The assembly of printed circuit boards is a multiple step process that includes surface mount technology (SMT) and through hole technology. In through hole assembly processes, the component leads are placed onto the board and the leads are soldered via a wave soldering process. Some SMT components can be placed on the bottom side of the board and soldered by the wave soldering process. In the SMT process, solder paste is deposited onto the connection pads of the printed circuit board, components are placed onto these pads, reflowed in a reflow furnace to melt the solder paste to form the electrical and mechanical connection of the component leads to the printed circuit board. In test, the assembled printed circuit boards are placed into a fixture that brings electrical power to the boards to make them live functioning boards. This group of active boards is then placed into an environmental stress system (ESS) chamber that will cycle between high and low temperature regimes for a number of cycles to determine if these stresses will initiate failures in the assembled boards. These failures will be analysed for cause. Air Products’ expertise, technologies and gas supply advantages can provide improved profits, uptime, defect reduction and improvement in the total cost of ownership for your printed circuit board assembly and test processes.