WHY ESD PROTECTION MATTERS
ESD or electrostatic discharge is the silent killer of mobile phones.
A small static charge invisible to the eyes can burn chips instantly or cause damage that appears days later.
Many phones work after repair but fail again due to hidden ESD damage.
Modern phone motherboards contain tiny and sensitive ICs that can get damaged even by 30 to 100 volts.
A human body can carry more than 5000 volts without any feeling — that’s why proper grounding is a must.
Following ESD SOP builds trust, reduces rework and protects every board you repair.
STEP-BY-STEP ESD & GROUNDING SOP
Setup a Common Ground Point (CGP)• Install a ground block or bench socket connected directly to earth ground.
• Use star grounding so every device connects separately to CGP.
• Label the CGP clearly and keep cords neat and secure.
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Ground the ESD Mat• Place an ESD-safe mat on your bench.
• Connect Mat Snap → CGP using a ground cord with a 1 MΩ resistor.
• Check with multimeter: Expected reading ≈ 1 MΩ between mat snap and CGP.
• If reading shows 0 Ω replace the cord — resistor is bypassed.
• Keep the mat clean and avoid plastic or paper on top.
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Wear and Ground the Wrist Strap• Strap must touch bare skin and fit tight on your wrist or arm.
• Connect strap cord → CGP (or to mat snap linked to CGP).
• Check with multimeter:
✔ Pass: 1–10 MΩ
Infinite: bad contact or broken cord⚠ 0 Ω: unsafe, replace immediately
The 1 MΩ resistor in strap protects you while bleeding static slowly to ground.
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Ground All Tools & Equipment• Ground the soldering station, rework gun, and any test device to CGP separately.
• Never daisy chain tools together.
• A star layout keeps all grounds equal and safe.
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Verify the Setup with a Multimeter• Use a digital multimeter (Fluke or equivalent).
- Mat snap → CGP ≈ 1 MΩ
- Strap clip → CGP 1–10 MΩ
- Soldering tip → CGP under 2 Ω
• Record readings weekly for consistency.
DAILY ROUTINE (60 SECONDS)
1. Test strap and mat cords before starting work
2. Inspect cords, snaps and CGP connections
3. Confirm CGP is connected to wall ground
4. Begin repairs only after all checks pass
That one-minute habit can save hours of frustration and costly rework.
STAR GROUNDING EXPLAINED
In a star layout every device connects individually to the CGP instead of linking through another tool.
This prevents voltage differences and stops static from flowing through the motherboard you’re working on.
QUICK REFERENCE VALUES
| Item | Expected Value | Notes |
|---|---|---|
| Wrist Strap Cord | ~1 MΩ | Built-in resistor |
| Strap → CGP | 1–10 MΩ | Pass range |
| Mat Snap → CGP | ~1 MΩ | Cord resistor |
| Mat Surface | 10⁶–10⁹ Ω | Dissipative layer |
| Solder Tip → CGP | < 2 Ω | Direct ground |
PROFESSIONAL TIPS• Maintain humidity between 40–60%
• Avoid plastic trays, papers or bubble wrap on the mat
• Store parts only in ESD-safe bags or boxes
• Replace damaged cords or mats quickly
• Train every team member to check grounding before touching a board
FINAL NOTE
Static is invisible but its damage is permanent.
Proper grounding is your shield against hidden failures and your mark of true professionalism.
A grounded workstation shows skill, care and pride in your work.
Be proud to follow ESD SOP — it defines a real technician!
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