This article relies largely or entirely on a single source .(September 2014) |
Electrostatic discharge materials (ESD materials) are plastics that reduce static electricity to protect against damage to electrostatic-sensitive devices (ESD) or to prevent the accidental ignition of flammable liquids or gases.
The properties relevant to a material in an ESD context are: [1] [2]
Material | Ohms per square | Shielding | Antistatic | Dissipation | Isolation | Purpose |
---|---|---|---|---|---|---|
Metals | < 10−3 | Yes | Yes | Too fast | No | Used as shielding layer in some moisture-barrier laminates (ESD bag). |
Metalized film | 10-1 to 102 | Yes | Yes | Too fast | Yes | Used as part of shielding laminates and some moisture-barrier laminates (ESD bag). Always appears silvery-translucent. |
Carbons (graphite powders and fiber) | 1 to 103 | Yes | Yes | Too fast | No | Not used in pure form as it generates powder easily. May be incorporated into composite materials. |
Conductive plastic (carbon-loaded) | 103 to 105 | 30% [1] | Yes | Yes | No | Used as a film to make ESD bags. Also used to make solid plastic pieces (e.g. boxes), foam, and bubble-wrap. Always appears opaque black. |
Dissipative plastic | 107 to 1011 | < 10% | Yes | Yes | Yes | Used as a film to make ESD bags. Also used as a part of shielding laminates. Also used to make foam and bubble-wrap. Typically translucent pink due to added coloring. |
Insulators and base polymers | > 1013 | No | No | No | Yes | Not an ESD material: charges will build up. |