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42 The PCB Magazine • July 2014 EMBEDDED RESISTORS IN LOW OHMIC APPLICATIONS continues Embedded resistor technology, primarily used in performance demanding military, aero- space and high density computing applications, has been increasingly used in the high-volume consumer electronics market. This migration into the consumer segment is happening be- cause designers can use embedded resistors as a solution to tight space constraints. Embedding can free up PCB real estate, reduce via and layer counts, eliminate the need for components on the bottom side of the PCB, and eliminate com- mon quality issues found in passive component SMT processes. The performance benefits of embedded pla- nar resistors can also be seen in high-frequency switching applications where the parasitic in- ductance of SMT components has an impact on performance. Reducing the parasitic effects im- proves signal quality. For this article, we are defining low-ohm values as greater than 10 ohms and less than 100 ohms. The advantage of embedded resistors in this range of resistance is realized in high- frequency data communication and front-end RF circuits. Embedded Resistor Applications A variety of resistor values can be achieved using embedded resistor material. The table be- low shows available OhmegaPly ® resistor values based on type of application. Termination resistors in high-speed digital communications are a prime application of em- bedded low ohm value resistors. The ohmic value of any resistor (R n ) used to terminate a high-speed digital signal is a function of the device impedance (Z n ) and/or the charac- teristic impedance of the circuit (Z 0 ) as shown: table 1: available Sheet resistivity and typical applications.