The abnormal electrostatic discharge of a no-connect metal cover in a ceramic packaging device

The human body model(HBM) stress of a no-connect metal cover is tested to obtain the characteristics of abnormal electrostatic discharge,including current waveforms and peak current under varied stress voltage and device failure voltage.A new discharge model called the "sparkover-induced model" is proposed based on the results.Then,failure mechanism analysis and model simulation are performed to prove that the transient peak current caused by a sparkover of low arc impedance will result in the devices’ premature damage when the potential difference between the no-connect metal cover and the chip exceeds the threshold voltage of sparkover.