ESD and cleanroom glossary

ESD terms

Term	Meaning
ESD	Electrostatic discharge: a sudden flow of charge between objects at different potential.
ESDS	ESD sensitive item: a part or assembly that static can damage.
EPA	ESD protected area: a marked space where ESD controls are in place.
HBM	Human body model: a test that simulates a discharge from a person.
CDM	Charged device model: a test that simulates a charged part discharging to a surface.
MM	Machine model: an older test that simulates discharge from a machine.
Conductive	Surface resistance below 1 x 10^4 ohm.
Static dissipative	Surface resistance from 1 x 10^4 up to below 1 x 10^11 ohm.
Insulative	Surface resistance of 1 x 10^11 ohm or more.
Anti-static	A material that generates little charge. It is not the same as dissipative.
Static shielding	Packaging that protects contents from external static fields and discharge.
Equipotential bonding	Connecting items together so they stay at the same voltage.
Ionisation	Using ions to neutralise charge on insulators that cannot be grounded.
Triboelectric charging	Charge made when two materials touch and separate.

Term	Meaning
MBB	Moisture barrier bag: a bag that blocks water vapour.
MSD / MSL	Moisture sensitive device and its moisture sensitivity level.
HIC	Humidity indicator card: shows the humidity inside a sealed bag.
Desiccant	A material that absorbs moisture inside a sealed bag.

Term	Meaning
ISO class	The cleanliness level of the air, set by particle counts under ISO 14644-1.
Particle count	How many particles of a given size are in a volume of air.
Lint free	A material made to release very few fibres. None is truly free of them.
Extractables	Chemicals a material can release into a solvent or surface.
Sealed edge	A wiper edge fused by heat or laser so it does not fray.
Tacky mat	A peel-off adhesive mat that lifts dust from shoes and wheels.
Gowning	Putting on cleanroom garments in a set order.
Autoclave	A steam steriliser.