【摘要】 <正> 一、前言铅锡合金在空气中有良好的化学稳定性和较低的熔点,并与合金焊料有类似的组份,所以,焊接性能优良,被广泛应用于电子工业中作为焊接性镀层。目前以光亮镀锡作焊接镀层虽有镀液成份简单、操作与维护容易等优点,但也存在一些不足之处。(1)电子产品日趋小型化,纯锡层在其表面会形成针状晶须,晶须有时长达几毫米,当它们互相接触更多还原

【Abstract】 The study is on the bright Pb-Sn alloy plating,with a bath composition of (g/l) stannous chloride 30-35,Pb acetate 10-20,citric acid 150-160,ammonium acetate 100- 120,boric acid 30-35,with composite Additive “YDZ-7” 12-16 & “YDZ-8” 12-16 ml/l; pH=5,Temp.:10-35℃,C/D:0.5-2.5 A/dm~2.Potential/Current Density curves show that the addition of citric acid-ammonium acetate,besides the composite additives has great effects on polarization of tho baths;while Anode Polarization curves set up the optimum operating current density for better anode dissolution not excess 3 A/dm~2. Measurements of Throwing power,Bath conductivity,Current efficiency and Deposition rate have been carried out,and the effects of operating conditions e.g.pH value, temperature and current density,as well as the tolerance for impurities or other heavy metals,are detailed.Methods of bath analysis and wastewater treatment are also appended.更多还原