Silicon-glass-silicon capacitive pressure transducer
First Claim
1. A silicon, capacitive pressure transducer comprising:
- a first piece of conductive silicon having disposed thereon a pedestal, said pedestal having a conductive surface;
a second piece of conductive silicon having a conductive surface thereon; and
a wall of glass joining said first piece of silicon with said second piece of silicon and providing a chamber between said pieces and said wall, the conductive surface on said pedestal being spaced a short distance from the conductive surface of said second piece of silicon, forming the plates of a capacitor, said distance and therefore the capacitance of said capacitor varying in response to changes in fluidic pressure external to said transducer, the length of said wall between said pieces of silicon being at least four times greater than the distance between said capacitor plates.
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Accused Products
Abstract
A silicon capacitive pressure transducer 34 comprising two wafers of silicon 14, 32 separated by borosilicate glass 18, 21, one of the wafers 14 having a borosilicate glass pedestal 26 thereon which is metallized 30 to provide one plate of a capacitor, the other plate of which is the surface of one of the silicon wafers 32. The distance between the upper surface of the glass pedestal and the lower surface of the silicon wafer is defined by a portion 18 of the borosilicate glass, the portion 21 of borosilicate glass being the same height as that of the glass pedestal 26. An embodiment of a transducer 34b employs a silicon pedestal 26b, wherein the glass portion 21b only provides separation of the silicon wafers 14b, 32b with lower parasitic capacitance.
38 Citations
4 Claims
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1. A silicon, capacitive pressure transducer comprising:
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a first piece of conductive silicon having disposed thereon a pedestal, said pedestal having a conductive surface; a second piece of conductive silicon having a conductive surface thereon; and a wall of glass joining said first piece of silicon with said second piece of silicon and providing a chamber between said pieces and said wall, the conductive surface on said pedestal being spaced a short distance from the conductive surface of said second piece of silicon, forming the plates of a capacitor, said distance and therefore the capacitance of said capacitor varying in response to changes in fluidic pressure external to said transducer, the length of said wall between said pieces of silicon being at least four times greater than the distance between said capacitor plates. - View Dependent Claims (2, 3, 4)
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Specification