Santa Barbara Research Center

Santa Barbara Sensor Technologies

Thomas E Wolverton

John J Brooks

Allen L DeForrest

Craig J Kent

Thomas A Trautt

William H Cushman

A threaded fastener and mating driver system is used to apply a uniform torque to the entire fastener body and thereby facilitate removal of stuck fasteners. The driver tool is a two stage driver with one stage driving the inner bore of the fastener and the second stage driving the fastener head. The two driver stages are linked via a series of pins, each pin acting as an individual lever, such that the two drivers apply torque equally to the fastener. The entire driver assembly is housed in a block which can be attached to a standard ratchet or driving tool. The fastener is designed to be installed using a single stage screwdriver and normally has a foil seal covering the bore drive portion of the fastener. If the fastener becomes stuck, the foil seal is broken and the two stage drive system, including a bore driver and a screw head driver, is inserted into the fastener to effect additional removal torque.

Fastener and tool combination for applying equivalent torque along

A flip-chip assembly and method for reducing the stress in its metal interconnections resulting from thermal mismatch includes a detector that has a radiation sensitive circuit on a substrate that is flip-chip connected to a layer of semiconductor material that is provided with a readout circuit. The substrate has a thermal coefficient of expansion (TCE) greater than the semiconductor layer such that operating the detector over a predetermined temperature range would stress the flip-chip connections. A first compensation layer on the readout chip has a TCE greater than the substrate's, and a second compensation layer on the first layer has a TCE approximately equal to the semiconductor layer's. The materials and thicknesses of the compensation layers are selected such that the TCE of a composite structure that includes the semiconductor and compensation layers is approximately equal to the substrate's TCE to avoid the stress over the predetermined temperature range. In the preferred embodiment, the composite structure is mounted on a platform, which has a TCE approximately equal to that of the substrate.

Thermally matched flip-chip detector assembly and method

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Goleta, CA, United States of America

Thomas E Wolverton