Thin film hybrid microcircuitry. Part 2, modulator circuit for an experimental fuze

This work consisted of the development of a thin film hybrid version of a specialized modulator circuit that had some very stringent requirements. The scheme that was followed used tracings of the outlines of resistors and conductors; also, templates were used to represent add-on devices to permit easy trial of a number of alternative layouts. Computerized thermal analyses were used to determine steady-state component temperatures before adopting the final circuit design. Standard thin-film processing methods were used to fabricate and package the circuits. A number of materials were tried in attempts to encapsulate the circuits for protection during temperature cycling. An encapsulating procedure using flexibilized epoxies was developed that eliminated circuit failures that appeared to be caused by encapsulation stresses. Further work needs to be done on circuit failures at elevated temperatures that are thought to be caused by corrosion or degradation of the aluminum metallization on silicon chip devices.