Abstract: A brushless DC micromotor made up of a stator coil and a rotor housed inside thereof with magnet poles formed therein, which micromotor is characterized in that the stator coil is formed by coaxially winding more than one coil sheet formed on an insulating sheet, on which coil sheet a plurality of coil patterns are continuously provided in series in the direction of winding. The motor of the present invention can be made smaller, thinner and lighter than the conventional counterpart made by the use of a wound copper wire coil.

Abstract: A method for electrically interconnecting a laminated printed circuit structure comprises the steps of inserting a solder-plated connecting conductor pin into a through hole bored through overlying interconnecting sections of the respective printed circuit sheets, applying pressure to both ends of the pin to compress and thicken the pin, and passing an electric current through the pin to solder the pin and the respective interconnecting sections to one another at the inner peripheral surface of the through hole.

Abstract: In a coreless-brushless motor in which a driving coil block is mounted on a stator yoke, a bearing is fixed to the stator yoke in alignment with the central portion of the driving coil block, a rotary shaft is rotatably supported by the bearing, a rotor yoke is affixed to the rotary shaft and a rotor magnet is mounted on the rotor yoke in adjacent and opposing relation to the driving coil block, a magnetoelectric transducer pellet is housed in a recess made in the stator yoke on the side of the driving coil block, for detecting magnetic fluxes emanating from the rotor magnet. The magnetoelectric transducer pellet is connected to wires of a flexible printed circuit sheet, which is disposed between the stator yoke and the driving coil block.

Abstract: A magnetoresistive element comprises first to fourth magnetoresistive parts formed on a substrate. The first and second magnetoresistive parts are connected in series, and the third and fourth magnetoresistive parts are also connected in series. These series connected parts are connected in parallel to one another, first and second terminals are provided at from both ends of the parallel connection and, third and fourth terminals are provided at the junction of the first and second magnetoresistive parts and at the junction of the third and fourth magnetoresistive parts, respectively. The resistive values of the first and second magnetoresistive parts in the absence of a magnetic field are substantially equal, and the resistance values of the third and fourth magnetoresistive parts in the absence of a magnetic field are also substantially equal.

Abstract: A metal member to be etched is subjected to chemical etching through a mask having a predetermined pattern whereafter that portion of the mask overhanging a side-etched portion resulting from the etching is bent down to be joined by an adhesive binder to the side wall of the side-etched portion to form an etching-resistant layer on the side wall. Then the metal member is subjected again to etching through the etching-resistant layer and the mask.

Abstract: Spiral type first and second coils of the same shape and size are arranged opposite one another on both surfaces of an insulating sheet, the insulating sheet is made by piling and bonding two insulating films to each other using a bonding agent, the inner ends of the first and second coils which are opposite to each other are connected to each other via the insulating sheet, the outer ends are so connected that all coils are connected in series, and terminals are provided on both ends of the series connection.