Process for making metalised openings in dielectric substrates containing interconnected conductive and/or resistive segments in thin film

摘要

A process is described for making metalised openings in dielectric substrates containing conductive and/or resistive segments pertaining to thin film hybrid circuits for microwave applications. The process comprises the phases of deposition of superimposed layers of TaN, Ti and Pd on the front surface; photomasking and depositing of gold along established pathways; removal of TaN, Ti and Pd outside of said pathways; photoengraving of gold, Pd and Ti at the resistors; drilling holes in zones lacking metal; vacuum sputtering of Ti and Pd on the front side and back side; depositing of a negative photoresist on the front side, photomasking of circular zones superimposed on the holes and partially on the conductive segments; developing, and addition of gold by galvanic means; elimination of the residual photoresist; selective chemical attack to eliminate the excess Pd and Ti. IMAGE