A Study of Current Distributions on the Printed Circuit Boards

Abstract

With the developments of modern central processing unit (CPU), electromagnetic field coming from the printed circuit boards (PCB) is becoming a serious electromagnetic noise source. In order to reduce the noise coming from the PCB, it is essential to evaluate the current distribution on the PCB.
This paper proposes one of the promising methodologies evaluating for the current distributions from the measured magnetic fields. At first, the unknown current distributions are modeled by the loop currents. Second, we derive a system of equations by means of the elliptical functional approach, and solve the system equations which unknown parameters and equations are matched. Finally, we have succeeded in obtaining the current distributions on model PCB. And then, we applied same procedure to measured magnetic field distributions on the PCB of workstations in time region by loop probe. We demonstrate the usefulness of our methodology by applying to these magnetic field distributions.