Advanced packaging of integrated passive devices for RF applications

Modern RF and wireless systems, in particular the portable and handheld consumer devices, are placing huge demands on component and assembly technologies. The integration of many different functions into one unit means that the component count has become very large. Since passive components form the majority of the devices mounted on the circuit board, there is considerable incentive to identify ways of reducing the number and/or size of these devices without compromising system performance. Interest is now focusing on the role that integrated passive devices (IPDs) can play in achieving some of these aims and a number of new approaches are emerging in this field. Integrated passive devices can provide a large number of passive components and functional blocks within a single device, reducing the overall complexity at the board level and improving the ease of assembly. In order to be effective, however, both the manufacturing and packaging technologies need to be selected to optimize performance, areal density and cost. Chip-scale packaging, combined with a thin film passive device technology and a large area format manufacturing capability offers a solution to these issues, as well as providing a package form factor compatible with existing surface mount assembly operation. This paper describes the thin film integrated passive technology and chip-scale packaging techniques which are being used to produce small outline, high performance integrated passive devices for use in a range of RF, wireless and digital applications.