Abstract: A pressure sensor includes a sensor chip. The sensor chip has two diaphragms, recessed portions that serve as first pressure inlet chambers disposed so as to respectively adjoin top surfaces of the diaphragms, and recessed portions that serve as second pressure inlet chambers disposed so as to respectively adjoin bottom surfaces of the diaphragms. A cavity is provided in the sensor chip such that, when a difference between pressures respectively applied to a top surface and bottom surface of the diaphragm is zero, an output voltage of a Wheatstone bridge circuit made up of strain gauges provided in the diaphragm is zero.

Abstract: A sensor element includes a sensor chip and a diaphragm base joined to a surface of the sensor chip. The sensor chip includes a first diaphragm for measuring differential pressure between a first pressure and a second pressure and a second diaphragm for measuring absolute pressure or gage pressure of the second pressure. The diaphragm base includes a third diaphragm to directly receive a fluid that is a measurement target and has the first pressure, and a fourth diaphragm to directly receive a fluid that is a measurement target and having the second pressure. The sensor element has a liquid amount adjustment chamber to make an amount of a first pressure transmission medium filled in a first pressure introduction path and an amount of a second pressure transmission medium filled in a second pressure introduction path to be equal to each other.

Abstract: A sensor chip of a sensor element includes a diaphragm for measuring a differential pressure between a first pressure and a second pressure, a diaphragm for measuring an absolute pressure or a gauge pressure of the second pressure, a first pressure introduction path that transmits the first pressure to the diaphragm for measuring a differential pressure, and a second pressure introduction path that transmits the second pressure to the diaphragms. When the transmission of the first pressure or the second pressure to the diaphragms is indicated by an equivalent circuit, a path for transmitting the first pressure and a path for transmitting the second pressure are symmetrically formed.

Abstract: A differential pressure gauge of the invention contains: a diaphragm layer disposed between first and second parts; and a wall between a first region on a pressure-receiving portion side and a second region on a first through-hole side within a second pressure chamber. The diaphragm layer covers the pressure-receiving portion over a first pressure chamber and has the first through-hole with one end disposed in the second pressure chamber away from the pressure-receiving portion. The wall is disposed with gaps formed from inner walls of the second pressure chamber. The first pressure chamber is formed through the first part, the second pressure chamber has an opening facing the diaphragm layer, the first part has a second through-hole continuing to the first through-hole, and a base has a third through-hole with one end disposed in the first pressure chamber and a fourth through-hole continuing to the second through-hole.

Abstract: A curved recess in a stopper includes a groove-pattern region and a groove-free region. When a sensor diaphragm reaches a bottom of the curved recess in the stopper, a groove-free region is divided into a ring-shaped first region with which a sensor diaphragm is in close contact and a ring-shaped second region disposed between an inner wall surface of a ring-shaped wall and the ring-shaped first region. The first region serves as a sealing region and the second region serves as a confinement region so that a pressure transmitting medium that remains in a space adjacent to the inner wall surface of the ring-shaped wall is confined in the confinement region, and abnormal deformation of the sensor diaphragm is prevented.

Abstract: A flow rate measurement error is reduced by a differential pressure type flowmeter that includes: a pipe; a laminar flow element disposed within the pipe; a first absolute pressure sensor measuring an absolute pressure P1 of a fluid upstream of the laminar flow element; a second absolute pressure sensor measuring an absolute pressure P2 of the fluid downstream; a temperature sensor measuring an ambient temperature T of the absolute pressure sensors; a pressure calculation section correcting an output signal from the first absolute pressure sensor based on the temperature T to be converted into the absolute pressure P1, and correcting an output signal from the second absolute pressure sensor based on the temperature T to be converted into the absolute pressure P2; and a flow rate calculation section calculating a flow rate of the fluid based on the absolute pressures P1 and P2 calculated by the pressure calculation section.

Abstract: The differential pressure gauge includes a base, a first part disposed on an upper surface of the base, a second part disposed on the first part, and a diaphragm layer disposed between the first part and the second part. A wall is formed in a second pressure chamber formed in the second part between a first region on a side including a pressure-receiving portion and a second region on a side including a first through-hole, with a gap defined with respect to inner walls of the second pressure chamber.

Abstract: A piezoresistive sensor includes a piezoresistive region to which first conductivity type impurity has been introduced, the piezoresistive region being formed in a semiconductor layer; a protection region to which second conductivity type impurity has been introduced, the protection region covering a top of a region in which the piezoresistive region is formed, the protection region being formed in the semiconductor layer; and contact regions to which the first conductivity type impurities have been introduced, the contact regions being connected to the piezoresistive region, the contact regions being formed so as to reach a surface of the semiconductor layer except a region in which the protection region is formed, in which the following inequality holds: impurity concentration of the piezoresistive region<impurity concentration of the protection region<impurity concentrations of the contact regions.

Abstract: A sensor chip of a sensor element includes a diaphragm for measuring a differential pressure between a first pressure and a second pressure, a diaphragm for measuring an absolute pressure or a gauge pressure of the second pressure, a first pressure introduction path that transmits the first pressure to the diaphragm for measuring a differential pressure, and a second pressure introduction path that transmits the second pressure to the diaphragms. When the transmission of the first pressure or the second pressure to the diaphragms is indicated by an equivalent circuit, a path for transmitting the first pressure and a path for transmitting the second pressure are symmetrically formed.

Abstract: A sensor element includes diaphragms that are respectively displaced by receiving pressures, and a plurality of pressure inlet passages (a first pressure inlet passage made up of through-holes, a groove, and recessed portions, and a second pressure inlet passage made up of a through-hole, a groove, and a recessed portion) that respectively transmit same or different pressures to the diaphragms. Each of the plurality of pressure inlet passages is filled with a pressure transmission medium capable of transmitting a pressure. A pressure is applied through part or all of the plurality of pressure inlet passages to each of the diaphragms.

Abstract: A sensor element includes a first diaphragm for measuring differential pressure between first pressure and second pressure and a second diaphragm for measuring absolute pressure or gage pressure of the second pressure. The sensor element has a first pressure introduction path (through holes, a groove, and a depression) through which the first pressure is transmitted to the first diaphragm. The sensor element has a second pressure introduction path (through holes, grooves, and depressions) through which the second pressure is transmitted to the first and second diaphragms. The sensor element has a liquid amount adjustment chamber (depression) configured to make an amount of a first pressure transmission medium filled in the first pressure introduction path and an amount of a second pressure transmission medium filled in the second pressure introduction path to be equal to each other.

Abstract: A pressure sensor includes a sensor chip. The sensor chip has two diaphragms, recessed portions that serve as first pressure inlet chambers disposed so as to respectively adjoin top surfaces of the diaphragms, and recessed portions that serve as second pressure inlet chambers disposed so as to respectively adjoin bottom surfaces of the diaphragms. A cavity is provided in the sensor chip such that, when a difference between pressures respectively applied to a top surface and bottom surface of the diaphragm is zero, an output voltage of a Wheatstone bridge circuit made up of strain gauges provided in the diaphragm is zero.

Abstract: A curved recess in a stopper includes a groove-pattern region and a groove-free region. When a sensor diaphragm reaches a bottom of the curved recess in the stopper, a groove-free region is divided into a ring-shaped first region with which a sensor diaphragm is in close contact and a ring-shaped second region disposed between an inner wall surface of a ring-shaped wall and the ring-shaped first region. The first region serves as a sealing region and the second region serves as a confinement region so that a pressure transmitting medium that remains in a space adjacent to the inner wall surface of the ring-shaped wall is confined in the confinement region, and abnormal deformation of the sensor diaphragm is prevented.

Abstract: A piezoresistive sensor includes a piezoresistive region to which first conductivity type impurity has been introduced, the piezoresistive region being formed in a semiconductor layer; a protection region to which second conductivity type impurity has been introduced, the protection region covering a top of a region in which the piezoresistive region is formed, the protection region being formed in the semiconductor layer; and contact regions to which the first conductivity type impurities have been introduced, the contact regions being connected to the piezoresistive region, the contact regions being formed so as to reach a surface of the semiconductor layer except a region in which the protection region is formed, in which the following inequality holds: impurity concentration of the piezoresistive region<impurity concentration of the protection region<impurity concentrations of the contact regions.

Abstract: A bottom surface of a sensor chip (or a lower surface of a first retaining member) that introduces the pressure of a measured fluid is joined to a bottom surface of a sensor chamber (or to an inner wall surface of a base body) to allow an enclosing chamber (formed by a pressure receiving chamber and a pressure guiding passage) between a pressure receiving diaphragm and the bottom surface of the sensor chip to communicate with a pressure guiding hole in the first retaining member. The sensor chamber is made open to the atmosphere. Thus, a wire bonding portion of a sensor diaphragm from which wires extend is positioned outside the enclosing chamber, and electrode pins and an enclosed liquid in the enclosing chamber are separated from each other.

Abstract: A bottom surface of a sensor chip (or a lower surface of a first retaining member) that introduces the pressure of a measured fluid is joined to a bottom surface of a sensor chamber (or to an inner wall surface of a base body) to allow an enclosing chamber (formed by a pressure receiving chamber and a pressure guiding passage) between a pressure receiving diaphragm and the bottom surface of the sensor chip to communicate with a pressure guiding hole in the first retaining member. The sensor chamber is made open to the atmosphere. Thus, a wire bonding portion of a sensor diaphragm from which wires extend is positioned outside the enclosing chamber, and electrode pins and an enclosed liquid in the enclosing chamber are separated from each other.

Abstract: A pressure sensor comprising: a sensor chip; a differential pressure diaphragm provided in the center portion of the sensor chip; a differential pressure gauge provided in the differential pressure diaphragm; a static pressure diaphragm provided at the outer peripheral portion of the differential pressure diaphragm; a first static pressure gauge formed at an edge portion of the static pressure diaphragm; and a second static pressure gauge formed at a center portion of the static pressure diaphragm.

Abstract: A pressure sensor including a sensor chip; a differential pressure diaphragm provided in the center portion of the sensor chip; a first differential pressure gauge formed along a radial direction relative to the center of the differential pressure diaphragm, provided on a first edge of the differential pressure diaphragm; a second differential pressure gauge formed along a circumferential direction, which is perpendicular to the radial direction, provided in the vicinity of the first differential pressure gauge on the first edge of the differential pressure diaphragm; and a static pressure diaphragm disposed between an edge portion of the sensor chip and one of the edges, other than the first edge, of the differential pressure diaphragm, provided to the outside of the differential pressure diaphragm.

Abstract: The pressure sensor according to the present invention has a sensor chip having a first semiconductor layer that has an opening portion, and a second semiconductor layer, formed on the first semiconductor layer, having a recessed portion that forms a diaphragm and a base, having a pressure guiding hole that is connected to the opening portion, bonded to the sensor chip. The recessed portion in the second semiconductor layer is larger than the opening portion of the first semiconductor layer. The opening portion of the first semiconductor layer has an opening diameter on the second semiconductor layer side that is larger than the opening diameter on the base side.

Abstract: A semiconductor substrate, provided with a differential pressure diaphragm, and a glass pedestal, which is provided on the bottom side of the semiconductor substrate, are provided, wherein: the bottom surface of the semiconductor substrate and the top surface of the glass pedestal are bonded together; a pressure introducing hole is formed in the glass pedestal so as to pass through the glass pedestal, connecting between the top and bottom surfaces of the glass pedestal; the pressure introducing hole is formed with a first diameter for the pressure introducing hole at the bottom surface of the glass pedestal from the bottom surface of the glass pedestal to a first position; and a second diameter for the pressure introducing hole at the top surface of the glass pedestal is larger than the first diameter; where a metal thin film layer is deposited on the bottom surface of the glass pedestal.