Electrostatic Discharge (ESD) is a sudden and uncontrolled transfer of electric charge that occurs between two objects with different electrical potentials. This phenomenon typically results from physical processes such as triboelectric charging (charging through friction), induction (charge separation due to a nearby electric field), and corona discharge (ionization in insulators like air due to high electric field intensity). When charged objects in these mechanisms suddenly approach or touch each other, the charge difference rapidly discharges in the form of an arc (spark).

^{An Image Representing ESD Occurrence (Generated by Artificial Intelligence)}

Static Electricity Sources and Charging Mechanisms

The formation of static electricity is classified into two main forms:

• Volumetric Static Electricity: Occurs within the internal structure of the material.
• Surface Static Electricity: Occurs on the external surface of the material and accounts for the vast majority of problems encountered in industry.

The main factors causing charging are:

• Friction (triboelectric effect): For example, walking on a wool carpet.
• Contact and separation: Two materials touching and then separating.
• Induction: Standing near a strong electric field.

This charging creates voltage (V) depending on the material's capacitance (C) and the amount of accumulated charge (Q).

Dangers and Effects of ESD

ESD causes serious malfunctions, especially in microelectronic circuits. 30-50% of product failures have been identified as being caused by ESD. Even ESD events in the 5V–100V range can cause permanent damage to microchips.

ESD occurs more easily in cold and low-humidity regions. For example, in regions like Alaska and Alberta, personnel wearing thermo-protective clothing increases electrostatic charge accumulation.

Protective Measures and ESD Control

Measures taken against ESD:

• Grounding Systems: Copper plate type grounders increase the effectiveness of grounding by increasing the surface area. Structures with high conductivity and low spreading resistance are preferred. Electrical charges are safely conducted to the ground through the grounding system.
• Antistatic Garments: ESD protective garments are typically made from a blend of cotton and conductive fibers (e.g., aluminum-coated). The knit topology of these garments is designed to prevent both charge spreading and sudden discharge. Conventional topologies include; homogeneous surface, conductive coating, unidirectional conductive structure, and grid-like.
• Workstations: Antistatic tables, mats, and wrist straps that use conductive materials instead of insulating surfaces prevent static charge accumulation. Established stations ensure the safe use of ESD-sensitive components during the R&D process.
• Environmental Humidity Control: Maintaining relative humidity in the 40–60% range significantly reduces static charge accumulation. As humidity increases, the amount of charge decreases.

Static Electricity and Lightning Risk in Aviation

Aircraft are subject to triboelectric charging during flight due to contact with ice crystals, rain, sand, and exhaust gases. External atmospheric fields also lead to the accumulation of charge. These charges discharge via:

• Corona discharge
• Electrical streaming
• Arcing

These high-voltage charges can cause electromagnetic interference in radio and navigation systems. For this reason, static discharge wicks placed on aircraft ensure the controlled discharge of charges into the atmosphere. In modern aircraft, especially with increased use of composite fuselages, conductive mesh structures within these low-conductivity structures ensure the dispersion of lightning current.