ESD Explained: What is Electrostatic Discharge?

Saline Lectronics Blog, manufacturing, Technology

You may have read or heard the acronym ESD and wondered, “what does ESD stand for?” We’re here to explain what ESD is and how you can prevent it from occurring.

ESD stands for electrostatic discharge. Under certain conditions, transference of electrical potential may occur when two materials with different charges come into proximity to each other. This common phenomenon, known as electrostatic discharge (ESD), can range in magnitude from a barely measurable electron movement all the way up to hundreds of millions of volts contained in the typical lightning strike of an ordinary thunderstorm.

Static electricity often causes ESD through a process known as tribocharging. When two materials make contact and then separate, a movement of electrical potential through the air between the two substances may occur resulting in an ESD event. One typical example is the static electricity sometimes discharged when a plastic comb rubs against dry human hair. A visible spark may be present, but many ESD events occur without the presence of one.

Damage Potential of Electrostatic Discharge

ESD is hazardous or destructive in many situations. Sparking is naturally a concern in any area where flammable gas or liquid is present, and these applications require strict safety measures to prevent static electricity build-up and discharge. Small, non-visible ESD events can also cause serious problems, especially in the area of sensitive electronic components and assemblies.

Integrated circuit microchips are especially vulnerable to ESD. A discharge as small as 30 v, which is not enough to detect with the physical senses, is more than enough to harm most ICs. During the manufacturing and assembly processes, damage that is not readily detectable may occur to components. An electronic part subjected to a small ESD may not immediately fail but can degrade over time and shorten lifespans for assembled devices.

ESD Prevention and Control

Creating a virtually static-free manufacturing environment requires diligence and innovation. Manufacturing personnel must thoroughly understand the destructive nature of ESD, and be committed to taking steps to reduce its presence. The added effort results in reduced material waste and improved quality. The following list contains some necessary steps for creating an ESD-protected work area.

  • Monitoring equipment: Meters capable of detecting and measuring all ESD events.
  • Static-reduced work areas: Floor mats made of conductive materials; anti-static wrist straps and dehumidifiers decrease the likelihood of ESD events occurring.
  • Use of Antistatic materials: Static-resistant packaging, paints and garments and footwear all contribute to product integrity and protection.

As engineers design automated manufacturing procedures, they commonly select static dissipative materials for any surface that will encounter sensitive electronic components. These special materials are able to conduct electricity, but do so very slowly. Any built-up static charges dissipate without the sudden discharge that can harm the internal structure of silicon circuits.