Electrostatic Discharge (ESD)

Electrostatic Discharge (ESD – Electrostatic Discharge) is the sudden and uncontrolled transfer of electric charge between two objects with different electrical potentials. This phenomenon typically results from physical processes such as triboelectric charging (charge generation through friction), induction (charge separation due to a nearby electric field), and corona discharge (ionization of insulating materials like air due to high electric field intensity).

When charged objects rapidly approach or come into contact, the potential difference discharges quickly in the form of an arc (spark).

For example, a person walking on a carpet under conditions of 10% relative humidity can generate potentials up to 35,000 volts. Voltages exceeding 3,500 V can cause a painful sensation, while those above 8,000 V can produce visible arcs.

A Visual Representing ESD Formation (Generated by Artificial Intelligence.)

Static Electricity Sources and Charging Mechanisms

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

• Volumetric Static Electricity: Occurs within the internal structure of a material.
• Surface Static Electricity: Occurs on the outer surface of a material and is the source of the majority of industrial problems.

Primary factors causing charging:

• Friktion (triboelectric effect): For example, walking on a wool carpet.
• Contact and Separation: The separation of two materials after contact.
• Induction: Being in close proximity to a strong electric field.

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

Dangers and Effects of ESD

ESD causes serious damage especially in microelectronic circuits. For instance, CMOS integrated circuits can be damaged by exposure to as little as 250 V of ESD. In manufacturing environments, 30–50% of product failures are attributed to ESD. ESD events in the 5 V–100 V range can also cause permanent damage to microchips.

In the electronics manufacturing industry, annual losses due to defective product returns amount to approximately 45 billion US dollars.

While a single damaged chip may result in a $5 loss, if that chip is mounted onto a circuit board, the loss increases to $50; at the system level, it can reach $500; and if a faulty product reaches the field, repair costs can rise to $5,000.

Environments Where ESD Accidents Occur

ESD occurs more readily in cold and low-humidity regions. For example, personnel in areas such as Alaska and Alberta often wear thermal protective clothing, which increases electrostatic charge accumulation. A person walking on polyethylene flooring in low humidity can become charged up to 12,000 V, while on a handmade carpet, charges can reach up to 35,000 V.

Protective Measures and ESD Control

Measures taken against ESD include:

• Grounding Systems: Copper plate-type grounders increase surface area to enhance grounding effectiveness. Structures with high conductivity and low spreading resistance are preferred. Electrical charges are safely directed to ground through grounding systems.
• Antistatic Clothing: ESD-protective garments are typically made from a blend of cotton and conductive fibers (e.g., aluminum-coated). The fabric topology is designed to prevent both charge accumulation and sudden discharge. Conventional topologies include homogeneous surfaces, conductive coatings, unidirectional conductive structures, and grid patterns.
• Workstations: Antistatic tables, mats, and wrist straps made from conductive materials replace insulating surfaces to prevent static charge buildup. These setups ensure the safe handling of ESD-sensitive components during R&D processes.
• Environmental Humidity Control: Maintaining relative humidity between 40% and 60% significantly reduces static charge accumulation. As humidity increases, the amount of accumulated charge decreases.

Static Electricity and Lightning Risk in Aviation

Aircraft in flight become triboelectrically charged through contact with ice crystals, rain, sand, and exhaust gases. External atmospheric fields also contribute to charge accumulation. These charges discharge via:

• Corona discharge
• Electrical streaming
• Arcing

Charges reaching high voltages can cause electromagnetic interference in radio and navigation systems. To mitigate this, static discharge wicks installed on aircraft allow controlled release of charges into the atmosphere. In modern aircraft, where composite fuselage materials with low conductivity are increasingly used, conductive mesh structures are integrated within these materials to safely dissipate lightning currents.