Method for manufacturing variable capacitance pressure transducers
First Claim
1. A method for manufacturing a variable capacitance pressure transducer, comprising the steps of:
- (a) from at least one area on a surface of a wafer of semiconductor material, removing a portion of the semiconductor material in the area to form at least one recess in the surface of the semiconductor material;
(b) doping the semiconductor material, at least in the region of the recess, to enhance its electrical conductivity in such region;
(c) forming a path of electrically conductive material connecting two spaced surfaces of a dielectric member through a hole extending between said two spaced surfaces; and
(d) anodically bonding the surface of said wafer containing said recess to one surface of said dielectric member to form a bonding area which provides an hermetic seal around the recess, said bonding area being such that the hole in the dielectric member is spaced from said recess in the semiconductor material and the path of electrically conductive material provides an electrical connection through said hole to the semiconductor material in said banding area.
1 Assignment
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Accused Products
Abstract
A method for manufacturing variable capacitance pressure transducers and an intermediate article of manufacture produced in the practice of this method. In the method, a wafer of doped silicion or other semiconductor material has portions of the semiconductor material removed from spaced areas to form a plurality of recesses in the surface of the semiconductor material. The material is doped to enhance its electrical conductivity. A dielectric material has one of its surfaces coated with spaced areas of electrically conductive material. The semiconductor material is attached to the coated surface of the dielectric material such that the surface recesses in the semiconductor material are in alignment with the conductive areas on the dielectric material. This produces a plurality of electrical capacitors suitable for use as pressure transducers. The capacitance of these transducers is varied as a function of changes in one or more fluid pressures acting in the plates of each of the capacitors, one of these plates being the doped semiconductor material and the other being a conductive area on the dielectric material. Fluid pressure between the plates may be established during manufacture. The intermediate article of manufacture produced by this process may then be cut into a plurality of separate pressure transducers.
38 Citations
8 Claims
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1. A method for manufacturing a variable capacitance pressure transducer, comprising the steps of:
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(a) from at least one area on a surface of a wafer of semiconductor material, removing a portion of the semiconductor material in the area to form at least one recess in the surface of the semiconductor material; (b) doping the semiconductor material, at least in the region of the recess, to enhance its electrical conductivity in such region; (c) forming a path of electrically conductive material connecting two spaced surfaces of a dielectric member through a hole extending between said two spaced surfaces; and (d) anodically bonding the surface of said wafer containing said recess to one surface of said dielectric member to form a bonding area which provides an hermetic seal around the recess, said bonding area being such that the hole in the dielectric member is spaced from said recess in the semiconductor material and the path of electrically conductive material provides an electrical connection through said hole to the semiconductor material in said banding area.
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2. A method for manufacturing a variable capacitance pressure transducer, comprising the steps of:
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(a) from at least one area on a surface of a wafer of semiconductor material, removing a portion of the semiconductor material in the area to form at least one recess in the surface of the semiconductor material; (b) doping the semiconductor material, at least in the region of the recess, to enhance its electrical conductivity in the region; (c) forming an area of conductive material on the surface of a dielectric member having first and second surfaces and a hole formed between said two surfaces; (d) forming a path of electrically conductive material between said two surfaces of the dielectric member through said hole; and (e) anodically bonding the surface of the semiconductor material to the surface of the dielectrical member such that the surface recess of the semiconductor material is in adjacent, spaced and substantially parallel alignment with the area of electrically conductive material on the dielectric member, thereby, to form an electrical capacitor, the capacitor having doped semiconductor material as one plate thereof spaced from another plate thereof comprising the electrically conductive area, the capacitance of the capacitor being variable as a function of changes in a fluid pressure acting on at least one of the plates of the capacitor, the anodic bonding of the surface of the semiconductor material to the surface of the dielectric member with the area of conductive material being such that the bond provides an hermetic seal around said recess and such that the hole in the dielectric member is spaced from the recess in the semiconductor material and the path of electrically conductive material provides an electrical connection to the semiconductor material through the dielectric member at said bond. - View Dependent Claims (3, 4)
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5. A method for manufacturing a variable capacitance pressure transducer, comprising the steps of:
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(a) from at least one area of a surface of a wafer of semiconductor material, removing a portion of the semiconductor material in the area to form at least one recess in the surface of the semiconductor material; (b) doping the semiconductor material, at least in the region of the recess, to enhance its electrical conductivity in the region; (c) on a surface of a dielectric member forming an area of conductive material; (d) in a first hole and a second hole formed through the dielectric member between two surfaces of the dielectric member, the first hole being at a location spaced from the area of conductive material and the second hole being at a location intersecting the area of conductive material, forming a path of electrically conductivity between the two surfaces of the dielectric member; and (e) anodically bonding the surface of the semiconductor material to the surface of the dielectric member such that the surface recess of the semiconductor material is in adjacent, spaced and substantially parallel alignment with the area of electrically conductive material on the dielectric member, thereby, to form an electrical capacitor, the capacitor having doped semiconductor material as one plate thereof spaced from another plate thereof comprising the electrically conductive area, the capacitance of the capacitor being variable as a function of changes in fluid pressure acting on the plates of the capacitor, and the anodic bonding of the surface of the semiconductor material to the surface of the dielectric member with the area of conductive material being such that the first hole in the dielectric member is spaced from the recess in the semiconductor material and the path of electrically conductive material provides an electrical connection to the semiconductor material through the dielectric member at the bond formed by said anodic bonding which provides a hermetic seal around the recess and the second hole being aligned so as to be positioned within the side boundaries of the recess. - View Dependent Claims (6, 7, 8)
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Specification