A copper/ceramic bonded body includes: a copper member made of copper or a copper alloy; and a ceramic member made of a silicon nitride, wherein the copper member and the ceramic member are bonded to each other, a magnesium oxide layer is provided on a ceramic member side of a bonded interface between the copper member and the ceramic member, a Mg solid solution layer is provided between the magnesium oxide layer and the copper member and contains Mg in a state of a solid solution in a Cu primary phase, and a magnesium nitride phase is present on a magnesium oxide layer side of the Mg solid solution layer.

A copper/ceramic bonded body includes: a copper member made of copper or a copper alloy; and a ceramic member made of a silicon nitride, wherein the copper member and the ceramic member are bonded to each other, a magnesium oxide layer is provided on a ceramic member side of a bonded interface between the copper member and the ceramic member, a Mg solid solution layer is provided between the magnesium oxide layer and the copper member and contains Mg in a state of a solid solution in a Cu primary phase, and a magnesium nitride phase is present on a magnesium oxide layer side of the Mg solid solution layer.

A module having a power semiconductor device and a ceramic capacitor which is configured for cooling the power semiconductor device.

A bonded body according to an embodiment includes a substrate, a metal member, and a bonding layer. The bonding layer is provided between the substrate and the metal member. The bonding layer includes a first particle including carbon, a first region including a metal, and a second region including titanium. The second region is provided between the first particle and the first region. A concentration of titanium in the second region is greater than a concentration of titanium in the first region.

A bonded body according to an embodiment includes a substrate, a metal member, and a bonding layer. The bonding layer is provided between the substrate and the metal member. The bonding layer includes a first particle including carbon, a first region including a metal, and a second region including titanium. The second region is provided between the first particle and the first region. A concentration of titanium in the second region is greater than a concentration of titanium in the first region.

Electrical insulating properties between adjacent copper plates are improved while a defect of a bonded substrate which is caused by concentration of stress to end portions of the copper plates is prevented. A bonded substrate includes a silicon nitride ceramic substrate, a copper plate, and a bonding layer. The copper plate and the bonding layer are disposed on the silicon nitride ceramic substrate. The bonding layer bonds the copper plate to the silicon nitride ceramic substrate. The bonding layer includes: an interplate portion between the silicon nitride ceramic substrate and the copper plate; and a protruding portion protruding from between the silicon nitride ceramic substrate and the copper plate. Exposure of the silicon nitride ceramic substrate is prevented at a position where the protruding portion is disposed.

The present disclosure relates to a method for manufacturing a ceramic heater. The method for manufacturing a ceramic heater according to the present disclosure comprises: separately charging a ceramic powder into a center portion and multiple split edge portions in a formation mold and leveling the charged ceramic powder; manufacturing a molded body or pre-sintered body of the ceramic powder from the leveled ceramic powder; disposing a high-frequency electrode or a heating element on the molded body or pre-sintered body of the ceramic powder and filling a second ceramic powder; and integrally sintering the molded body or pre-sintered body of the ceramic powder and the second ceramic powder.

A circuit base of the present disclosure includes a base made of ceramic, a joint layer located on the base, and a metal layer located on the joint layer. The metal layer contains copper. The joint layer contains aluminum, silicon, and oxygen.

A silicon nitride substrate includes silicon nitride and magnesium, in which when a surface of the silicon nitride substrate is analyzed with an X-ray fluorescence spectrometer under the specific Condition I, XB/XA is 0.8 or more and 1.0 or less.

Provided is a method for producing a silicon nitride sintered body including: a step of molding and firing a raw material powder containing silicon nitride, in which an α-conversion rate of the silicon nitride contained in the raw material powder is less than or equal to 30 mass %. A thermal conductivity (at 20° C.) of the silicon nitride sintered body exceeds 100 W/m.Math.K and a fracture toughness (K.sub.IC) is greater than or equal to 7.4 MPa.Math.m.sup.1/2.