| 摘要 |
PROBLEM TO BE SOLVED: To provide a package structure, wherein a ceramic plate of an insulating substrate is prevented from cracking under an external force applied in assembly condition, while a high assembly precision is provided in a bonding process in which a main circuit assembly is assembled into an enclosure. SOLUTION: A power main circuit assembly 5, in which a power semiconductor element 5a, is mounted on an insulating substrate 5b which has as backing material is a ceramic plate 5b-1 is inserted, from below, in a substrate fitting hole 1a opened at the bottom surface of an enclosure 1, and a bonding agent 7 is used to fit tightly between its periphery and a stepped seat surface 1a-1 formed at the periphery on the rear surface side of the substrate-fitting hole 1a. With the rear surface of the insulating substrate 5b and the rear surface of the enclosure 1 on the same plate, the thickness of the layer of bonding agent 7 filled between the stepped seat surface 1a-1, of the substrate-fitting hole 1a and the periphery of the insulating substrate 5b is set to 0.5±0.3 mm, a projected spacer 11 comprising rubber-like elasticity is inserted, distributedly in the upper-surface periphery of the ceramic plate 5b-1 while facing the stepped seat surface 1a-1 so as to ensure a prescribed layer thickness of bonding agent in a bonding process. |
