Is My Coating Emitting Light Slowly? I May Not Understand The Effect Of Copper Sulfate in The Acidic Brightness Copper Process!

What role does copper sulfate in the acidic bright copper plating process play?
copper sulphate
Copper sulfate is the main salt in the plating solution, and there are significant differences in the concentration control of copper sulfate under different acidic bright copper plating processes. For example, in the low copper and high acid formula, the copper sulfate content of the plating solution needs to be controlled between 80-120g/L. This formula is mostly used for bright copper plating of circuit boards. Bigley's Cu-100 circuit board acid copper process is one of its representatives.
In this series of articles, we discuss the high copper and low acid formula. The copper sulfate content of the plating solution needs to be controlled between 150-220g/L, and the production should be controlled within the range of 180-210g/L. Bigley's Cu-510 acid copper brightener is a representative.
Why should we value the main salt? Because the main salt plays a role as a metal salt that forms the components of the coating, it is an indispensable component in the plating solution. So what happens when the main salt concentration is high or low?
When the copper sulfate content in the acidic bright copper plating solution is low, the dispersion ability of the plating solution is good. However, the current efficiency and cathode current density of the plating solution are low, which will slow down production efficiency and affect the light output speed.
In production, it is not difficult to find that some people control copper sulfate too high in order to pursue a high allowable current density. In fact, this is incorrect. When the content of copper sulfate is high, due to the same ion effect, crystals will precipitate at the edge of the liquid surface of the anode bag or plating tank wall, affecting the quality of the coating, leading to anode passivation, and significantly reducing the dispersion ability of the plating solution.
epilogue
In electroplating production, in addition to adding an appropriate amount of main salt to maintain moderate concentration polarization, additives are also needed to generate electrochemical polarization. Bigley's Cu-510 is a high dye type acid copper brightener with a wide range of current density, resulting in fast deposition speed. At the same time, its filling degree is as high as 75%, and the brightness of the coating obtained in the acid bright copper plating process is very good, which can meet the requirements of customers on the market.