It is the sudden electric unwanted current that may cause damage to electronic equipment. Integrated circuits can suffer permanent damage when subjected to high voltages; as a result, there are now a number of antistatic devices that help prevent static build up.
Causes of Electrostatic Discharge
The human body has an electric field and under specific conditions can generate a large voltage, often called as static electricity.
ESD occurs when an imbalance in the amounts of positive and negative electrical charges on the surface of an object is released as in lightning. The amount of energy released when you touch a metal object can be quite large. The buildup of energy with nylon clothes can reach 21,000 volts and just 10 volts is enough to ruin a computer chip.
The actual amount of energy in a given ESD event depends on the types of materials involved (wool fabrics generate less than nylon), the humidity (low humidity offers less resistant to the discharge), the amount of physical energy (friction) involved, and how quickly the energy is released.
The major cause of ESD damage is improper handling of electronic devices. A semiconductor device can be damaged by ESD during handling before it is installed.
Maintain a habit of “grounding” yourself to the computer chassis or wear a ground strap. Don’t move around while installing or handling a part; doing so can generate additional voltages, negating any effort you have made to eliminate ESD. ESD-suppression devices should be used which include
- Antistatic mats: Non-conducting pads placed on the work surface and on the floor in front of the work area.
- Antistatic wristband: A wristband with a grounding strap connected to the chassis of the PC.
- Antistatic pouches: A sealed, antistatic pouch used to store any sensitive electronic device, like hard disk drives.
- Antistatic pad: An insulating foam pad in which individual chips with exposed pins should be embedded if needed.