| abstract |
A semiconductor device includes a circuit substrate having a first metal layer on a first side, a second metal later on a second side, and an insulating layer between the first and second metal layers. A semiconductor chip is on the first side of the circuit substrate. A metal plate is on the second side. A solder layer is between the metal plate and the second metal layer. The second metal layer includes a protruding region which extends to a first thickness towards the metal plate, a first recessed region, and a second recessed region, each adjacent to the protruding region. The first recessed region extends to a second thickness that is less than the first thickness, and the second recessed region extends to a third thickness that is less than the first thickness. |