Multi-chip substrate

An interconnect substrate comprising a metal-polymer composite incorporating microelectronic circuitry, which interconnect substrate is characterized by the feature that the polymer comprises alternating layers of thermoset and thermoplastic resins, said alternating layers having been built by solvent casting of one layer atop another layer, said thermoplastic resins being resistant to the highest temperature to which the interconnects substrate may be heated, said thermoset resins being selected from the group consisting of bismaleimides, thermosetting polyimides, polyimides, benzocyclobutenes and cyanate esters, said thermoplastic resins being selected from the group consisting of, polyesters including polyarylates, polyamides, polyvinylacetals, and phenoxy resins, said substrate having a durable base.