3.1 ESD Program Governance
Electrostatic Discharge (ESD) is the silent killer of yield. A discharge of <100V—too small for a human to feel—can puncture a gate oxide, causing latent failures that only appear months after shipment. Governance is not administrative; it is the control logic that ensures our physical infrastructure (flooring, ionization, grounding) continuously suppresses static charge below the Human Body Model (HBM) and Charged Device Model (CDM) damage thresholds of our most sensitive components.
Program Roles & Decision Authority
Effective ESD control requires a separation of powers between those who execute the process and those who define the physics.
ESD Program Manager (EPM):
- Function: System Architect.
- Authority: Has absolute veto power over any material, equipment, or process entering the ESD Protected Area (EPA).
- Mandate: Defines the technical standard (ANSI/ESD S20.20 / IEC 61340) and manages the Approved Products List (APL).
Facility Manager:
- Function: Infrastructure Owner.
- Mandate: Maintains the "Hard Ground" (Earth) integrity (< 1 Ω), relative humidity levels (40% – 60% RH), and dissipative flooring properties.
Operations Lead:
- Function: Execution.
- Mandate: Enforces daily discipline (wrist straps, smocks, footwear testing) among line operators.
Training Logic & Access Control
Access to the EPA is a privilege, not a right. Training certification acts as the digital key.
Decision Logic: Training Tiers
- IF personnel enters the EPA (Cleaning, Logistics, Management) → THEN Tier 1: ESD Awareness required (Annual).
- Focus: "Don't Touch" policy, boundary recognition, footwear testing.
- IF personnel handles open components (Operators, Technicians) → THEN Tier 2: ESD Handling Certification required (Bi-Annual).
- Focus: Grounding physics, ionization usage, packaging rules.
- IF personnel audits the system (QA, EHS) → THEN Tier 3: TR53 Compliance Verification training required.
- Focus: Resistance measurements, field meter usage, charge decay analysis.
Pro-Tip: Integrate ESD testing turnstiles with the door access system. No Pass (footwear/wrist strap) = No Entry. This removes the "human enforcement" variable.
The Approved Products List (APL)
The EPA is a whitelist environment. Only materials proven to be dissipative or conductive may enter.
Material Qualification Protocol
Do not rely on vendor datasheets. Vendors often test under ideal conditions (12% RH vs 50% RH).
- Step 1: Request a sample.
- Step 2: Condition sample at 12% RH for 48 hours (simulating worst-case winter dryness).
- Step 3: Measure Surface Resistance (Rtt/Rtg).
- IF 1.0 x 10^4 ≤ R < 1.0 x 10^9 Ω → THEN Pass (Dissipative).
- IF R < 1.0 x 10^4 Ω → THEN Caution (Conductive – Risk of rapid discharge/spark).
- IF R ≥ 1.0 x 10^9 Ω → THEN Fail (Insulative – Charging Hazard).
Critical Rule: All insulators (standard tape, plain plastic binders, styrofoam cups) are banned from the EPA unless treated or neutralized by ionization.
Pro-Tip: Pink Poly bags (anti-static) rely on chemical surfactants that degrade over time. Expire them after 12 months or verify resistance before use.
Final Checklist
Control Parameter | Specification / Limit | Frequency | Owner |
EPA Grounding | < 1.0 Ω AC Impedance to Earth | Annually | Facilities |
Flooring Resistance | < 1.0 x 10^9 Ω | Quarterly | ESD Manager |
Personal Grounding | Wrist Strap: < 35 MΩ Footwear: < 100 MΩ | Daily (Entry) | Operations |
Ionization Offset | ± 35 Volts balance | Monthly | Maintenance |
Humidity Control | 30% – 60% RH | Continuous | Facilities |
APL Compliance | 100% of materials on Whitelist | Random Audit | QA / ESD |