The printing work station is the first and most important work station in the process of SMT, the printing quality determines the quality of SMT to a great extent, so it is very important to understand the basic operation principle of printing machine.
Printing machine is mainly divided into three structures
1. Vision positioning system
It is divided into visual recognition MARK and CAMERA 2D inspection. The PCB CAMERA lens can check the coverage of solder paste. But 3D inspections require a corresponding matching function of machine.
2. Wipe System
It is divided into wet wipe, vacuum cleaning and dry cleaning. When the wet wipe paper and plate contact, we should control the amount of solvent. There can be no better situation than the wipe paper is just used up when wiping is completed.
3. Solder paste filling system
The system consists of scraper and steel, solder paste is rolling on the steel sheet. It will cause poor printing if the solder paste doesn’t roll. The pressure of squeegee generally shouldn’t be set too high, or will cause the blade wrap.
We can complete the final print with these three steps.