Product Code: ICA12_M504

Diagnostic and Simulation of ps-Laser Glass Cutting - Invited Presentation - 40 Minutes
Authors:
Urs Eppelt, Fraunhofer Institute for Laser Technology, Nonlinear Dynamics of Laser Processing, RWTH Aachen Univ.; Aachen Germany
Simone Russ, TRUMPF Laser GmbH + Co. KG; Schramberg Germany
Claudia Hartmann, Fraunhofer Institute for Laser Technology; Aachen Germany
Mingying Sun, Fraunhofer Institute for Laser Technology; -
Christof Siebert, TRUMPF Laser- und Systemtechnik GmbH; Ditzingen Germany
Wolfgang Schulz, Fraunhofer Institute for Laser Technology, Nonlinear Dynamics of Laser Processing, RWTH Aachen Univ.; Aachen Germany
Presented at ICALEO 2012

Consumers ask for thinner and lighter mobile devices such as smart phones and tablet computers. The biggest potential for a reduction of weight and thickness is being found in OLED or LCD displays. By the use of thinner glass conventional manufacturing methods such as mechanical scribing and breaking are much more difficult to apply: cracks and chipping result in poor edge strength, grinding is needed as a post-processing step. In particular chemically hardened glass that is designed as a scratch resistant cover protecting the display is very hard to cut with conventional methods. Laser processing could be a promising solution, offering high-quality cutting edges but in turn requiring a deep understanding of ultra-short-pulsed laser ablation of dielectrics, which sometimes can give surprising results, such as unexpected rear side processing, unpredictable ablation rates or breaking strengths, etc. In our cooperation between the laser manufacturer TRUMPF and the research institute Fraunhofer ILT we have tackled the task of modeling & simulation in parallel with experimental diagnostic and industry-oriented process development. The task involves describing nonlinear absorption of photons in dielectrics, beam propagation in nonlinear media and dealing with (thermo-)mechanics of brittle material in order to derive modification strategies to current laser technologies, guiding modeling with appropriate measurements and evaluation of those technologies in industry-oriented laser manufacturing systems.