Product Code: ICAL07_M601

TWIST - A New Method for the Micro-Welding of Polymers with Fibre Lasers
Authors:
Alexander Olowinsky, Fraunhofer Institute for Laser Technology; Aachen Germany
Andrei Lucian Boglea, Fraunhofer Institute for Laser Technology; Aachen Germany
Arnold Gilllner, Fraunhofer Institute for Laser Technology; Aachen Germany
Presented at ICALEO 2007

The interest for performing laser micro-welds for joining polymeric materials was significantly amplified by the advances in the micro-injection molding and hot embossing technologies which made possible the realization of low cost complex polymeric Microsystems. The complexity and reduced dimension of the joining area of these polymeric devices require innovative approaches for their complete construction. One possible solution is given by the transmission laser beam welding which has been already adopted successfully for a wide range of industrial applications, however, with some limitations in the minimum weld seam width and maximum processing speed. Aiming to overcome these limitations, the purpose of the present research is to evaluate the applicability of fibre lasers for the transmission welding of thermoplastics and based on their ability to be focused into small spots to develop a new technique for performing narrow weld seams with an increased processing speed. Consequently, a new maskless method called TWIST Transmission Welding by an Incremental Scanning Technique was developed for the laser micro-welding of polymers. TWIST experimental results for welding of Polypropylene and PMMA where weld seams width down to 100 µm and even below were achieved with a processing speed up to 18 m/min are presented and discussed