How to improve the problem of porosity in PCBA processing and welding

When a pcba manufacturer board is soldered, there will be pores, which are commonly called bubbles. Porosity usually occurs during reflow soldering and wave soldering. A large number of pores cause damage to the PCB board. Here are several methods to prevent pores from PCBA processing and soldering.
1. Bake
Bake PCBs and components that have been exposed to the air for a long time to prevent moistness.
2. Control of solder paste
The solder paste contains moisture and is prone to pores and tin beads. First, select a good quality solder paste. The temperature and stirring of the solder paste are strictly carried out 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 needs to be carried out in time.
3. Workshop humidity control
Monitor the humidity in the workshop in a planned way and control it 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. 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 needs to 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 welding bubbles in PCBA processing, PCB design, furnace temperature, tin wave height, PCB humidity, chain speed, solder composition, flux (spray size), etc. are analyzed. It is possible to get a better process by going through debugging.
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