Desco - Questions And Answers

What would be the ESD advantages of having a system made of stainless steel as opposed to painted steel? Or is there really not much of a difference at all? -Anonymous

Depending on the thickness of the paint and the material composition the painted surface may add more protection from ESD Events. If the paint is not antistatic, then there is a concern with triboelectric generation. Even if the paint is insulative, a thin coating may still be somewhat conductive because of the underlying metal substrate. Test the painted surface according to the ESD S4.1 for electrical resistance.

Regardless, the SS surface is a great conductor and good material choice for a clean room, but not the best choice for ESD control, as the VERY conductive surface will cause an ESD Event whenever a charged conductor is brought into near proximity or contact. This is why most ESD controlled work surfaces are dissipative in the 1x10⁶ to 1x10⁹ ohms range as the suggested guideline for RTG on work surfaces stated in the ESD S4.1.

The main principal of ESD Control is to control ESD. A metal-to-metal contact will cause an ESD, not control it. But a metal to dissipative contact will bleed (slowly equalize) the charge imbalance in a controlled manner. If the painted (equipment) surface changed the contact resistance to the dissipative range, then the surface would better protect it’s contents and nearby electronics from ESD Events and possibly EMI (from an ESD Event).

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