| 摘要 |
PROBLEM TO BE SOLVED: To effectively prevent a thermorunaway and stabilize the operation. SOLUTION: A cooling layer 8 for cooling a semiconductor element layer 3 is bonded to the semiconductor element layer 3 for controlling a quantity of current, through a cooling face 11. The semiconductor element layer 3 and cooling layer 8 are in such a relationship that the semiconductor element layer 3 is cooled in different degrees of cooling depending on many different places inside the semiconductor element layer 3. Because the semiconductor element layer 3 is cooled in different degrees of cooling depending on places inside the layer 3, temperature of heating regions of the semiconductor element layer 3 are rationalized, specifically, made even, thus preventing a thermorunaway. The semiconductor element layer 3 consists of multilayers 3 which are planarly bonded to each other by bonding faces, and a heat loss is different in many regions of each bonding face between the multilayers 3. Even if a heat loss is of such a type, the bonding faces are cooled by the cooling layer having a reverse thermal gradient, and thus a temperature distribution is rationalized, specifically, made even. |
