Factors affecting the thickness of electroplating copper

Copper plating thickness of printed circuit board is one of the most important parameters in PCB, because the control of parameters directly affects the performance, quality and reliability of printed circuit board. Electrochemical copper is widely used in the manufacturing of PCBs, which involves depositing a copper metal layer through electrochemical reactions in corrosive liquids. However, the control of copper plating thickness on boards depends on multiple factors.

First of all, one of the factors affecting the thickness of copper plating on printed circuit boards is the additives in the electrolyte. The additives in the electrolyte have a significant impact on the thickness of copper electroplating, such as sulfate ions, chloride ions, and hydrofluoric acid, which can all affect the electrochemical reaction rate of the electrode, thereby affecting the thickness of copper electroplating. But different additives also have their applicable range and the maximum value they can reach.

Secondly, electrode design is also an important factor affecting the thickness of electroplating copper. Improper electrode design can lead to local potential differences on the electrode surface, resulting in uneven electrodeposition, namely premature surface tanning and uneven plating copper thickness. In practical work, it has an impact on the application of important hot spots on PCB boards. Therefore, in the electrode design phase, the electrolyte flow and current density distribution should be predicted in advance, and the electrode design should be carried out according to this law, so as to achieve the best speed and uniformity of electrodeposition.

Finally, there is another important factor, which is the treatment and preparation of the electrode surface, which is the key to affecting the thickness of copper deposition and coating. For example, before copper electrolysis, it is necessary to ensure the surface smoothness of the PCB, the removal of adsorbents and other substances, the removal of tin (Sn) compounds on the surface, and further treatment to ensure that the PCB surface reaches the ideal surface state before electrodeposition. Otherwise, bubbles or uneven copper deposition may occur during the electrodeposition process.

There are many factors influencing the thickness of copper plating on printed circuit board, but they mainly include additives in the electrolyte, electrode design, and electrode surface treatment. At the same time, these factors have an important impact on the performance, quality, and reliability of PCBs. Therefore, in the preparation process of PCB, all these factors should be fully considered and scientifically and reasonably controlled to ensure the optimal control of copper plating thickness on the printed circuit board.