Tips to Fight ESD
As electronic technology advances, electronic circuitry gets progressively smaller. As the size of components is reduced, so is the microscopic spacing of insulators and circuits within them, increasing their sensitivity to ESD. Industry experts estimate that average electronics product losses due to static discharge range from 8 to 33%. Others estimate the actual cost of ESD damage to the electronics industry as running into the billions of dollars annually. It is therefore critical to be aware of the most sensitive items being handled in your factory as the need for proper ESD protection increases every day. Here are some tips on how to get ahead of the game:
1. Establish and identify an ESD Protected Area (EPA)
An ESD Protected Area (EPA) is a defined space within which all surfaces, objects, people and ESD Sensitive Devices (ESDs) are kept at the same potential:
- All surfaces, products and people are linked to ground.
- Movable items, such as containers and tools, are bonded by virtue of standing on a grounded surface or being held by a grounded operator.
- Everything that does not readily dissipate a charge must be excluded from the EPA.
A good to place to start your fight against ESD is our example of an EPA as it lists all products required in a proper EPA.
Example of an EPA
A few things to remember:
- The ESD protected area should have signage to clearly identify where it is.
- Only trained or escorted people are to be allowed in the EPA.
- All conductors including Personnel must be grounded. Operators must either wear wrist straps or footwear in combination with an ESD floor. ESD worksurfaces (e.g. mats) are to be grounded.
- Wrist straps and footwear are to be tested daily. For wrist straps a conintuous monitor can be used instead.
- Periodic checks of installed products (e.g. ESD worksurfaces, ESD flooring etc.) are required.
- Remove all non-essential insulators or neutralise essential insulators with ionisers.
- Only handle unpackaged ESDs in an EPA when grounded.
- Wristbands are to be worn snug; the grounding tab of foot grounders must be placed under the foot in the shoe; ESD smocks need to cover all clothing on the torso.
- Use packaging with shielding properties to store or transport ESDS outside the EPA.
2. Identify ESD sensitive items (ESDs)
It is critical to be aware of the most sensitive item being handled in your factory. From goods-in through to dispatch packaging shielding properties should be used to protect ESDs during transport and storage. Any ESD sensitive item should be identified with the ESD sensitivity symbol, either on itself or its container. The ESD Sensitivity Symbol (also called Susceptibility or Warning Symbol) identifies items that can be damaged by ESD and should ONLY be unpackaged and handled while grounded at an ESD protected workstation.
3. Provide ESD control training
This is probably the most important point of all. You can have the best EPA in the world but if your staff don't know about ESD and the problems it creates, it will be money wasted. People handling ESDs are still a major source of ElectroStatic charges and discharges. Operators need training and need to be vigilant that ESD control procedures are followed. In order for an ESD control programme to be effective, operators must be aware of:
- the threat of ESD,
- understand & adhere to the rules of controlling static electricity
- and know how to properly use ESD control items.