PCBA Tech - Reasons for the thickness of the electroplated film in PCBA processing is too thin and thick

Reasons for the thickness of the electroplated film in PCBA processing is too thin and thick

During PCBA processing, there may be a plating film layer, but if the thickness of the plating film layer does not exceed the standard thickness, it will not affect the use of the PCB board, but if it is too thin and thick, it may affect the soldering and welding of the PCBA board. Follow-up use. Then we will probably understand the reasons for the thick and thin electroplating film.

PCBA electroplating 1. The essence of the electroplating process is the process of reducing metal ions to metal crystals to form the coating. Therefore, the factors that affect the thickness of the coating are also the factors that affect the electrocrystallization process. From an electrochemical point of view, Faraday's law and electrode potential equation can be used as the basis for analyzing the factors affecting the thickness of the coating;
2. First of all, according to Faraday’s law, the amount of metal ions reduced to metal in the electrode is proportional to the amount of electricity. Therefore, current is an important factor affecting the thickness of the coating. Specific to the electroplating process, it is the effect of current density, which is high. The deposition rate of the coating is also high;

3. Of course, the plating time is also an important factor in determining the thickness of the coating. Obviously, in general, time and current density are directly proportional to the thickness of the coating;
4. In addition to current density and time, temperature, main salt concentration, anode area, bath stirring, etc., will all affect the thickness of the coating, but after analysis, temperature, main salt concentration, anode area, and bath stirring are all affected by How the current density affects the thickness of the coating;
5. The current density can be increased when the temperature is high, and the current density can also be increased by stirring the plating solution, which is beneficial to increase the thickness of the coating. It is important to maintain the anode area to maintain the normal current distribution and the normal dissolution of the anode, which has a direct effect on the thickness of the coating. The main salt concentration can only be allowed to work within the normal current density range if the main salt concentration is in the normal range.

These are the reasons for the thicker and thinner electroplating film. You can refer to it when designing and processing PCBA to avoid unnecessary losses.