工艺条件对线路板化学镀钯的影响

Effect of Process Conditions on Electroless Palladium Plating on Circuit Boards

线路板镍层上传统化学镀金过程中存在镍层腐蚀问题,本文针对本公司开发的线路板化学镀镍钯金工艺的化学镀钯配方,研究了化学镀钯温度和pH对沉积速率、钯层形貌和镀金后镍腐蚀的影响。结果表明,在45℃~60℃区间化学镀钯沉积速度随温度呈近线性增加;在pH为6.0~8.0之间镀钯沉积速率随pH值增加也缓慢增加。在50℃,pH=7.2时化学镀钯沉积速率稳定,镀层结晶细致,能够有效减少镀金时产生的镍腐蚀,得到的镍钯金镀层平均断裂拉力为2.0 g,断裂模式均为模式A-3焊点肩部断裂,具有良好的金线邦定性能。

For circuit board,corrosion of the nickel layer occurs during the traditional electroless gold plating on the nickel layer.Our company developed a process for electroless nickel palladium plating on circuit boards.The effects of electroless palladium plating temperature and pH on the deposition rate,palladium plating layer morphology and nickel layer corrosion during gold plating were studied.The re⁃sults show that the deposition rate of electroless palladium plating in the temperature range of 45~60℃increases nearly linearly with temperature.The deposition rate of palladium plating in the pH range of 6.0 and 8.0 also increase slowly with the increase of pH value.When the temperature is 50℃and the pH value is 7.2,the deposition rate of electroless palladium plating is stable,and the crystallization of the coating is fine,which can effectively reduce the nickel corrosion during gold plating.The average break⁃ing force of the nickel palladium coating is 2.0 g.The fracture mode is determined to be mode A-3 solder joint fracture.The fracture mode was determined to be A-3 solder joint fracture.The obtained nickel-palladium gold coating showed good gold wire bonding performance.