A circuit board includes a metal circuit plate, a metallic heat diffusing plate disposed below the metal circuit plate and having an upper surface and a lower surface, a metallic heat dissipating plate below the heat diffusing plate, an insulating substrate disposed between the metal circuit plate and the heat diffusing plate, and an insulating substrate disposed between the heat diffusing plate and the heat dissipating plate. A grain diameter of metal grains contained in the heat diffusing plate decreases from each of the upper surface and the lower surface of the heat diffusing plate toward a center portion of the heat diffusing plate in a thickness direction.

To improve a TCT characteristic of a circuit substrate. The circuit substrate comprises a ceramic substrate including a first and second surfaces, and first and second metal plates respectively bonded to the first and second surfaces via first and second bonding layers. A three-point bending strength of the ceramic substrate is 500 MPa or more. At least one of L1/H1 of a first protruding portion of the first bonding layer and L2/H2 of a second protruding portion of the second bonding layer is 0.5 or more and 3.0 or less. At least one of an average value of first Vickers hardnesses of 10 places of the first protruding portion and an average value of second Vickers hardnesses of 10 places of the second protruding portion is 250 or less.

A ceramic circuit substrate having high bonding performance and excellent thermal cycling resistance properties, having a circuit pattern provided on a ceramic substrate with a braze material layer interposed therebetween, and a protruding portion formed by the braze material layer protruding from the outer edge of the circuit pattern, wherein: the braze material layer includes Ag, Cu, Ti, and Sn or In; and an Ag-rich phase is formed continuously for 300 μm or more, towards the inside, from an outer edge of the protruding portion, along a bonding interface between the ceramic substrate and the circuit pattern, and has a bonding void ratio of 1.0% or less.

A power module substrate 10 is provided with: an insulating substrate 1; and a metal sheet 2 that is joined to the insulating substrate 1 via a brazing material 3, wherein regarding the surface roughness, in the thickness direction, of the lateral surface of the metal sheet 2, the surface roughness of a corner 2a farthest from the center of the metal sheet 2 is larger than the surface roughness of plane parts 2b, which bound the corner, in at least a plan view. Also provided is a power module 100 which is formed by mounting an electronic component 40 on this power module substrate 10.

A method of manufacturing a gas turbine engine component (10) and the component so formed. The method includes: stacking a plurality of CMC layers (16) along a metal core (30) to form a stack of disconnected CMC layers, wherein adjacent edge faces (46) of the layers define a surface (44); additively depositing ceramic material (14) to only selected portions of the surface (44) to bond together at least some of the layers at their respective edge faces; and selecting locations for the depositing of the ceramic material to achieve a predetermined mechanical characteristic of the resulting component.

A power module substrate includes an insulating substrate and a metal plate. The metal plate is joined to the insulating substrate with a brazing material in between. As to surface roughness of a lateral surface of the metal plate in a thickness direction, the surface roughness of at least a corner part farthest from a center of the metal plate in plan view is larger than the surface roughness of plane parts sandwiching the corner part.

A second main surface of the copper plate is opposite a first main surface of the copper plate, and is bonded to a silicon nitride ceramic substrate by the bonding layer. A first portion and a second portion of an end surface of the copper plate form an angle of 135° to 165° on an outside of the copper plate. An extended plane of the first portion and the second main surface form an angle of 110° to 145° a side where the second portion is located. A distance from the second main surface to an intersection of the first portion and the second portion in a direction of a thickness of the copper plate is 10 to 100 μm. The second main surface extends beyond the extended plane of the first portion by a distance of 10 μm or more.

A ceramic structural body includes a substrate that is composed of a ceramic(s), a hole that is opened on a surface of the substrate, and a seal material that is positioned at an opening portion of the hole.

A turbine blade having an airfoil portion includes a first ceramic matrix composite (CMC) component having a first outer surface and a second ceramic matrix composite (CMC) component having a second outer surface. The second CMC component is positioned adjacent the first CMC component such that the first outer surface and the second outer surface align with one another and at least partially define the airfoil portion. A ceramic bead is at least partially formed at an interface between the first CMC component and the second CMC component. The formation of the bead melts a portion of the first CMC component and the second CMC component, such that the ceramic bead, the first CMC component, and the second CMC component become a single contiguous component and the bead fixedly attaches the first CMC component and the second CMC component. The bead includes a bead outer surface that extends outward beyond the first outer surface and the second outer surface and an overlayer is deposited onto the airfoil portion, the overlayer bonded to the first outer surface, the second outer surface, and the bead outer surface.

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.