Extrapolated voltage based on ultra-low human body electrification experiment

With the rapid development of electronic industry technology, the electrostatic discharge(ESD) sensitivity voltage of electronic products has been lowered than the 50 V human body model(HBM) voltage. However, the existing ESD protected area (EPA) configuration standard works only for the electronic products whose ESD sensitive voltage is not less than 100 V. In order to study the configuration of EPA to achieve ultra-low human charge voltage, this paper investigates on the human walk experiment according to the ANSI/ESD S20.20 standard. Under high humidity conditions, the ESD mitigation floor and shoes with resistance widely below the 10⁹ Ω standard are selected in the experiment for testing the system resistance of the human body and the walk charge voltage. Based on the short-term experimental data, the Chebyshev inequality is used to extrapolate the possible maximum voltage in a certain probability level which approves practical significance. The performed empirical research highlights innovatively that although the HB walk voltage is positively correlated with its system resistance, the discreteness is relatively large. If the system resistance is the only parameter used to control the HB charge voltage, we can not achieve good enough results. A risk assessment related to EPA protection reliability is determined based on the extrapolated voltage with suggestions to reduce EPA failures.