Fast throughputs in solar cells with the help of the disk laser

Prenovatec disk lasers are Q-switched and incorporate the best possible beam quality (TEM00). The laser systems have a very high peak pulse power which is gained by raising a pulse set point. A galvo deflection head allows for a very rapid and precise positioning of the individual pulses. They are therefore suited specifically for material processing of solar cells. Therefore, the disk laser guarantees for minimal heat affected zones into the material with the corresponding pulse length and in cutting or structuring very little material melt out occurring on the cutting edges. The silicon itself is virtually not stressed or weakened in the process.

No matter if cutting, scribing or drilling takes place each of these non contact and mechanically minimal load processing methods occurs free from wear and the material removal is done in several passes without using assist gases. This enhances the efficiency and reduces the negative influences of the basic material.

In industrial applications approx. 3,000 holes per second can be percussion drilled. In doing so, holes approx. 50 µm in diameter are drilled into the wafer. These boreholes are for having the cells plated through. Cutting and isolating of wafers are also areas of application in which the disk laser excels.

The advantages of the disk laser in micro cutting at a glance:

•   Reduced burr formation and melt out
•   Minimal heat affected zones HAZ
•   High pulse to pulse stability
•   Virtually no micro cracks
•   Low operating costs

300 µm Silicon wafer after laser cutting

Laser pulse in silicon during percussions drilling

Hole in 200 µm silicon