EMI Bites: Challenges of Plastic Enclosures for ESD Protection
What happens when your device has a plastic enclosure instead of a metallic one?
Why this matters:
- Plastic enclosures don’t trigger ESD events like metal chassis can.
- However, plastic offers poor insulation: ESD can still reach and damage internal circuits.
- Plastic enclosures don’t shield against electromagnetic fields created by nearby ESD events.
- Without a metal chassis, there’s no easy low-impedance path to discharge ESD safely.
Key Insight:
Plastic enclosures reduce one risk but create others, especially by offering no shielding or discharge path.
How to protect devices with plastic enclosures:
- Add internal conductive coatings or shielding layers inside the enclosure.
- Use dedicated ESD protection components near sensitive circuits.
- Design an alternative low-impedance discharge path for ESD energy.
- Test for radiated ESD effects, not just direct contact.
—Dario
P.S. Want more EMI control strategies to pass EMC?