Solutions to common problems in screen printing of solar cells

1. How does printing speed affect printing results?

Increasing the printing speed will make the filling effect of the slurry on the mesh worse. It will also make the printing flatness worse and easily cause gourd-shaped grid lines. Within a certain range, increasing the printing speed can increase the height of the grid lines and reduce their width.

2. What is the impact of slurry viscosity on printing results?

If the viscosity of the slurry is too low, the printed graphics will be easily enlarged, resulting in bubbles and burrs;

If the viscosity of the slurry is too high, it will lead to poor ink permeability, orange peel and small holes.

Within the permissible range, the lower the viscosity of the slurry, the better.

3. What is the relationship between pressure and spacing?

The greater the pressure, the greater the gap. Because when the pressure is high, the contact area between the scraper and the screen will bulge more. If the gap is small, the pressure on the silicon wafer will become greater, which is easy to cause fragmentation. The two parameters cannot be changed separately, otherwise it will affect the printing quality and increase the fragmentation rate.

4.What is the role of each temperature zone during the sintering process?

Room temperature ~ 300℃: Volatilization of solvent.

300℃~500℃, organic resin is discharged and oxygen is needed.

Above 400°C, glass softens.

Above 600°C, the glass reacts with the anti-reflection layer to achieve conductivity.

5. What should I do if aluminum beads appear?

If the printing is too thick, adjust the parameters, reduce the distance between the plates, and increase the printing pressure;

If the pile surface is too large, remind the pile maker to improve the process;

If the slurry does not match, improve the slurry.