Abstract: A power supply unit of an arc discharge device includes a semiconductor module 1 and a radiator fitted onto the semiconductor module 1. The semiconductor module 1 includes a module casing 2 and common units 3a to 3c retained by the module casing 2. Each of the common units 3a to 3c has: a ceramic substrate 50 having a circuit surface disposed with a semiconductor element 54 and a radiation surface on a side opposite to the circuit surface and a package 35 that exposes the radiation surface and seals the circuit surface with heat resistant resin. The radiator is fitted onto the module casing 2 to be thereby brought into abutting contact with all of the radiation surfaces of the common units 3a to 3c.

Abstract: To suppress warpage of a ceramic substrate, and to prevent a reduction in radiation efficiency. A power semiconductor module includes a module casing fitted with a radiator, and a common unit retained by the module casing. The common unit has: a ceramic substrate having a circuit surface disposed with a semiconductor element, and a radiation surface brought into abutting contact with the radiator; and a package formed by exposing the radiation surface and sealing the circuit surface with heat resistant resin. The circuit surface and the radiation surface are respectively formed of metal layers 51 formed on the ceramic substrate, and the metal layer 51 forming the radiation surface has: by forming a buffer pattern 512 including a groove part extending along a circumferential part thereof, a radiation pattern 510 formed on an inner side of the buffer pattern 512; and an outer peripheral pattern 511 formed on an outer side of the buffer pattern 512.

Abstract: [Summary] [Object] To suppress warpage of a ceramic substrate, and to prevent a reduction in radiation efficiency. [Means for Settlement] A power semiconductor module includes a module casing fitted with a radiator, and a common unit retained by the module casing. The common unit has: a ceramic substrate having a circuit surface disposed with a semiconductor element, and a radiation surface brought into abutting contact with the radiator; and a package formed by exposing the radiation surface and sealing the circuit surface with heat resistant resin. The circuit surface and the radiation surface are respectively formed of metal layers 51 formed on the ceramic substrate, and the metal layer 51 forming the radiation surface has: by forming a buffer pattern 512 including a groove part extending along a circumferential part thereof, a radiation pattern 510 formed on an inner side of the buffer pattern 512; and an outer peripheral pattern 511 formed on an outer side of the buffer pattern 512.

Abstract: [Object] To incorporate more semiconductor elements in a small-sized lightweight power semiconductor module provided in an arc discharge device. [Means for Settlement] A power supply unit of an arc discharge device includes a semiconductor module 1, and a radiator fitted onto the semiconductor module 1. The semiconductor module 1 includes a module casing 2, and common units 3a to 3c retained by the module casing 2. Each of the common units 3a to 3c has: a ceramic substrate 50 having a circuit surface disposed with a semiconductor element 54, and a radiation surface on a side opposite to the circuit surface; and a package 35 that exposes the radiation surface, and seals the circuit surface with heat resistant resin. The radiator is fitted onto the module casing 2 to be thereby brought into abutting contact with all of the radiation surfaces of the common units 3a to 3c. Based on such a configuration, more semiconductor elements can be incorporated in a small-sized lightweight power semiconductor module.

Abstract: A safety device of an electric circuit is provided, in which a thermal fuse securely prevents an accident from occurring when an overcurrent protector is extraordinarily overheated. The safety device includes: first protective means in an overcurrent protector for protecting the electric circuit from an overcurrent, which generates heat to increase its electrical resistance when an overcurrent flows in the electric circuit, whereby reducing or cutting off the overcurrent; and second protective means including a thermal fuse situated in the vicinity of the overcurrent protector containing: a first electrode having a first conductor pattern connected to the overcurrent protector; a second electrode having a second conductor pattern insulated from the first electrode by a gap; and solder connecting the first and second electrodes and melting by heat from the overcurrent protector so as to split into two parts toward the first and second electrodes.

Abstract: A safety device for preventing a trouble caused by an abnormal overheating of an electric circuit is provided, which includes: a circuit board; a first circuit pattern; a second circuit pattern; a first electrode connected to the first circuit pattern; a second electrode connected to the second circuit pattern, while enclosing the first electrode without a break, the second electrode being standoff-insulated from the first electrode; and a solder fuse portion made of a solder and formed over and inside the second electrode for bridging the first and second electrodes, wherein the solder fuse portion in a melted state separates onto the first and second electrodes by surface tension of the solder, whereby a circuit between the first and second circuit patterns is broken.

Abstract: A circuit protective device with a positive temperature coefficient element is provided, which includes: a positive temperature coefficient (hereinafter "PTC") element, made of a conductive composition having a PTC characteristics, provided for shutting off an electric circuit; a circuit board having the PTC element and electrodes to be connected with the PTC element; and a slot formed on the circuit board so as to prevent a low resistance conductive passage from being formed between the electrodes, the low resistance conductive passage being made of powder of the conductive composition released from the PTC element. And also an electric junction box with the above circuit protective device is provided. Thus, the circuit protective device or the electric junction box with the circuit protective device wherein a low resistance conductive passage made of a carbonaceous powder to be released from the PTC element is not formed between the electrodes of the PTC element can be realized.

Abstract: The connection structure of a circuit protection element for securely connecting at least two lead terminals of the circuit protection element to a circuit board includes terminal connection elongated holes each provided in the circuit board for connecting the lead terminals to the circuit board by soldering. The circuit board is positioned in such a way that the elongated direction of the elongated terminal connection hole is positioned in a downward direction. When an abnormal current is applied to the circuit, or when the circuit protection element fails to heat itself up to a high temperature, the solder melts. Thereby, the lead terminals easily disengage from the terminal connection holes so that the circuit protection element falls freely from the circuit board. Thus, the circuit is surely cut off easily.