초록 ▼

A capacitive pressure transducer utilizing a plate of electrically conductive semi-conductor material sandwiched between a pair of plates of inorganic electrically insulating material and electrostatically bonded thereto. A pair of concentric circular recesses are etched in the plates in such a way

A capacitive pressure transducer utilizing a plate of electrically conductive semi-conductor material sandwiched between a pair of plates of inorganic electrically insulating material and electrostatically bonded thereto. A pair of concentric circular recesses are etched in the plates in such a way as to form cavities on opposing sides of the conductive plate and to define a diaphragm area on that plate. Apertures are drilled through the insulating plates to expose the cavities to the pressures to be measured. The surfaces of the insulating plates in the cavities have deposited on them electrically conductive surfaces which form capacitors with the diaphragm area on the conductive plate. A stress relief area is provided on the high pressure side surrounding the diaphragm area. In that stress relief area, the conductive plate is unrestrained by the adjacent insulating plate. Provision of this stress relief makes it possible to extend the pressure range of the transducer beyond the range which would normally be useful for the dimensions of the particular transducer.

대표청구항 ▼

In a pressure transducer of the capacitor type in which a plate of electrically conductive semi-conductor material is sandwiched between a pair of plates of inorganic electrical insulating material electrostatically bonded thereto, wherein a pair of concentric circular recesses are etched in said pl

In a pressure transducer of the capacitor type in which a plate of electrically conductive semi-conductor material is sandwiched between a pair of plates of inorganic electrical insulating material electrostatically bonded thereto, wherein a pair of concentric circular recesses are etched in said plates to form cavities on opposing sides of said conductive plate to define a diaphragm area on said conductive plate, apertures are drilled through said insulating plates, and the surfaces of one of said insulating plates in said cavities has deposited thereon an electrically conductive film forming a capacitor with the diaphragm area of said conductive plate, the improvement comprising: a stress relief area surrounding said diaphragm area so that deflection of said conductive plate is unrestrained by the adjacent insulating plate on the high pressure side for prevention of overpressure failure of said transducer.