Media compatible pressure transducer
First Claim
1. An absolute pressure transducer, comprising:
- (a) a wafer of a semiconductor material having located on a bottom surface thereof, first and second recesses defining first and second active diaphragm areas,(b) a first sensor means located on a top surface of said wafer above and within said first active area as defined by said first recess, and second sensor means located on said top surface of said wafer above and within said second active area as defined by said second recess,(c) means adapted to apply a first pressure to said top surface of said wafer to cause said first and second sensor means to respond thereto,(d) means adapted to apply a second pressure to said second recess to cause only said second sensor means to respond thereto, and(e) means coupling said first and second sensor means in a bridge configuration to provide an output indicative of said second pressure applied to said recess as referenced to said first pressure.
0 Assignments
0 Petitions
Accused Products
Abstract
There is disclosed an absolute pressure transducer which is adaptable for use in various deleterious mediums. A single wafer contains a gage sensor configuration on one portion and an absolute sensor configuration on another adjacent portion. An active diaphragm area is defined for each sensor configuration by forming a depression beneath the sensor locations. A base member is bonded or secured to the wafer at the side containing the depressions. An aperture is directed through the base member to communicate with the depression associated with the gage sensor configuration and is employed as an external pressure port. The top surface of the wafer which contains the sensors is exposed to a relatively clean source of pressure to thereby enable the absolute sensor section to monitor this pressure, while the gage sensor section responds to both pressures.
151 Citations
17 Claims
-
1. An absolute pressure transducer, comprising:
-
(a) a wafer of a semiconductor material having located on a bottom surface thereof, first and second recesses defining first and second active diaphragm areas, (b) a first sensor means located on a top surface of said wafer above and within said first active area as defined by said first recess, and second sensor means located on said top surface of said wafer above and within said second active area as defined by said second recess, (c) means adapted to apply a first pressure to said top surface of said wafer to cause said first and second sensor means to respond thereto, (d) means adapted to apply a second pressure to said second recess to cause only said second sensor means to respond thereto, and (e) means coupling said first and second sensor means in a bridge configuration to provide an output indicative of said second pressure applied to said recess as referenced to said first pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 16)
-
-
10. An absolute pressure transducer, comprising:
-
(a) a wafer of a semiconductor material having a top and bottom surface with relatively thin side surfaces, said bottom surface having first and second circular recesses adjacent one another and relatively of the same diameter manifesting a first and second diaphragm area, (b) a base plate secured to said bottom surface to cover said recesses with said base plate having an aperture communicating solely with said second circular recess, (c) a first piezoresistive circuit arrangement mounted on said top surface of said wafer above said first depression with a peripheral sensor located near an edge of said recess and a central sensor located near the center of said recess, (d) a second piezoresistive circuit arrangement mounted on said top surface of said wafer above said second recess with a peripheral sensor located near an edge of said recess and a central sensor located near the center of said recess, (e) means for applying a reference pressure to said top surface of said wafer, (f) means for applying another pressure to said aperture in said base plate for directing the same solely to said second recess, and (g) means coupling said piezoresistive sensors in a circuit arrangement to cause said circuit to provide an output indicative of said another pressure as referenced to said reference pressure. - View Dependent Claims (15, 17)
-
Specification