ISOTROPIC ETCHING OF SILICON STRAIN GAUGES

摘要

A method of etching a silicon diffused resistance pressure transducer assembly (13) of a transducer (10) mounted on a glass base (14) providing a thin flexible area on the transducer in the region of the diffused resistors (15) and a thick rigid area in the region where the transducer is mounted to the glass base (14). To accomplish this, the transducer (10) is first bonded to the glass base (14) which is tubular, thus providing a circular area on the backside (16) of the transducer (10) open to ambient. This open area is then filled with an isotropic etchant which etches silicon material but which has little effect on glass material. Thus, the region of the diffused resistors (15) is etched out to provide a thin flexible area while leaving a thick area where the transducer (10) is mounted to the glass base (14).