An insulated circuit board having a ceramic substrate, a circuit layer on which a circuit pattern is formed and that is bonded to one surface of the ceramic substrate, and a metal layer bonded to the other surface of the ceramic substrate. The circuit layer has a first circuit layer that is bonded to the ceramic substrate and is made of aluminum and a second circuit layer that is bonded to the upper surface of the first circuit layer and is made of copper, the metal layer has a first metal layer that is bonded to the ceramic substrate and is made of aluminum and a second metal layer that is bonded to the upper surface of the first metal layer and is made of copper, and the thicknesses of the first circuit layer and the first metal layer are each 0.2 mm or more and 0.9 mm 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%.

The disclosure provides seals for devices that operate at elevated temperatures and have reactive metal vapors, such as lithium, sodium or magnesium. In some examples, such devices include energy storage devices that may be used within an electrical power grid or as part of a standalone system. The energy storage devices may be charged from an electricity production source for later discharge, such as when there is a demand for electrical energy consumption.

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 bonded interface between the ceramic member and the Cu member, a CuSn layer which is positioned on the ceramic member side and in which Sn forms a solid solution in Cu, a first intermetallic compound layer which is positioned on the Cu member side and contains Cu and Ti, and a second intermetallic compound layer which is positioned between the first intermetallic compound layer and the CuSn layer and contains P and Ti are formed.

The present invention provides a metal-ceramic base material and the like which allow a ceramic base material and a desired metal material to be easily joined. A metal-ceramic base material (30) to be joined to a metal material (40), includes: a ceramic base material (20); and a metal film (25) provided on the ceramic base material (20), the metal film (25) being formed by thermal spray of a mixed powder material containing aluminum, alumina, and nickel, at least part of the nickel being exposed on a surface of the metal film (25).

An insulated circuit board having a ceramic substrate, a circuit layer on which a circuit pattern is formed and that is bonded to one surface of the ceramic substrate, and a metal layer bonded to the other surface of the ceramic substrate. The circuit layer has a first circuit layer that is bonded to the ceramic substrate and is made of aluminum and a second circuit layer that is bonded to the upper surface of the first circuit layer and is made of copper, the metal layer has a first metal layer that is bonded to the ceramic substrate and is made of aluminum and a second metal layer that is bonded to the upper surface of the first metal layer and is made of copper, and the thicknesses of the first circuit layer and the first metal layer are each 0.2 mm or more and 0.9 mm or less.

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.

The present invention provides a ceramic metal circuit board including a ceramic substrate and metal plates bonded to both surfaces of the ceramic substrate through respective bonding layers, wherein a metal film is provided on a surface of one metal plate bonded to one surface of the ceramic substrate; and at least a part of another metal plate bonded to another surface of the ceramic substrate is not provided with the metal film. Preferably, a protruding portion is formed as a portion of the bonding layer so as to protrude from a side surface of each of the metal plates. According to the above-described configuration, it is possible to provide a ceramic circuit board which is easy to use according to the parts to be bonded and is excellent in heat-cycle resistance characteristics.

A method for producing a metal-ceramic substrate with electrically conductive vias includes: attaching a first metal layer in a planar manner to a first surface side of a ceramic layer; after attaching the first metal layer, introducing a copper hydroxide or copper acetate brine into holes in the ceramic layer delimiting a via, to form an assembly; converting the copper hydroxide or copper acetate brine into copper oxide; subjecting the assembly to a high-temperature step above 500 C. in which the copper oxide forms a copper body in the holes; and after converting the copper hydroxide or copper acetate brine into the copper oxide, attaching a second metal layer in a planar manner to a second surface side of the ceramic layer opposite the first surface side. The copper body produces an electrically conductive connection between the first and the second metal layers.

A soldering material (1) for active soldering, in particular for active soldering of a metallization (3) to a carrier layer (2) comprising ceramics, wherein the soldering material comprises copper and is substantially silver-free.