| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a manufacturing method of circuit board for power module with heat sink capable of joining a circuit board for power module with a heat sink without causing any joint failure on joint boundary.SOLUTION: A vacuum heating furnace is cooled being controlled so that the difference in cooling rate at a center P and at corners K which are farthest from the center (that is, four corners in the periphery of a metal layer 13) is smaller than 5.0×10(°C/minute) in a joint boundary G. The temperature range to control the cooling rate difference at the center P and the corners K within 5.0×10(°C/minute) in the joint boundary G, is achieved at least in a cooling and solidifying process of a brazing filler metal, when a temperature range from a joint temperature of the brazing filler metal to a temperature lower by 10°C than the solidus wire temperature of the brazing filler metal is lowered.</p> |
