Product Code: ICA10_M402

Enhancing Process Stability in Infrared Laser Micro Welding of Copper using Frequency Converted Short Prepulses
Authors:
Anas Moalem, Laser Zentrum Hannover e.V.; Hannover Germany
Philipp von Witzendorff, Laser Zentrum Hannover e.V.; Hannover Germany
Maik Frede, neoLASE GmbH; Hannover Germany
Rainer Kling, Laser Zentrum Hannover e.V.; Hannover Germany
Presented at ICALEO 2010

We present an approach in which the advantages of two laser concepts are combined in a cost effective joint process: While IR spot welding laser sources are available with high mean powers (up to 500W), 532nm radiation provides a more reliable, yet limited heat source for copper processing.
A significant improvement in process reliability of copper welding is observed, when using a single, 532nm nanosecond laser pulse at the beginning of an IR laser spot weld process. The quality is analysed by determining the variation of the weld spot diameter. The results are discussed and indicate, that the 532nm short pulse is normalising the initial conditions, in particular the absorptivity, for the IR welding process.
Spot welding requires low repetition rates in the order of 10Hz. Therefore, the demonstrated investigation is carried out with a prototype of a small and robust short pulsed laser module.