Abstract: An angular velocity sensor includes a tuning-fork oscillator having a pair of arms jointed by a trunk, the pair of arms extending in parallel to each other, first and second driving piezoelectric elements arranged only on one surface of the trunk with a gap therebetween in an extending direction of the arms, and angular velocity detecting piezoelectric elements arranged on surfaces of the arms in parallel with the one surface of the trunk on which the first and second piezoelectric elements are arranged.

Abstract: An angular velocity sensor comprises a driving element, a detecting element, and a feedback element, all of which are disposed on an element forming face of an oscillator. An electrostatic capacitance of the feedback element is set to be equal to that of the detecting element. As a result, a synchronous detection circuit can reduce the offset signal due to a phase difference between signals from the feedback element and the detecting element.

Abstract: The output of a synchronous detector is made precise by reducing the offset included in the outputs of detecting piezoelectric elements. This is carried out by applying one y-axis direction exciting force to one movable piece from one pair of driving piezoelectric elements and another y-axis direction exciting force to another movable piece from another pair of driving piezoelectric elements.

Abstract: A manufacturing method of semiconductor devices adaptable for use in microelectronics devices such as angular-rate sensors includes the steps of preparing a silicon wafer having a lamination of a p-type silicon substrate and an n-type epitaxial layer as formed thereon, defining on a specified surface of the wafer a plurality of recess portions each having a reduced-thickness portion on the opposite surface side which consists of the epitaxial layer, forming plural through-going holes in each reduced-thickness portion by causing a gel- or oil-like coolant medium made of a thermally conductive material to be disposed in contact with one surface of the reduced-thickness portion of the silicon substrate and by effecting dry etching of certain region from the other surface of the reduced-thickness portion, and thereafter removing the medium. This medium serves to absorb and dissipate heat generated at the reduced-thickness portion during the dry etching.

Abstract: A frame body and a tuning fork-shaped vibratory element are made of a single crystalline silicon substrate. The vibratory element has arms extending parallel to each other. The respective sides of the frame body are located face to face with a predetermined distance from the arms. Thin portions are formed between thick portions located partially on the arms of the vibratory element. Piezo-resistant elements for detecting angular velocity are disposed on the thin portions. When electrostatic force is imposed between the sides of the frame body and the arms, the arms are excited to vibrate. At this time, when angular velocity is imposed, the arms vibrate in the direction crossing at right angles with the excited direction. The piezo-resistant elements detect vibration of the arms caused by the angular velocity with stabilized characteristics and higher sensitivity.

Abstract: A displacement detector to obtain high-precision displacement detection with a small-sized, low-cost apparatus. A displacement detector comprises rectangular teeth formed on the outer circumference surface at a pitch of .lambda., a gearwheel made of a magnetic material, a magnet having a width larger than the pitch .lambda. of the gearwheel and so disposed that the N-pole thereof faces the teeth, and a pair of MREs constructed by alternately connecting the long strip portions and short strip portions thereof to have a zigzag shape. A uniform cyclic magnet field from the magnet to the gearwheel is formed within a gap between the gearwheel and the magnet. On the same phase of the magnet field are disposed the pair of MREs so that the directions of the long strip portions thereof and the directions of the magnetic force lines make angles of approximately 45.degree. and approximately 135.degree., respectively.

Abstract: It is intended to provide an etching method for semiconductor devices in which the etching depth or the thickness of a thin thickness portion can be precisely controlled. According to experiment results, when a P-type substrate in which an N-type epitaxial layer is formed is immersed in an etching solution such as KOH or the like, and a voltage for reverse bias of PN junction is applied between an electrode plate opposing the substrate and the epitaxial layer to perform electrochemical etching, it has been found that the distance from the PN junction plane to the etching stop position is approximately equal to a depletion layer width at the substrate side of the PN junction portion. Namely, the etching stops at the forward end of the depletion layer.

Abstract: A method of manufacturing a magnetoresistance element that can accurately sort out truely defective products from apparently defective products due to the manufacturing processes. Manufacturing processes for MR elements includes a MR element formation process, a magnetic field application process and an electric inspection process. In the magnetic field process, the magnetic field application is limited to a range within 75.degree. to the longitudinal direction of a MR element pattern. By performing the magnetic field application process before the electric inspection process, the anisotropic magnetic field due to a shape magnetic anisotropy of the MR element can be aligned almost in a fixed direction, defective products due to the manufacturing processes can exactly be sorted out from the apparently defective products in the electric inspection process, so that the yield rate can be improved.

Abstract: A method of manufacturing a magneto-electric conversion device having a large rate of change of magnetic resistance and which is easy to position with respect to a magnetized surface, and a moving subject displacement detector using a magneto-electric conversion device manufactured by that method. A magnet which rotates together with the rotation of a drive gear is magnetized in alternately differing north and south poles, arranged in an equal sized section from a center portion thereof. An IC chip is positioned opposite to and at a distance from the magnetized surface of the magnet. Magneto-electric conversion devices are located on the IC chip. These magneto-electric conversion devices are formed by repeated alternate depositions, onto a surface of a single-crystal silicon substrate, of magnetic cobalt films having a thickness of several to several tens of angstroms and non-magnetic copper films having a thickness of several to several tens of angstroms.

Abstract: A plasma etching process for forming a recess or opening on a silicon substrate by generating plasma between a pair of electrodes in an anode-coupled planar-type plasma etching apparatus and etching the silicon substrate located on one of the electrodes with the plasma, an improvement residing in that an etchant is a mixed gas of sulfur hexafluoride and oxygen and an etching mask covering the substrate, except for a portion where the recess or opening is to be formed, is made of chromium or a chromium compound. Preferably the distance between the electrodes is 10 to 30 mm, the volume ratio of sulfur hexafluoride to oxygen is 90:10 to 60:40, the pressure of the etchant gas is 0.15 to 0.4 Torr (20 to 53 Pa), and the temperature of the substrate is not less than 40.degree. C.

Abstract: A hybrid integrated circuit having a lead frame electrically connected to electronic components by means of a silver (Ag) paste, the hybrid integrated circuit comprising: an electroless-plated coating on the lead frame, the coating being free from an insulating surface oxide layer at least in a connection area in which the electrical connection is provided. A process of producing this hybrid integrated circuit comprises: a first step of electroless-plating a lead frame by using a phosphorus-containing reducing agent to form a coating on the lead frame; a second step of mounting electronic components on the lead frame and then electrically and mechanically connecting the former to the latter by means of an electroconductive paste; and a third step of maintaining the surface of the electroless-plated coating free from a phosphorus-containing oxide layer during the connecting operation.

Abstract: A method for producing a semiconductor device that is capable of solving problems related to dicing a metal thin film used for electrochemical etching. According to the method, an n type epitaxial thin layer is formed on a p type single-crystal silicon wafer. An n.sup.+ type diffusion layer is formed in a scribe line area on the epitaxial layer. An n.sup.+ type diffusion layer is formed in an area of the epitaxial layer which corresponds to a predetermined portion of the wafer. An aluminum film is formed over the diffusion layers. The aluminum film has a clearance for passing a dicing blade. Portions of the wafer are electrochemically etched by supplying electricity through the aluminum film and the diffusion layers, to leave portions of the epitaxial layer. The wafer is diced into chips along the scribe line area. Each of the chips forms a separate semiconductor device.

Abstract: This invention relates to a magnetoresistive element used for a magnetic sensor, etc. A ferromagnetic magnetoresistive element thin film is formed so as to be electrically connected to and so as to overlap the upper end portion of an aluminum wiring metal on a substrate. Through using a vacuum heat treatment with a temperature between 350.degree. and 450.degree. C., a Ni--Al-based alloy is formed at the overlapping portion. Therefore, even when a surface protection film of silicon nitride is subsequently formed by plasma CVD on the substrate, the alloy prevents the nitriding of the upper end portion of the aluminum wiring metal. Accordingly, the surface can be protected from moisture by the silicon nitride film without increasing the contact resistance between the magnetoresistive element thin film and the wiring metal. Instead of the Ni--Al-based alloy, other conductive metals such as TiW, TiN, Ti, Zr, or the like may be used.

Abstract: A semiconductor strain sensor includes a base, a peripheral section, a central section and a flexible beam. The peripheral section is bent to the base. Bonding strain is generated at a bonding portion between the base and the peripheral section. The central section extends from the peripheral section. The flexible beam extends from the central section and includes a strain detecting element. The strain detecting element changes its electric characteristic when strain is applied thereto. A thickness of the flexible beam is thinner than that of the central section. The bonding strain is transmitted from the bonding portion to the strain detecting element through a transmission path. The transmission path is bent. The bonding strain is attenuated because it is dispersed at a bending portion of the transmission path. The sensor accurately detects the strain to be detected without a bad influence of the bonding strain.

Abstract: A semiconductor device including a substrate, a semiconductor element formed on the substrate, a terminal formed on the substrate and electrically connected to the semiconductor element, and a protective resistor formed on the substrate and electrically connected between the semiconductor element and the terminal. The resistor is composed of a ferromagnetic magnetoresistive material including Ni alloy. The device may be extended to detect magnetism by adding a magnetoresistive element composed of a ferromagnetic magnetoresistive material including the same Ni alloy as for the protective resistor and deposited at the same time. The device is superior in an anti-noise characteristic and is integrated. Furthermore, the device for detecting magnetism is formed with a lower cost.

Abstract: According to this invention, a device for detecting magnetism comprises; a substrate, an interposed insulating layer containing impurities therein, formed on the substrate, and a ferromagnetic magnetoresistive element formed on the interposed layer, wherein at least a portion of the interposed layer on which the ferromagnetic magnetoresistive element is formed has a concentration of impurities of less than a predetermined value. Further, in the device of this invention, the surface of the layer interposed between the substrate and the ferromagnetic magnetoresistive element has a surface roughness of less than 120 and an angle between a contacting surface of a conductive wiring and the ferromagnetic magnetoresistive element and the surface of the interposed layer is less than 78 degrees.

Abstract: A current detecting device comprises a substrate, a magnetism sensing member made of ferromagnetic magnetoresistance element, an insulating member, and a conducting member, and these members are formed by a photolithography technique such that the magnetism sensing member is electrically isolated from the conducting member by the insulating member. When a current flows into the conducting member, the magnetism sensing member responds to a magnetic field generated by the current. At this time, the resistance of the magnetism sensing member changes due to a magnetoresistance effect in accordance with the intensity of the current. Therefore, the current can be measured by detecting the resistance change. In such a current detecting device, there is no reactance component thereby achieving high sensitivity when detecting the current.

Abstract: An apparatus for optically detecting the attachment state of extraneous matters to a translucent shield member. The optically detecting apparatus comprises a light-emitting unit having a plurality of light-emitting elements each emitting a light ray toward the translucent shield member, a photoelectric transducer unit having a plurality of transducer elements each receiving each of the light rays reflected on the translucent shield member, and a data processing unit coupled to the transducer unit. The transducer unit generates detection signals corresponding to the quantities of the received light rays and the data processing unit successively compares the level of each of the detection signals with a predetermined level to produce binary signals in accordance with the results of the comparison so that a binary signal pattern is defined at the respective transducer elements.

Abstract: A potentiometer includes a magnetoresistive element made of ferromagnetic material. A device applies a magnetic field to the magnetoresistive element. An absolute value of the magnetic field applied to the magnetoresistive element is equal to or greater than a saturation magnetic field with respect to the ferromagnetic magnetoresistive element. The magnetic field applying device is movable relative to the magnetoresistive element.

Abstract: When applying a bias field in the direction of the easy axis of magnetization of a signal field-detecting MR element assembly, a leakage magnetic field of a magnetic recording medium adapted to generate a signal field is applied as the desired bias field without using any exclusive bias field application device. The magnetic recording medium and the thin-film MR element assembly are arranged in a manner that they make a predetermined angle.