European cost action 531: Basic research on lead-free soldering

The Restriction of the use of certain Hazardous Substances in Electrical and Electronic Equipment became European law on July 1, 2006. According to this directive, lead should be eliminated from electrical and electronic equipment (besides other materials like mercury, cadmium, chromium (VI), and polybrominated biphenyls and polybrominated diphenylether), and with that also from the traditional solder materials. In addition to being able to conform to the RoHS directive, another reason why the industry was in need of new solders was the increased demands on modern solder materials: e.g. the electronic components are becoming ever smaller, and the solders have to sustain higher temperatures and more severe temperature fluctuations; the surface to bulk ratio changes, which leads to different microstructural behavior; new technologies like the flip chip method require solder ball sizes of 50-100 μm and smaller. Therefore, the last 15 to 20 years saw many efforts around the world to develop new lead-free solder materials. Various research teams throughout the world have been working on different aspects of "lead-free soldering", but at the beginning there were hardly any organized opportunities for a regular information exchange between them. In this situation, the structure of the European COST program offered a good opportunity to better coordinate basic research on this subject. Therefore, two scientists from the University of Vienna, Herbert Ipser and Adolf Mikula, initiated a research action on "Lead-free Solder Materials" within this COST program: COST Action 531. It started officially in March 2002 with the first meeting of the Management Committee in Brussels and it ends in the first half of 2007. It was clear from the beginning that such a COST-based network would provide a sound base for information exchange as well as for identification of opportunities for collaboration. It would also contribute EUROPEAN COST ACTION 531: BASIC RESEARCH ON LEAD-FREE SOLDERING