The pores produced by the circuit board welding process, which is what we often say, the reflow soldering and wave soldering of the circuit board sometimes produce pores, pcb manufacturers here to share how to prevent the pores caused by circuit board soldering.

　　SMT production line

　　1, PCB and components baking

　　Bake PCBs and components that have been exposed to the air for a long time to prevent moisture.

　　2, the control of solder paste

　　 Solder paste contains water and is prone to pores and solder beads. First select a good quality solder paste. The temperature recovery and stirring of the solder paste are strictly performed according to the operation. The time that the solder paste is exposed to the air is as short as possible. After the solder paste is printed, reflow soldering should be carried out in time.

　　3. Workshop humidity control

　　 The humidity in the workshop is monitored in a planned way, and it is controlled between 40-60%.

　　4. Set a reasonable furnace temperature curve

　　 Test the furnace temperature twice a day, optimize the furnace temperature curve, and the heating rate should not be too fast.

　　 5. Control flux spraying

　　 During wave soldering, the spraying amount of flux should not be too much, and the spraying should be reasonable.

　　 6. Optimize furnace temperature curve

　　 The temperature of the preheating zone must meet the requirements, not too low, so that the flux can be fully volatilized, and the speed of passing the furnace cannot be too fast.

There may be many factors that affect the circuit board soldering bubbles, which can be analyzed from the aspects of PCB design, PCB humidity, furnace temperature, flux (spray size), chain speed, tin wave height, solder composition, etc. It needs to be debugged many times. It is possible to get a better process.