Section IV. ELECTROSTATIC DISCHARGE (ESD) AWARENESS
Scope. It is essential to understand the nature of electrostatic discharge (ESD), what causes it, and the
problems it can cause. This section contains information on the areas of major concern.
Electrostatic Discharge (ESD). A sudden and rapid transfer of electrons or charge between two objects.
An example of ESD is the shock received after walking across a carpet and touching a metallic object,
like a door knob.
Electrostatic Discharge Sensitive (ESDS) Items. All noninstalled electronic components, circuit cards
and assemblies with sensitive labels. Items that fall within the Federal Supply Class (FSC) 5905, 5960,
5961, or 5962 should be treated as sensitive unless known to be otherwise.
ESD Protective Material. Conductive, antistatic, and static dissipative are all types of materials that are
used to protect against ESD. Static dissipative materials are preferred because the charge dissipates
across the surface at a controlled rate.
Typical Prime Charge Sources. Means of generating electrostatic charges (voltage) and their relationship to
relative humidity are shown in table 8-7.
Table 8-7. Means of Static Charge Generation and the Associated Voltages
MEANS OF STATIC GENERATION
ELECTROSTATIC VOLTAGES WITH
10 - 20 %
65 - 90 %
PERCENTAGE OF RELATIVE HUMIDITY
WALKING ACROSS CARPET
WALKING ON VINYL FLOOR
WORKER AT WORKBENCH
Change 3 8-26