perfromanceElectrical Performance Advantages of Ultra-Thin Dielectric Materials Used for Power-Ground Cores in High Speed, Multilayer Printed Circuit Boards Joel Peiffer 3M Company St. Paul, MN Bob Greenlee Merix Corporation Forest Grove, OR Istvan Novak Sun Microsystems Burlington, MA Introduction Thin layers (50 um) of FR-4 material have been used for power-ground cores for a number of years to improve electrical performance. These thin power-ground cores serve as distributed capacitor layers to assist in power supply decoupling. However, with the ever-increasing speeds of circuits and the trend to lower voltages and higher switching speeds, these thin layers no longer provide the required electrical properties (low impedance, high capacitance) necessary for next generation, high speed digital cir……