Embedded passives

Driven by ever growing demands of miniaturization, increased functionality, high performance, and low cost for microelectronic products and packaging, new and unique solutions in IC and system integration, such as system-on-chip (SOC), system-in-package (SiP), system-on-package (SOP), have been hot topics recently. Despite the high level of integration, the number of discrete passive components (resistors, capacitors, or inductors) remains very high. In a typical microelectronic product, about 80% of the electronic components are passive components, which are unable to add gain or perform switching functions in circuit performance, but these surface-mounted discrete components occupy over 40% of the printed circuit/wiring board (PCB/PWB) surface area and account for up to 30 percent of solder joints and up to 90 percent of the component placements required in the manufacturing process. Embedded passives, an alternative to discrete passives, can address these issues associated with discrete counterparts, including substrate board space, cost, handling, assembly time, and yield [1, 2]. Figure 14.1 schematically shows an example of realization of embedded passive technology by integrating resistor and capacitor films into the laminate substrates. Fig. 14.1 Schematic representation of the size advantages of the embedded passives as compared to discrete passives By removing these discrete passive components from the substrate surface and embedding them into the inner layers of substrate board, embedded passives can provide many advantages such as reduction in size and weight, increased reliability, improved performance and reduced cost, which have driven a significant amount of effort during the past decade for this technology. This chapter provides a review on most recent development in embedded inductors, capacitors, and resistors. © 2009 Springer-Verlag US.