氨碱性蚀刻液中铜溶解过程的化学动力学

Chemical kinetics for copper dissolution process in alkaline ammonia solution

氨碱性溶液是印制电路板工业中采用最为广泛的蚀刻溶液,但是关于溶液中铜溶解过程的动力学研究还比较缺乏。研究利用模拟实验的方法,定量地研究了铜溶解反应的化学动力学性质。当速度梯度G值大于7 570 s^(-1)时,铜溶解速率不受混合强度影响的传质速率限制;在反应前120 s内,平均单位面积铜溶解质量与反应时间呈线性关系,反应的速率常数约为0.137 3 mg/(cm^2·s);溶液Cu^(2+)浓度低于0.8 mol/L时,铜溶解速率随Cu^(2+)浓度增大而线性增大,此区间反应符合一级反应动力学;Cu^(2+)浓度约为1.0 mol/L时溶解速率最大;温度对反应速率的影响非常显著,升高温度反应速率增加较快,50℃时溶解速率可达21.106μm·L/(min·mol);溶解反应的Arrhenius活化能Ea约为23.7 k J,频率因子A约为1.43×10~5。

Alkaline ammonia solution is widely used as etching solution in industries of printed circuit board.However,it is lack of kinetics research for copper solution process in etching solution. Simulation experiment method was employed to investigate the chemical kinetics characteristics of copper solution reaction. When velocity gradient G was over 7 570 s^（- 1）,copper dissolution rate was not influenced by mass transfer rate determined by stirring intensities. In first 120 s of the reaction,the average mass of copper dissolution per unit area kept linear relation with reaction time. The kinetic constant of the reaction was about 0. 137 3 mg/（ cm^2· s）. When concentration of cupric ion was lower than 0. 8 mol/L,the dissolution rate of copper linearly increased with cupric ion and complied with first order dynamical reaction. When the cupric ion concentration was about 1. 0 mol/L,the dissolution rate reached maximum value. The temperature had greatly significance on reaction rate,the reaction rate rapidly increased with temperature,and the dissolution rate reached up to 21. 106 μm·L/（ min·mol） at 50℃. The activation energy Eafor dissolution reaction in Arrhenius rule was about 23. 7 k J and the frequency factor A was about 1. 43 × 10^5.