| 摘要 |
PROBLEM TO BE SOLVED: To realize a soldering method with which the formation of void is prevented by improving the wettability of the solder and the solder can firmly be connected with surfaces by using the solder suitable to electronic parts and a circuit substrate. SOLUTION: A non-melted solder 12 at a first layer is supplied on the circuit substrate, heated and melted (Figure a, b) and on this layer, a non-melted solder 14 having the same composition as the solder 12 at the first layer, is supplied, heated and melted (Figure c) and on the molten solder layers, a base chip 16 is piled and further, heated (Figure d) and the circuit substrate 10 and the base chip 16 are soldered (Figure e). Since anyone is not piled on the substrate when the solder 12 is melted, entraped bubble is easily exhausted. On the wetting defective portion 12a of the molten solder layer 12, the solder 14 is supplemented. In this way, the void formed in the solder layer can positively be reduced. COPYRIGHT: (C)2004,JPO |
