Patent ID: 8632874

Claim:
A circuit subassembly, comprising: a core, wherein the core comprises a core dielectric substrate layer having a first surface and an opposite second surface, wherein the composition of said core dielectric substrate layer is based on 1,2-polybutadiene, polytetrafluoroethylene, or a liquid crystal polymer; and a first core wiring layer disposed on the first surface of the dielectric substrate layer; and a dielectric layer having a thickness of about 5 to about 100 micrometers disposed on the first core wiring layer, wherein the dielectric layer is formed from a dielectric composition comprising, based on the total volume of the composition: about 15 to about 65 volume percent of a dielectric filler; and about 35 to about 85 volume percent of a thermosetting composition comprising: an unmodified poly(arylene ether), and a carboxy-functionalized polybutadiene or polyisoprene polymer.