Definitions Related To Electrostatic

Antistatic
This can mean a wide variety of things, and is deprecated by the writers of 61340-5-1. Although the term is widely used, it is better to avoid it if possible.

ESD
ElectroStatic Discharge. When the electric field strength in air becomes sufficiently high, its insulating properties break down and charge can flow away in a rapid discharge. ESD can have very short duration high current levels and an cause ignition of flammable materials or damage to electronic components.

ESDS
ElectroStatic Dischage Sensitive device. An electronic component that could be damaged by ESD.

Field work
Handling of ESDS within a temporary EPA, for example at the customer's site.

EPA
ESD Protected Area. An area in which static electricity is kept below levels that could cause damage to electronic components handled within the area.

Ground
In the IEC 61340-5-1:2007, three types of ground are recognised, and may all be referred to as "ground"

• electrical mains protective earth. This is the usual method of connecting EPA ground to mains electrical safety earth.

• functional ground. A ground stake or other separate earth.

• equipotential bonding. In a case where no earth connection is available, it is sufficient to connect all ESD control items to a common connection point.

Intimate packaging
In IEC 61340-5-1:1998, this was defined as packaging that makes contact with ESDS, for example the inner surface of an ESD protective bag. It is not defined in 61340-5-1:2007.

Proximity packaging
In IEC 61340-5-1:1998, this was defined as material not making contact with ESDS but which is used to enclose one or more devices. For example the outer surface of an ESD protective bag, or ESD packaging used to contain ESDS already within other packaging. It is not defined in 61340-5-1:2007.

Secondary packaging
In IEC 61340-5-1:1998, this was defined as material used primarily to give additional physical protection to the outside of a proximity package. E.g. cardboard boxes, padded bags, polythene wrap. It is not defined in 61340-5-1:2007.

Low charging
In IEC 61340-5-1:1998, this was defined as packaging exhibiting properties which minimises any charge generation. It is not defined in 61340-5-1:2007.

Conductive
The word "conductive" has a range of meanings within the context of different standards and should be treated with care.

1. any material that conducts electricity, i.e. not an insulator

2. Within the old 61340-5-1:1998 "electrostatic conductive" packaging material was defined to have surface resistance between 10²ohms and 10⁵ohms. It is not defined in 61340-5-1:2007.

3. "conductive" has no specific meanings for other materials or equipment under 61340-5-1 although it is often generally used to indicate materials having resistance values < 10⁶ohms

4. specific meanings for other equipment are possible, e.g. "conductive footwear"

Dissipative
The word "dissipative" has a range of meanings within the context of different standards and should be treated with care.

1. Within the 61340-5-:1998, "electrostatic dissipative" packaging material was defined as having surface resistance between 10⁵ohms and 10¹¹ohms. It is not defined in 61340-5-1:2007.

2. "dissipative" has no specific meanings for other materials or equipment under 61340-5-1 although it is often generally used to indicate materials having resistance values < 10¹²ohms and > 10⁶ohms

3. specific meanings for other equipment are possible, e.g. "conductive footwear"

Electrostatic discharge shielding packaging
Packaging, barrier or enclosure that limits the passage of ESD current and attenuates the energy resulting from an electrostatic discharge such that the maximum energy from 1 000 V HBM ESD applied to the outside of the packaging is less than or equal to 50 nJ measured inside the packaging.

Surface resistance
This is the resistance of a surface measured by a concentric ring electrode test method defined in 61340-5-1and IEC 61340-2-3: 2000. It is NOT the same as "surface resistivity" and is typically about a factor of 10 less than surface resistivity as measured in the old EN100015 method.

Point-to-point resistance
The is the resistance measured between two electrodes placed on a surface, defined in 61340-5-1, IEC 61340-2-3: 2000 and ESD S11.11- 2001

Resistance-to-ground
This is the electrical resistance measured from a point to the ESD facility electrical earth (usually mains power earth).