| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a power converter which reduces a cost and realize highly time efficient reflow soldering.SOLUTION: A manufacturing method of power converter comprises: a first process of increasing the pressure of a preliminary structure 11, placing the structure in formic acid gas atmosphere which is set to atmospheric pressure or higher, and maintaining pressure; together with the process, a second process of increasing the temperature of the preliminary structure such that the temperature of solder 4a or the like becomes less than its melting temperature and the temperature of a resin case 3 becomes less than heat-resistant lower limit temperature of the resin, and increasing the temperature of the formic acid gas atmosphere so as to become reduction start temperature or higher of formic acid; subsequently, a third process of bringing the formic acid gas atmosphere to an inert gas atmosphere which is set to atmospheric pressure or higher; subsequently, a fourth process of maintaining the temperature of the solder and the resin case after increasing the temperature of the preliminary structure such that the solder becomes a molten state and the temperature of the resin case is less than heat-resistant lower limit temperature of the resin; a fifth process of discharging inert gas during execution of this process to make the atmosphere of preliminary structure vacuum; and a sixth process of decreasing the temperature of the solder in the molten state to coagulate the solder subsequently from the fourth and fifth process.SELECTED DRAWING: Figure 3 |
