A metal-ceramic substrate (1) comprising an insulating layer (11) comprising a ceramic and having a first thickness (D1), and a metallization layer (12) bonded to the insulation layer (11) and having a second thickness (D2),
wherein the first thickness (D1) is less than 250 μm and the second thickness (D2) is greater than 200 μm and wherein the first thickness (D1) and the second thickness (D2) are dimensioned such that a ratio of an amount of the difference between a thermal expansion coefficient of the metallization layer (12) and a thermal expansion coefficient of the metal-ceramic substrate (1) to a thermal expansion coefficient of the metal-ceramic substrate (1)
has a value less than 0.25, preferably less than 0.2 and more preferably less than 0.15 or even less than 0.1.

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 copper/ceramic bonded body includes: a copper member made of copper or a copper alloy; and a ceramic member made of a silicon nitride, wherein the copper member and the ceramic member are bonded to each other, a magnesium oxide layer is provided on a ceramic member side of a bonded interface between the copper member and the ceramic member, a Mg solid solution layer is provided between the magnesium oxide layer and the copper member and contains Mg in a state of a solid solution in a Cu primary phase, and a magnesium nitride phase is present on a magnesium oxide layer side of the Mg solid solution layer.

In a copper-ceramic bonded body of the present invention, at a bonding interface of a copper member and a ceramic member, there are formed a nitride compound layer containing one or more nitride forming elements selected from Ti, Nb, Hf, and Zr, and an Ag—Cu eutectic layer, in order from the ceramic member side, the thickness of the nitride compound layer is 0.15 μm or more and 1.0 μm or less, an intermetallic compound phase formed of an intermetallic compound that contains the nitride forming element and Si is present between the copper member and the ceramic member, and Cu and Si are present at the grain boundary of the nitride compound layer.

Methods of forming ceramic matrix composite structures include joining at least two lamina together to form a flexible ceramic matrix composite structure. Ceramic matrix composite structures include at least one region of reduced inter-laminar bonding at a selected location between lamina thereof. Thermal protection systems include at least one seal comprising a ceramic matrix composite material and have at least one region of reduced inter-laminar bonding at a selected location between lamina used to form the seal. Methods of forming thermal protection systems include providing one or more such seals between adjacent panels of a thermal protection system.

In a silicon nitride substrate including a silicon nitride sintered body including silicon nitride crystal grains and a grain boundary phase, a plate thickness of the silicon nitride substrate is 0.4 mm or les, and a percentage of a number of the silicon nitride crystal grains including dislocation defect portions inside the silicon nitride crystal grains in a 50 μm×50 μm observation region of any cross section or surface of the silicon nitride sintered body is not less than 0% and not more than 20%. Etching resistance can be increased when forming the circuit board.

A power module substrate according to the present invention is a power module substrate in which a copper sheet made of copper or a copper alloy is laminated and bonded onto a surface of a ceramic substrate (11), an oxide layer (31) is formed on the surface of the ceramic substrate (11) between the copper sheet and the ceramic substrate (11), and the thickness of a AgCu eutectic structure layer (32) is set to 15 m or less.

A bonded body of the present invention includes a ceramic member formed of ceramics and a Cu member formed of Cu or a Cu alloy. In a bonding layer formed between the ceramic member and the Cu member, an area ratio of a Cu.sub.3P phase in a region extending by up to 50 m toward the Cu member side from a bonding surface of the ceramic member is equal to or lower than 15%.

A light generator comprises a light conversion device and a light source arranged to apply a light beam to the light conversion element. The light conversion device includes an optoceramic or other solid phosphor element comprising one or more phosphors embedded in a ceramic, glass, or other host, a metal heat sink, and a solder bond attaching the optoceramic phosphor element to the metal heat sink. The optoceramic phosphor element does not undergo cracking in response to the light source applying a light beam of beam energy effective to heat the optoceramic phosphor element to the phosphor quenching point.

An insulated heat dissipation substrate including: a ceramic substrate; and a conductor layer bonded onto at least one of main surfaces of the ceramic substrate, wherein the conductor layer includes: an upper surface; a lower surface; and a side surface 1 connecting the upper surface with the lower surface; the ceramic substrate includes: a lowest portion; a side surface 2 connecting the lowest portion with the side surface 1 of the conductor layer; and a bonding surface at a position higher than the lowest portion, the bonding surface being bonded to the lower surface of the conductor layer; an absolute value (||) is 20 or less on average; and the side surface 1 has a receding portion from an end of the upper surface in the normal direction relative to the tangential line of the contour of the conductor layer as viewed in plane.