The NEMI Roadmap Perspective on Integrated Passives

Today's circuit boards have a large percentage of their area taken up by passive components. This space has become a target for further reduction of the system's sizes. A designer has several choices in how to accomplish the implementation of passive functions. These choices include discrete components, arrays, networks and Integrated Passive Devices (IPDs) and embedded components. The choices involve tradeoffs in cost, performance and space utilization. This paper will focus on IPDs and Embedded Passives; the analysis will be based on the methodology used for the National Electronic Manufacturing Initiative (NEMI) Roadmap. Resistor and capacitor arrays now account for 500 of the 2200 passive components placed on a typical Pentium III Motherboard. However, Embedded Passives are being driven more by high performance products than by the space considerations of hand-held devices. Planar distributed embedded decoupling capacitance layers can replace multiple discretes while maintaining signal integrity and improving EMI suppression. A typical cell phone has 500 passives out of the 550 devices on the circuit board. Finding the space needed for new circuit features will entail using very small discrete components, IPD modules or “super-components” and eventually embedded passives. The trade-offs and time frame for these changes will be discussed in detail. The requirements for future implementation will be cited.