摘要 |
FIELD: metallurgy. ^ SUBSTANCE: part, a p.c.b. coated by copper film, or a copper wire terminal, or a copper strip terminal, is dipped into, soldering bath, said part after soldering being subjected to processing by air knife or stamp. After Cu concentration in bath with solder exceeds check value and Ni concentration drops below said value, replenishing leadless solution is fed into bath, consisting mainly of Sn and containing, at least, Ni in amount of 0.01 wt % to 0.5 wt %. After feeding leadless solder of said composition, solder concentration, changed abruptly, quickly returns into required range. ^ EFFECT: soldering without changing solder. ^ 5 cl, 2 dwg |