Hitachi, Ltd.

Michitaka Shimazoe

Yoshitaka Matsuoka

Yukio Takahashi

Satoshi Shimada

Kazuji Yamada

Masanori Tanabe

Yasumasa Matsuda

Mitsuo Ai

Hideyuki Nemoto

Motohisa Nishihara

Yoshimi Yamamoto

Yasushi Shimizu

Kousuke Nakamura

Yasuo Matsushita

Masatoshi Tsuchiya

Ichiro Kimura

Katsuya Katohgi

Keiji Miyauchi

Ryozo Akahane

In a semiconductor pressure transducer in accordance with the present invention, an oxide film is formed on a semiconductor base having a strain gauge resistor element for the purpose of protecting the strain gauge resistor element. Over the oxide film, a conductive metal film is formed which does not overlap with the strain gauge resistor element through said oxide film.

Semiconductor pressure transducer

A load cell comprises a semiconductor diaphragm which includes an outer flange portion, a central rigid portion having a smaller thickness than the outer flange portion and a thin resilient portion provided between the outer flange portion and the central rigid portion. At least two piezo-resistors constituting at least part of a bridge circuit are formed in the resilient portion. The load cell further comprises a first glass block secured to the central rigid portion, and a second glass block for securing the outer flange portion. A load is applied to the semiconductor diaphragm through the first glass block, wherein measurement of the applied load is effected by detecting variation in resistance of the resistor bridge circuit.

Load cell

A differential pressure measuring transducer assembly including a measuring diaphragm formed of semiconductor material having gauge resistance elements on one surface thereof and a central boss area of large thickness and a peripheral support flange on the other surface thereof defining therebetween an annular portion of small thickness. The measuring diaphragm is attached at the peripheral support flange to a glass support member and a metallic support member formed with pressure conducting bores respectively communicating with each other. The metallic support member is formed of material having a Young's modulus substantially equal to that of the measuring diaphragm.

Differential pressure measuring transducer assembly

A pressure transducer comprising a silicon diaphragm on which a semiconductor strain gauge is formed and which has a diaphragm portion deformable in response to a pressure, an insulating support which is made of borosilicate glass having the silicon diaphragm rigidly mounted thereon and which is provided with a pressure introducing hole in its central part, a metallic support which is cylindrical, which is made of an iron-nickel alloy similar in the thermal expansion coefficient to the borosilicate glass and on which the glass insulating support is rigidly mounted, and a metallic housing within which the integrated structure consisting of the silicon diaphragm, the glass insulating support and the metallic support is arranged; the silicon diaphragm, the insulating support and the metallic support being joined by the anodic bonding, the metallic support being rigidly welded to the metallic housing at its lower end part.

Pressure sensitive apparatus

A semiconductor pressure transducer comprising a disc-shaped pressure-responsive diaphragm; a pair of radial strain gauge units having a piezoresistance effect, formed by injecting an impurity in the radial direction in the surface of the diaphragm; and a pair of tangential strain gauge units having a piezoresistance effect, formed by injecting an impurity in the tangential direction in the surface of the diaphragm, wherein the distance from the pair of the radial strain gauge units to the center of the circular diaphragm is greater than the distance from the pair of the tangential strain gauge units to the center of the circular diaphragm.

A semiconductor pressure transducer includes a monocrystalline semiconductor diaphragm, the outer edges of which are fixed. When subjected to pressure, the transducer produces radial strains of opposite polarity in a central portion thereof and a portion surrounding the central portion close to the edge of the strain inducing region. The diaphragm contains a plurality of elongated resistances formed of semiconductor material of the same conductivity type which are electrically isolated from the diaphragm, per se. Resistances of an individual set which lie in proximity to one another are combined in the form of a bridge. The longitudinal direction of resistances forming one set of opposing arms of the bridge extend along axes of the same crystal system as the longitudinal direction of the elongated resistances forming the other set of opposing arms of the bridge. However, the longitudinal directions of the separate sets of resistances forming the opposing arms of the bridge lie in directions so that they do not orthogonally intersect each other.

A semiconductor pressure transducer comprises a circular diaphragm formed of a single crystal semiconductor material, at least a first strain gauge element having a piezoresistance effect and formed by injecting an impurity into the diaphragm in a linear region extending in parallel with a predetermined axis which extends transversely of the surface of the diaphragm, at least a second strain gauge element having the piezoresistance effect and formed by injecting an impurity into the diaphragm in a linear region extending in the direction perpendicular to the axis, and means for securing the diaphragm at the outer peripheral portion thereof. The distance between the second strain gauge element and the center of the diaphragm is differed from the distance between the center of the first strain gauge element and the latter.

Growing community of inventors

Mito, Japan

Michitaka Shimazoe