Hitachi Metals, Ltd.

Hitachi, Ltd.

Proterial, Ltd.

Hisayuki Imamura

Junichi Watanabe

Youichirou Kaga

Shigeyuki Hamayoshi

Suguru Fujita

Tsunehiro Kawata

Masahisa Sobue

Hiroyuki Teshima

Kenji Hayashi

Hiroyuki Itoh

Hiroshi Hozoji

Toshiaki Morita

Kazuhiro Suzuki

Hiroyuki Nagatomo

Hiromi Kikuchi

Mitsuaki Chiba

Provided is a large-sized silicon nitride sintered substrate and a method for producing the same. The silicon nitride sintered substrate has a main surfaceof a shape larger than a square having a side of a length of 120 mm. A ratio dc/de of the density dc of the central area and the density de of the end area of the main surfaceis 0.98 or higher. The void fraction vc of the central area of the main surfaceis 1.80% or lower, and the void fraction ve of the end area is 1.00% or lower. It is preferred that the density dc of the central area is 3.120 g/cmor higher, the density de of the end area is 3.160 g/cmor higher, and a ratio ve/vc of the void fraction vc of the central area and the void fraction ve of the end area is 0.50 or higher.

Silicon nitride sintered substrate, silicon nitride sintered substrate sheet, circuit substrate, and production method for silicon nitride sintered substrate

In order to address the problem in that, by increasing the gate resistance of a power semiconductor element, while variation of switching time can be controlled, loss due to the gate resistance becomes larger and power efficiency for the entire system is lowered, the present invention provides an insulating substrate capable of uniformizing switching speeds of circuit elements while suppressing influence on power efficiency of the circuit elements. In the insulating substrate according to the present invention, part of a wiring layer is formed as a control signal circuit layer, and part of the control signal circuit layer is formed as a resistance layer that increases input resistance when the circuit element receives a control signal.

Insulating substrate and semiconductor device using same

A method for producing a ceramic circuit substrate comprising the steps of forming brazing regions each comprising brazing material powder and an organic binder on a ceramic substrate; setting metal plates on the ceramic substrate via the brazing regions, and heating the ceramic substrate, the brazing regions and the metal plates to bond the metal plates to the ceramic substrate via brazing layers made of the brazing material, thereby forming a bonded body; and cleaning the bonded body with a hypochlorite-containing agent.

Ceramic circuit substrate and its production method

To provide a brazing material for maintaining bonding strength between ceramic substrate and metal plate at a conventionally attainable level, while addition amount of In is reduced, and a brazing material paste using the same. A mixture powder provided by mixing alloy powder composed of Ag, In, and Cu, Ag powder, and active metal hydride powder, the mixture powder containing active metal hydride powder with a 10-to-25-&#x3bc;m equivalent circle average particle diameter by 0.5 to 5.0 mass %, the equivalent circle average particle diameters for the alloy powder, Ag powder, and active metal hydride powder having a relationship: alloy powder&#x2267;active metal hydride powder&#x3e;Ag powder, and the powder mixture having a particle size distribution of d10 of 3 to 10 &#x3bc;m, d50 of 10 to 35 &#x3bc;m, and d90 of 30 to 50 &#x3bc;m, and in the frequency distribution, a peak of the distribution existing between d50 and d90.

Brazing material, brazing material paste, ceramic circuit substrate, ceramic master circuit substrate, and power semiconductor module

A manufacturing method with which a high thermal conductivity silicon nitride substrate having excellent sintering performance can be manufactured without the occurrence of a molding crack or degreasing crack, as well as to provide a silicon nitride substrate, and a silicon nitride circuit board and a semiconductor module using the silicon nitride substrate. In the manufacturing method, in which a slurry is produced by mixing a silicon nitride powder, a sintering additive powder, and a binder in an organic solvent which is a dispersion medium, and the slurry is formed into a sheet, followed by degreasing and sintering, the oxygen content of the silicon nitride powder is 2.0 mass % or less and the specific surface area of the same is 3 to 11 m/g, the additive ratio of the sintering additive powder is 4 to 15 mol %, and the water content ratio of the organic solvent is 0.03 to 3 mass %.

Silicon nitride substrate manufacturing method, silicon nitride substrate, silicon nitride circuit substrate, and semiconductor module

A circuit board and a semiconductor module with high endurance against thermal cycles, and which is hard to be broken under thermal cycles, even if thick metal circuit board and thick metal heat sink are used, corresponding to high power operation of a semiconductor chip are provided. This circuit board includes, an insulating-ceramic substrate, a metal circuit plate bonded to one face of the insulating-ceramic substrate, a metal heat sink bonded to another face of the insulating-ceramic substrate, wherein (t&#x2212;t)/t/K&#x3c;1.5, where, a thickness of the insulating ceramics substrate is t, a thickness of the metal circuit plate is t, a thickness of the metal heat sink is t, and an internal fracture toughness value of the insulating ceramics substrate is K.

Circuit board and semiconductor module using this, production method for circuit board

In the silicon nitride substrate concerning an embodiment of the invention, degree of in-plane orientation fa of &#x3b2; type silicon nitride is 0.4-0.8. Here, degree of in-plane orientation fa can be determined by the rate of the diffracted X-ray intensity in each lattice plane orientation in &#x3b2; type silicon nitride. As a result of research by the inventors, it turned out that both high fracture toughness and high thermal conductivity are acquired, when degree of in-plane orientation fa was 0.4-0.8. Along the thickness direction, both the fracture toughness of 6.0 MPa&#xb7;mor higher and the thermal conductivity of 90 W/m&#xb7;K or higher can be attained.

Silicon nitride substrate, a manufacturing method of the silicon nitride substrate, a silicon nitride wiring board using the silicon nitride substrate, and semiconductor module

A semiconductor device having both high strength and high thermal radiation that is capable of being applied to mounting on automobiles experiencing many thermal cycles, and a manufacturing method thereof are provided. A circuit boardfor a resin encapsulated semiconductor module device has a configuration where a silicon nitride platewith a thickness of 0.635 mm has copper plates of 1.0 mm and 0.8 mm bonded to both sides thereof via active metal. A copper plateis bonded to the surface side of the silicon nitride plateand a prescribed circuit pattern is formed on the copper plateTin-silver-copper cream solder layersandwith a thickness of 200 &#x3bc;m are formed at a prescribed location on the circuit patternon which a semiconductor elementis mounted and at a prescribed location of a base plateon which the circuit boardis disposed. Nickel particleshaving a maximum particle size of 100 &#x3bc;m and an average particle size of 70 &#x3bc;m are dispersed in the solderon the base plateof good thermal conductivity. A semiconductor element (chip)the circuit boardand the base plateare disposed on predetermined locations. Thereafter, they are set in a reflow oven (not shown in the drawings) for reflow soldering. After the inside of the reflow oven is replaced by a nitrogen atmosphere, the reflow oven is heated to 280&#xb0; C. At the time when solder is melted, the inside of the oven is decompressed to 1 Pa, nitrogen is introduced, and the reflow oven is cooled to about room temperature, thereby completing the solder bonding step. After flux is washed, an outer casewith an insert-molded outlet terminalis adhered to the base plateand a predetermined connection is conducted via an aluminum bonding wireThen, silicone gelis injected into a package delimited via the base plateand the outer caseand the silicone gelis heat-hardened, thereby completing a resin encapsulated semiconductor device A.

Resin encapsulated semiconductor device and the production method

A silicon nitride sintered body comprising Mg and at least one rare earth element selected from the group consisting of La, Y, Gd and Yb, the total oxide-converted content of the above elements being 0.6&#x2013;7 weight %, with Mg converted to MgO and rare earth elements converted to rare earth oxides REO. The silicon nitride sintered body is produced by mixing 1&#x2013;50 parts by weight of a first silicon nitride powder having a &#x3b2;-particle ratio of 30&#x2013;100%, an oxygen content of 0.5 weight % or less, an average particle size of 0.2&#x2013;10 &#x3bc;m, and an aspect ratio of 10 or less, with 99&#x2013;50 parts by weight of &#x3b1;-silicon nitride powder having an average particle size of 0.2&#x2013;4 &#x3bc;m; and sintering the resultant mixture at a temperature of 1,800&#xb0; C. or higher and pressure of 5 atm or more in a nitrogen atmosphere.

Silicon nitride powder, silicon nitride sintered body, sintered silicon nitride substrate, and circuit board and thermoelectric module comprising such sintered silicon nitride substrate

A silicon nitride sintered body comprising Mg and at least one rare earth element selected from the group consisting of La, Y, Gd and Yb, the total oxide-converted content of the above elements being 0.6-7 weight %, with Mg converted to MgO and rare earth elements converted to rare earth oxides REO. The silicon nitride sintered body is produced by mixing 1-50 parts by weight of a first silicon nitride powder having a particle ratio of 30-100%, an oxygen content of 0.5 weight % or less, an average particle size of 0.2-10 &#x3bc;m, and an aspect ratio of 10 or less, with 99&#x2212;50 parts by weight of &#x3b1;-silicon nitride powder having an average particle size of 0.2-4 &#x3bc;m; and sintering the resultant mixture at a temperature of 1,800&#xb0; C. or higher and pressure of 5 atm or more in a nitrogen atmosphere.

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Tokyo, Japan

Hisayuki Imamura