Surface trace electrical feedthru for conducting electricity across a pressure envelope

Abstract

A method for producing an electrical feedthru wherein a thin liquid conductive film is deposited into a shallow trough of an insulating machinable substrate. The conductive film and substrate are fired and then the resulting bound composite is ground flush with the adjacent surface of the insulating machinable substrate. The surface cohesion of the fired composite, and the resulting high quality surface finish of the grinding operation, combined with an elastomeric seal, create low leakage barriers capable of supporting a pressure differential while allowing isolated electrical conduction across a pressure or vacuum envelope. The method produces a space saving feedthru which allows a high signal line density in a limited space, is relatively simple to assemble, allows for disassembly rework, can be 'designed into' unique geometries of varied applications, and which has a single O-ring sealing across all traces. The resulting electrical trace can be soldered directly to a signal carrying wire, pin/socket, or attached via a contact spring or other mechanical attachment. No epoxies are used, thus avoiding thermal limitations and outgassing contamination.