The integrity and reliability of electronic assemblies is critical to our every day lives whether they are used in domestic, transport, communications, industrial or security applications. The European electronics assembly industry faces many issues with achieving high quality joints at the time of manufacture and also once the assemblies are in service. Even if a high quality joint is manufactured it may degrade through a number of mechanisms over time; these negative mechanisms are accelerated by extreme service environments such as elevated and sub-zero temperatures and vibration.An estimated 1014 soldered joints are made in Europe each year; the cost of electronic assembly failure to the European Community can be severe resulting in loss of productivity, facilities or even lives.The MicroStir project will develop small scale friction stir welding (FSW) for use in electronic connections and encapsulations seeing harsh service environments. FSW has proven to be a high integrity joining technology at a macro scale and has already been scaled down for sub-millimetre joining, termed micro friction stir welding (µFSW). The MicroStir project will develop tooling, procedures and prototype production assembly equipment in order that industry may take advantage of µFSW to produce high integrity, stable joints.Using the MicroStir project developments European manufacturers and consumer will be able to guarantee electronics assembly performance and avoid the occurrence of defects such as tin whiskers which can disable safety critical equipment without warning.