A method of joining a metal-ceramic substrate having metalization on at least one side to a metal body by using a 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 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.

A composite fiber composed of at least a metal sintered body and a ceramic sintered body. In the composite fiber, the metal sintered body and the ceramic sintered body are adjacent to each other. The composite fiber having the metal sintered body and the ceramic sintered body can have a tensile strength of 5 kgf/mm.sup.2 or more.

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.

Provided is an electronic apparatus including a metal wiring. The metal wiring includes a plurality of first regions covered with a solder layer, a second region provided between two first regions of the plurality of first regions, and a third region having a nitrogen amount of 20 atoms % or more. An oxygen amount is largest in the second region, followed by at least one of the plurality of first regions, and then by the third region. The nitrogen amount may be largest in the third region, followed by at least one of the plurality of first regions, and then by the second region.

A method for manufacturing a metal-ceramic substrate (1) includes providing a ceramic layer (10), a metal layer (20) and a solder layer (30) coating the ceramic layer (10) and/or the metal layer (20) and/or the solder layer (30) with an active metal layer (40), arranging the solder layer (30) between the ceramic layer (10) and the metal layer (20) along a stacking direction (S), forming a solder system (35) comprising the solder layer and the active metal layer (40), wherein a solder material of the solder layer (30) is free of a melting point lowering material and bonding the metal layer (20) to the ceramic layer (10) via the solder system (35) by means of an active solder process.

A method for producing a metal-ceramic substrate with a plurality of 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 a plurality of 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 plurality of 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 solder material (30) for bonding a metal layer (20) to a ceramic layer (10), in particular for forming a metal-ceramic substrate as a carrier for electrical components, comprising: a base material and an active metal, wherein the solder material (30) is a foil comprising the base material in a first layer (31) and the active metal in a second layer (32), and wherein the foil has a total thickness (GD) which is less than 50 μm, preferably less than 25 μm and particularly preferably less than 15 μm.

In an insulating circuit substrate, aluminum sheets formed of aluminum or an aluminum alloy are laminated and bonded to a surface of a ceramic substrate and, in the aluminum sheets, Cu is solid-solubilized at a bonding interface with the ceramic substrate and a ratio B/A between a Cu concentration A mass % at the bonding interface and a Cu concentration B mass % at a position of 100 μm in a thickness direction from the bonding interface to the aluminum sheets side is 0.30 or more and 0.85 or less.