There may be some reasons why the circuit plate surface plate is not tin.
Design reasons of the engineering data produced. Each PCB circuit board is designed to meet the needs of customers, so the work of the engineering department is very important, once there is a problem, it will cause great trouble to the future production behind.
The construction personnel operated wrongly. When the staff in the computer operation, they need to adjust the power, temperature and welding methods. If the operation is wrong, there will be problems.
There is a problem with the board card storage mode. According to the different surface treatment of the board card, the storage methods are also different, for example, some boards are OSP, immersion gold, tin spraying, etc., the storage period of the tin spray circuit board is generally about a week, the surface treatment process of the OSP circuit board is stored for 3 months, if it is immersion gold multi-layer circuit board can be preserved for a long time.
