There are many factors that affect the quality of SMT printing, but one of the important factors is the scraper of SMT printer.

1. Speed of SMT press scraper
There is a great relationship between the speed of the scraper and the viscosity of the solder paste. The slower the speed of the scraper, the greater the viscosity of the solder paste. Similarly, if the speed of the scraper is very fast, the viscosity of the solder paste will be smaller. The adjustment of this parameter should refer to the composition of solder paste, the density of PCB components and the minimum component size.

2. Pressure of blade in SMT press
The pressure of the squeegee of the solder paste printing machine has a great influence on the printing. Too much pressure will cause the paste to print very thin. The ideal speed and pressure of the scraper should just scrape the solder paste from the steel plate surface. There is a certain conversion relationship between the speed of the scraper and the pressure, that is, reducing the speed of the scraper is equal to increasing the pressure of the scraper, and increasing the speed of the scraper is equal to reducing the pressure of the scraper.

3. Width of blade in SMT press
If the scraper of solder paste printing machine is too wide relative to PCB, it needs more pressure and more solder paste to participate in its work, which will cause the waste of solder paste. Generally, the width of the scraper is the length of PCB (printing direction) plus about 50 mm, and the scraper head should be ensured to fall on the metal template.