Abstract: There is provided an evaporation source adapted for use in a vapor deposition apparatus in which by heating, in an induction heating method, a crucible filled with a vapor deposition material, the entire crucible including a cap body attains a top-heat state. An evaporation source is provided with: a crucible filled with the vapor deposition material; a cap body to close an upper surface opening of the crucible; and an induction heating coil disposed around the crucible and the cap body. Further, the cap body is provided with a discharge part which allows the passage of the vapor deposition material evaporated or sublimated by heating. The cap body is provided on an external surface thereof with projections each having a corner part.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a silicon nitride circuit board in which metal plates are attached on front and rear sides of a silicon nitride substrate having a three-point flexural strength of 500 MPa or higher, wherein assuming that a thickness of the metal plate on the front side is denoted by t1, and a thickness of the metal plate on the rear side is denoted by t2, a numerical relation: |t1?t2|?0.30 mm is satisfied, and a warp is formed in the silicon nitride substrate so that the silicon nitride substrate is convex toward the metal plate on one of the front side or the rear side; and warp amounts of the silicon nitride substrate in a long-side direction and a short-side direction both fall within a range from 0.01 to 1.0 mm. It is preferable that a longitudinal width (L1) of the silicon nitride substrate falls within a range from 10 to 200 mm, and a transverse width (L2) of the silicon nitride substrate falls within a range from 10 to 200 mm.

Abstract: The present invention provides a silicon nitride circuit board in which metal plates are attached on front and rear sides of a silicon nitride substrate having a three-point flexural strength of 500 MPa or higher, wherein assuming that a thickness of the metal plate on the front side is denoted by t1, and a thickness of the metal plate on the rear side is denoted by t2, a numerical relation: |t1?t2|?0.30 mm is satisfied, and a warp is formed in the silicon nitride substrate so that the silicon nitride substrate is convex toward the metal plate on one of the front side or the rear side; and warp amounts of the silicon nitride substrate in a long-side direction and a short-side direction both fall within a range from 0.01 to 1.0 mm. It is preferable that a longitudinal width (L1) of the silicon nitride substrate falls within a range from 10 to 200 mm, and a transverse width (L2) of the silicon nitride substrate falls within a range from 10 to 200 mm.

Abstract: The present invention provides a silicon nitride circuit board in which metal plates are attached on front and rear sides of a silicon nitride substrate having a three-point flexural strength of 500 MPa or higher, wherein assuming that a thickness of the metal plate on the front side is denoted by t1, and a thickness of the metal plate on the rear side is denoted by t2, a numerical relation: |t1?t2|?0.30 mm is satisfied, and a warp is formed in the silicon nitride substrate so that the silicon nitride substrate is convex toward the metal plate on one of the front side or the rear side; and warp amounts of the silicon nitride substrate in a long-side direction and a short-side direction both fall within a range from 0.01 to 1.0 mm. It is preferable that a longitudinal width (L1) of the silicon nitride substrate falls within a range from 10 to 200 mm, and a transverse width (L2) of the silicon nitride substrate falls within a range from 10 to 200 mm.

Abstract: The present invention provides a silicon nitride circuit board in which metal plates are attached on front and rear sides of a silicon nitride substrate having a three-point flexural strength of 500 MPa or higher, wherein assuming that a thickness of the metal plate on the front side is denoted by t1, and a thickness of the metal plate on the rear side is denoted by t2, a numerical relation: |t1?t2|?0.30 mm is satisfied, and a warp is formed in the silicon nitride substrate so that the silicon nitride substrate is convex toward the metal plate on one of the front side or the rear side; and warp amounts of the silicon nitride substrate in a long-side direction and a short-side direction both fall within a range from 0.01 to 1.0 mm. It is preferable that a longitudinal width (L1) of the silicon nitride substrate falls within a range from 10 to 200 mm, and a transverse width (L2) of the silicon nitride substrate falls within a range from 10 to 200 mm.

Abstract: 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.