In the LCO (Laser Contact Opening) process the protection of the sensitive front side of the cell is especially important. Scratching and contaminants impair the solar cell, sometimes beyond the limits of what is considered a good part, or they increase the Light Induced Degradation (LID). 3D-Micromac’s microCELLTM OTF utilizes ultrasonic sonotrodes for wafer handling for contactless transport through the system. With that, any imprints, microfissures and breakages caused by grippers, handling equipment or suction on the processing tables are a thing of the past.
The processing of the cells takes place “on the fly”. With that the time-consuming handling and positioning of the cells inside the machine becomes obsolete. Instead, the wafers are transported underneath the laser source on a conveyor. No stops are required to reposition the solar cells. The relative movements of the cells are automatically compensated by integrated optics during the laser structuring process. This optimally exploits the full capacity of the laser, enabling much higher throughput. With gross throughputs of 3,600 cells per hour, microCELLTM OTF lies roughly 10 percent higher than typical rates for comparable systems in the industry.