Gulton Industries, Inc.

Carlyle A Mounteer

Ronald L Poteet

Robert Earle Ghiselin

Maurice Yang

In an improved strain gage for measuring pressure differentials within areas of varying pressure there is provided a flexible sapphire diaphragm having disposed thereon a Wheatstone bridge. The diaphragm being attached to a base portion by way of a glass bonding material. The base portion's function being to support the flexible diaphragm without interfering with the measurement of strain. The diaphragm having a recess extending to a predetermined depth thereby defining a recessed area having a peripheral edge in order to create pressure points at the peripheral edge of the recess adjacent the recessed area of the diaphragm.

Strain gage

A transducer operating on the strain gauge principle having integral temperature compensation and calibration resistors is disclosed. In the presently preferred embodiment, a silicon dioxide layer is disposed on a silicon substrate. Platinum alloy strain gauge resistors are disposed on the silicon dioxide layer and form a Wheatstone bridge circuit configuration. Laser trimable chromium nitride, platinum alloy and gold temperature compensation and calibration resistors are formed on the silicon dioxide layer from the same films used to form the strain gauge, adhesion layers, conductors and bonding pads, to permit the transducer to be calibrated such that its electrical characteristics are in conformance to specified tolerances when the transducer is subjected to temperature variations.

Semiconductor strain gauge with integral compensation resistors

A transducer which includes a metal strain gage material formed on a flexible monocrystalline silicon diaphragm is disclosed. The transducer is fabricated to a large extent with semiconductor processing steps. Gold is diffused into a platinum-tungsten gage material. This allows the gage material to be chemically etched in the presence of other metals to define the active gage resistors. In the presently preferred embodiment, these resistors are formed over thin areas of the diaphragm to provide increased linearity and sensitivity.

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Irvine, CA, United States of America

Carlyle A Mounteer