Predicting Field Coupling to an IC Using Measured Coupling Factors

High-strength electric and magnetic fields can capacitively or inductively couple energy to integrated circuits (ICs) and cause them to fail. While measurements can show when an IC will fail, they do not provide insight into the mechanisms for failure. Modeling the response of the IC to these fields is challenging, in part because of the small features of the IC and the large amount of circuitry information that must be included from the IC and printed circuit board. The goal of the following work is to develop a methodology for predicting the voltage or current on the pins of the IC from incident electric or magnetic fields. The method is based on measuring “coupling factors,” which show the relationship between a specific field component and the IC response. These coupling factors can be determined by placing the IC in a known electric or magnetic field within a transverse electromagnetic cell and measuring the response. The developed technique was validated by predicting the response of a commercially available 8-bit microcontroller to the electromagnetic fields generated by the nearby discharge of an electrostatic discharge gun. The proposed approach allows the prediction of the waveforms and a better understanding of failure mechanisms without the need to know or model IC geometry and circuitry.