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AssigneeCase Western Reserve University
InventorsJaroslav Hynecek, Wen H. Ko, Eugene T. Yon
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A fluidtight, hermetically sealed, miniature transducer adapted to be inserted into the human body and useful for directly monitoring internal fluid or pneumatic pressures within the human body is disclosed. Semiconductor strain gauge elements constituting a piezoresistive bridge are formed by diffusion on the surface of one side of an integral flexible, rectangular, silicon diaphragm area of a single crystal silicon base. A single crystal silicon cover is eutectically bonded to the base by a metallic laminate seal. The base, cover, and seal define an evacuated fluidtight chamber containing the strain gauge elements. Electrical conductors, which include diffused conductor paths under an insulating oxide layer, extend from the piezoresistive bridge to contact pads outside the fluidtight chamber. The contact pads can be connected to a readout device for electrically measuring the pressure differential between the evacuated chamber and fluid external to the transducer as a function of time.
A transducer for measuring fluid or pneumatic pressure comprising a semiconductor base member, at least a portion of said base member being a thin flexible diaphragm, a piezoresistive bridge formed on a surface of a side of said diaphragm, said bridge having at least one electrical parameter which changes in response to flexing of said surface of said diaphragm, a cover member, a seal bonding said cover member to said base member, said members and said seal defining a fluidtight chamber containing said piezoresistive bridge, and electrical conductor means extending from said piezoresistive bridge to a point external to said fluidtight chamber, said conductor means including diffused conductor paths on said base member where said conductor means passes from said fluidtight chamber to said point external to said fluidtight chamber.
A transducer for measuring fluid or pneumatic pressure comprising a single crystal, silicon base member with an integral flexible diaphragm, a diffused piezoresistive bridge formed on a surface of said diaphragm, said bridge having at least one electrical parameter which changes in response to the deformation of said surface of said diaphragm, a single crystal, silicon cover member, a laminate seal bonding said cover member to said base member, said members and said seal defining an evacuated fluidtight chamber containing said piezoresistive bridge, and electrical conductor means extending from said piezoresistive bridge to a point external to said fluidtight chamber, said conductor means including diffused conductor paths on said base member where said conductor means passes from said fluidtight chamber to said point external to said fluidtight chamber.
A method of assembling a pressure transducer comprising the steps of:
Dependencies are inferred from the claim text.