Beam Shaping For Micro Via Drilling, Dicing Micro Trimming

摘要

The design of beam shaping optics for laser micromachining applications must be optimized for maximum beam efficiency and quality across a given image plane. The need for faster UV and IR laser processes for drilling microvias, dicing and trimming wafers led to our utilization of hybrid optics and shaping methods, where standard refractive and computer generated holographic and diffractive optics could be meshed together to construct a system that would out perform optical beam delivery technology occupying the marketplace today. This paper covers the beam shaping technology developed, the computer modeled beam shaping and propagation plots over the length of a industry standard system as well as a comparison of the computer model images to the actual results from testing, using profilometer techniques. The later portions of the paper cover the final image formed at the target plane, including uniformity, various shapes, optical efficiency and an example of image stability while using a step and scan technique through a standard galvanometer system over a 25 mm x 25 mm field size. Specific performance details will be shared with regards to total system performance as well. A further section covers a brief overview of materials processing attributes including several specific material cross sections and scanning electron images as well as various errors created by misalignment of specific elements of the shaper with respect to the beam delivery system.