Screen printing

In screen printing, the mesh and buses of silver are printed on the front; furthermore, the buses of silver are printed on the back. Subsequently, aluminium paste is dispensed over the whole surface of the back for passivation and surface reflection.

Screen printing is one of the most critical processes to maintain high yield. Solar wafers are becoming thinner and larger, so careful printing is required to maintain a lower breakage rate. On the other hand, high throughput at the printing stage improves the throughput of the whole cell production line.

In this process it is essential to detect cell breakage or failures in printing immediately, so defective cells can be removed and quality improved. High printing quality requires accurate cell positioning during handling.