Abstract: A method of manufacturing a semiconductor device includes the steps of bonding a semiconductor chip to a first side of a circuit board, bonding a metal base for dissipating heat produced by the semiconductor chip to a second side of the circuit board, and forming a dam on the metal base by a dam material so as to restrict flow of a solder used in bonding a plurality of the circuit boards to the metal base.

Abstract: A method of manufacturing a semiconductor device includes the steps of bonding a semiconductor chip to a first side of a circuit board, bonding a metal base for dissipating heat produced by the semiconductor chip to a second side of the circuit board, and forming a dam on the metal base by a dam material so as to restrict flow of a solder used in bonding a plurality of the circuit boards to the metal base.

Abstract: A semiconductor device includes a solder dam for restricting the flow of solder during manufacturing. The device includes a semiconductor chip bonded to a first side of a circuit board, a metal base for dissipating heat produced by the semiconductor chip, the metal base being bonded to a second side of the circuit board, and a dam material disposed on the metal base in a predetermined pattern for restricting the flow of solder used in bonding a plurality of the circuit boards to the metal base. By employing the solder dam, solderability is not impaired, device contamination can be avoided, and a highly reliable semiconductor device can be produced.

Abstract: A semiconductor device includes a solder dam for restricting the flow of solder during manufacturing. The device includes a semiconductor chip bonded to a first side of a circuit board, a metal base for dissipating heat produced by the semiconductor chip, the metal base being bonded to a second side of the circuit board, and a dam material disposed on the metal base in a predetermined pattern for restricting the flow of solder used in bonding a plurality of the circuit boards to the metal base. By employing the solder dam, solderability is not impaired, device contamination can be avoided, and a highly reliable semiconductor device can be produced.

Abstract: A semiconductor device of the invention is formed of an insulative case frame with a frame portion having elongated coupling holes, a radiator base plate covering a first opening of the insulative case frame, a circuit board with semiconductor chips bonded to the radiator base plate, a resin sealant filled in an inner space of the case frame for covering the circuit board, an insulative cover plate closing a second opening of the insulative case frame, and at least one lead frame having elastic coupling protrusions and inner leads. The elastic coupling protrusions are elastically retained in the elongated coupling holes to securely connect the lead frame to the case frame.

Abstract: A semiconductor device is formed of an insulative case frame having a frame portion; a lead pin block having a base and a plurality of lead pins with inner leads formed in the base, the lead pin block being installed inside the frame portion; a base plate attached to the frame portion for covering a first opening; a circuit board bonded to an inner face of the base plate and having semiconductor chips thereon connected to ends of the inner leads; a gel resin sealant filling an inner space of the insulative case frame over the circuit board and the semiconductor chips; and an insulative cover plate placed on the insulative case frame for closing a second opening of the insulative case frame. A sealing agent is disposed between the lead pin block and the frame portion to seal a gap therebetween, and an air vent is formed in the base of the lead pin block to communicate between the inner space and atmosphere.

Abstract: In a power semiconductor device having a power circuit 1 and a control circuit 2 incorporated in a resin case 4, said circuits being mounted on different substrates 1a and 2a and interconnected internally, and power terminals 6 and control terminals 7 connected to the power and control circuits, respectively, being drawn out of the case, the power terminals 6, the control terminals 7 and lead pins 13 are preliminarily molded by an insert technique together with the case as the power terminals 6 and the control terminals 7 are arranged at the peripheral edge of the case 4 whereas the lead pins 13 for establishing interconnection between the power and control circuits are arranged on a pin block 12 provided at the middle stage within the case, and the substrate 1a for the power circuit is mounted on a heat dissipating metal base 11 combined with the bottom side of the case 4 and the substrate 2a for the control circuit on the pin block 12, with the power terminals, control terminals and the pin block being sold

Abstract: Ethylene glycol mono-t-butyl ether is produced by contacting a starting mixture of feed materials comprising ethylene glycol di-t-butyl ether and ethylene glycol with a strongly acidic cation-exchange material, thereby to react said ethylene glycol and ethylene glycol di-t-butyl ether to produce ethylene glycol mono-t-butyl ether; the reaction is carried out at about 30.degree. to 130.degree. C. under an atmospheric pressure or an increased pressure; the molar ratio of the feed ethylene glycol to the feed ethylene glycol di-t-butyl ether is about 1:0.01 to 1:20; the feed material may be a mixture comprising ethylene glycol di-t-butyl ether, ethylene glycol and at least one member selected from the group consisting of ethylene glycol mono-t-butyl ether, diisobutylene, and triisobutylene; also the reaction can be carried out by either a batch process or a continuous flowing process.

Abstract: An improved process for producing ethylene glycol mono-tert-butyl ether by reacting ethylene glycol with isobutylene in the presence of a catalyst of strongly acidic cation-exchange material is disclosed which enables the production of ethylene glycol mono-tert-butyl ether in a high yield while suppressing the formation of by-product ethylene glycol di-tert-butyl ether by previously adding ethylene glycol di-tert-butyl ether to the reaction system and conducting the reaction at temperatures of about 60 to 130.degree. C.