In the proofing process, soldering tin is a very important step.Insufficient solder joints will have a very serious impact on the performanceand appearance of circuit boards. Therefore, when proofing, try to avoid thesituation that the solder paste is not full.

Why the solder paste is not full in SMT fast proofing?

1. If the flux in the solder paste is not active enough, it will not beable to better remove the oxide on the PCB pad, which will have a certainimpact on the tin.

2. During SMT rapid proofing, the expansion rate of soldering flux isvery high, and it is easy to cause voids.

3. When soldering solder paste, if the wetting performance of flux doesnot meet the standard, the solder paste will not be full when soldering.

4. If there is a serious oxidation phenomenon in PCB pads or SMD solderjoints, it will affect the tin plating effect.

5. If the solder paste is not fully stirred and the flux and solderpowder are not fully fused before use, the solder paste of some solder jointswill be not full.

6. If the amount of solder paste used during soldering is too small, thesoldering will not be full enough, resulting in vacancy.