US 12,396,092 B2
Ceramic circuit board and semiconductor device using same
Takayuki Naba, Chigasaki Kanagawa (JP); Keiichi Yano, Yokohama Kanagawa (JP); and Hiromasa Kato, Nagareyama Chiba (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and TOSHIBA MATERIALS CO., LTD., Yokohama (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and TOSHIBA MATERIALS CO., LTD., Yokohama (JP)
Filed on Aug. 3, 2023, as Appl. No. 18/364,547.
Application 18/364,547 is a continuation of application No. PCT/JP2022/005407, filed on Feb. 10, 2022.
Claims priority of application No. 2021-023071 (JP), filed on Feb. 17, 2021.
Prior Publication US 2023/0380060 A1, Nov. 23, 2023
Int. Cl. H05K 1/03 (2006.01); H05K 1/02 (2006.01); H05K 3/38 (2006.01)
CPC H05K 1/0306 (2013.01) [H05K 1/0265 (2013.01); H05K 1/0271 (2013.01); H05K 3/388 (2013.01); H05K 2201/06 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A ceramic circuit board comprising a ceramic substrate and a metal plate bonded together via a bonding layer, wherein
when the ceramic circuit board is observed through a cross-section defined by a thickness direction and lateral direction of the ceramic circuit board:
a side surface of the metal plate has an inclined shape;
the bonding layer has a bonding-layer protruding portion which protrudes by 20 μm or more and 150 μm or less from an edge where the bonding layer is in contact with the side surface of the metal plate;
an angle BAC is 110 degrees or more, where a point A is on the edge, a point B is on a side surface of the metal plate that is 20 μm away from the point A inward in the lateral direction, and a point C is on a surface of the bonding-layer protruding portion that is 20 μm away from the point A outward in the lateral direction;
Hm denotes an average value of Vickers hardness at ten locations in a region between a line in the lateral direction passing through the point B and an interface between the metal plate and the bonding layer;
300>Hm>Hb and Hm/Hb<2, where Hb denotes an average value of Vickers hardness at ten locations in the bonding layer; and
a ratio R of an area where a component of the bonding layer other than that of the metal plate is present in the region is 5% or more and 20% or less.