MANUFACTURING METHOD OF SUBSTRATE FOR POWER MODULE WITH HEAT SINK

摘要

PROBLEM TO BE SOLVED: To provide a substrate for a power module with a heat sink which is formed by brazing a metal layer to the heat sink with flux so as to avoid peeling in a joint part between a ceramic substrate and the metal layer and achieves high joint reliability.SOLUTION: In a manufacturing method of a substrate for a power module with a heat sink, the heat sink is joined to the substrate for the power module to manufacture the substrate for the power module with the heat sink. The manufacturing method includes: a primary brazing process where reactive powder P reacting with the flux is applied to a side surface 13c in a metal layer 13 of the substrate for the power module and a substrate joining surface 13b of the metal layer is brazed with a ceramic substrate 11 using a brazing material to form the substrate for the power module; and a secondary brazing process where a heat sink joining surface 13a of the metal layer is joined to the heat sink by brazing using the flux. In the primary brazing process, the reactive powder is held by the brazing material leaked from a space between the substrate joining surface of the metal layer and the ceramic substrate.