The present invention provides a ceramic circuit board comprising: a ceramic substrate and a metal circuit plate bonded to the ceramic substrate through a brazing material layer; wherein the brazing material layer is composed of Al-Si group brazing material and an amount of Si contained in the brazing material is 7 wt% or less. In addition, it is preferable to form a thinned portion, holes, or grooves to outer peripheral portion of the metal circuit plate. According to the above structure of the present invention, there can be provided a ceramic circuit board having both high bonding strength and high heat-cycle resistance, and capable of increasing an operating reliability as electronic device.

Ceramic circuit board

A method of power electronic packaging includes a practicable and reliable method of fabricating power circuit modules and associated connections that are compatible with the standard top layer metalization of commercially available power devices. A planar single- or multi-layer membrane structure is attached to a carrier frame, and a via pattern is formed in the membrane. Power devices are aligned and attached to the planar membrane structure; a top layer interconnect structure is formed by metalizing the vias and the film; and a circuit is formed by patterning a deposited metal layer. The carrier frame is removed, and upper and lower thermal base plate sub-assemblies are attached to the power device-on-membrane structure. The planar device-on-membrane structure accommodates different types of power devices having variations in thickness. The thermal base plate sub-assemblies may include integral, high-performance heat exchangers for providing a low thermal resistance path to the ambient.

Power electronic module packaging

A highly reliable copper circuit-joined board that, in mounting a semiconductor element, a lead frame or the like on a ceramic substrate, enables the semiconductor element, the lead frame or the like to be strongly joined to the substrate without breaking or deformation of the substrate found in conventional joining methods, such as brazing and joining using a copper/copper oxide eutectic crystal. Any one of an interposing layer comprising a brazing material layer comprising silver and/or copper as a main component and an active metal or an interposing layer having a two-layer structure comprising a first interposing layer comprising the brazing material layer or a high-melting metallizing layer and a second interposing layer, having a melting point of 1000° C. or below, comprising Ni, Fe, Cu as a main component in that order from the substrate side, is formed on a ceramic substrate, and a conductor layer, comprising copper as a main component, which, in both the lengthwise and widthwise directions, is at least 0.05 mm shorter than the interposing layer, is formed on the interposing layer to prepare a copper circuit-joined board. The copper circuit-joined board may comprise the base board having thereon an outer layer comprising Ni as a main component. A semiconductor element is mounted on the copper circuit-joined board to prepare a semiconductor device.

Copper circuit junction substrate and method of producing the same

A bond coat of a thermal barrier coating system for components designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The composition of the bond coat has graded thermal expansion properties that moderate the transition between a metal substrate and a thermal-insulating ceramic layer of a TBC protecting the substrate, while also reducing the service temperature of the bond coat so as to reduce its rate of oxidation. Preferably, the bond coat has multiple layers, with the coefficients of thermal conductivity of the individual bond coat layers being very close to that of the substrate in order to promote heat transfer from the outward layer of the bond coat to the substrate. By minimizing the service temperature of the bond coat while grading the thermal expansion properties through the coating system, a more spall-resistant coating system is achieved.

Graded bond coat for a thermal barrier coating system

A system includes a thermal interface material (TIM) to transfer heat from a die to a heat spreader. The system includes a heat transfer subsystem disposed on the backside surface of the die. In one embodiment, the heat transfer subsystem comprises a first heat transfer material and a second heat transfer material discretely disposed within the first heat transfer material. A method of bonding a die to a heat spreader uses a die-referenced process as opposed to a substrate-referenced process.

Integrated heat spreader package for heat transfer and for bond line thickness control and process of making

A composite substrate 30 is constituted by an alumina substrate 16, a metallic layer 34, and a copper sheet 26 bonded to the alumina substrate 16 via the metallic layer 34. The metallic layer 34 is constituted by a tungsten sub-layer 34a having a low coefficient of thermal expansion, a tungsten/silver-copper alloy mixture sub-layer 34b, and a silver-copper alloy sub-layer 34c having a high coefficient of thermal expansion. In the mixture sub-layer 34b, the ratio of the percentage content of the silver-copper alloy to that of the tungsten increases with distances from the alumina substrate 16.

Ceramic-metal composite structure and process of producing same

PURPOSE:To efficiently obtain an AlN substrate excellent in surface smoothness at a low cost by an ordinary-pressure sintering method while obviating the necessity of surface grinding work by placing a sheet-like AlN green compact to which rare earth elements are added on a sintered compact of AlN having smooth surface and then subjecting the above to sintering CONSTITUTION:An AlN sintered compact in which density, thermal conductivity at room temp, and surface roughness Ra of unground sintered compact are regulated to >=320g/cm , >=70W/mK, and <=015mum, respectively, is formed into an AlN substrate useful for substrate for semiconductor packaging, crucible for use in a Czochralski method, etc The AlN substrate is produced by placing a sheet-like green compact, prepared by adding rare earth elements or rare earth-containing compounds (the oxides, carbonates, etc, of Y are preferred) by 001-10 internal wt% expressed in terms of oxide to an AlN powder in which average grain size, oxygen content, and impurity content are regulated to <=5mum, <=20wt%, and <=05wt%, respectively, and compacting the resulting mixture, on a sintered compact composed principally of AlN and/or BN and having smooth surface and then carrying out sintering in a nonoxidizing atmosphere at 1600-2000 degC

Aluminum nitride substrate and its production

A composite substrate 30 comprises an alumina substrate 16, a metal layer 34 and a copper plate 26 bonded to the alumina substrate 16 through the metal layer 34. The metal layer 34 comprises a tungsten layer 34a having a low thermal expansion coefficient, a mixed layer 34b of tungsten and a silver-copper alloy, and a silver-copper alloy layer 34c having a high thermal expansion coefficient. In the mixed layer 34b, the ratio of silver-copper alloy content to tungsten content progressively increases as portion of the layer is gradually away from the alumina substrate 16.

Ceramics-metal composite body and method of producing the same

PURPOSE:To improve the thermal shock resistance of porcelain by using a calcium phosphate compd having a specified molar ratio of Ca to P and lithium aluminosilicate as essential components CONSTITUTION:Prescribed powdery starting materials are mixed, molded, dried and sintered at 1,000-1,350 degC in the air to obtain calcium phosphate-based porcelain contg lithium aluminosilicate This porcelain contains the lithium aluminosilicate consisting of 5-70wt% Al2O3, 30-95wt% SiO2 and 01-30wt% Li2O by 3-95wt% (expressed in terms of Al2O3, SiO2 and Li2O) and a calcium phosphate compd having 1-2 molar ratio of Ca to P by 5-97wt% (expressed in terms of P2O5 and CaO) as essential components SiO2, Al2O3, Li2O, P2O5 and CaO account for >=90wt% of the amt of the porcelain and a phase made of hydroxyapatite and/or beta-calcium phosphate coexists with a phase made of a solid soln of beta-spodumene and/or a solid soln of beta-eucryptite in the porcelain

Hirano Masanori

Papers

Ceramic-metal composite structure and process of producing same

Aluminum nitride substrate and its production

Ceramics-metal composite body and method of producing the same

Calcium phosphate-based porcelain containing lithium aluminosilicate