Capacitive pressure transducer assembly with improved output lead design
First Claim
1. A pressure transducer assembly in which pressure changes displace a diaphragm whose position determines electrical characteristics of the transducer assembly, comprising:
- base substrate means having top and bottom substantially planar end surfaces, and having a peripheral portion with a lead bonding area thereon;
flexible diaphragm means, relatively thin with respect to a thicker distance between said top and bottom base substrate end surfaces, having a planar central portion and a surrounding peripheral portion;
mounting means for mounting said peripheral portion of said diaphragm means to said base substrate means top surface, said mounting means, said diaphragm planar central portion and said base substrate top surface generally forming an internal cavity wherein a reference pressure exists, said diaphragm central portion being displaceable with respect to said base substrate top surface in response to sensed pressure changes to thereby alter electrical characteristics of said transducer assembly,said base substrate means peripheral portion and lead bonding area extending laterally with respect to and beyond the perimeter of said diaphragm means and having, in said lead bonding area, at least one lead through hole from said top to bottom base substrate surfaces for receiving an electrical lead;
said transducer assembly including at least a planar electrode metallization mounted on said diaphragm central portion and having a radial outward projection;
metallization deposited adjacent said lead through hole on of said base substrate means;
an electrical output lead positioned in said through hole and extending to at least said top and bottom base substrate surfaces; and
connection means for electrically connecting said diaphragm electrode to said lead and connecting said lead to said base substrate metallization adjacent said lead through hole,wherein said adjacent through hole metallization is positioned on said base substrate top surface, and wherein a planar projection of said adjacent through hole metallization extends generally inwardly and overlaps, but is spaced apart from, said diaphragm electrode radial outward projection, and wherein said connecting means comprises means for electrically connecting said adjacent base substrate through hole metallization inward projection and said diaphragm means electrode outward projection in said area of overlap.
1 Assignment
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Accused Products
Abstract
A ceramic capacitive pressure transducer adaptable for use in automobiles is disclosed. The pressure transducer comprises a relatively thin diaphragm 13 having a capacitive electrode 20 thereon, a base substrate 10 having an opposing electrode 22 thereon, and an annular sealing ring 16 mounting the diaphragm to the base substrate. The base substrate has a peripheral lead bonding area 24 extending laterally beyond the perimeter of the diaphragm with two lead through holes 25, 26 in the bonding area. Metallic output leads 35, 36 are positioned in each of the lead through holes and mechanically and electrically bonded to lead metallizations 27, 28, 30, 31 deposited on the base substrate peripheral portion 24, and one (36) of the output leads is electrically connected to the diaphragm electrode 20 by means of a conductive material 37 inserted through an additional hole 33 in the base substrate located within the perimeter of the diaphragm and in an area of overlap between an outward radial projection 21 of the diaphragm electrode and an inward projection 32 of one (28) of the lead metallizations on the base substrate.
34 Citations
19 Claims
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1. A pressure transducer assembly in which pressure changes displace a diaphragm whose position determines electrical characteristics of the transducer assembly, comprising:
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base substrate means having top and bottom substantially planar end surfaces, and having a peripheral portion with a lead bonding area thereon; flexible diaphragm means, relatively thin with respect to a thicker distance between said top and bottom base substrate end surfaces, having a planar central portion and a surrounding peripheral portion; mounting means for mounting said peripheral portion of said diaphragm means to said base substrate means top surface, said mounting means, said diaphragm planar central portion and said base substrate top surface generally forming an internal cavity wherein a reference pressure exists, said diaphragm central portion being displaceable with respect to said base substrate top surface in response to sensed pressure changes to thereby alter electrical characteristics of said transducer assembly, said base substrate means peripheral portion and lead bonding area extending laterally with respect to and beyond the perimeter of said diaphragm means and having, in said lead bonding area, at least one lead through hole from said top to bottom base substrate surfaces for receiving an electrical lead; said transducer assembly including at least a planar electrode metallization mounted on said diaphragm central portion and having a radial outward projection; metallization deposited adjacent said lead through hole on of said base substrate means; an electrical output lead positioned in said through hole and extending to at least said top and bottom base substrate surfaces; and connection means for electrically connecting said diaphragm electrode to said lead and connecting said lead to said base substrate metallization adjacent said lead through hole, wherein said adjacent through hole metallization is positioned on said base substrate top surface, and wherein a planar projection of said adjacent through hole metallization extends generally inwardly and overlaps, but is spaced apart from, said diaphragm electrode radial outward projection, and wherein said connecting means comprises means for electrically connecting said adjacent base substrate through hole metallization inward projection and said diaphragm means electrode outward projection in said area of overlap. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A pressure transducer assembly in which pressure changes displace a diaphragm whose position determines electrical characteristics of the transducer assembly, comprising:
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base substrate means having top and bottom substantially planar end surfaces, and having a peripheral portion with a lead bonding area thereon; flexible diaphragm means, relatively thin with respect to a thicker distance between said top and bottom base substrate end surfaces, having a planar central portion and a surrounding peripheral portion; mounting means for mounting said peripheral portion of said diaphragm means to said base substrate means top surface, said mounting means, said diaphragm planar central portion and said base substrate top surface generally forming an internal cavity wherein a reference pressure exists, said diaphragm central portion being displaceable with respect to said base substrate top surface in response to sensed pressure changes to thereby alter electrical characteristics of said transducer assembly; said base substrate means peripheral portion and lead bonding area extending laterally with respect to and beyond the perimeter of said diaphragm means, and having, in said lead bonding area, at least one metallization on the top surface of said peripheral portion; said transducer assembly including at least a planar electrode metallization mounted on said diaphragm central portion and having a radial outward projection; an electrical output lead electrically connected on said peripheral portion to said top surface metallization, wherein a projection of said top surface metallization extends generally inwardly and overlaps, but is spaced apart from, said diaphragm electrode radial outward projection; and wherein said base substrate means includes a through hole positioned in the area of overlap between the base substrate top surface metallization inward projection and the diaphragm electrode radial outward projection, whereby said through hole aids in bonding said base substrate top surface metallization to said diaphragm electrode; and connection means for electrically connecting said diaphragm electrode to said base substrate top surface metallization whereby a strong bond between the diaphragm electrode and the base substrate means top surface metallization is provided. - View Dependent Claims (14, 15, 16)
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17. A pressure transducer assembly in which pressure changes displace a diaphragm whose position determines electrical characteristics of the transducer assembly, comprising:
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base substrate means having top and bottom substantially planar end surfaces, and having a peripheral portion with a lead bonding area thereon; flexible diaphragm means, relatively thin with respect to a thicker distance between said top and bottom base substrate end surfaces, having a planar central portion and a surrounding peripheral portion; mounting means for mounting said peripheral portion of said diaphragm means to said base substrate means top surface, said mounting means, said diaphragm planar central portion and said base substrate top surface generally forming an internal cavity wherein a reference pressure exists, said diaphragm central portion being displaceable with respect to said base substrate top surface in response to sensed pressure changes to thereby alter electrical characteristics of said transducer assembly; said base substrate means peripheral portion and lead bonding area extending laterally with respect to and beyond the perimeter of said diaphragm means, and having, in said lead bonding area, at least one metallization on the top surface of said peripheral portion; said transducer assembly including at least a planar electrode metallization mounted on said diaphragm central portion and having a radial outward projection; an electrical output lead electrically connected on said peripheral portion to said top surface metallization, wherein a planar projection of said top surface metallization extends generally inwardly and overlaps, but is spaced apart from, said diaphragm electrode radial outward projection; and connection means positioned in the area of overlap between the base substrate top surface metallization inward projection and the diaphragm electrode radial outward projection for electrically connecting said diaphragm electrode to said base substrate top surface metallization in said area of overlap. - View Dependent Claims (18, 19)
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Specification