OSP process of PCB board

1. In addition to the oil

The effect of oil removal directly affects the film forming quality. Poor oil removal, the film thickness is not uniform. On the one hand, the concentration can be controlled within the process range by analyzing the solution. On the other hand, also should often check whether the effect of oil removal is good, if the effect of oil removal is not good, it should be replaced in time in addition to oil.

2. Micro erosion

The purpose of microetching is to form a rough copper surface for easy film formation. The thickness of micro-etching directly affects the film forming rate, so it is very important to keep the stability of micro-etching thickness to form a stable film thickness. Generally, it is appropriate to control the microetching thickness at 1.0-1.5um. Before each shift, the micro-erosion rate can be measured, and the micro-erosion time can be determined according to the micro-erosion rate.

3. Into a film

DI water should be used for washing before film formation to prevent contamination of film forming liquid. DI water should also be used for washing after film formation, and the PH value should be controlled between 4.0 and 7.0 to prevent the film from being polluted and damaged. The key of OSP process is to control the thickness of anti-oxidation film. The film is too thin and has poor thermal impact ability. In reflow welding, the film can not withstand high temperature (190-200°C), which ultimately affects the welding performance. In electronic assembly line, the film can not be well dissolved by flux, which affects the welding performance. The general control film thickness is more appropriate between 0.2-0.5um.