Abstract: 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 portion 9 is constituted by four trapezoidal inclined surfaces 13 of a substantially identical shape which are annularly combined so as to define an outer peripheral surface of a frust-pyramidal space. A weight 3 is so constructed as to have an abutting portion including a linear portion 3d which abuts against the inclined surfaces 13 constituting the inner peripheral surface of the support portion 9 when the weight 3 makes a maximum displacement in a direction where a diaphragm portion 11 is located. The abutting portion 3d has a circular outline shape as seen from a side where a weight fixing portion 7 is located.

Abstract: 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 portion 9 is constituted by four trapezoidal inclined surfaces 13 of a substantially identical shape which are annularly combined so as to define an outer peripheral surface of a frust-pyramidal space. A weight 3 is so constructed as to have an abutting portion including a linear portion 3d which abuts against the inclined surfaces 13 constituting the inner peripheral surface of the support portion 9 when the weight 3 makes a maximum displacement in a direction where a diaphragm portion 11 is located. The abutting portion 3d has a circular outline shape as seen from a side where a weight fixing portion 7 is located.

Abstract: 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.

Abstract: 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.