Analysis of Causes of Excessive Chloride Ion Consumption in Electroplating Copper

At present, with the development of high-density and high-precision printed circuit boards, more stringent requirements are placed on the sulfate copper plating process. Various factors in the copper plating process must be controlled at the same time to obtain high-quality coatings. The reason for the excessive consumption of chloride ions is analyzed below for the phenomenon of excessive consumption of chloride ions during the copper plating process.

Antecedents of excessive consumption of chloride ions.

During copper plating, the “dull” phenomenon appears in the low current area of ​​the circuit board, and the concentration of chlorine cubes is low. Generally, after adding hydrochloric acid, the “dull” phenomenon of the coating in the low current density area of ​​the board can disappear. The chloride ion concentration can reach the normal range, and the board surface 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 the low chloride ion concentration, and the real reason needs to be analyzed. If a large amount of hydrochloric acid is added. Firstly, other consequences may occur. Secondly, the production cost will be increased, which is not conducive to the competition of enterprises.

Correctly analyze the reason for “the coating is dull in the low current density area”.

By adding a large amount of hydrochloric acid to eliminate the phenomenon of “the coating is not bright in the low current density area”, means that if the chloride ion is too small, it is necessary to add hydrochloric acid to increase the concentration of the chloride ion to reach the normal range, so that the coating in the low current density area is bright. If you need to add double the amount of hydrochloric acid to bring the concentration of chloride ions into the normal range? What is consuming a lot of chloride ions? Too high chloride ion concentration will cause the brightener to be consumed quickly. It shows that chloride ions will react with brightener, and excess chloride ions will be consumed. Conversely, excess brightener will also consume chloride ions. Because too little chloride ion and too much brightener are the main reasons that cause the coating in the low current density area to be not bright, it can be seen that the main reason for the excessive consumption of chloride ions in copper plating is that the concentration of brightener is too high.