Hannu Salmela

Electrostatic field limits and charge threshold for field induced damage to voltage susceptible devices

We have studied electrostatic field and charge threshold limits for damage to MOSFET devices in order to understand the ESD damage risks during handling in electronics production and assembly processes. The study covers both field induced charged device model (CDM) and charged board model (CBM) cases. The charging electrostatic field for failure can be even two orders of magnitude lower for a device on a board than at component level. The charge level for failure remains approximately constant. Our results show that charge threshold for failure would serve as a good guide for ESD risks of voltage susceptible MOSFETs as discrete components and when assembled to PWBs.

Electrostatic field limits and charge threshold for field-induced damage to voltage susceptible devices ☆

We have studied electrostatic field and charge threshold limits for damage to MOSFET devices in order to understand the ESD damage risks during handling in electronics production and assembly processes. The study covers both field induced charged device model (CDM) and charged board model (CBM) cases. The charging electrostatic field for failure can be even two orders of magnitude lower for a device on a board than at component level. The charge level for failure remains approximately constant. Our results show that charge threshold for failure would serve as a good guide for ESD risks of voltage susceptible MOSFETs as discrete components and when assembled to PWBs.

Experimental comparison of probes for air discharge measurements

Publisher Summary This chapter presents a study on the performance of three different kinds of passive resistor-transmission line discharge probes—an unshielded ball probe developed at Physikalish-Technische Bundesansalt (PTB-probe), a shielded ball probe having an earthed hemispherical shield with the electrostatic discharge (ESD) current collected on a coaxial wire tip and developed at Electrostatics Solutions Ltd. (ESL-probe), and a needle-like shielded probe developed at SP Swedish National Research and Testing Institute (SP-probe). Different kinds of probes have been developed during the past years for the measurement of air discharges—spark and brash discharges—to evaluate the ESD risks without the use of explosive atmospheres or destructive tests of electronics. The chapter evaluates their possible application in assessment of ignition hazards or ESD damage risks to electronic components. The results show that there is no single probe type that is ideal for all kinds of situations. There are significant differences among the probe responses in their ability to initiate ESD, charge transferred, and peak ESD current.