Micro-scale mechanical properties of fine feature flip chip with lead free solders

January 2008 will see the implementation of the Waste Electrical and Electronic Equipment Directive in the European Community and initiatives in Japan and strong lobbying in the USA will see a requisite, substantial shift in joining systems used for electronics, electronic components and fine mechanical devices. There has been a number of worldwide efforts to seek replacement lead-free solders, which have included activities to identify candidate alloy systems, characterize and optimize the processing of these materials and understanding the properties of such materials with respect to toxicity, mechanical integrity and long term reliability. In parallel with these changes in materials, there is still the evolution towards finer feature, functionally denser and increasingly miniaturized devices and systems.