Laser processes in photovoltaic manufacturing 1. Trepanning drilling of holes in multi-crystalline silicon with q-switched disc laser ROFIN StarDisc. With smaller diameters of 200 to 500 µm this process is used for manufacturing MWT (metal wrap through) cells. 2. Percussion drilling of 3.500 holes / sec with StarDisc. Used for EWT (emitter wrap through) cell production. 3. Laser scribing and breaking of silicon wafers. Fast cutting of mono and polycrystalline silicon wafers can be conducted with very high precision and low heat input by using the same ablation process as for edge isolation and drilling.