How to Prevent Electrostatic Discharge (ESD) Damage to Chips

How to Prevent Electrostatic Discharge (ESD) Damage to Chips

1. Understanding the Risk

When humans, tools, or materials accumulate static electricity, a sudden discharge (ESD) can occur when they contact sensitive components.

A discharge as low as 50–100 volts can permanently damage semiconductor junctions — while the human body can carry up to 30,000 volts of static in dry conditions.

Typical consequences of ESD include:

Immediate device failure (catastrophic damage)

Latent failure (chip seems fine but degrades over time)

Parameter drift (performance instability)

Yield loss in production

2. Engineering Measures to Prevent Chip ESD Damage

(1) Use of Ionizing Equipment

Ionizing bars, blowers, or guns neutralize static electricity in the air and on materials.

They release positive and negative ions that balance surface charges on:

PCB surfaces

Plastic trays and carriers

Film and packaging materials

Operator clothing or gloves

In chip packaging and SMT assembly lines, ionizers are installed:

Above conveyors and feeders

Near bonding, inspection, or packaging areas

At component transfer or loading stations

➡️ Result: Prevents charge buildup and discharge between tools, machines, and chips.

(2) Grounding Systems (Earthing)

All conductive equipment, workbenches, and operators must be properly grounded:

ESD-safe workbenches connected to a common ground line

Grounded soldering irons and pick-and-place machines

Operators wearing wrist straps and heel straps connected to ground

➡️ This provides a controlled discharge path and prevents voltage accumulation.

(3) ESD-safe Materials and Tools

Replace standard materials with ESD-safe versions, such as:

Conductive or dissipative flooring and mats

Antistatic tools (tweezers, trays, boxes, etc.)

ESD-safe packaging (black conductive bags, pink antistatic bubble film)

Ionized air guns for manual cleaning

➡️ These materials have surface resistance between 10⁶–10⁹ Ω, ensuring safe, gradual charge dissipation.

(4) Humidity and Environment Control

Maintain humidity in the production area between 40%–60% RH.

Dry air increases static buildup dramatically.

Use humidifiers, cleanroom ionizers, and air filters to ensure stable conditions.

(5) Operator Training and Procedures

Even with ESD-safe equipment, improper human handling can cause damage.

Operators should be trained to:

Always wear grounded wrist straps or ESD shoes

Avoid touching chip leads or pads directly

Handle components in ESD-safe containers

Check grounding points regularly

➡️ Periodic ESD audits ensure compliance and equipment integrity.

(6) Continuous Monitoring Systems

Modern ESD control systems use real-time monitors to track:

Ion balance and discharge voltage

Ground line continuity

Operator grounding status

When any parameter drifts from the safe range, alarms or indicators warn the operator.

➡️ This ensures continuous, measurable ESD control — critical in semiconductor packaging, wafer assembly, and test lines.

(7) ESD Protection Design at the Chip Level

Chip designers add on-chip ESD protection circuits, such as:

Diodes or SCR structures on I/O pads

Resistive paths to dissipate voltage

Clamping circuits to limit surge current

These protect sensitive gates and junctions during handling or test, complementing external ESD control.

3. Typical ESD Protection Setup in a Semiconductor Plant

A complete system includes:

Area Main ESD Protection Measures

Wafer Fab (Front-End) Ionizers, conductive benches, humidity control

Die Bonding / Wire Bonding Ionizing bars & blowers near bonding heads

Molding / Packaging ESD-safe trays, grounded machines

Inspection / Testing Grounded probers, shielded handlers

SMT Assembly Ionizers at feeders, soldering, and conveyors

Storage / Logistics Conductive racks, ESD-safe bags

4. Summary

To prevent chip ESD breakdown, a multi-layer protection system is essential:

Eliminate static at the source — use ionizers and maintain humidity.

Provide safe discharge paths — grounding for people and equipment.

Use ESD-safe tools and packaging — control charge transfer.

Train operators and monitor systems — maintain process discipline.

Design chip-level ESD protection — absorb residual surges.

➡️ Together, these ensure zero static damage, higher yield, and long-term reliability of semiconductor devices.