At present, with the development of printed circuit boards to high density and high precision, more stringent requirements are put forward for sulfate copper plating process, and various factors in the copper plating process must be controlled at the same time in order to obtain high quality coating. In view of the phenomenon of excessive chloride ion consumption in the copper plating process, the reasons for excessive chloride ion consumption are analyzed below.
The antecedents of excessive chloride ion consumption appear
When copper plating, the low current area of the circuit board surface appears "dull" phenomenon, and the chlorine concentration is low; Generally, after adding hydrochloric acid, the "dull" phenomenon of the coating in the low current density area of the plate can disappear, the chloride ion concentration in the plating solution can reach the normal range, and the plate coating is bright. If a large amount of hydrochloric acid is added to solve the "dull" phenomenon of the coating in the low current density area, it is not necessarily caused by too low chloride ion concentration, and the real reason needs to be analyzed. If you take to add a large amount of hydrochloric acid: one, may have other consequences, two to increase production costs, is not conducive to enterprise competition.
Correct analysis of "low current density area coating luster" reasons
By adding a large amount of hydrochloric acid to eliminate the "low current density area coating is not bright" phenomenon, indicating that if there are too few chloride ions, it is necessary to add hydrochloric acid to increase the concentration of chloride ions to reach the normal range, so that the coating in the low current density area is bright. What if you have to multiply hydrochloric acid to get the chloride concentration to the normal range? What's consuming a lot of chloride? The concentration of chloride ions is too high, and the brightener will be consumed quickly. It shows that chloride ions will react with brightener, and excess chloride ions will be consumed. In turn, excess brightener also consumes chloride ions. Because too few chloride ions and excessive brightener are the main reasons for the plating in the low current density area is not bright, it can be seen that the main reason for the excessive consumption of chloride ions in copper plating is the concentration of brightener is too high.