Electronics

Consistent humidity levels (30%-50% RH), as part of an overall ElectroStatic Discharge (ESD) program of static electricity reduction, help to increase productivity, decrease waste from damage to components and to improve indoor air quality for both manufacturing and employee health. Most organizations do not recommend operations below 30% RH. The right humidity levels help you avoid:

• Catastrophic and latent component damage 
• Dust in the area
• Gluing problems
• Fluid viscosity inconsistencies

Static Electricity Problems

With humidity over 40% RH, surface resistance is lowered on floors, carpets, table mats and other areas. Moisture in the air forms a thin protective “film” on surfaces.

When humidity drops below 30%-40% RH, this protection disappears and normal employee activities lead to objects being charged with static electricity. When employees come in contact with work tables and components, the sparks fly. It’s annoying to people, but ESD often seriously damages electronic components.

Static electricity charge passes from ungrounded worker to a component. You first feel shocks at about 3,000 volts, but many electronic components may be damaged with a shock of as little as 500 volts! The chart below shows the improvement in ESD with controlled relative humidity conditions.

Optimum RH levels increase surface conductivity and decrease electrostatic discharges; reduced RH levels allow electrostatic charges to accumulate and spark. As the table shows, increasing RH substantially reduces (but does not eliminate) electrostatic charges and ESD.  

Controlled relative humidity between 40% and 60% in conjunction with an on-going ESD program is desirable in areas to be protected from static electricity. These humidity levels also increase the effectiveness of antistatic and ionization equipment.