| 摘要 |
PURPOSE:To reduce cracks largely by forming a barrier metal layer on the outer circumference of a thick plating layer and a thin metallic layer reacting with solder on the outside of the barrier metal layer. CONSTITUTION:A barrier metal 6 is formed between solder 4 and thick plating 2. The barrier metal prevents a reaction between the thick plating 2 and solder 4, and is shaped so that a reaction layer between the thick plating 2 and solder 4 is not formed. A thin metallic layer 7 is shaped outside the barrier metal 6 in order to improve affinity with solder 4. Accordingly, cracks are reduced largely. |
