Georg Hoppe

Fraunhofer ISE

Friday, May 23, 2025, 14:00

Fraunhofer ISE | T-Gebäude | T-6.01

Solar energy plays a central role in sustainable energy supply. To meet the growing demand for renewable energy, manufacturing capacity needs to be expanded into the terawatt range. In solar cell manufacturing, laser processing is an established standard method. In order to contribute to lower electricity generation costs, both the laser system costs and throughput must be optimized.

To achieve this, a novel on-the-fly laser processing concept is presented, in which solar cells are transported on a simple conveyor belt and processed while still in motion. Combined with a high-speed scanner, throughput can be increased more than sevenfold from 1,900 wafers per hour (wph) to 13,400 wph. However, speed fluctuations on the conveyor belt limit the precision of laser processing.

To solve this, a measurement and control device has been developed, which measures the speed of the workpiece and adjusts the laser beam position in real time to compensate for the speed variations, enabling more accurate structures. The aim of this work is to achieve high precision through the use of sensors and control technology rather than high mechanical precision. Due to the sampling delay of the tracking hardware, the control bandwidth is limited. To compensate for this, a signal prediction method using Kalman filtering is introduced, which offsets the sampling delay and improves estimation accuracy.

The defense will be held in German.