Process and System Technologies for Laserbeam Micro Welding
- Prof. Dr.-Ing. Dr. h.c. M . Geiger
- Prof. Dr.-Ing. K. Feldmann
Since the importance of microelectrical as well as micromechanical components as parts of industrial products is still increasing, suitable joining techniques must be available. Especially for metallic components laser micro welding offers interesting properties, e.g. high temperature strength of the joints, small-dimension capability and applicability of a broad spectrum of materials. To fulfil the high quality demands the entire processing chain has to be optimized. Within this dissertation the special example of contacting leads of housed electronic components with the tracks of the printed circuit is investigated in detail. The aim is a comprehensive provision of system as well as process related knowledge to perform controlled joining processes applying pulsed laser power. Based on FE-simulations of the temperature fields and discussion of the coupled effects of absorption and oxidation new devices and working strategies were developped. In detail, there are a module for touch-down-force related coplanarity check, a device for pulse shaping, a control for turning mirrors, a backreflection diagnosis integrated in the welding head as well as an imaging ratio-pyrometer. Applying this knowledge technological investigations were performed to join comb shaped specimen with the copper tracks on different typical substrates of the electronics production. Thereby the demands as well as the potential of this special process were derived.