The industrial maturity of ultrashort pulsed lasers has triggered the development of a plethora of material processing strategies. Recently, the combination of these remarkable temporal pulse properties with advanced structured light concepts has led to breakthroughs in the development of laser application methods, which will now gradually reach industrial environments. We review the efficient generation of customized focus distributions from the near-infrared down to the deep ultraviolet, e.g., based on nondiffracting beams and three-dimensional-beam splitters, and demonstrate their impact for micro- and nanomachining of a wide range of materials. In the beam shaping concepts presented, special attention was paid to suitability for both high energies and high powers.
Industrial ultrafast lasers such as TRUMPF’s TruMicro Series are indispensable tools in many precision machining processes. Large 24/7 applications range from machining of sapphire or glass to ceramics, polymers, and metals in industries from the automotive sector to consumer electronics. In typical installations such pico- and femtosecond lasers currently operate at average power levels up to 150 W, often with nonlinear frequency conversion to the visible or UV. Based on the advanced amplifier technology pioneered by AMPHOS we introduce our new hybrid fiber–InnoSlab amplifier generation TruMicro Series 6000, capable of producing the highest average power at utmost flexibility and reliability.
Drilling processes by ultrashort laser pulses meet the demand for high-end applications in the display and electronics industry. Especially the manufacturing of microstructures requires highest accuracy and minimal damage of the workpiece. A variety of applications, like the production of blind holes in multi-layer stacks or through holes in metal foils demand specific processing constraints. For example, applications like fine metal mask (FMM) require exact rectangular hole shape as well as tailored taper angles and minimized residual particle contamination. In large scale production environments, the total throughput also becomes decisive. To achieve these challenging needs, the spatial and temporal energy deposition are crucial parameters. In this context, beam shaping offers unique potential for controlling and scaling these micromachining processes. To pursue this approach, we present a novel adaptive beam shaping setup combined with a flexible TRUMPF TruMicro femtosecond laser. Our investigations target percussion drilling applications with various intensity distributions. We discuss methods for process optimization by controlling the spatial and temporal energy deposition. This enables us to analyze the correlation between micromachining results and the tailored absorption. Our investigations aim on shaping several beam properties like phase, amplitude, polarization and propagation characteristics using a liquid-crystal-on-silicon-spatial-light-modulator (LCOS-SLM). By correcting aberrations with a closed-loop setup, we generate robust process specific top-hat like intensity distributions.
Ultrafast micromachining has found broad applications in a variety of scientific and industrial fields. Different materials and competing customer requirements (surface quality vs. processing speed vs. surface structure etc.) call for parameter studies prior to volume production as well as pulse parameter flexibility during operation. Up to now, often a nonoptimized point of operation for either best speed or quality had to be chosen due to limited laser source flexibility. TruMicro Series 2000 introduces true inter- and intra-process flexibility for pulse parameters such as pulse duration, pulse energy and pulse spacing up to GHz bursts. As of now, switching the pulse duration is possible within 300 fs and 20 ps in less than 600 ms without affecting beam pointing or energy stability. Therefore, intra-process pulse parameter changes allow maximization of the ablation-volume efficiency in one step and surface-quality optimization in a second, finalizing step. Additionally, inter-process pulse parameter changes enable material changes in between workpieces. In this contribution, we show how this novel flexibility for the first time leads to comprehensive and automated parameter studies that allow for next-generation process understanding and the clear selection of enhanced points of operation. We demonstrate how ablation of various materials can be increased by employing bursts on a nanosecond timescale where a simple increase in fluence would result in cone-like protrusions. Choosing the suitable timescale for energy deposition can either maximize energy efficiency of ablation or optimize ablation quality. With the TruMicro Series 2000, both optima can be combined to one efficient, high-quality process.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print format on
SPIE.org.