all teachings therein.
USPTO Backgrounds
USPTO Backgrounds