Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Pi R&d Co., Ltd.

Ken Takanashi

Dai Nakajima

Masakazu Fukada

Fumitaka Tametani

Junichi Yamashita

Kazuaki Hiyama

Khalid Hassan Hussein

Shinji Hatae

Toshiyuki Goshima

Maw Soe Win

Seiichi Oshima

Sigemasa Segawa

Jun Yamagata

Disclosed is a polyimide composition for semiconductor devices, which has a rheological characteristics suited for screen printing and dispense coating, which has an improved wetting property with various coating bases, by which continuous printing of 500 times or more can be attained, with which blisters, cissing and pinholes are not generated after printing and drying or during drying or curing, which can coat a desired area. A method of forming a film in a semiconductor and semiconductors having the film formed by this method as an insulation film, protective film or the like are also disclosed. The composition for semiconductor devices contains a mixed solvent of a first organic solvent (A) and a second organic solvent (B); and a polyimide resin having at least one group selected from the group consisting of alkyl groups and perfluoroalkyl groups in recurring units, and having thixotropic property, the polyimide resin being dissolved in the mixed solvent.

Polyimide resin composition for semiconductor devices, method of forming film in semiconductor devices using the same and semiconductor devices

In a power module (), a free-wheeling diode (A), an IGBT (B), and a capacitor () for smoothing direct current are disposed directly on a surface (BS) of a conductive heat sink (B) with through holes (BH). The rear electrodes of the free wheeling diode (A), the IGBT (B), and the capacitor () are bonded to the heat sink (B) for example with solder, whereby the diode (A), the IGBT (B), and the capacitor () are electrically connected with the heat sink (B). The front electrodes of the diode (A), the IGBT (B), and the capacitor () are connected with each other for example by wires (). In the heat sink (B), a cooling medium flows through the through holes (BH). Such a configuration allows miniaturization of the power module and improves the cooling performance and reliability of the power module.

Power module

In a powder module ( ), a free-wheeling diode ( A), an IGBH ( B), and a capacitor ( ) for smoothing direct current are disposed directly on a surface ( BS) of a conductive heat sink ( B) with through holes ( BH). The rear electrodes of the free-wheeling diode ( A), the IGBT ( B), and the capacitor ( ) are bonded to the heat sink ( B) for example with solder, whereby the diode ( A), the IGBT ( B), and the capacitor ( ) are electrically connected with the heat sink ( B). The front electrodes of the diodes ( A), the IGBT ( B), and the capacitor ( ) are connected with each other for example by wires ( ). In the heat sink ( B), a cooling medium flows through the through holes ( BH). Such a configuration allows miniaturization of the power module and improves the cooling performance and reliability of the power module.

To prevent malfunction or breakdown due to a surge voltage in a power converter for converting DC into AC or the like so as to supply electric power to a load, not only a control signal is transmitted via a level shift circuit which is provided correspondingly to each of switching semiconductor elements forming a main circuit and shifts a level of a reference potential at its output side so as to follow variations of a reference potential of the switching semiconductor element to the switching semiconductor element, but a DC control power source for supplying electric power to the level shift circuit and a negative pole of the switching semiconductor element are connected to each other through at least one of an inductor and a resistance.

Power converter

Obtained is a power module which is excellent in electromagnetic shielding effects, is rarely influenced by external noises and acts as an external noise source with difficulty. An insulating substrate (,) is bonded through a solder (,) to a top surface of a heat sink (,) fixed to a support plate (,). A DC capacitor (,) is fixed to a bottom face of the heat sink (,) by adhesion. A control substrate (,) having a control IC (,) mounted thereon is fixed to the support plate (,). Moreover, a plurality of electrodes (,), a DC side electrode and refrigerant inlet-outlet (,) and a control connector (,) are provided on the support plate (,). A case (,) is fixed to a peripheral portion of the support plate (,), and surrounds the insulating substrate (,), the control substrate (,), the heat sink (,) and the DC capacitor,together with the support plate (,). Both the case (,) and the support plate (,) have conducting property.

In a circuit board having four-layered conductive pattern on which a control circuit is arranged, wiring sub-patterns 133a in the first layer are divided into four areas A1-A3 and A8, for respective sets of circuit parts having same power potentials. Respective sub-patterns belonging to the areas A1-A3 are partially or fully surrounded by wiring sub-patterns PEa1 PEa3 connected to negative power potentials of circuit parts belonging to respective areas, respectively. Similarly, at least part of a wiring patten Pa2 for transmitting an input signal to a semiconductor active element is surrounded by a wiring pattern PEa4. Penetration of electric noises to the wiring patterns for the control circuit, in particular to the wiring pattern for transmitting the input signal to semiconductor element, is decreased to thereby prevent misoperation due to electric noises.

Noise resistant semiconductor power module

Respective side ends (20s, 1s) of a T.sub.1 electrode (20) and a gate electrode (1) of a TRIAC (70) are mutually adjacent and located on a P.sub.1 layer (13). The side ends (20s, 1s) are connected electrically by a resistance area (13a) which is made of the same material as a semiconductor material used to make the P.sub.1 layer (13). A gate current branches into first and second branch currents (I.sub.GT1, I.sub.GT2). Because the second branch current does not contribute to the turn on of the TRIAC, undesirable (dv/dt) turn on is prevented.

Growing community of inventors

Tokyo, Japan

Ken Takanashi