摘要 |
Lead-free solder compositions suitable for joining electronic devices to printed wiring boards, which comprises by weight 0.2 to 0.9 % copper, 0.006 to 0.07 % nickel, 0.03 to 0.08 % bismuth, less than 0.5 % silver, less than 0.010 % phosphorus, and a balance of tin and inevitable impurities. A solder composition embodying this invention finds particular application in automated wave-soldering machines where conventional lead-free solders dissolve excessive copper from printed wiring circuitry and component terminations. |