Study On Air Electrostatic Discharge And Energy Characteristics Of LCM

Display screen is an important part of modern electronic equipment.With the development of new technology,the application of display screen is more and more extensive,and its demand is constantly growing.With the increasingly semiconductor manufacturing technology and structure and the continuous improvement of circuit integration,the sensitivity of electronic devices to electrostatic discharge is also increasing.Display modules are subject to electrostatic discharge during manufacturing,production and use.In actual production and life,air discharge is the main cause of interference and damage to electronic equipment.Electrostatic discharge can result in the potential failure,software damage or hardware failure of the display and touch screen.The most likely path to disturb or damage the display is the displacement current through the glass.By analyzing the physical structure of the display screen and the forms of electrostatic discharge in the process of production and use,the failure mechanism of electrostatic discharge on the display screen is theoretically clarified.Then,the effects of discharge voltage,discharge polarity and ESD simulator approach speed are studied by air electrostatic discharge experiment and displacement current measurement.The charge density can be calculated based on the displacement current waveform and distribution.The main research contents and conclusions of this paper are as follows:1.In the study of the electrostatic discharge form and failure mechanism of the display screen,the results show that: the display module will be subject to electrostatic discharge in the process of manufacturing,production and use;in actual production and life,air discharge is the main cause of interference and damage to electronic equipment.The damage of display module caused by electrostatic discharge mainly includes IC and touch layer.2.The effects of discharge voltage,discharge polarity and approach speed were clarified through the experimental study on the air electrostatic discharge.The experimental results show that within a certain voltage range,the peak value of discharge current decreases with the increase of discharge voltage,and the rise time increases with the increase of discharge voltage.The higher the simulator approach speed is,the larger the discharge current peak value will be,and the smaller the rise time will be.3.In the air electrostatic discharge experiment of the display screen,the effects of discharge voltage,discharge polarity,proximity speed and the thickness of glass on the display screen surface were studied.The experimental results show that the peak current decreases with the increase of discharge voltage in a certain voltage range.The rise time increases with the discharge voltage.The peak current and total energy of positive discharge are much higher than that of negative discharge.The peak value of discharge current increases with the increase of the approaching speed,and the rise time decreases with the increase of the approaching speed.The peak value of discharge current decreases with the increase of the surface glass thickness.4.The displacement current through the display screen is measured by a self-designed device.The experimental results show that as the distance between the measuring point and the discharge point increases,the peak value of the displacement current waveform decreases,the rising time increases,and the peak value of the positive polarity discharge is larger and has a wider diffusion range.The charge density decreases as the distance from the discharge point increases.Although the peak value of negative polarity discharge current is lower than that of positive polarity,the charge density is higher,this indicates that the negative polarity discharge has the hazard of causing higher damage risk.