A method for producing a semi-finished metal product (2), in particular a semi-finished copper product, for a metal-copper substrate, in particular for a copper-ceramic substrate, including: providing a first metal layer (11), in particular a first copper layer, and a second metal layer (12), in particular a second copper layer, joining the first metal layer (11) and the second metal layer (12) to form the semi-finished metal product (2), wherein, chronologically before the first metal layer (11) is joined to the second metal layer (12) by means of different temperature treatments, a grain growth in the first metal layer (11) and/or the second metal layer (12) is initiated in such a way that in the produced semi-finished metal product (2), in particular in the produced metal-copper substrate, a first grain size in the first metal layer (11) differs from a second grain size in the second metal layer (12).

The invention relates to a copper/ceramic composite comprisinga ceramic substrate which contains aluminum oxide, a coating which lies on the ceramic substrate and which is made of copper or a copper alloy, wherein the copper or the copper alloy has a particle size number distribution with a median value d.sub.50, an arithmetic mean value d.sub.arith, and a symmetry value S(Cu)=d.sub.50/d.sub.arith; the aluminum oxide has a particle size number distribution with a median value d.sub.50, an arithmetic mean value d.sub.arith, and a symmetry value S(Al.sub.2O.sub.3)=d.sub.50/d.sub.arith; and S(Al.sub.2O.sub.3) and S(Cu) satisfy the following condition: 0.7<S(Al.sub.2O.sub.3)/S(Cu)1.4.

The present invention discloses a polyimide-based composite carbon film with high thermal conductivity and a preparation method therefor. The preparation method includes: uniformly coating the surface of a polyimide-based carbon film with an aqueous graphene oxide solution, and then covering the same with another polyimide-based carbon film uniformly coated with an aqueous graphene oxide solution; repeating such operation; after the polyimide-based carbon films are dried, bonding the polyimide-based carbon films by means of graphene oxide so as to form a thick film; bonding the polyimide-based carbon films more tightly by means of further low-temperature hot pressing; and finally, obtaining a thick polyimide-based carbon film with high thermal conductivity by repairing defects by means of low-temperature heating pre-reduction and high-temperature and high-pressure thermal treatment. The thick polyimide-based carbon film with high thermal conductivity has a thickness greater than 100 m and an in-plane thermal conductivity of even reaching 1700 W/mK or above.

One aspect is a logic power module, with at least one logic component, at least one power component and a substrate. The logic element and the power component are provided in separate areas on the substrate. The logic component on the substrate is provided by thick printed copper; and the power component is provided by a metal-containing thick-film layer, and, provided thereon, a metal foil.

In a ceramic sintered body, the Zr content is 17.5 mass %-23.5 mass % in terms of ZrO.sub.2, the Hf content is 0.3 mass %-0.5 mass % in terms of HfO.sub.2, the Al content is 74.3 mass %-80.9 mass % in terms of Al.sub.2O.sub.3, the Y content is 0.8 mass %-1.9 mass % in terms of Y.sub.2O.sub.3, the Mg content is 0.1 mass %-0.8 mass % in terms of MgO, the Si content is 0.1 mass %- and 1.5 mass % in terms of SiO.sub.2, and the Ca content is 0.03 mass %-0.35 mass % in terms of CaO. The total content of Na and K is 0.01 mass %-0.10 mass %, when the K content is converted to K.sub.2O and the Na content is converted to Na.sub.2O. The balance content is 0.05 mass % or less in terms of oxide.

The invention relates to a method for producing a metal-ceramic substrate including first and second metallizations and at least one ceramic layer incorporated between the first and second metallizations. Advantageously, first and second metal layers and the at least one ceramic layer are stacked superposed, and in such a way that the free edge sections, of the first and second metal layers respectively, project beyond the edges of the at least one ceramic layer and the first and second metal layers are deformed toward each other in the region of the projecting free edge sections and directly connected to each other in order to form a gas-tight, sealed metal container enclosing a container interior for receiving the at least one ceramic layer. Subsequently, the metal layers forming the metal container with the at least one ceramic layer received in the container interior are hot isostatically pressed together in a treatment chamber at a gas pressure between 500 and 2000 bar and at a process temperature between 300 C. and the melting temperature of the metal layers for producing a preferably flat connection of at least one of the metal layers and the at least one ceramic layer, and at least the projecting free edge sections, which are connected to each other, of the metal layers for forming the first and second metallization are subsequently removed.

A silicon carbide-natured refractory block includes a fire-resistant block body, and a calcination coated layer.

The fire-resistant block body includes a silicon carbide-natured refractory having a predetermined configuration. The calcination coated layer includes silicon oxide made by heating an outer superficial portion of the fire-resistant block body to oxidize at least some of silicon carbide therein to turn the silicon carbide into the silicon oxide. The silicon oxide sinters the calcination coated layer to increase the corrosion resistance.

The invention relates to a copper-ceramic composite comprising: a ceramic substrate containing alumina; a copper or copper alloy coating on the ceramic substrate; the alumina has a mean grain shape factor R.sub.a(Al.sub.2O.sub.3), defined as the arithmetic mean of the shape factors R of the alumina grains, of at least 0.4.

The present invention relates to a copper ceramic substrate incorporating a ceramic carrier, and a copper layer joined to a surface of the ceramic carrier, wherein the copper layer incorporates at least one first layer, which faces the ceramic carrier and has an average first grain size, and a second layer, which is arranged on the face of the copper layer facing away from the ceramic carrier and has an average second grain size, the second grain size being smaller than the first grain size.

An apparatus can include a ceramic component, a metal component, and a glass sealing material that bonds the ceramic and metal components to each other. In an embodiment, the coefficients of thermal expansion of the components and glass sealing material can be within 4 ppm/ C. of one another. The metal component may be relatively oxidation resistant. The glass sealing material may have a relatively low amount of an amorphous phase as compared to one or more crystalline phases within the glass sealing material. The apparatuses can exhibit good bond strength even after long term exposure to high temperature, thermal cycling to a high temperature, or both. In an embodiment, the metal component may allow another metal component of a different composition to be used without a significant impact on the integrity of the bonded apparatus.