Electrostatically bonded pressure transducers for corrosive fluids
First Claim
1. In a differential transducer for corrosive or conductive fluids, the improvement comprising in combination:
- an integrated bonded structure of a semiconductor wafer including a semiconductor diaphragm containing embedded strain gages and being sandwiched between layers of material electrically insulating and isolating said diaphragm and strain gages from said corrosive or conductive fluids, and first and second tubes electrostatically bonded to said layers on opposite sides of said semiconductor wafer for guiding corrosive or electrically conductive fluids to said layers at said semiconductor diaphragm;
said semiconductor wafer extending beyond the perimeter of at least one of said tubes; and
said strain gages having embedded electrical leads extending beyond said perimeter for attachment of electrical contact wires outside said one tube and being inlaid in said semiconductor wafer at least in a region covered by said one tube.
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Accused Products
Abstract
Differential transducers for corrosive or electrically conductive fluids have a first tube for guiding such fluids toward one side of a semiconductor diaphragm containing embedded strain gages, and a second tube for guiding such fluids toward an opposite side of that semiconductor diaphragm. These tubes are made of an electrically insulating material temporarily convertible to an electrical conductor for electrostatic bonding. The semiconductor diaphragm is provided in a semiconductor wafer extending beyond the perimeter of at least the first tube. The strain gages are provided with embedded electrical leads extending beyond the above mentioned perimeter for attachment of electrical contact wires outside the first tube, while providing these leads inlaid in the semiconductor wafer at least in a region to be covered by the first tube. The wafer including the semiconductor diaphragm is integrally sandwiched between layers of material providing electrical conduction for electrostatic bonding at the tubes and electrical insulation and isolation of the diaphragm and strain gages from corrosive or electrically conductive fluids guided toward the diaphragm by the tubes. Each of the tubes is temporarily converted to an electrical conductor, and these first and second tubes are electrostatically bonded to the above mentioned layers with the aid of the above mentioned electrical conduction, to form the tubes, layers and wafer with semiconductor diaphragm, strain gages and electrical leads into an integrated bonded structure.
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Citations
20 Claims
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1. In a differential transducer for corrosive or conductive fluids, the improvement comprising in combination:
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an integrated bonded structure of a semiconductor wafer including a semiconductor diaphragm containing embedded strain gages and being sandwiched between layers of material electrically insulating and isolating said diaphragm and strain gages from said corrosive or conductive fluids, and first and second tubes electrostatically bonded to said layers on opposite sides of said semiconductor wafer for guiding corrosive or electrically conductive fluids to said layers at said semiconductor diaphragm; said semiconductor wafer extending beyond the perimeter of at least one of said tubes; and said strain gages having embedded electrical leads extending beyond said perimeter for attachment of electrical contact wires outside said one tube and being inlaid in said semiconductor wafer at least in a region covered by said one tube. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 19)
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11. In a method of making a differential transducer for corrosive or electrically conductive fluids guided by a first tube toward one side of a semiconductor diaphragm containing embedded strain gages, and guided by a second tube toward an opposite side of said semiconductor diaphragm, the improvement comprising in combination the steps of:
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making said tubes of an electrically insulating material temporarily convertible to an electrical conductor for electrostatic bonding; providing said semiconductor diaphragm in a semiconductor wafer extending beyond the perimeter of at least said first tube; providing said strain gages with embedded electrical leads extending beyond said perimeter for attachment of electrical contact wires outside said first tube, while providing said leads inlaid in said semiconductor wafer at least in a region to be covered by said first tube; integrally sandwiching said wafer including said semiconductor diaphragm between layers of material providing electrical conduction for electrostatic bonding at said tubes and electrical insulation and isolation of said diaphragm and strain gages from corrosive or electrically conductive fluids guided toward said diaphragm by said tubes; temporarily converting each of said tubes to an electrical conductor; and electrostatically bonding said first and second tubes to said layers with the aid of said electrical conduction to form said tubes, layers and wafer with semiconductor diaphragm, strain gages and electrical leads into an integrated bonded structure. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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20. In a method of making a differential transducer for corrosive or electrically conductive fluids guided by a first tube toward one side of a semiconductor diaphragm containing embedded strain gages, and guided by a second tube toward an opposite side of said semiconductor diaphragm, the improvement comprising in combination the steps of:
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making said tubes of an electrically insulating material temporarily convertible to an electrical conductor for electrostatic bonding; providing said semiconductor diaphragm in a semiconductor wafer extending beyond the perimeter of at least said first tube; providing said strain gages with embedded electrical leads extending beyond said perimeter for attachment of electrical contact wires outside said first tube, while providing said leads inlaid in said semiconductor wafer at least in a region to be covered by said first tube; integrally sandwiching said wafer including said semiconductor diaphragm between layers of material providing electrical insulation and isolation of said diaphragm and strain gages from corrosive or electrically conductive fluids guided toward said diaphragm by said tubes, and being temporarily convertible to an electrical conductor for electrostatic bonding to said tubes; temporarily converting each of said tubes and said layers of material to an electrical conductor; and electrostatically bonding said first and second tubes to said layers with the aid of said electrical conduction to form said tubes, layers and wafer with semiconductor diaphragm, strain gages and electrical leads into an integrated bonded structure.
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Specification