| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress defects resulting from a solder not containing load to a minimum by soldering a substrate containing a copper-base terminal and a lead terminal containing a surface, comprising alloy of tin and copper together with a solder alloy of tin and copper. SOLUTION: Plural electronic parts 12 and mounted on a printed circuit substrate 10. Even electronic part 12 contains a lead 14 soldered to a terminal pad 16 of copper on the printed circuit substrate 10. This structure avoids the use of lead material which is environmentally toxic as a solder for attaching a lead terminal permanently to the terminal pad 16. Thus, a solder 18 inserted between an end of the lead 14 and the terminal pad 16 comprised a solder alloy of tin and copper, and relating to each lead of the electronic parts 12, a core is coated with such material which gets intimate with a solder as tin- copper alloy. Thus, the solder conforms with the copper terminal pad 16 and the lead 14 of the printed circuit substrate 10, so that by soldering, the solder 18 is permanently fused with each terminal pad 16.</p> |
