Hokuriku Electric Industry Co., Ltd.

Yoshiyuki Nakamizo

Masato Ando

Tsutomu Sawai

Shigeru Hirose

Takeshi Arikura

Megumi Hashizaki

Hideki Kobayashi

The present invention provides a semiconductor acceleration sensor wherein a semiconductor element is prevented from being damaged even when at least part of a weight is disposed in an internal space of a semiconductor sensor element and the mass of a weight is accordingly increased. An inner peripheral surface of a support portionis constituted by four trapezoidal inclined surfacesof a substantially identical shape which are annularly combined so as to define an outer peripheral surface of a frust-pyramidal space. A weightis so constructed as to have an abutting portion including a linear portionwhich abuts against the inclined surfacesconstituting the inner peripheral surface of the support portionwhen the weightmakes a maximum displacement in a direction where a diaphragm portionis located. The abutting portionhas a circular outline shape as seen from a side where a weight fixing portionis located. A stopper structure is constituted by the inclined surfacesand the abutting portionof the weight, for restricting a displacement range of the weightin the direction where the diaphragm portionis located.

Semiconductor acceleration sensor and process for manufacturing the same

An acceleration detecting device capable of permitting a weight, a diaphragm and a base to be precisely positioned on a casing of a measuring equipment or the like. The weight, diaphragm and base are integrally formed of a metal material into a single unit. An insulating casing is integrally formed while incorporating the single unit as an insert therein. The insulating casing has a recess defined by a side wall thereof, which is formed with a window for exposing a part of the base therethrough. The recess of the casing is closed with a metal cover member, which is mounted on the casing. The cover member is integrally provided with a contactor which is elastically forced against the base through the window. The base is electrically connected to ground terminals of terminal fitments.

Acceleration detecting device

An acceleration sensor capable of restraining a reduction in output thereof due to an electrostatic capacity between acceleration detecting electrodes and output electrodes. A low-dielectric layer is arranged between a connection line and a piezoelectric ceramic substrate. Another low-dielectric layer is arranged between additional connection lines and output electrodes, and the substrate. The low-dielectric layers are formed of a material substantially reduced in relative dielectric constant as compared with the substrate. The low-dielectric layers reduce an electrostatic capacity generated between wiring patterns and the output electrodes, and a counter electrode pattern, to thereby reduce the amount of spontaneous polarization charges accumulated in the electrostatic capacity.

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Toyama, Japan

Yoshiyuki Nakamizo