doi: 10.3850/978-981-11-0749-8_741
A New Laser Drilling Method for Producing High Aspect Ratio Micro Through Holes
Vahid Nasrollahi, Pavel Penchev and Stefan Dimov
School of Mechanical Engineering, University of Birmingham,UK
Abstract
The most important requirements in the laser drilling of high aspect ratio micro holes are the throughput and quality, i.e. geometrical accuracy and minimum HAZ. To address these requirements, the paper presents a new laser drilling method that can increase the achievable aspect ratios by a factor of two at least. This method is based on a simple concept of drilling through holes from two sides. A pilot laser micro processing setup was developed to implement this method that integrates a rotary stage, a specialized modular workpiece holding device and a software tool to account for any errors resulting from the use of rotary re-positioning movements. An experimental validation was carried out to assess the alignment accuracy of through holes produced with the proposed method and also the improvements that it offers in terms of quality and throughput, in comparison to the conventional one-side laser machining technique. The results show that by using the proposed two-sides’ drilling method the alignment error can be in an acceptable range while there are substantial improvements in terms of processing time and quality of the produced through holes.
Keywords: Laser micro drilling, High aspect ratio holes.
