Pivotable self-centering elastomer pressure-wafer probe

Abstract

A test probe for testing an integrated circuit formed on an integrated circuit die. The probe comprises a printed circuit board interface having an opening in its center. A flexible membrane is formed on a bottom surface of the printed circuit board interface that is flexible in the middle thereof. A plurality of electrical traces and a plurality of bumps are formed on the flexible membrane that terminate at a plurality of termination pads that permit interfacing of the integrated circuit to the external test equipment. A clear plastic window is secured to the printed circuit board interface an a portion thereof protrudes into the opening in the interface. A cone shaped retainer having a circular opening at its center that abuts a bottom surface of the clear plastic window. A pivotable elastomer member having a truncated conical cross section abuts the bottom surface of the clear plastic window. A clear plastic pressure and pivot plate is disposed between the flexible membrane and a bottom surface of the pivotable elastomer member. When the probe is assembled, the flexible membrane is disposed in its flexed position, extending outward relative to the non-flexible portion thereof. The flexible membrane is moved into its flexed position by the force created by the force exerted thereon by the pivotable elastomer member and clear plastic pressure and pivot plate. The elastomer member compresses during interconnection to the integrated circuit, and deflects, as required, to permit tilting of the flexible membrane and thus proper mating of the bumps and pads on the integrated circuit. Upward movement of the die and integrated circuit provides the force to ensure contact between the bumps and pads and to tilt the flexible membrane when required. The probe is especially suitable for very small integrated circuit die patterns, such as are used in testing die whose die patterns are less than 250 inches square.