Driven by ecological awareness and short-running fossil combustibles, photovoltaic is gaining ever increasing importance for the production of energy. In order to achieve a reduction of manufacturing costs and increase the efficiency in parallel, e.g. the cell design of solar cells is continuously developed and improved. One approach is the so-called Back-Contact Cell Design. With it, the efficiency of solar cells can be significantly improved by a redesign of the front-side contacts that are covering considerable portions of the active area. The basic idea is to shift as much contact area as possible towards the back side of the cell. This is achieved by drilling holes of different size using a laser. Employing the EWT (emitter wrap-through) concept, electrical contacts are being transferred from the front side towards the rear side. One of the obstacles for the industrial use of the EWT-technology so far was the relatively low throughput with high investment costs.

To stay abreast of changes, 3D-Micromac AG has further developed and advanced the established microDrill-EWT systems and with immediate effect offers an improved laser and optic concept in their machines. In EWT technology, hole diameters amount to 30 to 80 µm and using a solid state laser with percussion drilling, up to 15,000 holes can be generated per second. In the process, drilled holes are machined free of cracks, at minimum heat affects, and without debris. This dedicated system can achieve a cycle time of only 2.5 seconds per cell.

On the basis of long standing experience in the range of laser micromachining, the development of these highly efficient and stable machine concepts could be established. These concepts distinguish themselves both by comparatively low investment costs and a significantly lower total cost of ownership.