Generating static
The following table shows that:
{Different activities generate different amounts of static electricity.
{Static electricity increases as humidity decreases.
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| Relative Humidity |
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Event | 55% | 40% | 10% |
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Walking across carpet | 7,500 V | 15,000 V | 35,000 V |
Walking across vinyl floor | 3,000 V | 5,000 V | 12,000 V |
Motions of bench worker | 400 V | 800 V | 6,000 V |
Removing DIPs from plastic tube | 400 V | 700 V | 2,000 V |
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Removing DIPs from vinyl tray | 2,000 V | 4,000 V | 11,500 V |
Removing DIPs from Styrofoam | 3,500 V | 5,000 V | 14,500 V |
Removing bubble pack from PCB | 7,000 V | 20,000 V | 26,500 V |
Packing PCBs in | 5,000 V | 11,000 V | 21,000 V |
These are then
NOTE: 700 volts can degrade a product.
Preventing electrostatic damage to equipment
Many electronic components are sensitive to ESD. Circuitry design and structure determine the degree of sensitivity. The following packaging and grounding precautions are necessary to prevent damage to electric components and accessories.
{To avoid hand contact, transport products in
{Protect all electrostatic parts and assemblies with conductive or approved containers or packaging.
{Keep electrostatic sensitive parts in their containers until they arrive at
{Place items on a grounded surface before removing them from their container.
{Always be properly grounded when touching a sensitive component or assembly.
{Avoid contact with pins, leads, or circuitry.
{Place reusable
Electrostatic discharge information | 29 |