HIGH SPEED LASER SCANNING SYSTEM FOR SILICON SOLAR CELL FABRICATION

摘要

A laser scanning apparatus that uses a polygonal mirror and a beam shaper for laser drilling of holes in one or more layers during solar cell fabrication is provided. The apparatus may be used to laser drill holes in a back side passivation layer of a solar cell during back electrical contact formation. The apparatus includes the use of a polygonal mirror to improve the speed of the back electrical formation of a solar cell. The apparatus may also include the use of a beam shaper to tune the profile of the beam to prevent damage to the underlying solar cell substrate during laser drilling operations. A laser scanning module is provided which controls the speed and timing of linear movement of substrates and the operation of the laser scanning apparatus in a closed loop manner for laser drilling of material layers disposed on the substrates.