Many people don’t realize that creating a safe electrostatic discharge workstation can enhance a worker’s productivity and reduce costs associated with damaged equipment. This guide covers all the elements you’ll need to properly set up an ESD workstation that is both safe and functional.
Setting up an ESD workstation
ESD workstations are typically set up in protective zones called EPAs, or electrostatic protected areas. ESD Association Standard ANSI/ESD S6.1-Grounding recommends using a two-step grounding process to set up a protected ESD workstation and EPA.
• Ground all components of the workstation and personnel to the same electrical ground point.
• Connect the common point ground to the equipment grounding conductor (EGC) or the third wire electrical ground connection.
The ESD Association specifies that “grounding is especially important for effective ESD control.” It’s also important to evaluate your ESD control measures on a regular basis, and clearly define what measures need to be taken to effectively carry out ESD safety.
From the floor up
Sensitive electronic equipment, tools, and products are highly susceptible to ESD events. Conductive and dissipative floor materials allow electrostatic charges and dissipation to follow a safe path to ground. Here’s a list of some of the different types of ESD workstation safety equipment:
• ESD matting — Made from antistatic and static dissipative materials with synthetic rubber.
• ESD foot grounder — Incorporates a 1 megohm safety resistor with a conductive surface and antistatic inner surface.
• Floor marking tape — Highly visible by marking ESD protection area boundaries.
• ESD refuse sack — Made with static dissipative materials for use in ESD protected areas.
• Conductive waste bin — Made with conductive fiberboard or polypropylene.
• EPA chair — Dissipates static electricity buildup.
• ESD flooring — Ensures that ESD charges are removed in a safe and controlled manner.
Workers make contact with the floor more than any other element in an ESD workstation or EPA. The more mobility the workspace requires, the greater the chances of ESD events occurring due to increased friction. Using the right floor materials and ESD-protected equipment will ensure you protect sensitive equipment, tools, and products from incurring damage.
ESD-safe workstation
ESD workstations should be designed for just one person (Photo 1). Multiple people working at one station will greatly increase the risk of ESD events occurring. ESD workstations should be situated in the EPA. Here’s a list of nine key elements to incorporate in an ESD workstation:
• Bench matting — Multi- or single-layered with a finish made from antistatic and static dissipative materials with synthetic rubber.
• ESD bags — Static shielding, conductive, and antistatic bags that protect contents from the damage of electromagnetic wave and static.
• ESD screwdrivers — Static dissipative materials that protect sensitive equipment.
• Earth bonding points — Stainless steel stud with mounting screw ring terminal to allow connection of wrist straps and grounding cords.
• Earth bonding plugs — Incorporates banana sockets and a 10-mm male steel stud.
• Conductive component boxes — Conductive coating with faraday cage protection and antistatic foam.
• Conductive PCB rack — Conductive properties protect circuit boards during transportation and storage.
• Conductive brushes — Conductive nylon and plastic brushes minimize static charges when cleaning PCB and other sensitive components.
• Ionizing blower — Ionizes a targeted workspace to eliminate static during production.
Make sure the workstations are equipped with grounding stations and that personnel are using grounding straps at all times. At the very least, the ESD workstation needs to be equipped with ESD matting, bonding points, and earth bonding plugs.
Dress to protect
Non-antistatic clothing poses a significant risk of generating electrostatic charges, which can cause damage to nearby equipment and products. Dry ESD workstationenvironments are especially sensitive to ESD events. Wearing static control clothing helps to reduce ESD risks (Photo 2). Here’s a list of three common types of protective clothing:
• Antistatic clothing — Made from static dissipative materials displaying the ESD symbol.
• ESD gloves — Gloves with protective coatings, or woven with copper or carbon thread, make them ideal for handling sensitive electronic parts and components.
• ESD wrist strap — These conduct ESD from the body to the antistatic mat, allowing safe removal of the charge.
The most important thing is to make sure antistatic clothing is grounded at all times.
Using the right supplies and equipment
The possibilities for producing electrostatic charges are almost endless. The ESD workstation should be equipped from all angles with ESD-safe supplies and equipment. Everything possible should be made or coated with static dissipative and conductive materials to reduce the risks of ESD occurring. Here’s a list of some common supplies and equipment that should be made available to workers:
• Conductive transit packs — Protects sensitive equipment during transport from static and physical damage.
• Antistatic ring binders — Made from specially developed PVC materials that are permanently antistatic.
• Conductive tote bins — Has static dissipative qualities that won’t wear or wash away.
• Wrist strap (Photo 3) and footwear tester — Indicates the status of footwear and wristbands by means of high and low fail indicators.
• IC workstation and mat cleaner — Low ionic, general purpose workstation cleaner that is biodegradable, alcohol-free, and odorless.
• ESD wash bottle — Cleanroom safe static dissipative wash bottle.
The more detailed workers are with the supplies and equipment they use, then the safer the ESD workstation will be.
Read the signs
EPAs need protection from electrostatically charged items, and potentially charged items that can cause damage if brought into the ESD workstation area. Workers need to know where the EPA starts and where it ends, as well as where to enter and exit the area. Using ESD and anti-static signs and labels will greatly enhance the safety of the EPA. Here are two types of ESD signage that should be used in a workstation:
• ESD labels — Yellow ESD caution labels that are suitable for automatic dispensing.
• EPA signage — ESD floor sign, protected area sign, caution sign, and exit sign protected with anti-static coating.
Creating an EPA with protected zones for ESD workstations will reduce the chances of generating electrostatic charges, allowing workers to improve their productivity and safely complete their activities. Examine the ESD risks in the facility, evaluate the capabilities of the organization to address safety issues, and then make a list of the ESD equipment, tools, and supplies needed to create a safe and productive workspace.
Tosh is chief operations officer at Antistat, Ipswich, United Kingdom. He can be reached at [email protected].
