Performance improvement of an ESD suppressor by studying its characteristics

Abstract

The finite-difference time-domain (FDTD) method was used to study the characteristics of an ESD suppressor. The obtained capacitance of the ESD suppressor filled with air was validated by measurement data and another numerical result obtained by time-domain moment method (TDMM). Under the same conditions, no large differences are found among the obtained capacitances for the ESD suppressor filled with air, neon, argon, and helium. But the ESD suppressor filled with air has a much higher trigger and clamping voltages than the ESD suppressor filled with neon, argon, or helium. Capacitance is found to decrease with the increase of the spark gap distance or the operating frequency. But the capacitance increases with increasing relative dielectric constant of the substrate or the overcoat. t is observed that ESD currents with a transient waveform reach a maximum value and decays sharply as the time increases under the condition of the spark gap distance of 5 μm. Outside the spark gap, the maximum electric field is below the breakdown strength, but the magnitude of the electric field radiated from ESD events is still very large when the distance from the ESD suppressor is less than 2 mm.