Abstract: A physical quantity sensor includes two substrates and a movable electrode that is disposed between the two substrates and is bonded to the two substrates. In the physical quantity sensor, the movable electrode has an elastically deformable diaphragm and one of the two substrates is an electrode substrate having a detection electrode on a detection surface opposite to the diaphragm to detect capacitance between the diaphragm and the detection electrode. In the physical quantity sensor, in a range between a room temperature and a bonding temperature when the two substrates and the movable electrode are bonded, coefficients of thermal expansion of the two substrates are smaller than that of the movable electrode and in a temperature range where the physical quantity sensor is used, a coefficient of thermal expansion of the movable electrode is between a first and second substrates.

Abstract: A physical quantity sensor includes two substrates and a movable electrode that is disposed between the two substrates and is bonded to the two substrates. In the physical quantity sensor, the movable electrode has an elastically deformable diaphragm and one of the two substrates is an electrode substrate having a detection electrode on a detection surface opposite to the diaphragm to detect capacitance between the diaphragm and the detection electrode. In the physical quantity sensor, in a range between a room temperature and a bonding temperature when the two substrates and the movable electrode are bonded, coefficients of thermal expansion of the two substrates are smaller than that of the movable electrode and in a temperature range where the physical quantity sensor is used, a coefficient of thermal expansion of the movable electrode is between a first and second substrates.

Abstract: An object of the present invention is to provide a low cost load sensor while securing compact dimensions, high reliability and quality, and also to provide a manufacturing method of the load sensor.

Abstract: An electric motor drive system is disclosed which includes a required number of motor driver circuits connected one to each motor armature coil. Fabricated in the form of an integrated circuit, each such motor driver circuit has a parasitic transistor unavoidably created between two neighboring transistors. The parasitic transistor would become conductive when the driver circuit output had a negative potential, adversely affecting the driver circuit operation. An additional transistor is provided in one embodiment of the invention in order to inhibit such action of the parasitic transistor. Becoming conductive when the driver circuit output goes negative, the additional transistor prevents conduction through the parasitic transistor. Another parasitic transistor is intentionally created in another embodiment for the same purpose.

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: An electric motor drive system is disclosed which includes a required number of motor driver circuits connected one to each motor armature coil. Fabricated in the form of an integrated circuit, each such motor driver circuit has a parasitic transistor unavoidably created between two neighboring transistors. The parasitic transistor would become conductive when the driver circuit output had a negative potential, adversely affecting the driver circuit operation. An additional transistor is provided in one embodiment of the invention in order to inhibit such action of the parasitic transistor. Becoming conductive when the driver circuit output goes negative, the additional transistor prevents conduction through the parasitic transistor. Another parasitic transistor is intentionally created in another embodiment for the same purpose.

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 electrode structure for a semiconductor device is formed on the semiconductor device, consisting of silicon formed on a substrate to detect a physical quantity of the substrate and converting it into an electric signal, and transfers the converted electric signal to the outside. The electrode structure for the semiconductor device has a barrier layer consisting of a high-melting metal nitride and formed on a contact area of the semiconductor device and an electrode wiring formed on the barrier layer. The barrier layer has different composition ratios of the high-melting metal nitride in correspondence to each stage in the thickness of the barrier layer, in which the composition ratios are a composition ratio making a powerful bond performance at a bonding border area with the electrode wiring, and a composition ratio in which a metal element of the electrode wiring does not diffuse into the semiconductor in the barrier layer.

Abstract: A pressure sensor based on electrostatic capacity method is disclosed, which comprises the main body of a pressure sensing element having one end surface as a pressured face and the other end surface as a back, for detecting the pressure of a measurement fluid acting on the pressured face, a seal member, a measure pattern on the back, and a one-chip IC. For size reduction, an input-output policy is provided near the main body of the pressure sensing element, and it effects input and output with respect to the pressure sensing element main body while preventing external disturbances and improving the accuracy of measurement.

Abstract: A pressure sensor of electrostatic capacitance type is disclosed, which detects the pressure of a measurement fluid acting on a pressured surface of an elastic diaphragm from a change in the electrostatic capacitance between opposed electrodes provided on opposed surface of a ceramic base and the elastic diaphragm. The base side electrode comprises a plurality of division electrode one enclosing the next inner one. Of these division electrodes the outermost one is grounded or held at a predetermined voltage, or it is covered by overcoat glass, and thus it is imparted with a function of stabilizing the measurement value. In an electrode hole for leading an electrode to the outside, a path is formed for leading atmospheric air or like fluid providing for the reference pressure for pressure measurement into the space defined between the base and elastic diaphragm.

Abstract: A driving circuit for driving a solenoid pump or the like, wherein a driving current supplied from a rechargeable battery 1 is alternately switched to on and off when flowing in an inductive element 2. The inductive element produces a driving force applied to the solenoid pump when the driving current flows therein. The inductive element generated a counter-electromotive force when the driving current flowing therein is interrupted. An accumulating circuit comprising a capacitor 5 is connected to the inductive element to accumulate the counter-electromotive force, and a releasing circuit 4 is connected to the accumulating circuit to release the counter-electromotive force accumulated in the accumulating circuit. The counter-electromotive force released from the releasing circuit produces a superfluous driving current and the latter current is superposed on the driving current supplied form the battery.