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Difficulty: MediumIntegrated Circuits

When replacing or handling Complementary Metal-Oxide-Semiconductor (CMOS) integrated circuits on a circuit board, why is it critical for a technician to wear an antistatic wrist strap connected to ground?

  1. A
    To bridge circuit board traces and allow insulating materials to conduct high current
  2. To safely dissipate static electricity from the body before it can puncture microscopic gate oxide layersAnswer
  3. C
    To switch internal bipolar transistor configurations from NPN mode to PNP mode during operation
  4. D
    To convert stray alternating current (AC) power line interference into direct current (DC)

Answer

To safely dissipate static electricity from the body before it can puncture microscopic gate oxide layers
CMOS integrated circuits contain field-effect transistors featuring microscopic silicon dioxide gate insulation layers. Because the human body can carry several thousand volts of static electricity unnoticed, touching an unprotected integrated circuit can cause electrostatic discharge (ESD) that punctures this insulation, causing irreversible chip failure. A grounded antistatic wrist strap safely discharges static electricity before it reaches sensitive components.

Step-by-Step Solution

1
Identify the internal construction of CMOS integrated circuits
CMOS devices use field-effect transistors that rely on extremely thin silicon dioxide insulating layers at their gates
Understanding the physical structure explains the component's vulnerability to high-voltage spikes
2
Determine the effect of electrostatic discharge (ESD) and the role of grounding
Static electricity accumulated on the human body can reach thousands of volts, which easily arcs across and destroys microscopic oxide insulation
A grounded antistatic wrist strap continuously bleeds electrostatic charges safely to ground before they can discharge into the IC

Key Concept

Electrostatic discharge (ESD) protection for CMOS integrated circuits
Estimated Time:1m 0s
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Topics

Integrated Circuits

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