1. The first is the quality of the steel mesh: the thickness of the steel mesh and the opening size determine the printing quality of the solder paste. Too much solder paste will produce bridging, too little solder paste will produce insufficient solder paste or virtual welding. The opening shape of the steel mesh and whether the opening wall is smooth also affect the release quality.
2, followed by solder paste quality: solder paste viscosity, printing rolling, service life at room temperature will affect the printing quality.
3. Printing process parameters: there is a certain restrictive relationship between the speed of the scraper, the pressure, the Angle of the scraper and the plate and the viscosity of the solder paste. Therefore, only by correctly controlling these parameters can we ensure the printing quality of solder paste.
4. Equipment accuracy: When printing high-density and narrow spacing products, the printing accuracy and repeat printing accuracy of the printing press will also have a certain impact.
5. Ambient temperature, humidity, and environmental hygiene: too high ambient temperature will reduce the viscosity of the solder paste, when the humidity is too high, the solder paste will absorb moisture in the air, the humidity will accelerate the evaporation of the solvent in the solder paste, and the dust in the environment will cause the solder joint to produce pinholes and other defects.
It can be seen from the above introduction that there are many factors affecting the quality of printing, and the printing solder paste is a dynamic process. Therefore, the establishment of a complete set of printing process control documents is very necessary, the selection of the correct solder paste, steel mesh, combined with the most suitable printing machine parameter setting, can make the entire printing process more stable, controllable, standardized.