| 摘要 |
A power module includes a heat exchanger and an IGBT. The heat exchanger is provided with: a rectangular-tube shaped case; comb-shaped cooling fins housed within the case; and a heat spreader, bonded to the upper surface of the case with a bonding agent. The IGBT is affixed to the upper surface of the heat spreader with a bonding agent. The cooling fins consist of a plurality of fin units which protrude vertically, in parallel and at intervals from each other, from both the top and bottom surfaces of a flat panel-shaped base section. The cooling fins are arranged so that the plurality of fins on the upper side of the base section and the plurality of gaps in the lower side of the base section are of the same width and overlap in the vertical direction, and so that the plurality of gaps in the upper side of the base section and the plurality of fins in the lower side of the base section are of the same width and overlap in the vertical direction. X-rays are applied to the power module so as to penetrate the bonded surface between the IGBT and the bonding agent almost vertically and air-bubble flaws (voids) within the bonding agent are examined, based on the x-ray transmission image. |
