PCB News - Circuit board factory: What is the reason why the tin on SMT chip processing is not round

Circuit board factory: What is the reason why the tin on SMT chip processing is not round

In the circuit board SMT chip processing, electric welding soldering tin is a key stage, which is related to the performance indicators of the circuit board and the beautiful appearance of the appearance design. In the specific manufacturing, due to some reasons, the tinting condition will be poor, such as The general spot soldering tin is not round, which will immediately jeopardize the quality of SMTSMT patch processing. The editor of Shenzhen Zhongke Circuit Board Factory will give you a detailed introduction to the reason why the spot soldering of the SMT chip processing of the circuit board factory is not round.

The key reason why the tin is not round in the spot welding of SMT chip processing in the circuit board factory:

1. Insufficient amount of solder paste at the spot welding position, resulting in a non-round tin on the spot, and a gap;

2. The expansion rate of the flux in the flux paste is too high, and cracks are very easy to appear;

3. The wetting performance of the flux in the flux paste is not very good, and it should not exceed the very good soldering regulations;

4. The PCB circuit board pad or SMD welding position has serious air oxidation, which will harm the actual effect of tinning;

5. The specificity of the flux in the flux paste is insufficient, and it is not possible to remove the air oxidation chemicals from the PCB circuit board pads or SMD welding positions;

6. If there is a part of the spot welding that the tin is not round, the reason will be that the red glue cannot be sufficiently mixed before application, and the flux and tin powder cannot be sufficiently combined;

7. The heating time is too long or the heating temperature is too high when passing through the reflow oven, which causes the specificity of the flux in the flux paste to be invalid.