Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Masato Fujino

Hidetoshi Iwatani

Masakazu Kazama

Choichiro Fujii

Yasuaki Saito

Soichi Watanabe

Kouichi Nitta

Tooru Harada

Shinji Matsumoto

In a power supply apparatus in which a source of a MOSFET is connected to a node of a rectifier diode and a choke coil through a resonance coil, a series circuit including a capacitor and a MOSFET is connected to a series circuit including the resonance coil and the rectifier diode, and the MOSFET and the MOSFET are driven by PWM control so that the MOSFET and the MOSFET are alternately turned on with a period in which both MOSFETs are turned off, a resistor is connected in parallel with the capacitor, and optionally another diode is connected in series with the resistor.

Power supply apparatus

A circuit substrate with a built-in coil has layers comprising respectively a wiring sheet, magnetic material, a flat coil, and magnetic material, which are overlaid. The wiring circuit sheet is made of polyimide, on which a circuit pattern is formed. The magnetic material is formed of a plurality of overlaid amorphous alloy sheets having slits and put together with adhesive. The flat coil may be formed by winding a copper wire covered with insulating film. The coil component, including the magnetic material and the flat coil, and the wiring circuit sheet are adhered to each other with the circuit pattern and the coil component being electrically connected to each other. According to one embodiment of the invention, the circuit substrate comprises a coil component with a flat coil and a pair of magnetic materials sandwiching the flat coil; and at least one wiring circuit sheet on which a circuit pattern is formed, the wiring circuit sheet being adhered to a surface of the coil component with the circuit pattern being electrically connected to the coil component.

Circuit substrate with a built-in coil

A coil contains a winding part and a core. The winding part is formed of plural laminated sheets each having a winding pattern. Plural winding patterns are formed on at least one sheet. Each of the winding patterns has a different number of turns, and the winding patterns are formed around the core so as to be coaxial in the same winding direction. The winding patterns formed on the other sheets are connected via a through-hole, and an end of the winding pattern is connected to an input/output portion formed outside of the sheet.

Coil

A layered coil, having high connection reliability, formed by alternately stacking a plurality of coil conductors and insulators. Outlet portions of the of coil conductors are connected with each other without using through holes. The coil conductors are formed on surfaces of insulating sheets so that the outlet portions of the coil conductors project from edges of the insulating sheets. The insulating sheets are stacked so that the outlet portions of the coil conductors can be connected, by spot welding or the like, with each other or with terminals in portions projecting from surfaces of the layered product.

Layered transformer coil having conductors projecting into through holes

An insulating structure for an external terminal of an electronic part is formed of two insulating housing parts abutting along a junction to define an insulating housing for an electronic part. There is an insulating projection on each housing part and projecting outwardly of the housing from the corresponding housing part, each projection having a U-shaped cross-section with the open sides of the projections facing each other with one projection inside the other and the cross-sections telescopingly interfitted. One of the projections has a cross-section extending into the wall of the corresponding housing part from the junction and the other projection has the cross-section projecting from the junction toward the one projection. The wall of one of said housing parts has a first wall portion extending into the end of the corresponding projection where it extends from the housing part, and this wall portion has a recess therein facing toward the projection on the other housing part, and the wall of the other of the housing parts has a second wall portion extending into the end of the corresponding projection where it extends from the housing part and fitting into the recess in said first wall portion. The recess and second wall portion fit tightly around the terminal of the electronic part. A metallic casing around the insulating housing has an opening therein with the edges of the opening abutting the outside surface of the projections. Leakage current from the terminal to the metallic casing must traverse a long path through the compactly arranged projections.

Growing community of inventors

Muko, Japan

Masato Fujino