Why is there a tin ball?

1. Before printing,The solder paste is not fully warmed upUnfreeze and stir evenly.
2. After printingNot reflux for too long, solvent volatile,Paste becomes dry powder and drops to ink.
3. The printing is too thick, and the excess Solder Paste overflows after the component is pressed down.
4. High temperature during reflux welding, resulting in boiling water.
5. The patch pressure is too high. The lower pressure causes the paste to collapse to the ink.
6. The environment humidity is too high, and the paste will collapse to the ink after printing.
7. the opening shape of the pad is poor. No anti-tin beads are processed. .
8. poor Solder Paste activity , dry fast, or there are too many small particles of TiN POWDER .
9. the solder paste has been exposed in the oxidation environment for too long to absorb moisture in the air.
10. insufficient preheating and uneven heating.
11. Print offset to paste some solder paste on the PCB.
12. the scraper speed is too fast, leading to poor side collapse and tin balls generated after reflux.
note: the diameter of tin balls must be less than 0.13mm, or 600 mm² contains less than 5.