The present invention relates to a method for producing a metal-ceramic substrate (1) comprising: —providing a ceramic element (30) and at least one metal layer (10), wherein the ceramic element (30) and the at least one metal layer (10) extend along a main extension plane (HSE), —joining the ceramic element (30) to the at least one metal layer (10) to form a metal-ceramic substrate (1), in particular by means of a direct metal joining method, a hot isostatic pressing method and/or a soldering method, and —machining the at least one metal layer (10) by means of a machine tool (40) and/or laser light in order to define a geometry, at least in some portions, of a side face (15) of the at least one metal layer (10) not running parallel to the main extension plane (HSE).

A method includes applying a sintering precursor material layer to each of a first surface and a second surface of a ceramic tile, and assembling a precursor assembly of a direct bonded copper (DBC) substrate by coupling a first leadframe on the sinter precursor material layer on the first surface of the ceramic tile and a second leadframe on the second surface of the sinter precursor material layer on a second surface of the ceramic tile such that the ceramic tile is disposed between the first leadframe and the second leadframe. The method further includes sinter bonding the first leadframe and the second leadframe to the ceramic tile to form a sinter bonded DBC substrate.

Provided herein are energy storage devices. In some cases, the energy storage devices are capable of being transported on a vehicle and storing a large amount of energy. An energy storage device is provided comprising at least one liquid metal electrode, an energy storage capacity of at least about 1 MWh and a response time less than or equal to about 100 milliseconds (ms).

A method for the joining of ceramic pieces includes applying a layer of titanium on a first ceramic piece and applying a layer of titanium on a second ceramic piece; applying a layer of nickel on each of the layers of titanium on the first ceramic piece and the second ceramic piece; applying a layer of nickel phosphorous to each of the layers of nickel on the first ceramic piece and the second ceramic piece; assembling the first ceramic piece and the second ceramic piece with the layers of titanium, nickel, and nickel phosphorous therebetween; pressing the layer of nickel phosphorous of the first ceramic piece against the layer of nickel phosphorous of the second ceramic piece; heating the first ceramic piece and the second ceramic piece to a joining temperature in a vacuum; and cooling the first ceramic piece and the second ceramic piece. A hermetic seal is formed between the first ceramic piece and the second ceramic piece.

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 bonded body according to an embodiment comprises a ceramic substrate, a copper plate, and a bonding layer provided on at least one surface of the ceramic substrate and bonding the ceramic substrate and the copper plate, in which the bonding layer contains Cu, Ti, and a first element being one or two selected from Sn and In, and the bonding layer includes a Ti-rich region in which a ratio (M.sub.Ti/M.sub.E1) of a mass M.sub.Ti of Ti to a mass M.sub.E1 of the first element being 0.5 or more and a Ti-poor region in which the ratio (M.sub.Ti/M.sub.E1) being 0.1 or less.

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 ceramic substrate is provided with a flat plate-shaped insulating base including a ceramic, a first brazing material layer provided on a first main surface of the insulating base, a second brazing material layer provided on a second main surface of the insulating base, a first metal layer including a metal and being fixed through the first brazing material layer to the insulating base on a first main surface-side, and a second metal layer including a metal and being fixed through the second brazing material layer to the insulating base on a second main surface-side. A difference between a thickness of the first brazing material layer and a thickness of the second brazing material layer at a given point is 4.0 .Math.m or less.

An electrostatic chuck includes a ceramic top plate layer made of a beryllium oxide material, a ceramic bottom plate layer made of a beryllium oxide material, a ceramic middle plate layer disposed between the ceramic top plate layer and the ceramic bottom plate layer, an electrode layer disposed between the ceramic top plate layer and the ceramic middle plate layer, and a heater layer disposed between the ceramic middle plate layer and the ceramic bottom plate layer. The electrode layer joins and hermetically seals the ceramic top plate layer to the ceramic middle plate layer, and the heater layer joins and hermetically seals the ceramic middle plate layer to the ceramic bottom plate layer.

The present invention provides a silicon nitride sintered substrate capable of reducing contamination caused by a boron nitride powder or the like used as a releasing agent and problems in bonding strength and dielectric strength at the time of laminating metal layers or the like, where the contamination is caused by a network structure provided by a silicon nitride crystal formed on the surface of the substrate in an unpolished state after sintering a silicon nitride powder. The silicon nitride substrate in an unpolished state after sintering is a silicon nitride sintered substrate where a cumulative volume of pores having a diameter in a range of 1 to 10 μm is not more than 7.0'10.sup.−5 mL/cm.sup.2 in a measurement by a mercury porosimetry. Preferably, Ra of the surface is not more than 0.6 μm and arithmetic mean peak curvature (Spc) of a peak is not more than 4.5 [l/mm].