An Overview of Electrostatic Discharge (ESD), Anti-Static Gloves, and ESD Protection

Interaction with electronic devices and systems has become more prevalent in our modern technological world, from circuit boards to hard drive components to advanced electronic hardware using metal-oxide-semiconductor (MOS) technology. Working with these devices means exposure to sensitive components such as resistors, capacitors, and LEDs. Several risks are associated with these components, including the danger of electrostatic discharge (ESD). ESD is a common concern and results from a sudden flow of electricity between two electrically charged objects due to a short circuit or a malfunction. The static electricity generated when this occurs is concerning, as it can potentially cause dangerous explosions, damaging equipment and endangering workers. 

In the late 1970s, the electronics industry began noticing equipment failure that could be traced back to electrostatic discharge incidents. By the 1980s, engineers developed structures to withstand these ESD events. However, by the early 2000s, user demand for increased electronic performance and 5G high-speed internet caused rates of ESD events to jump once again. To address these issues, the ESD Association set global standards and best practices for static control to help mitigate the losses and hazards of these events. They are the only organization accredited by ANSI to create electrostatic standards, and they continue to develop ways to minimize or avoid ESD as technologies change.

Electrostatic discharge is dangerous and damaging and can pose life-threatening risks to workers. As NASA highlights, only 20 volts of ESD can severely damage expensive electronic equipment and potentially risk human life. Therefore, it is essential to implement correct ESD grounding techniques and proper ESD protection in all facilities where ESD may occur. This article will explore ESD, highlight the current standards, identify the protection required, ANSI-rated anti-static gloves, and name some of the industries most impacted. Let's charge ahead!

What Is Electrostatic Discharge?

Electricity is all around us. Everything, including the human body, is made up of atoms that contain positive and negative charges. Opposite charges, like negative and positive, attract each other; like charges, such as negative and negative or positive and positive, repel each other. Most of the time, all is well, and there is a balance in the charges, rendering them neutral. However, sometimes an imbalance occurs when two different materials come in contact and are rubbed together. During this process of rubbing against each other, one of the materials becomes positively charged and the other negatively charged. The positively charged substance now has an electrostatic charge. That electrostatic charge builds up until it is released, resulting in an ESD event.  

Examples of ESD include the shock we feel when walking on a carpet and touching a metal doorknob or the static electricity we experience after removing our clothes from a dryer. Lightning is a more extreme example of electrostatic discharge. Although most ESD events are not dangerous, they can be costly in industrial environments where expensive equipment is utilized. When a static charge discovers a path to ground from a sensitive component, the sudden current flow and energy can overload components on a device. The charge's intense temperature can melt or vaporize tiny components, causing the device to fail. And just because a device doesn't fail immediately, it can still be permanently damaged by latent failure, resulting in a potentially catastrophic failure on the front line of expensive production equipment. Estimates place ESD damage at the root of as much as one-third of product losses in an electronics manufacturing environment, particularly in the age of semiconductors.

Electrostatic Discharge Program

There is a golden rule in preventing electrostatic discharge: Avoid Charges! Since humans carry electric charges on their skin and clothes, proper electric control plans must be in place across common areas to allow for electric discharge. According to the ESD Association, a plan should incorporate the following:

1.    Protective Designs – determine the optimal protection deterrents for products and assemblies to counteract the effects of ESD.

2.    Defined Control Levels – based on specific needs in particular environments.

3.    Identify and Specify – define which areas are electrostatic-protected areas (EPAs), that is, where ESD-susceptible (ESDS) items should be handled.

4.    Decrease Electrostatic Charge Generation – remove all static-generating processes and offer appropriate ground paths to reduce potential discharge events.

5.    Neutralize Materials – ground dissipative static materials.

6.    Protect Products – harness static control in packaging and material-handling products.

Establishing an electric control plan is a company's most critical foundational step to ensure limited electrostatic discharge and to protect the integrity of products handled. These plans establish a designated environment with materials and equipment to limit electrostatic potentials. In addition, personnel must schedule electrostatic discharge training and be certified to work in these areas.

For more information about ESD control plans, visit these helpful websites:

• Saab Automobile Report Sample Control Document
• Technology Roadmap

Industries and Activities Associated with ESD

ANSI explains that electrostatic discharge susceptible (ESDS) items are typically microcircuits, distinct semiconductors, film resistors, hybrid devices, printed circuit boards (PCBs), and piezoelectric crystals. The ESD Association reveals that these components are commonly found in the assembly, cleanrooms, inspection, receiving departments, R&D, repair centers, packaging, and field service areas of many facilities. Let's turn these areas into more specific settings many will recognize.

Here are a variety of situations where electrostatic discharge is a concern:

• Assembly operations in an aerospace manufacturing facility
• Automotive production and assembly of electronic systems
• Manufacturing fiber optics
• Mechanical and electrical repair of electronic equipment
• Paper manufacturing processes using rollers that generate electricity
• Painting operations 
• PC assembly and construction, including circuit board handling
• Precision packaging and manufacturing of thin-film-transistor-based flat panel displays
• Sensitive assembly operations in a PCB factory
• Smartphone and electronic device fixes and upgrades
• Static-sensitive device handling in medical device manufacturing
• Setting up workplace servers

ESD Protection and Standards

ANSI/ESD S20.20 is the overarching ANSI standard for all facets of an ESD control program. It covers the requirements to design, implement, and maintain an organization's ESD control plan. In addition, ANSI/ESD SP17.1 describes the techniques and tools used to handle ESD-susceptible (ESDS) items.

 Here is a list of the standard gear used around sensitive electronic equipment:

• Anti-Static Mat – helps prevent and shield equipment from electrostatic discharge. ANSI/ESD S4.1 is the test method used.
   
• ESD Floor Mat – transfers charges from a person to the flooring and is often made from carbon fibers. ANSI/ESD STM7.1 is the test method used.  
   
• Footwear – is made of conductive materials to prevent one's feet from generating electricity. ANSI/ESD STM 9.1 is the testing standard used.
   
• Electrostatic Discharge Clothing – offer protection from the static electricity often generated by clothing. ANSI/ESD STM 2.1 is the test method used.
   
• Electrostatic Discharge Strap – connects a person to a known ground point. ESD S1.1 is the test method used.
   
• ESD Seat Cushion – provides a line of defense in a person's chair from generating charges. ANSI/ESD STM 12.1 is the test method used.

Numerous other gear options are highlighted in ANSI/ESD S20.20, including hand tools, mobile equipment, and ionization.

Click here to continue reading this blog in its entirety and learn about ESD-specific gloves.

Previously Featured on MCR Safety's blog.