Azbil Corporation

Yamatake Corporation

Hirofumi Tojo

Tomohisa Tokuda

Nozomi Kida

Masayuki Yoneda

Ayumi Tsushima

Tatsuo Tanaka

Yoshiyuki Ishikura

Rina Ogasawara

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.

Pressure sensor

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.

Sensor device with multiple simultaneous pressure measurements

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.

Pressure sensor element for measuring differential pressure and a diaphragm base having a set of diaphragms displaced by receiving pressures where a set of pressure inlet passages respectively transmit different pressures to the set of diaphragms

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.

Differential pressure gauge with improved signal-to-noise ratio suppression

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.

Pressure sensor chip

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&#x3c;impurity concentration of the protection region&#x3c;impurity concentrations of the contact regions.

Piezoresistive sensor

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.

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.

Pressure sensor having a diaphragm

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.

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.

Pressure sensor and manufacturing method thereof

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.

Pressure sensor and manufacturing method

A diaphragm is formed at a predetermined location of a sensor chip made of semiconductor material, and a sensor gauge for differential pressure or pressure sensing-use is provided on the sensor chip that includes at least the diaphragm. The sensor gauge has a plurality of sensor gauges synergistically forming a bridge circuit, and are connected to one another with semiconductor resistors, the semiconductor resistors and the sensor gauges are covered with an insulating film, and the number of contact holes, passing through a portion of the insulating film, for electrode line-out use for forming contacts electrically connected to the semiconductor resistors does not exceed the number of sensor gauges.

In a pressure sensor comprising a diaphragm formed on a portion of a chip made of semiconductor material and that senses pressure on the diaphragm by electrically converting the displacement corresponding to that pressure, the provision of the diaphragm with an aspect ratio of at least a size such that the derivative of the characteristic curve of the allowable pressure resistance of the pressure sensor, defined by setting the aspect ratio obtained by dividing the length of one side of the diaphragm by the thickness of the diaphragm as the horizontal axis and by setting the allowable pressure resistance of the pressure sensor as the vertical axis, becomes nearly zero, enables a pressure sensor having high sensitivity and high pressure resistance.

Growing community of inventors

Tokyo, Japan

Hirofumi Tojo