| 摘要 |
PROBLEM TO BE SOLVED: To reduce assembly labor, and to improve reliability for a heat cycle, by setting a circuit, a cooling plate, a base plate, and a heat sink to a specific metal, and by jointing the radiation plate to the base plate or the heat sink via a junction layer with a specific alloy layer. SOLUTION: A circuit is mounted onto one surface of a ceramics substrate, and a heat sink is mounted to the cooling plate of a circuit substrate where the cooling plate is formed on an opposite surface via a base plate or without the base plate. In this case, when electric conductivity and thermal conductivity are considered, copper or copper alloy is optimum as the material of the circuit, the cooling plate, the base plate, and the heat sink. When the durability for thermal stress is valued, aluminum or aluminum alloy and, furthermore, copper- third metal-aluminum cladding foil can be used. Also, the heat sink is jointed to the cooling plate of the circuit substrate or the base plate via a junction layer with an alloy layer containing Al and Ni constituents. |
