温度对化学镀镍磷合金基体上置换镀金过程的影响

Effect of Temperature on the Immersion Gold Process Based on Electroless Ni-P Alloy Substrate

摘要:

运用X 射线荧光光谱仪、原子力显微镜及开路电极电势等方法系统研究了三种磷含量（4%，9%及11%）的化学镀Ni-P基体上的置换镀金沉积过程，并分析了镀金温度对该沉积过程的影响。结果表明：置换镀金过程中沉积速率、表面粗糙度和电极电势均发生明显的变化，对应了镀金时Ni-P电极表面状态的变化，与Ni-P合金基体中磷含量和镀金温度高低均有一定的关系。在磷含量不同的Ni-P合金基体上置换镀金时，沉积速率及电极电势随时间变化的规律基本相似。同一温度下镀金时，Ni-P合金基体中磷含量越高，电极电势越高，初始沉积速率越低。温度对置换镀金过程的影响较为复杂。在50-80℃范围内升高温度，镀金层粗糙度变小，电极电势变正；而当温度为90℃时，镀层粗糙度明显变大，电极电势也变负。镀金层的粗糙度大小与金层外观有一定的关系，即外观良好的镀金层，其粗糙度一般较小。

Abstract:

The immersion gold process based on electroless Ni-P alloy substrate with three P contents (4%, 9% and 11%) was investigated by X-ray fluorescence spectrometer, atomic force microscopy and open circuit potential measurementand analysis. The effects of temperature on the gold deposition process were also discussed. The results show that the deposition rate and electrode potential are changed during the immersion gold process. In the same temperature, a higher P content often leads to a high electrode potential and a low initial deposition rate. However, the effect of temperature on immersion gold is relatively complex. In the range of 50-80℃, a high temperature results in a positive potential and a better surface morphology of the gold coating with a smaller surface roughness, while a more negative potential and a bigger surface roughness are obtained at a higher temperature(90℃).