DANGEROUS PARASITICS OF SOCKETED CDM ESD TESTERS

HBM, non-socketed and socketed CDM testing were performed on HF-ICs. B y applying HBM and non-socketed CDM stress weak pins were located by s elective stress. Socketed CDM, however, caused a damage at the weak pi ns, even when they were excluded from testing. Socketed and non-socket ed CDM caused the same electrical failure signature. After insulating the weak pins from the tester circuitry, these pins survived the socke ted CDM test without damage and the failure threshold increased. This behaviour is explained by the discharge of the parasitic tester capaci tance through the weak pins, while other pins are tested. (C) 1997 Els evier Science Ltd.