US 9,812,377 B2
Semiconductor module and inverter device
Takayuki Yamada, Tokyo (JP); and Noriyuki Besshi, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Chiyoda-Ku, Tokyo (JP)
Appl. No. 14/911,661
Filed by MITSUBISHI ELECTRIC CORPORATION, Chiyoda-ku, Tokyo (JP)
PCT Filed Jul. 31, 2014, PCT No. PCT/JP2014/004027
§ 371(c)(1), (2) Date Feb. 11, 2016,
PCT Pub. No. WO2015/033515, PCT Pub. Date Mar. 12, 2015.
Claims priority of application No. 2013-183224 (JP), filed on Sep. 4, 2013.
Prior Publication US 2016/0197028 A1, Jul. 7, 2016
Int. Cl. H01L 23/473 (2006.01); H01L 25/07 (2006.01); H01L 23/373 (2006.01)
CPC H01L 23/473 (2013.01) [H01L 25/072 (2013.01); H01L 23/3735 (2013.01); H01L 2224/32225 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A semiconductor module, comprising:
a ceramic circuit board having a first conductor layer on a first surface of a ceramic base and a second conductor layer on a second surface of the ceramic base on an opposite side to the first surface;
a semiconductor element mounted on the first conductor layer;
a heat sink having a third surface and a fourth surface on an opposite side to the third surface, the second conductor layer and the third surface being joined via a joint layer;
a fin provided to the fourth surface of the heat sink; and
a refrigerant-channel forming casing firmly fixed to the heat sink along a circumferential edge so as to wrap the fin, wherein:
the third surface of the heat sink has,
a convex portion in which a convex plane has an area smaller than a joint area to the joint layer,
a first stepped portion provided to an edge of the convex portion, a thickness of the heat sink in a portion corresponding to the first stepped portion being smaller than a thickness of the heat sink in a portion corresponding to the convex portion, and
a second stepped portion provided to an edge of the first stepped portion, a thickness of the heat sink in a portion corresponding to the second stepped portion being further smaller than the thickness of the heat sink in the portion corresponding to the first stepped portion;
the joint layer is joined to the convex portion and the first stepped portion of the heat sink and joined to the second stepped portion while a surface of the second stepped portion is exposed partially; and
an edge of the second conductor layer is encapsulated with the joint layer and the second stepped portion is directly adjacent to the first stepped portion.