Universal nondestructive MM-wave integrated circuit test fixture

Claim 1

An MMIC test fixture in which the measurement planes can be positioned directly adjacent to the MMIC edges and comprising: an elongated rectangular base including a shallow recess in the base upper surface; first and second ridge transition housings each including a three-sided elongated trench in a lower surface, said trench with the upper surface of said base forming a guide for RF waves when the lower surfaces of the housings are placed in contact with the upper surface of said base, an elongated ridge member extending into said trench from the housing and having length, height and thickness, the thickness of the ridge member being reduced toward one end, the height being reduced to zero at the other end by a cosine taper; a chip carrier having a transmission line disposed thereon and having a plurality of electrical contact pads connected to respective electrical contacts on two opposite edges of an aperture in said chip carrier said edges being parallel to said RF transmission line, said aperture being adapted to receive an MMIC having bias contacts and RF contacts, said chip carrier being disposed in the recess of said base; a bias module having a plurality of spring-loaded contacts which engage respective ones of the pads of said chip carrier to provide appropriate voltages to the MMIC; and a solder preform beneath said chip carrier and an electrically conductive subcarrier beneath said solder preform, said subcarrier including an electrically nonconductive mesa extending upwardly through said solder preform and into an aperture in said chip carrier, said mesa being embedded in an upper surface of the subcarrier, said MMIC lying in a plane common with that of the RF transmission line of said chip carrier.