Abstract: A base plate for a power module includes: a metal plate, a ceramic base plate joined to the metal plate, and a release agent provided in a joint surface between the metal plate and the ceramic base plate. A remaining amount of the release agent is less than 5 as an amount of boron measured by fluorescence X-ray analysis, and a crystal grain straining region in the joint surface is equal to or less than 40%, or an amount of crystal grain straining in the joint surface is equal to or less than 0.03%.

Abstract: A circuit board including conductive layers bonded to both surfaces of an insulating ceramic substrate, with a brazing material disposed therebetween. The conductive layers comprise at least 99.98% by mass of aluminum, and display an average crystal grain diameter within a range from 0.5 mm to 5 mm and a standard deviation ? for that crystal grain diameter of no more than 2 mm. Each conductive layer comprises at least 20 ppm of Cu, Fe and Si. The surface area of the crystal with the maximum crystal grain diameter within the conductive layers accounts for no more than 15% of the surface area of the insulating ceramic substrate.

Abstract: The present invention relates to a power module in which an insulated circuit board is fixed to one main surface of a heat discharge plate. It is an object thereof to provide a power module in which the heat discharge characteristics are improved without any marked warping being generated, and that has an extended heat cycle longevity. In the power module 10 of the present invention, a square insulated circuit board 12 is fixed to one main surface of a heat discharge plate 11. The heat discharge plate 11 is formed of an Al based alloy plate having a thickness A of 3 to 10 mm, and the insulated circuit board 12 having a side B of 30 mm or less in length is brazed directly onto the heat discharge plate 11. It is-preferable that the brazing material used is one or two or more brazing materials selected from Al—Si, Al—Ge, Al—Cu, Al—Mg, and Al—Mn based brazing materials.

Abstract: A circuit board including conductive layers bonded to both surfaces of an insulating ceramic substrate, with a brazing material disposed therebetween. The conductive layers comprise at least 99.98% by mass of aluminum, and display an average crystal grain diameter within a range from 0.5 mm to 5 mm and a standard deviation ? for that crystal grain diameter of no more than 2 mm. Each conductive layer comprises at least 20 ppm of Cu, Fe and Si. The surface area of the crystal with the maximum crystal grain diameter within the conductive layers accounts for no more than 15% of the surface area of the insulating ceramic substrate.

Abstract: This power module substrate (1) is provided for satisfying both long life with respect to heat cycle and satisfactory thermal conductivity. The power module substrate is provided with an insulating substrate (2) a circuitry layer (3) laminated on one side of insulating substrate, a metal layer (4) laminated on the other side of insulating substrate, a semiconductor chip (5) loaded onto circuitry layer by means of solder (7), and a radiator (6) joined to metal layer. Circuit layer and metal layer are composed of copper of at least 99.999% purity. Temperature cycling life can be extended since there is no accumulation of internal stress even when subjected to repeated heat cycle. In addition, since circuitry layer and metal layer are composed of copper having satisfactory thermal conductivity, heat from semiconductor chip can be efficiently released by transferring to the side of radiator.

Abstract: The present invention relates to a power module in which an insulated circuit board is fixed to one main surface of a heat discharge plate. It is an object thereof to provide a power module in which the heat discharge characteristics are improved without any marked warping being generated, and that has an extended heat cycle longevity.

Abstract: A heat sink is obtained that has high thermal conductivity as well as satisfactory moldability and corrosion resistance by using a malleable material made of aluminum or aluminum alloy. Liquid cooled heat sink 11 has a passage 23 in which coolant is able to pass, and is joined to a ceramic substrate. A plurality of through holes 12 extending from one end to the other end are formed by a plurality of dividing walls 13 through 15 in flat casing 12 of which both ends are open, and notches 16 are formed on one or both ends of the plurality of dividing walls. Corrugated fins 17 are respectively inserted into each of the plurality of through holes, and each through hole is demarcated into a plurality of slots 12b extending from one end to the other end of the casing by these fins. Both ends of the casing are closed by a pair of covers 18 and 19, and coolant inlet 18a and outlet 18b are formed in the covers.

Abstract: A power module substrate includes a ceramic substrate having a circuit pattern formed thereon, and a metal frame with which the ceramic substrate can be joined to a water-cooling type heat sink. The metal frame has a thickness equal to that of the ceramic substrate or the ceramic substrate having the circuit pattern, and is provided with plural perforations formed therein. Metal thin sheets having through-holes in communication with the corresponding perforations, and containing contacting portions having the undersides thereof contacted to at least a part of the circumferential surface of the ceramic substrate are disposed on the surface of the metal frame. In a semiconductor device, a semiconductor element is mounted onto the circuit pattern, and the power module substrate is joined directly to the water-cooling type heat sink by inserting male screws through the through-holes and the perforations, and screwing the male screws in the female screws of the water-cooling type heat sink.

Abstract: A heat sink is obtained that has high thermal conductivity as well as satisfactory moldability and corrosion resistance by using a malleable material made of aluminum or aluminum alloy. Liquid cooled heat sink 11 has a passage 23 in which coolant is able to pass, and is joined to a ceramic substrate. A plurality of through holes 12 extending from one end to the other end are formed by a plurality of dividing walls 13 through 15 in flat casing 12 of which both ends are open, and notches 16 are formed on one or both ends of the plurality of dividing walls. Corrugated fins 17 are respectively inserted into each of the plurality of through holes, and each through hole is demarcated into a plurality of slots 12b extending from one end to the other end of the casing by these fins. Both ends of the casing are closed by a pair of covers 18 and 19, and coolant inlet 18a and outlet 18b are formed in the covers.

Abstract: The present invention for solving the problem of suppressing the load caused by heat stress applied on an insulation substrate, reducing the manufacturing coat of a power module substrate, and improving productivity provides a power module substrate in which a buffer layer having a surface area one to three times as large as the surface area of the insulation substrate is laminated and bonded between the insulation substrate and the heat sink, wherein the buffer layer is formed using a material having a thermal expansion coefficient between the thermal expansion coefficients of the insulation substrate and the heat sink, the insulation substrate being preferably formed using AlN, Si3N4 or Al2O3, the buffer layer being preferably formed using AlSiC, and a carbon plate or a composite material of AlC, besides the thickness of the buffer layer being preferably 1.