一种可焊性半光亮镀镍工艺

目的解决镀镍层可焊性不良的问题,使得光电子器件外壳镀镍层可焊性满足回流焊要求,并且保存半年后可焊性不降低。方法以氨基磺酸镍为体系,考察温度、p H值、电流密度与沉积速率的关系,采用回流焊和浸润法对镀层可焊性进行表征,并考察镀层的质量、结合力及盐雾性能指标。结果镀液体系在比较宽泛的电流密度和温度范围内,都能得到可焊性优良的镀层,其沉积速率随电流密度的增大呈线性增加。浸润法和回流焊接试验表明,镀层可焊性满足要求。在稳态湿热(45℃,RH=95%)环境中48 h或恒温烘烤(150℃,1 h)后,镀层可焊性仍均满足要求。结论在电流密度1~5 A/dm2,p H值3.2~4.4,温度40~55℃的条件下能得到优良的可焊性镀层,满足回流焊对镀层可焊性的要求,并且放置半年后可焊性不降低。

Solderability of a Kind of a Semi-bright Nickel Plating Process

ABSTRACT:Objective To solve the problem of poor solderability of nickel plating layer, make the solderability of the optoelec-tronic device shell meet the requirements of reflow soldering and guarantee the solderability not to reduce after storage for half a year. Methods Taking nickel amino-sulfonate as a system, this paper investigated the relationship among temperature, pH, current density and deposition rate by adopting the reflow soldering and Tin dipping method to characterize the solderability of the coating and investigated the coating quality, bonding force and performance metrics in the salt spray test. Results The plating solution sys-tem can obtain a plating layer with good solderability within broader ranges of current density and temperature. The deposition rate increased as a linear with the increasing current density and the solderability was proved good. The infiltrating and reflow soldering experiments showed that the solderability of the plating layer all met the requirements in the 45 ℃ steady-state humid environment (95% RH for 48 h) or under the condition of constant baking at 150 ℃ for 1 hour. Conclusion When the current density is be-tween 1 A/dm2 and 5 A/dm2 , pH is 3. 2 to 4. 4 and the temperature control is between 40℃ and 55℃, the excellent solderability of plating layer can be obtained and meet the requirements of reflow soldering on the solderability of plating layer and can be kept for half a year with no reduction.