| 摘要 |
PROBLEM TO BE SOLVED: To simply and accurately inspect the radiation capacity of a multilayered power module. SOLUTION: A current is supplied to the multilayered power module 20 to be inspected by a transient heat resistance measuring instrument 26 and the threshold value voltage (Vth) of an element 10 changed before and after the supply of a current is related to a current passing time (T) to be measured to calculate the change quantity (ΔVth) of the threshold value voltage before and after the supply of the current at every current supply time. Then, the judge means 28 employs a calculated value, representing the difference (ΔVth<SB>n+1</SB>-ΔVth<SB>n</SB>) between the change quantities of the threshold value voltages at specific two current supply times (T<SB>n</SB>and T<SB>n+1</SB>) divided by the difference (T<SB>n+1</SB>-T<SB>n</SB>) between the specific two current supply times to obtain a calculation time and this calculation value, as judge data for grasping the presence of the radiation flaw of the specific member of a plurality of the members which constitute the multilayered power module 20 to be inspected. COPYRIGHT: (C)2008,JPO&INPIT
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