Model for ESD LCD upset of a portable product

A hybrid method is developed to model Electro-Static Discharge (ESD) LCD (Liquid Crystal Display) upset in a portable product. It combines ESD scanning, full-wave simulation and circuit simulation. This methodology is applied in the investigation of system-level ESD problem of the LCD of the portable product by the following steps. First, the sensitive area of the portable product causing the failure is located by ESD scanning. Using the local injection measurement currents, a behavioural SPICE model is then developed to simulate the ESD failure. Third, a full wave block-level model is used to extract the current densities at the sensitive regions; those current densities are imported into the SPICE model to predict ESD upset levels. The combined model is verified by testing its ability to simulate the upset level of four system level ESD test conditions, leading to satisfactory results.