Background The use of lead in electronic equipment was banned on 1 July 2006, as laid down by Directive 2002/96/EC on Waste of Electrical and Electronic Equipment (WEEE), and Directive 2002/96/EC on the Reduction of Hazardous Substances (RoHS). This ban was expected to have a particular impact on the aeronautical and military sectors; the equipment these sectors use has to respond to specific requirements, such as reliability, security and maintainability. Moreover, the alternatives to the use of lead in the consumer electronic sector are not always appropriate. Because the aeronautic, space and military sectors purchase Components On The Shelves (COTS) in low volume, it is not possible for them to demand that component manufacturers continue to sell components with leaded pins. So, the stocks of leaded components will disappear in the near future. This obliges the aeronautic, space and military companies to store enough leaded components for their current programmes and to transition to full lead-free assemblies and finally to ban lead on all the future electronic boards. Objectives The beneficiary, EADS, aimed to develop a demonstration clean technology that uses lead-free soldering that is able to stand up to extreme conditions. The technique, using new alloys, will allow the recycling and reuse of the material. It will be transferable to other sectors that wish to increase the durability of their equipment. A key objective of the GEAMCOS project was to evaluate the transition to lead-free assemblies in terms of reliability. Indeed, the modifications induced by the assembly processes must satisfy the requested level of reliability for such on-board products. The innovative aspect of this project was to adapt customer technologies to aeronautic and military constraints. Results A first step of the GEAMCOS project was to produce assemblies with leaded components and with lead-free solder and full lead-free processes. In both cases, critical components were selected and the boards designed in order to follow the electrical behaviour during the different environmental tests. The alloy Sn3Ag0.5Cu was used as a lead-free alternative to SnPbAg. These boards were subjected to accelerated ageing tests (thermal cycling, humidity and vibrations tests) and analysed before, during and after tests, to observe failure and evaluate their lifespan. The test boards showed an overall similar degree of reliability under the assessed conditions. The project also developed some innovative techniques for modelling electronic assemblies and the optimal thermal cycle conditions were determined by these models. Modelling was also used to correlate simulation results of lead-free assemblies with the experimental data. At the end of the project, a functional demonstration model used for radio equipment and usually assembled with a conventional SnPb process was manufactured with a full lead-free one by two assemblers: Novatech (the usual EADS subcontractor) and ACTIA. All the boards withstood the qualification needs, and thus could be upgraded with lead-free technology while achieving the reliability necessary for this product. Finally, generic guidelines were drawn on the lead-free processes and on the logistic organisation for dissemination to assembly manufacturers. Even though the lead-free process is costly, it greatly reduces lead toxicity, a major driving issue (15% of all lead found in landfills is the result of WEEE). However, some negative environmental impacts are associated with this process: the process leads to an increase in energy consumption due to the higher solder temperatures that are required; and the extraction of silver resources, which are scarcer than lead, has a greater environmental impact. The project concludes that emphasis should be put on the promotion of the collection and recovery of electronic waste. Further information on the project can be found in the project's layman report (see "Read more" section).