Baking the PCB and Components which exposed in the air for a long time to remove moisture.
2. Control Solder Paste
Solder paste contains water and can easily produce stomatas and tin beads.First of all we should use good quality solder paste. Solder paste backing to warm and stirring are strictly carried out according to operation. Time of solder paste exposing in the air should be as short as possible. After printing the solder paste,PCBA boards need reflow soldering at time.
3. Control Workshop Humidity
Systematically monitor the humidity of workshop and control between 40-60%.
4. Set Reasonable Furnace Temperature Curve
Test the furnace temperature twice a day, optimize the furnace temperature curve, the heating rate can not be too fast.
During wave soldering, the spray quantity of the flux can not be oversprayed and it must be reasonable.
6.Optimize the Furnace Temperature Curve
Preheat zone temperature need to meet the requirements, not too low, so that flux can be fully volatile. In addition, the speed of boards passing the furnace can not be too fast.
There are many factors causing the PCBA soldering blister. We should analyzed these factors from the PCB design, PCB humidity, temperature, flux (spray size), chain speed, tin, wave height, solder composition, etc. Then we could get a better process after many debugging.
FASTPCBA is an OEM PCB&PCBA manufacturer with rich experience. We strictly control above six main factors to avoid blister and provide clients high quality boards.