Having our own internal capability for high quality assembly of SMD PCBs for prototyping and small manufacturing batch runs has always been essential to meet customer lead times. Without a large multi-zone heater reflow oven and the possibility of tweaking parameters to optimise production yield, this is not a straightforward task. This has been compounded by the move to lead-free soldering and the same PCB having a large range of size and weight of components and tracking / flooding. Historically a modest size convection reflow oven has been used by SPS but it was apparent that a higher performance oven would be required for future use. An internal review of different reflow technologies was carried out by our production department and advice sought from various suppliers. After poor results from trialling a popular oven specifically designed for low volume / batch work, advice was sought from Electronics Yorkshire. They recommended using vapour phase technology which SPS was familiar with as a technology as it has been used for many years for soldering copper base plates to the underside of the DBC in isolated power modules.