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7.6 Ionization & Insulator Control

Grounding only works for conductors. Insulators (plastic housings, connector bodies, circuit board fiberglass) cannot be grounded; charge stays on them until it naturally decays (hours/days) or discharges into a sensitive component.

7.6.1 Active Neutralization (Ionization)

  • Requirement: Ionizers (overhead fans or point-of-use snakes) are mandatory at stations where essential insulators are handled (e.g., final assembly into plastic cases).
  • Performance Limits:
    • Decay Time: 1000V to 100V in < 2 seconds.
    • Offset Voltage (Balance): The ionizer must produce a balanced stream (± 35V). If the ionizer becomes unbalanced, it charges the product.

7.6.2 Packaging & Handling

  • Shielding: ESDS (Electrostatic Discharge Sensitive) items must be transported in Metal-In Shielding Bags (Silver). Pink Poly (Dissipative) bags are only for non-sensitive items; they do not shield against external fields.
  • Carts: Transport carts must have drag chains or conductive casters to maintain electrical contact with the ESD floor.

Final Checklist

Control

Limit

Maintenance Interval

Ionizer Decay

< 2.0 Seconds

Quarterly Calibration

Ionizer Balance

± 35 Volts

Quarterly Calibration

Shielding Bags

Metal-In Required

Visual Check

Cart Grounding

< $1.0 \times 10^9$ Ohms

Monthly Probe