Impedance Compensation for Interconnection Structure with Large Inductance on PCB Using Capacitors

Bonding wires and via holes are widely used in print circuit boards (PCBs) to provide the connection paths for signal transmission. However, these interconnection structures may have large equivalent inductance, resulting in impedance discontinuity and signal reflection. In this paper, an impedance compensation strategy using capacitors for the interconnection structures with large inductance was proposed. Based on the size and material of the PCB, an electromagnetic field model of the PCB before and after compensation was developed. In addition, a distributed parameter equivalent circuit model was also developed to validate the electromagnetic field model. Both the signal reflection and loss of the PCB after compensation with capacitors decrease significantly. The obtained equivalent circuit model was used to predict the improvement of the signal integrity of the compensated circuit board.