Measurement technique developed to evaluate transient EMI in a photo bay

A new technique for quantifying the magnitude and the rate of ESD-induced transient electromagnetic interference (ESD-EMI) was developed. The developmental steps taken leading up to histograming of the peak-to-peak voltage of the multiple EMI transients as a measurement technique are presented as motivation for the technique. An application of this technique is presented with EMI rate measurement results with and without ionization in Photobay 2 at International SEMATECH. The rate of ESD-EMI events recorded in the bay was 30 times greater with the ionizers off than with them on. The technique uses a very high sampling rate (4 GS/s) digitizing oscilloscope, with a wide bandwidth (>1.5 GHz), and a histogram technique to acquire a spectrum of amplitudes of the transient events.