TRANSDUCER FORMED IN PERIPHERALLY SUPPORTED THIN SEMICONDUCTOR WEB

A thin web supported by a peripheral frame is formed from a single crystal of silicon, the web and frame being of opposite conductivity types. A lower resistivity region is diffused into the web, and the web is covered by an insulating layer having holes through which conductors are deposited in contact with each end of the diffused region. The resulting transducer can be used as a thermocouple or strain gage. For use as a thermocouple, one of the junctions between the diffused region and a conductor is situated near the center portion of the web. The diffused region comprises one leg of the thermocouple, and one of the conductors functions as the other leg. The frame acts as a heat sink relative to the center portion of the web, making the junction near the center portion a hot junction and the junction near the frame a cold junction. For use as a diaphragm type strain gage the diffused region is made to transverse most of the web. The frame serves as a mounting base that is integral with the strain gage. The resistance of the diffused region changes in proportion to the change of the dimensions of the diffused region that result from the application of a force normal to the plane of the web.