Transient behavior of SCRS during ESD pulses

Silicon controlled rectifiers (SCRs) are widely used ESD protection elements exhibiting extremely good voltage clamping and high failure current threshold. However, the turn-on behavior of the SCR is often a matter of concern. A detailed transient study of the 3-D current and temperature distribution in a SCR during a high current square pulse is presented leading to design options with shorter delay between trigger point and full clamp performance.