There are a variety of methods for reflowing a circuit board, but they all rely on a single principle: heat up the solder paste (a mixture of flux and solder) until the flux burns off and the ...

2 Solder balling occurs if the solder paste spatters (small explosive) or the solder paste slump and the flux spreads. 1- 1.5°C/second ramping rate is recommended to minimize those defects.