A method for manufacturing active metal-brazed a nitride ceramics substrate having excellent joining strength, includes: a step of preparing a mixed raw material; a step of forming a green sheet of the mixed raw material by a tape casting method; a step of removing a binder by performing degreasing; a step of performing sintering; a step of forming an aluminum nitride sintered substrate by performing gradual cooling; and a step of printing a conductive wiring pattern with active metal paste on the aluminum nitride sintered substrate.

A joined body 20 according to the present invention includes a first member 22 made of a porous ceramic, a second member 24 made of a metal, and a joint 30 formed of an oxide ceramic of a transition metal, the joint 30 joining the first member 22 to the second member 24. Alternatively, a joined body may include a first member made of a dense material, a second member made of a dense material, and a joint formed of an oxide ceramic of a transition metal, the joint joining the first member to the second member.

The present disclosure relates to a brazed superabrasive assemblies and method of producing brazed superabrasive assemblies. The brazed superabrasive assemblies may include a plurality of braze alloy layers that are positioned opposite a stress relieving layer. The stress relieving layer may have a solidus temperature that is greater than a solidus temperature of the plurality of braze alloy layers.

Methods of forming a metallic-ceramic brazed joint are disclosed herein. The method of forming the brazed joint includes deoxidizing the surface of metallic components, assembling the joint, heating the joint to fuse the joint components, and cooling the joint. In certain embodiments, the brazed joint includes a conformal layer. In further embodiments, the brazed joint has features in order to reduce stress concentrations within the joint.

A multilayer component and a mathod for producing a multilayer component are disclosed. In an embodiment a multilayer component includes a ceramic main element and at least one metal structure, wherein the metal structure is cosintered and wherein main element is a varistor ceramic having 90 mol % of ZnO, from 0.5 to 5 mol % of Sb.sub.2O.sub.3, from 0.05 to 2 mol % of Co.sub.3O.sub.4, Mn.sub.2O.sub.3, SiO.sub.2 and/or Cr.sub.2O.sub.3, and <0.1 mol % of B.sub.2O.sub.3, Al.sub.2O.sub.3 and/or NiO.

A structure body according to an embodiment of the present disclosure includes: a first base having one surface, and having a density lower than a density that is determined by a crystal structure and a composition of a constituent material; a second base disposed to face the one surface of the first base; and a buffer layer provided between the first base and the second base, and containing at least a metal element.

A piezoelectric thin-film element includes a first electrode layer, a piezoelectric thin film stacked on the first electrode layer, and a second electrode layer stacked on the piezoelectric thin film. A performance index P of the piezoelectric thin film is defined as (d.sub.33,f).sup.2?Y/?. d.sub.33,f is a piezoelectric strain constant of thickness longitudinal vibration of the piezoelectric thin film. Y is a Young's modulus of the piezoelectric thin film. ? is a permittivity of the piezoelectric thin film. The performance index P is from 10% to 80.1%.

A ceramic circuit substrate according to the present invention includes a ceramic substrate, a copper circuit made of a copper-based material bonded, via a bonding layer, to a surface of the ceramic, and a copper heat sink made of the copper-based material bonded, via a bonding layer, to the other surface of the ceramic. The bonding layers each include a brazing material component including two or more kinds of metals, such as Ag, and an active metal having a predetermined concentration. The bonding layers each include a brazing material layer including the brazing material component, and an active metal compound layer containing the active metal. A ratio of a bonding area of the active metal compound layer in a bonding area of each of the bonding layers is 88% or more.

Provided is a polycrystalline ceramic substrate to be bonded to a compound semiconductor substrate with a bonding layer interposed therebetween, wherein at least one of relational expression (1) 0.7<.sub.1/.sub.2<0.9 and relational expression (2) 0.7<.sub.3/.sub.4<0.9 holds, where .sub.1 represents a linear expansion coefficient of the polycrystalline ceramic substrate at 30 C. to 300 C. and .sub.2 represents a linear expansion coefficient of the compound semiconductor substrate at 30 C. to 300 C., and .sub.3 represents a linear expansion coefficient of the polycrystalline ceramic substrate at 30 C. to 1000 C. and .sub.4 represents a linear expansion coefficient of the compound semiconductor substrate at 30 C. to 1000 C.

A ceramic-metal structure in which a metallic body (2) is inserted into or disposed above a through hole (4h) of a ceramic substrate (4) and which includes an annular pad layer (6) disposed around the through hole; an annular ring member (8) joined to the pad layer via a first brazing filler portion (10) and having a coefficient of thermal expansion smaller than that of the metallic body; a second brazing filler portion (12) intervening between the ring member and metallic body; and brazing filler flow prevention layers (7a, 7b) covering an outer surface of the pad layer so as to expose a central region (6c) of the outer surface of the pad layer facing the first brazing filler portion. The first brazing filler portion joins the central region and the ring member without projecting to a radially inner or outer side of the flow prevention layers.