Effects of Plating Conditions on Thermal Peeling of Tin or Solder Plated Phosphor-bronze

The effects of plating conditions on the thermal peeling of tin or solder plated phosphor-bronze were examined. Main findings are summarized as follows. 1. The resistance to thermal peeling of reflowed tin films with 0.5μm copper undercoat was highest when plated in a phenolsulfonate bath, while that of reflowed tin films with no undercoat was highest when plated in a sulfate bath. 2. Thermal peeling took place more readily and was less sensitive to plating bath composition for bright solder films than for reflowed tin films. In phosphor-bronze that was bright solder plated in a methanesulfonate bath, thermal peeling was observed after aging at room temperature for 16, 000h. 3. An arrhenius type relation was obtained between the aging time to peeling and aging the temperature.