Semiconductor pressure sensor.

摘要

An absolute pressure transducer includes a hollow glass tube (4) supporting across one end thereof a differential pressure responsive semiconductor plate (2) having piezoresistive elements diffused therein and an evacuated sealed chamber (8) within the tube exposed to the plate (2). Making the transducer (1) and providing the evacuated chamber (8) within the tube (4) adjacent to the plate (2) includes the steps of mounting the plate (2) across the end of the tube (4) to form a first fluid-tight seal therewith, inserting a loose glass plug (6) within the tube to define the chamber (8), exposing the interior of the tube (4) to a vacuum (70), concurrently heating the tube in the vicinity of the plug to allow the heated tube wall (10) to constrict around the plug in response to the internal vacuum and to fuse with the plug to form a second fluid-tight seal therewith and allowing the tube and plug to cool to trap the vacuum in the chamber.