Embedded resistors in printed wiring boards

Embedded passives is currently one of the most interesting technologies among the printed wiring board industry. Especially embedded resistors and capacitors are nowadays topics in every single PWB conference around the globe. It is widely accepted opinion that embedded passives are an essential part of tomorrow´s HDI printed wiring boards. This paper discusses the embedded resistors technology. Main drives for the technology are PWB size reduction, increased functionality, improved high frequency performance, and also increased reliability and cost savings. This paper tries to explain why these benefits are gained using the technology and how we can achieve them. The paper introduces the most interesting commercially available materials and takes a look into the fabrication of different techniques, not forgetting to address the important design aspects. Different case studies about the space and cost reduction as well as test results are presented. As mass production is a target, an important issue of infrastructure is briefly discussed as well.