Patent ID: 7220490

Claim:
A multilayer substrate comprising: A. an adhesive layer having: i. 100 weight parts polyimidosiloxane component; ii. a polymer adjuvant comprising a plurality of epoxy moieties or derivatives of epoxy moieties, being present in a weight part amount within a range between and including the following weight part quantities per 100 parts by weight of the polyimidosiloxane component: and 50, and the polymer adjuvant comprising less than or equal to 500 ppm halogen; iii. a plasticizer, being present in a weight part amount within a range between and including the following weight part quantities per 100 parts by weight of the polyimidosiloxane component: 5, and 80, and iv. a halogen-free flame-retardant filler in an amount of 2–100 parts by weight per 100 parts by weight of the polyimidosiloxane component, and B. a polyimide base film having an inner side that is in contact with the adhesive layer, the polyimide base film and the adhesive layer each having a coefficient of thermal expansion, wherein the difference in coefficient of thermal expansion between the base film and the substrate is greater than or equal to 5 ppm/° C. (measured between 50° C. and 250° C.), and said base film having a modulus greater than 400 kPSI.