Abstract: A membrane test probe (10) for use in testing integrated circuit chips (50) has a thin flexible membrane (30) bearing test contacts (40,42) that is stretched across an opening of a rigid-flex substrate (12). The membrane is manufactured with uniform radial tension by a lamination fixture having a steel pressure plate (76) that includes an annular groove (78). A high temperature O-ring (80) is positioned in the groove against the radially inner wall (82) of the groove with the radially outer wall of the groove being displaced from the outer part of the O-ring. The O-ring has a thickness greater than the depth of the groove and when the steel pressure plate is pressed against the membrane to press it against its substrate the O-ring pushes a portion (92) of the membrane into a shallow groove (16) in the substrate and deforms radially outwardly. As the O-ring deforms radially outwardly, it exerts a radially outwardly directed tension on the membrane which is cured in this radially stretched condition.

Abstract: A circuit is produced by using a formed mandrel (10,12) and semi-additive techniques for creating circuit traces. A stainless steel mandrel (10) flash plated with copper (14) includes a depression (12) which will form a raised interconnection feature (24). Using a photolithographically formed pattern of photoresistive material (16) on the mandrel the selected pattern of circuit traces (18,20) and raised features (24) are electroplated onto the flash plated mandrel. After stripping the photoresist (16), a dielectric substrate (26) is laminated to the circuit traces, effectively encapsulating the traces on three sides. After removing the laminated circuit traces and dielectric from the mandrel the flash plated copper (14) is removed and the circuit covered with an insulation coverlay.

Abstract: A pressure type contact (10) for flexible or conventional wire cable terminations is fabricated from electroformed thin metallic wafers in which one wafer is plated with a raised conductive interconnection feature. The raised feature is formed by placing a small lump (44) of electrically conductive resin on a substrate (12) and then electrolytically forming on the substrate a trace (18) having an enlarged connector pad (20) that completely covers the cured projecting resin lump.