Trends in electronic packaging and assembly for portable consumer products

In this paper, an overview is given of trends in electronic packaging and assembly for portable consumer products. Regarding components, the focus is on thinner and smaller packages with a higher lead count. To save board space, integrated passive components in CSP format are being developed. The use of modules that provide a complete function is increasing. Advantages are flexibility, diversity, and cheaper and simpler second-level assembly (the high-density interconnect is limited to the interior of the module). Both motherboards and interposer substrates (used in packages and modules) are characterised by smaller features to accommodate the higher I/O density, and reduced thickness to limit the overall electronic assembly height. For the same reasons, techniques and materials are developed to enable embedded passives. New substrate materials are developed with better electrical and thermal behaviour to comply with RF requirements. With respect to assembly processes, package assembly is done more and more on wafer or substrate level to save costs, increase production volume, and facilitate package miniaturisation. Standard reflow soldering is optimised to enable the integration of CSPs and flip-chips on the motherboard. In some areas, conductive gluing is used, for example to get smaller bump pitches on flip-chips. Finally, due to a market pull and legislation, assembly processes, components, and materials have to be adapted to realise environmentally friendly products. Special attention is paid to the elimination of lead, volatile organic compounds, and halogens.