Among the printed circuit board suppliers, SMT carries out mass production. Firstly, the solder paste is required to be smoothly and continuously transferred to the PCB pad through the stencil or dispenser printing.If the printing quality of solder paste is not good, it will block the hole in the steel stencil, which causes the pcb printing production to not work properly, thus affecting the production delivery period.
What are the reasons for the volatilization of solder paste performance?
The reason is that there is a lack of a printing aid or insufficient amount in the PCB solder paste. In addition, the shape of the alloy powder is poor, and the particle size distribution does not meet the requirements, which may cause a decrease in printing performance.
The easiest way to test is to use a QFP stencil with a center-to-center distance of 0.5mm or 0.63mm to print 30 to 50 PCBs. Observe whether the holes on the stencil are blocked, and whether there is excess solder paste on the reverse side of the stencil. And then observe whether the solder paste pattern on the PCB is uniform and there is no defect. If there is no such abnormal phenomenon, it is generally considered that the solder paste printability is good.
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