Product Code: ICAL06_M805

SHADOW®- New Applications in Electronics and Micromechanics
Authors:
Alexander Olowinsky, Fraunhofer - ILT; Aachen Germany
Arnold Gillner, Fraunhofer ILT; Aachen Germany
Jens Gedicke, Fraunhofer ILT; Aachen Germany
Kilian Klages, Fraunhofer ILT; Aachen Germany
Reinhart Poprawe, Fraunhofer ILT; Aachen Germany
Presented at ICALEO 2006

The laser beam spot welding is a well known industrial process for contacting in electronics industry. The spot welding suffers the risk of weld splatters and melt ejections especially in welding of copper materials. The SHADOW® process with its advantages of low distortion and minimum contamination has been reported in previous presentations. This paper presents a new approach replacing a point by small circles. The reduction of the diameter of a circular weld seam to the dimensions of the focal diameter leads to lower stresses and therefore lower distortion. Additionally the required pulse energy could be reduced. In conclusion the new process allows a good control of the weld depth depending on the power of the laser pulse. The paper will conclude with two examples in the field of electronics and watch making will illustrate the capabilities of the process and the industrial application of SHADOW® welding for mass production: Laser beam welding has been chosen as joining technology for welding heatsinks (HS) to leadframes (LF). The welds are accomplished as circular SHADOW®-welds using a galvoscanner. The high welding speed and the low energy input reduces the stress and distortion in the components.