ESD marking and ESD symbol

ESD Control program is setup with the sole intention to protect ESD sensitive or ESD susceptible (ESDS) items such as Integrated Circuits, Boards and Assemblies from ESD damage.
In the Electronics manufacturing line or assembly, we will notice that a variety of ESD materials and ESD equipments are used as part of an ESD control system to protect the ESD sensitive items from ESD damage.

Some of the ESD materials are:
• ESD wrist strap
• ESD flooring material
• ESD shoes
• ESD garment
• ESD foot grounder
• ESD mat

Some of the ESD equipments are:
• ESD hand tool
• ESD air ionizer
• ESD trolley or ESD cart

As there are many electronic devices, materials and equipments used in the ESD protected area, it is important for the employee to be able to distinguish those ESDS electronic devices, ESD materials or ESD equipments from those that are not.
The electronic devices that are susceptible to ESD damage can be distinguished through the ESD susceptibility symbol which it is either paper labeled or molded permanently on the plastic packaging that hold them.
The ESD susceptibility symbol has a reaching hand inside a triangle, with a slash across the hand. Although the color for the symbol is arbitrary, the common color is yellow for the hand with black as the background. Red color, however is not allowed as it suggests hazard to employee.


When the ESD susceptibility symbol is seen on a packaging material, it basically means that the devices inside the packaging is susceptible to ESD damage and necessary ESD precaution is required by the employee when handling the devices.
Similarly the ESD materials and ESD equipments can be distinguished through the ESD protective symbol placing on them.
The ESD protective symbol has a reaching hand inside a triangle and an arc outside the triangle. The arc is in bold. Again the color for the symbol is arbitrary; the common color used is yellow for the hand and black as the background. Red color, however is not allowed as it suggests hazard to employee.


When ESD protective symbol is seen on the any material or equipment, it simply means that the material or the equipment is safe to be used in the EPA area. They are able to provide protection to the ESDS electronic devices or assemblies being handled.
ESD symbol or ESD marking for ESDS electronic devices, ESD material and ESD equipment are crucial in the ESD Control program. Without them, many of the ESDS electronic devices may be wrongly handled without proper ESD precaution and many of the ESD materials or ESD equipments may be wrongly interpreted of their functionality.
ESD symbol or ESD marking on ESD materials or ESD equipments is definitely an advantage. However, it still remain the responsibility of the ESD coordinator to select and evaluate the ESD materials and ESD equipments by following the ESD documents and standards to ensure the material or equipments are fit for use in the EPA.

ESD Protected area or EPA

An ESD Protected area or rather known as EPA is an area where workers work and deal with ESD sensitive items in a safe environment from harmful electrostatic charges. From a quick glance, this EPA is decorated with many and different type of ESD protective materials and equipments which are used to control the generation and accumulation of electrostatic charges, such as ESD mat, ESD wrist strap, ESD tote box, ESD air ionizer, ESD chair, ESD flooring etc. The EPA is normally identified with a clear signage to indicate that the area is an ESD Protected area.


Controls at EPA
When working in an EPA, workers are required to wear wrist strap while handling the ESD sensitive parts in a seated position.

Tailoring could be made when workers are dealing with hazardous voltage. The use of wrist strap can be exempted with some technical justifications.

The work surface shall be grounded and both conductive and dissipative work surfaces are allowed to be in the EPA, depending on the product’s requirement.

Non essential process insulator such as coffee cup, plastic bottle and personal plastic bag are not allowed to be in an ESD Protected workstation. When essential process insulators are needed on the workstation, the 2kV/inch rule is applied.
When scanning the workstation with a static field meter, a source that gives any reading above the 2Kv in an inch distance shall be kept in a distance at least 30 cm away from the ESD sensitive parts.
Alternatively, ESD air ionizers can be used to neutralize the electrostatic charges on the insulative source or other mitigating ways such as shielding technique can be applied.

Workers shall be trained periodically while working in an EPA. Any untrained visitors such as vendors, customers and external auditors shall be accompanied by a trained worker while in the EPA.

Jigs, tools or surface of automated equipment that has direct contact with the ESD sensitive parts shall be dissipative or conductive in nature and grounded.

ESD garments that are worn by workers shall be checked periodically to ensure
continuous functionality during use in the EPA.

Most established organizations have installed ESD flooring in the EPA. While the presence of ESD flooring definitely make ESD controls much easier, it must be noted that ESD flooring does not work alone and in fact it only works effectively with the presence of ESD footwear.

It is the role of the ESD Coordinator to ensure ESD controls at the ESD Protected area is complying with ANSI/ESD S20.20 standard requirements.