| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the occurrence of peeling between a outside connecting pad of an electronic device and solder used for connecting the pad to an external electric circuit board, and consequently, electronic components are not able to operate normally over a long period. SOLUTION: The region containing copper in an amount <=3 wt.% of a copper - nickel - tin alloy 21, formed between a plated nickel layer 17 for coating the external connecting pad 15 of the electronic device 1 and the solder 3 used for connecting the pad 15 to the external electric circuit board 2, is adjusted to be >=40% of the area of the pad 15.</p> |
