Abstract: A thin-film resistor (5) provided on a strain-generating part (2) via an insulating film (4) and an electrode thin-film (6) including an electrode pad (10) arranged in the thin-film resistor (5) are provided. The thin-film resistor (5) includes a strain-detecting thin-film resistive part (8) and an electrode connection (9) connected to the resistive part (8). The electrode connection (9) is formed to extend to the electrode pad (10). The electrode pad (10) includes an external-connection bonding area (12) and a testing probe area (13) formed at different positions. The electrode pad (10) is disposed on a tubular rigid body (1) provided at the outer peripheral edge of a strain-generating part (2).

Abstract: An adapter (2) disposed between joint (1) and diaphragm (3) includes an axis portion (21) and a flange (22) projecting radially from the axis portion (21). The axis portion (21) is arranged so that one end thereof does not interfere with the joint (1) and the other end is welded to the diaphragm (3), and the joint (1) is caulked to a peripheral edge of the flange (22). Since the diaphragm (3) is not directly joined to the joint (1), welding is not performed near the joint (1), but can be performed in a wide space where equipment is suitably arranged. In addition, caulking operation of the joint (1) to the adapter (2) can be performed by pressing a caulking portion (12C) formed in advance in the joint (1) against the outer peripheral edge of the flange (22), so that a wide space is unnecessary for caulking.

Abstract: An electric wire insertion hole (41) arranged in a housing (4), an ventilation path of inside space (422) of which one end is opened to a pressure sensor internal space (7) and an intersection portion (421) communicating the both each other are provided. Since the electric wire insertion hole (41) and the intersection (421) intersect at right angles, water or dust entering into the electric wire insertion hole (41) does not enter a lot into the intersection (421). Therefore, water or dust hardly enters into the pressure sensor internal space (7). There is no need of a waterproof or a dustproof filter or the like to prevent water or dust, hence low cost manufacturing can be achieved.

Abstract: A pressure sensor (1) includes a diaphragm (21) with a bottom formed of a thin-wall portion (210) and a pressure introducing joint (10), in which an austenitic precipitation hardening Fe—Ni heat resisting steel having high mechanical strength is used for the diaphragm (21), while an austenitic stainless steel that is relatively inexpensive is used for the pressure introducing joint (10). The diaphragm (21) and the pressure introducing joint (10) are integrated by welding, and Ni content of a weld portion is appropriately adjusted. Thereby, the pressure sensor (1) achieves high accuracy and reliability, and usage amount of the expensive austenitic precipitation hardening Fe—Ni heat resisting steel can be minimized in manufacturing the pressure sensor (1). Also, since the austenitic stainless steel has an excellent corrosion resistance, the pressure sensor (1) can be used in measurement of a fluid with high corrosiveness.

Abstract: An apparatus for detecting an amount of strain comprises a strain generating part, an electrical insulating layer and sensing elements. The strain generating part is a member to which strain is to be applied. The electrical insulating layer is formed on the strain generating part. The sensing elements are formed on the electrical insulating layer. Each of the sensing elements is made of a silicon film. The silicon film comprises a poly-crystalline main layer and a poly-crystalline interface-layer, which comes into contact with the electrical insulating layer.

Abstract: A fluid pressure sensor (1) for measuring the pressure of a fluid comprises a diaphragm portion (12) which is a strain generating body, a silicon oxide film (21) as an insulating film, and a strain gauge (20) made of crystalline silicon, and austenitic precipitation hardening type Fe—Ni heat-resisting steel excellent in mechanical strength and corrosion resistance is used for the diaphragm portion (12). The silicon oxide film (21) is formed with the internal stress thereof adjusted to the range from ?150 to 130 MPa. With this feature, the fluid pressure sensor (1) ensures high precision and reliability, and may be used even for measurement of a highly corrosive fluid.

Abstract: A pressure sensor (1) includes a diaphragm (21) with a bottom formed of a thin-wall portion (210) and a pressure introducing joint (10), in which an austenitic precipitation hardening Fe—Ni heat resisting steel having high mechanical strength is used for the diaphragm (21), while an austenitic stainless steel that is relatively inexpensive is used for the pressure introducing joint (10). The diaphragm (21) and the pressure introducing joint (10) are integrated by welding, and Ni content of a weld portion is appropriately adjusted. Thereby, the pressure sensor (1) achieves high accuracy and reliability, and usage amount of the expensive austenitic precipitation hardening Fe—Ni heat resisting steel can be minimized in manufacturing the pressure sensor (1). Also, since the austenitic stainless steel has an excellent corrosion resistance, the pressure sensor (1) can be used in measurement of a fluid with high corrosiveness.

Abstract: An electric wire insertion hole (41) arranged in a housing (4), an ventilation path of inside space (422) of which one end is opened to a pressure sensor internal space (7) and an intersection portion (421) communicating the both each other are provided. Since the electric wire insertion hole (41) and the intersection (421) intersect at right angles, water or dust entering into the electric wire insertion hole (41) does not enter a lot into the intersection (421). Therefore, water or dust hardly enters into the pressure sensor internal space (7). There is no need of a waterproof or a dustproof filter or the like to prevent water or dust, hence low cost manufacturing can be achieved.

Abstract: A pressure sensor includes: a main body case including a housing (1) and a joint (2); an electronic circuit (3) housed inside the main body case to convert detected pressure into electrical signals to send out; a connecting metal piece (5), one end (51)of which abuts on an electrode (31) of the electronic circuit (3); a terminal (4), one end (41) of which is joined to the other end (52) of the connecting metal piece (5) and the other end (42) of which is disposed outside the main body case; and a cushion (7) biasing the one end (51) to the electrode (31). The one end (51) and the electrode (31) are electrically connected by biasing force of the cushion (7), which eliminates welding, enabling manufacturing at low cost.

Abstract: An adapter (2) disposed between joint (1) and diaphragm (3) includes an axis portion (21) and a flange (22) projecting radially from the axis portion (21). The axis portion (21) is arranged so that one end thereof does not interfere with the joint (1) and the other end is welded to the diaphragm (3), and the joint (1) is caulked to a peripheral edge of the flange (22). Since the diaphragm (3) is not directly joined to the joint (1), welding is not performed near the joint (1), but can be performed in a wide space where equipment is suitably arranged. In addition, caulking operation of the joint (1) to the adapter (2) can be performed by pressing a caulking portion (12C) formed in advance in the joint (1) against the outer peripheral edge of the flange (22), so that a wide space is unnecessary for caulking.

Abstract: A pressure sensor 10 included an upper substrate 30 having a detection face 30A, a diaphragm 20 provided with a space from the detection substrate 30 and displaceable to and from the upper substrate 30, fixed electrodes 32, 33 provided on the detection face 30A of the upper substrate 30, and a first signal fetching section 22 electrically connected to the diaphragm 20, and the diaphragm 20 is formed by dry-etching single-crystal silicon with the specific resistance lowered to 1.0 ?·cm or below by mixing dopant lowering the resistance value.

Abstract: A thin-film resistor (5) provided on a strain-generating part (2) via an insulating film (4) and an electrode thin-film (6) including an electrode pad (10) arranged in the thin-film resistor (5) are provided. The thin-film resistor (5) includes a strain-detecting thin-film resistive part (8) and an electrode connection (9) connected to the resistive part (8). The electrode connection (9) is formed to extend to the electrode pad (10). The electrode pad (10) includes an external-connection bonding area (12) and a testing probe area (13) formed at different positions. The electrode pad (10) is disposed on a tubular rigid body (1) provided at the outer peripheral edge of a strain-generating part (2).

Abstract: An absolute-pressure type of pressure sensor is provided. The sensor has a pressure detecting device having a metal diaphragm. Strain gauges are disposed on one surface of the diaphragm, whose other surface is formed to receive fluid to be detected. The sensor comprises a lid, relay board, two seal rings, and input/output terminal. The lid provides a reference pressure space. The relay board is electrically connected to the gauge and composed of laminated ceramic members having both of through holes formed to pass through both sides thereof and a protrusion formed outwardly. The two seal rings are located to face the two sides of the board, respectively. The one seal ring air-tightly connects the relay board and the diaphragm. The other seal ring air-tightly connects the relay board and the lid. The terminal is electrically connected to the relay board and mounted on the protrusion of the relay board.

Abstract: A method of manufacturing strain-detecting devices is provided. First, plural cylindrical substrates, each of which has one end closed by a diaphragm, are fixedly placed at predetermined positions of a fixing plate. A positioning marker is previously given to the fixing plate. The fixing plate having the substrates is then assembled into a jig. The jig sustains the substrates so that an outer surface of the diaphragm of each substrate is held at the same level. Through positioning the substrates, all the diaphragms are then positioned in place in a plane direction of the fixing plate with reference to the positioning marker. A strain gage portion is simultaneously formed on each of all the diaphragms. The fixing plate is then disassembled from the jig. In this step, the substrates with the strain gage portions, i.e., strain-detecting devices, are separated from the fixing plate.

Abstract: An apparatus for detecting an amount of strain comprises a strain generating part, an electrical insulating layer and sensing elements. The strain generating part is a member to which strain is to be applied. The electrical insulating layer is formed on the strain generating part. The sensing elements are formed on the electrical insulating layer. Each of the sensing elements is made of a silicon film. The silicon film comprises a poly-crystalline main layer and a poly-crystalline interface-layer, which comes into contact with the electrical insulating layer.

Abstract: A pressure sensor 10 comprises an upper substrate 30 having a detection face 30A, a diaphragm 20 provided with a space from the detection substrate 30 and displaceable to and from the upper substrate 30, fixed electrodes 32, 33 provided on the detection face 30A of the upper substrate 30, and a first signal fetching section 22 electrically connected to the diaphragm 20, and the diaphragm 20 is formed by dry-etching single-crystal silicon with the specific resistance lowered to 1.0 &OHgr;·cm or below by mixing dopant lowering the resistance value.

Abstract: An absolute-pressure type of pressure sensor is provided. The sensor has a pressure detecting device having a metal diaphragm. Strain gauges are disposed on one surface of the diaphragm, whose other surface is formed to receive fluid to be detected. The sensor comprises a lid, relay board, two seal rings, and input/output terminal. The lid provides a reference pressure space. The relay board is electrically connected to the gauge and composed of laminated ceramic members having both of through holes formed to pass through both sides thereof and a protrusion formed outwardly. The two seal rings are located to face the two sides of the board, respectively. The one seal ring air-tightly connects the relay board and the diaphragm. The other seal ring air-tightly connects the relay board and the lid. The terminal is electrically connected to the relay board and mounted on the protrusion of the relay board.

Abstract: A pressure sensor (1) has a circuit board (5) having a circuit portion (11) for amplifying an electric signal detected by a pressure detecting element (2C) and attached with an IC die (16), and a terminal (12) for inputting and outputting the electric signal from the circuit portion (11). The circuit portion (11) and the terminal (12) have a frame (11A, 12D) formed by a metal plate, the metal plate being provided with resin molds (14, 15). The circuit portion (11) and the terminal (12) are continuously formed, so that steps for soldering etc. is not necessary.

Abstract: A pressure sensor has a joint (1) having a pressure port (13), a pressure detecting device (2) bonded to the joint (1) to convert fluid pressure to an electric signal and a housing (5) provided to an output side of the pressure detecting device (2), the pressure sensor further including a flange member (3) bonded to the joint (1) and having a through-hole (26) for the pressure detecting device (2) to be inserted and a connector (6) bonded to the flange member (3) to fix the housing (5).

Abstract: A method of manufacturing strain-detecting devices is provided. First, plural cylindrical substrates, each of which has one end closed by a diaphragm, are fixedly placed at predetermined positions of a fixing plate. A positioning marker is previously given to the fixing plate. The fixing plate having the substrates is then assembled into a jig. The jig sustains the substrates so that an outer surface of the diaphragm of each substrate is held at the same level. Through positioning the substrates, all the diaphragms are then positioned in place in a plane direction of the fixing plate with reference to the positioning marker. A strain gage portion is simultaneously formed on each of all the diaphragms. The fixing plate is then disassembled from the jig. In this step, the substrates with the strain gage portions, i.e., strain-detecting devices, are separated from the fixing plate.