How to Determine if an Electrostatic Discharge (ESD) Accident is Occurred
Electrostatic discharge (ESD) hazards have become a major concern in the electronics industry and many other sectors. ESD accidents are also common. So, when an accident occurs, how can we quickly determine if it was caused by ESD? For accidents suspected of being caused by ESD, in addition to the routine accident investigation and analysis, the following procedures should be followed for classification and confirmation:
**I.** Check and analyze whether the necessary conditions for ESD ignition exist.
**1.** Through analysis of relevant operating equipment, material properties, personnel operations, and environmental conditions, infer the equipment and objects that may be carrying ESD, their degree of charge, and the object, conditions, and type of discharge.
**2.** Collect and measure necessary technical parameters and estimate the possible discharge energy.
**3.** Make a preliminary opinion on whether ESD is the source, or draw a corresponding conclusion for relatively simple and obvious cases.
**II.** For more complex cases, depending on actual needs and possibilities, select some or all of the following items for further testing, and draw a corresponding conclusion after combining the actual situation with analysis.
1. Collect or measure all relevant technical parameters, including ambient temperature and humidity, ventilation conditions, types of combustible materials, location of the release source, and possible distribution of explosive gas concentrations; existing fire and explosion prevention measures and their actual effectiveness; flow rate and velocity of materials related to static electricity, personnel actions and operations; and the possibility of other non-static ignition sources.
2. Analyze and inspect remaining debris. This involves selecting objects (mainly metal parts) that may have carried static electricity and discharged, and observing their micromorphology using an electron microscope to identify the presence of high-temperature melting micro-craters resembling "volcano craters." This helps determine the specific location of the electrostatic discharge and confirm the cause of the accident.
3. When the degree of charging and discharge energy of an object is difficult to determine quantitatively or semi-quantitatively using analytical methods, it is necessary to conduct physical simulation experiments based on the specific conditions at the time of the accident for verification. Simulation experiments can be conducted on-site or in other suitable locations.
4. Conduct further comprehensive analysis of the relevant data, observe whether the interrelationships between various data conform to objective laws and whether there are any contradictions, and if necessary, collect or test other data (including non-electrostatic technical data) to draw a final conclusion.