Electrostatic discharge (ESD) safety: Which measure most directly reduces a technician’s ESD potential while working on sensitive electronics?

Introduction / Context:
Electrostatic discharge can damage semiconductor devices long before a human can feel a shock. Proper ESD control practices are vital when assembling, servicing, or transporting electronics.

Given Data / Assumptions:

• Work is performed at a bench with typical ESD controls available.
• The goal is to directly reduce a person’s electrostatic potential relative to ground and the device under service.
• Normal ESD-safe procedures (grounding points, mats) are in place or can be used.

Concept / Approach:

An antistatic wrist strap, when properly connected to a verified ground through a high-value resistor, equalizes potential between the technician and the equipment, preventing sudden discharges into components. While de-ionizing fans reduce ambient charge on surfaces and in air, the wrist strap directly controls the human body charge—the most common discharge source during handling.

Step-by-Step Solution:

Verification / Alternative check:

Use an ESD tester to confirm strap continuity and proper resistance to ground. Observe reduced failure rates and avoid latent defects associated with ESD events.

Why Other Options Are Wrong:

• De-ionizing fans: Helpful, but they do not directly and reliably ground the technician.
• Rubber gloves with cap: Not an ESD control method and can increase triboelectric charging.
• A static meter: Diagnostic tool; does not reduce potential on its own.
• None of the above: Incorrect because a wrist strap is the standard control.

Common Pitfalls:

Failing to test the strap; clipping to floating or painted metal; removing the strap mid-task; ignoring ESD-safe packaging and footwear.

Final Answer:

A wrist strap