Continuous voltage monitoring techniques for improved ESD auditing

A technique for continuously measuring the voltage on static sensitive devices, tools or fixtures during handling and processing is described. This technique uses an electrometer and identifies when a device is floating, grounded, or when dangerous metal contact to device inputs is made. The technique is used to show that an ungrounded device can have a surprisingly high voltage, and that ionization during handling may not significantly reduce the peak voltage on the device. It is concluded that continuous voltage monitoring provides critical information about the device and process and helps an ESD auditor understand, solve and even prevent serious ESD problems.