The present invention provides a power module substrate including an insulating substrate, a circuit layer which is formed on one surface of the insulating substrate, and a metal layer which is formed on the other surface of the insulating substrate, in which the circuit layer has a first aluminum layer made of aluminum or an aluminum alloy which is bonded to the insulating substrate and a first copper layer made of copper or a copper alloy which is bonded to the first aluminum layer by solid-phase diffusion, the metal layer has a second aluminum layer made of aluminum or an aluminum alloy, and a relationship between a thickness t.sub.1 of the circuit layer and a thickness t.sub.2 of the second aluminum layer of the metal layer satisfy t.sub.1<t.sub.2.

Preventing a deformation when a metal layer made of copper or copper alloy is brazed on an aluminum-made cooler, a power-module substrate with cooler having low thermal resistance and high bonding reliability is provided: a circuit layer made of copper or copper alloy is bonded on one surface of a ceramic board and a metal layer made of copper or copper alloy is bonded on the other surface of the ceramic board; a second metal layer made of aluminum or aluminum alloy is bonded to the metal layer by solid-phase diffusion; and a cooler made of aluminum alloy is brazed on the second metal layer with Al-based Mg-included brazing material.

A method of joining a metal-ceramic substrate having metallization on at least one side to a metal body by using metal alloy is disclosed. The metal body has a thickness of less than 1.0 mm and the metal alloy contains aluminum and has a liquidus temperature of greater than 450° C. The resulting metal-ceramic module provides a strong bond between the metal body and the ceramic substrate. The resulting module is useful as a circuit carrier in electronic appliances, with the metal body preferably functioning as a cooling body.

A shock absorbing member 50 having a ceramic bonded body 15 having: a plurality of first sheet-like members 5 each having a ceramic containing 60 mass % or more of boron carbide and each having a thickness of 0.1 to 50 mm; and a bonding layer arranged between the first sheet-like members 5 adjacent to each other, the bonding layer bonding surfaces to be bonded facing each other of the first sheet-like members adjacent to each other, wherein the bonding layer has a bonding material containing at least one metal selected from the group consisting of aluminum, copper, silver, and gold.

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-μm 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≧active metal hydride powder>Ag powder, and the powder mixture having a particle size distribution of d10 of 3 to 10 μm, d50 of 10 to 35 μm, and d90 of 30 to 50 μm, and in the frequency distribution, a peak of the distribution existing between d50 and d90.

A light-emitting ceramic and a light-emitting device. The light-emitting ceramic comprises a YAG substrate and light-emitting centers and diffusion particles evenly dispersed in the YAG substrate. The light-emitting centers are lanthanide-doped YAG fluorescent powder particles of 10-20 μm in grain size. The particle size of the scattering particles is 20-50 nm. The YAG substrate is a lanthanide-doped YAG ceramic. Also, the grain size of the YAG substrate is less than the grain size of the YAG fluorescent powder particles.

A power module substrate 10 is provided with: an insulating substrate 1; and a metal sheet 2 that is joined to the insulating substrate 1 via a brazing material 3, wherein regarding the surface roughness, in the thickness direction, of the lateral surface of the metal sheet 2, the surface roughness of a corner 2a farthest from the center of the metal sheet 2 is larger than the surface roughness of plane parts 2b, which bound the corner, in at least a plan view. Also provided is a power module 100 which is formed by mounting an electronic component 40 on this power module substrate 10.

An optical component includes an optical device comprising a bonding face and an optically polished end face, and a metal film formed on the bonding face of the optical device and for bonding the optical device onto a substrate. The metal film includes a main covering portion covering a region except an end part of the bonding face on the side of the end face and an end part-covering portion covering the bonding face in the end part. A non-covered part, which is not covered by the metal film, is provided between the main covering portion and end part-covering portion.

To prevent braze stain and improve solder bondability of a semiconductor chip without deteriorating bondability between a metal plate and a ceramic substrate: a producing method of a power-module substrate by braze-bonding a metal plate which is blanked by press working on a metal raw-plate on one surface of a ceramic substrate: in the metal plate, a height of burrs is 0.021 mm or smaller, a thickness of a fracture surface is 0.068 mm or larger; the metal plate is stacked on the ceramic substrate so as to stack a surface thereof on a side at which the burrs are generated is in contact with the one surface of the ceramic substrate and brazed.

A cover lid for use with a semiconductor package is disclosed. First, a polyamide mask is applied to one surface of the lid plate. Next, the exposed areas of the surface, as well as the sides of the lid plate, are metallized. The polyamide mask can then be removed. This reduces pullback and shrinkage of the metallized layer, while lowering the manufacturing cost and process times.