A method of connecting two CMC substrates that includes providing two substrates; placing one substrate approximate to the other substrate, such that at least a portion of the two substrates overlap and define a brazing area; placing a brazing material approximate the brazing area; defining a primary raster pattern that encompasses the brazing area and a portion of the two substrates outside the brazing area; defining a secondary raster pattern that encompasses the brazing area; allowing a laser to scan the primary raster pattern to preheat the brazing area to a temperature below the brazing material's melting point; allowing the laser to scan the secondary raster pattern to heat the brazing area to a temperature that is above the brazing material's melting point; melting and allowing the brazing material to flow within the brazing area; and cooling the brazing area to form a brazed joint connecting the two substrates.

The present invention provides a high thermal conductive silicon nitride sintered body having a thermal conductivity of 50 W/m.Math.K or more and a three-point bending strength of 600 MPa or more, wherein when an arbitrary cross section of the silicon nitride sintered body is subjected to XRD analysis and highest peak intensities detected at diffraction angles of 29.3±0.2°, 29.7±0.2°, 27.0±0.2°, and 36.1±0.2° are expressed as I.sub.29.3°, I.sub.29.7°, I.sub.27.0°, and I.sub.36.1°, a peak ratio (I.sub.29.3°)/(I.sub.27.0°+I.sub.36.1°) satisfies a range of 0.01 to 0.08, and a peak ratio (I.sub.29.7°)/(I.sub.27.0°+I.sub.36.1°) satisfies a range of 0.02 to 0.16. Due to above configuration, there can be provided a silicon nitride sintered body having a high thermal conductivity of 50 W/m.Math.K or more, and excellence in insulating properties and strength.

A circuit board includes a metal circuit plate, a metallic heat diffusing plate disposed below the metal circuit plate and having an upper surface and a lower surface, a metallic heat dissipating plate below the heat diffusing plate, an insulating substrate disposed between the metal circuit plate and the heat diffusing plate, and an insulating substrate disposed between the heat diffusing plate and the heat dissipating plate. A grain diameter of metal grains contained in the heat diffusing plate decreases from each of the upper surface and the lower surface of the heat diffusing plate toward a center portion of the heat diffusing plate in a thickness direction.

To improve a TCT characteristic of a circuit substrate. The circuit substrate comprises a ceramic substrate including a first and second surfaces, and first and second metal plates respectively bonded to the first and second surfaces via first and second bonding layers. A three-point bending strength of the ceramic substrate is 500 MPa or more. At least one of L1/H1 of a first protruding portion of the first bonding layer and L2/H2 of a second protruding portion of the second bonding layer is 0.5 or more and 3.0 or less. At least one of an average value of first Vickers hardnesses of 10 places of the first protruding portion and an average value of second Vickers hardnesses of 10 places of the second protruding portion is 250 or less.

A milling device is rotatable in one direction around a longitudinal center axis defining a forward direction and an opposite rearward direction, and includes a front part and a rear part. The front part has cutting edges, each having a longitudinal extension, and chip flutes, each having a longitudinal extension. The front part is made of a monolithic piece of ceramic. The rear part is configured to be fixed in a rotatable tool body or a rotatable chuck. The rear part is also made of a monolithic piece of cemented carbide. A front end surface of the rear part has a smaller area than a rear end surface of the front part. The front end surface of the rear part and a rear end surface of the front part are permanently bonded or brazed to each other by a joint.

A ceramic circuit substrate having high bonding performance and excellent thermal cycling resistance properties, wherein a ceramic substrate and a copper plate are bonded by a braze material containing Ag and Cu, at least one active metal component selected from Ti and Zr, and at least one element selected from among In, Zn, Cd, and Sn, wherein a braze material layer, after bonding, has a continuity ratio of 80% or higher and a Vickers hardness of 60 to 85 Hv.

A method for manufacturing an electrostatic chuck with multiple chucking electrodes made of ceramic pieces using metallic aluminum as the joining. The aluminum may be placed between two pieces and the assembly may be heated in the range of 770 C to 1200 C. The joining atmosphere may be non-oxygenated. After joining the exclusions in the electrode pattern may be machined by also machining through one of the plate layers. The machined exclusion slots may then be filled with epoxy or other material. An electrostatic chuck or other structure manufactured according to such methods.

A carrier substrate (1) for electrical components, in particular metal-ceramic substrate (1) for electrical components, comprising an insulation layer (10), the insulation layer (10) preferably having a material comprising a ceramic or a composite comprising at least one ceramic layer, a component metallization (20) which is formed on a component side (BS) and has a first primary structuring (21), and a cooling part metallization (30) which is formed on a cooling side (KS) opposite the component side (BS) and has a second primary structuring (31), wherein the insulation layer (10), the component metallization (20) and the cooling part metallization (30) are arranged one above the other along a stacking direction (S), and
wherein the first primary structuring (21) and the second primary structuring (31), as viewed in the stacking direction (S), run congruently at least in portions.

A sintered body includes a crystal grain containing silicon nitride, and a grain boundary phase. If dielectric losses of the sintered body are measured while applying an alternating voltage to the sintered body and continuously changing a frequency of the alternating voltage from 50 Hz to 1 MHz, an average value ε.sub.A of dielectric losses of the sintered body in a frequency band from 800 kHz to 1 MHz and an average value ε.sub.B of dielectric losses of the sintered body in a frequency band from 100 Hz to 200 Hz satisfy an expression |ε.sub.A−ε.sub.B|≤0.1.

In a ceramic/copper/graphene assembly, a ceramic member, a copper member formed of copper or a copper alloy, and a graphene-containing carbonaceous member containing a graphene aggregate are joined. At a joining interface between the copper member and the graphene-containing carbonaceous member, an active metal carbide layer containing a carbide of one or more kinds of active metals selected from Ti, Zr, Nb, and Hf is formed on a side of the graphene-containing carbonaceous member, and a Mg solid solution layer having Mg dissolved in a matrix phase of Cu is formed between the active metal carbide layer and the copper member.