The ESD Handbook

6ESD Events and Protection Circuits

6.1 Human Body Model (HBM)

ESD protection is needed to avoid failure from ESD events associated with events in manufacturing and handling. Hence, ESD protection circuits are needed [1–222]. A fundamental model used in the electrostatic discharge (ESD) industry is known as the human body model (HBM) pulse [46–52]. The model was intended to represent the interaction of the electrical discharge from a human being, who is charged, with a component, or object. The model assumes that the human being is the initial condition. The charged source then touches a component or object using a finger. The physical contact between the charged human being and the component or object allows for current transfer between the human being and the object. A characteristic time of the HBM event is associated with the electrical components used to emulate the human being. In the HBM standard, the circuit component to simulate the charged human being is a 100 pF capacitor in series with a 1500 Ω resistor. This network has a characteristic rise time and decay time. The characteristic decay time is associated is associated with the time of the network

where R_HBM is the series resistor and C_HBM is the charged capacitor. This is a characteristic time of the charged source.

6.1.1 HBM Pulse Waveform

Figure 6.1 shows the HBM pulse waveform.

6.1.2 HBM Equivalent Circuit ...