Analysis and prevention on NC-ball induced ESD damages in a 683-pin BGA packaged chipset IC

Abstract

An abnormal failure mechanism due to ESD zapping on the Non-Connected (NC) balls of a 683-pin BGA packaged chipset IC is presented. Failure analyses, including Scanning Electronic Microscopy (SEM) photographs and the measurement of current waveforms during ESD zapping, had been performed with a new proposed equivalent circuit to give clear explanation on this unusual phenomenon. Several methods to prevent such failure mechanism are also discussed. (C) 2003 Elsevier Ltd. All rights reserved.