2.2 ESD Models

Several models are often cited when specifying the ESD protection level for integrated circuits. The two most prominent of these models are the Human Body Model (HBM) and the Charged Device Model (CDM). The purpose of these models is to standardize a testing methodology that quantifies how susceptible a device is to damage from an ESD event. The ratings are typically provided as a ± voltage value. The magnitude of the voltage indicates the passing voltage where no observed damage has occurred on a set of characterization samples. For any given device, the higher the voltage magnitude, the lower the susceptibility to damage.

Human Body Model (HBM)

The HBM is the most commonly used model for characterizing an IC’s susceptibility to ESD damage. The model seeks to emulate the discharge that will occur when a charged human touches an electronic contact of an IC.

The HBM model and test procedures are overseen by the ESDA1 Association and JEDEC®2. The governing standard is JS-001-2017: ESDA/JEDEC Joint Standard for Electrostitic Discharge Sensitivity Testing – Human Body Model (HBM) – Component Level.

Charged Device Model (CDM)

The CDM is an alternative to HBM and is more applicable to a manufacturing environment where contact is most likely between an electronic device and production equipment, such as handlers and a tester. CDM events are common in a manufacturing environment where metal to metal contact is possible. The CDM test procedures and models, like HBM, are overseen by JEDEC. The governing standard is JS-002-2018: ESDA/JEDEC Joint Standard for Electrostatic Discharge Sensitivity Testing – Charged Device Model (CDM) – Device Level.

1 ESD Association – A professional voluntary association dedicated to advancing the understanding of EOS and the theory and practice of ESD avoidance.
2 Joint Electron Device Engineering Council (JEDEC) is a world wide body responsible for many electronic device standards.