Many firms consider all components ESD sensitive. However, it is critical to be aware of the most sensitive item being handled.
Any ESD sensitive item should be identified with the ESD susceptibility symbol, either on itself or its container. The ESD Susceptibility Symbol (also called Sensitivity or Warning Symbol) identifies items that can be damaged by ESD and must be un-packaged and handled by a properly grounded operator at an ESD protected workstation.
Most firms use the ANSI/ESD S20.20 document to construct their ESD control plan which is based on handling ESD sensitive items having a Human Body Model withstand voltage of 100 volts or greater. The Human Body Model simulates discharges from a person and increasingly tests an electronic device at higher and higher discharges until it fails, thus establishing the device’s withstand voltage.
There are three ESD Awareness Symbols defined in ANSI/ESD S8.1:
To view information about each symbol please click the link or image above.
ESD Susceptibility Symbol
The ESD susceptibility symbol incorporates a reaching hand in a triangle with a slash through it and is used to indicate that an electrical or electronic device or assembly is susceptible to damage from an ESD event. Used to identify ESDS [ESD sensitive items] and that personnel should be grounding when unpackaging or handling that item. It is also referred to as the ESD sensitivity symbol or ESD warning symbol.
Application: The ESD susceptibility symbol should be used on assemblies and devices that have a sensitivity to ESD events. The symbol may be incorporated on a sticker used to close or seal ESD protective packaging to indicate that materials inside the package are ESD susceptible.
Format: The symbol is a reaching hand with defined fingers and fingernail, in a contrasting triangle with a slash in front of the hand.
Color: The choice of color for this symbol is arbitrary. The color red shall not be used because it suggests a hazard to personnel. The preferred color is a yellow hand and slash on a black background.
Note: Three Arrows In A Circle Symbol, per ESD Handbook ESD TR20.20 “Military organizations sometimes use MIL-STD-1285 for hardware marking and that document once required the use of the “three arrows in a circle” symbol. That symbol has been changed for consistency with industry marking to the “hand in triangle” ESD Susceptibility symbol”
ESD Protective Symbol
The ESD protective symbol differs from the ESD susceptibility symbol, by the addition of an arc around the outside of the triangle and the omission of the slash across the hand and the triangle.
Application: The ESD protective symbol should be used to identify items that are specifically designed to provide ESD protection for ESDS items. Examples of these are packaging, ESD protective clothing and personnel grounding equipment. The ESD protective symbol should also be used on items designed to replace static generative materials. Examples of these items are ESD protective work station equipment, trash can liners, and chairs. The item is to be ESD protective or non-static generative by design.
Color: The choice of color for this symbol is arbitrary. The color red shall not be used because it suggests a hazard to personnel. The preferred color is a yellow hand on a black background.
Note: In Europe per Packaging standard EN 61340-5-3 there is a requirement to place a letter under the triangle denoting the product’s primary ESD control function:
S electrostatic discharge shielding
F electrostatic field shielding
C electrostatic conductive
D electrostatic dissipative
If the letter is “L” the primary ESD control property is low charging (antistatic); if “EPA” is meant to indicate the product is designed to be used in an ESD protected area.
ESD Common Point Ground
This symbol is established to indicate an ESD common point ground, which is defined by ANSI/ESD-S6.1 as “a grounded device where two or more conductors are bonded.”
Application: The ESD common point ground symbol should be used to indicate the location of an acceptable common point ground as defined by ANSI/ESD-S6.1.
Format: This symbol consists of a bold outer circle inside of which are the words, ESD COMMON POINT GROUND, in bold type. Inside that are two thick contrasting circles and one thick circle that may fill the center or extend to the center where a snap, plug or other fastener may be connected.
Color: The choice of color for this symbol is arbitrary but black or white on green is suggested. The color red shall not be used because it suggests a hazard to personnel.
Note: In Europe, for the same purpose the Earth Bonding Point symbol is used:
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This is the third in a series of blogs concerning the Basics of ESD. Be sure to sign up for our blog to follow the series.