Trends in electronic packaging and assembly for portable consumer products

Abstract

In this paper, an overview is given of trends in electronic packaging and assembly for portable consumer products. With regard to 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 higher I/O density, and reduced thickness to limit the overall electronic assembly height. For the same reasons, techniques and materials have been developed to enable embedded passives. New substrate materials have been developed with better electrical and thermal behaviour to comply with RF requirements. In assembly processes, package assembly is done increasingly at 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 adhesive is used, e.g. to get smaller bump pitches on flip-chips. Finally, due to market demand and legislation, assembly processes, components, and materials must be adapted to realise environmentally friendly products. Special attention is paid to the elimination of lead, volatile organic compounds, and halogens.