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US 5,174,156 AGranted
Pressure transducer with reduced offset signal
AssigneeHoneywell Inc.
InventorsRalph H. Johnson, Ernest F. Brose, II
Life of this patent
Estimating the term…
Abstract
A structure and method of making a piezoresistive transducer with reduced offset current. The transducer is comprised of a piezoresistive die having a support rim and a diaphragm, and a support housing having a wall and an aperture. The shape of the diaphragm is matched with the shape of the aperture while the shape of the support rim is matched with the shape of the wall. By matching these shapes, temperature induced stresses are reduced, thus reducing temperature induced offset currents.
Claims16
A pressure transducer, comprising:
- a die comprising a support rim and a diaphragm, said support rim being formed to have a first shape and cross sectional area, said diaphragm being formed to have a second shape and area in a major surface;
- a first tube having a wall and an aperture therethrough, said tube being in physical contact with said die and being adaptive to allow a fluid to contact said diaphragm, said tube being formed so that said aperture has generally the same shape and cross sectional area as said second shape and area, and said wall structure has a shape and cross sectional area generally the same as said first shape and cross sectional area;
- a second tube joined to said die at said major surface of said diaphragm, said second tube being generally identical to said first tube;
- and
- means for joining said first and second tubes with said die.
2 more elements
The pressure transducer, comprising:
- a die comprising a support rim and a diaphragm, said support rim being formed to have a first rectangular shape and cross sectional area, said diaphragm being formed to have a second rectangular shape and area in a major surface;
- a first tube having a wall and an aperture therethrough, said tube being in physical contact with said die and being adapted to allow a fluid to contact said diaphragm, said tube being formed so that said aperture has the generally same rectangular shape and cross sectional area as said second rectangular shape and area, and said wall structure has a rectangular shape and cross sectional area generally the same as said first rectangular shape and cross sectional area;
- a gas tight cap in physical contact with said major surface to create an evacuated chamber over said diaphragm thus enabling the pressure transducer to measure absolute pressures;
- and
- means for joining said tube and said cap with said die.
2 more elements
A pressure transducer, comprising:
- a die having a support rim and a diaphragm attached thereto, said support rim being defined by a first rectangular shape, said diaphragm being defined by a second rectangular shape and area;
- a first tube having a wall and an aperture therethrough, said tube being attached to said die with said aperture being aligned with said diaphragm and said wall being aligned with said support rim, said aperture having generally the same rectangular shape and cross sectional area as said second rectangular shape and area, said wall having the same rectangular shape as said first rectangular shape and an inner perimeter generally the same as an inner perimeter of said support rim.
Dependencies are inferred from the claim text.