HP EliteBook 630 Maintenance and Service Guide - Page 38

Preventing electrostatic damage to equipment, Personal grounding methods and equipment

Page 38 highlights

Table 4-1 Static electricity occurrence based on activity and humidity (continued) Relative humidity Event Motions of bench worker 55% 400 V 40% 800 V Removing DIPs (dual in-line packages) from plastic tube 400 V 700 V Removing DIPs from vinyl tray 2,000 V 4,000 V Removing DIPs from polystyrene foam 3,500 V 5,000 V Removing bubble pack from PCB (printed circuit board) 7,000 V 20,000 V Packing PCBs in foam-lined box 5,000 V 11,000 V Multiple electric components can be packaged together in plastic tubes, trays, or polystyrene foam. 10% 6,000 V 2,000 V 11,500 V 14,500 V 26,500 V 21,000 V NOTE: As little as 700 V 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 static electricity damage to electronic components. ● To avoid hand contact, transport products in static-safe containers such as tubes, bags, or boxes. ● Protect all electrostatic parts and assemblies with conductive or approved containers or packaging. ● Keep electrostatic-sensitive parts in their containers until they arrive at static-free stations. ● 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-sensitive parts from assemblies in protective packaging or conductive foam. Personal grounding methods and equipment Using certain equipment can prevent static electricity damage to electronic components. ● Wrist straps are flexible straps with a maximum of 1 MΩ ±10% resistance in the ground cords. To provide proper ground, a strap must be worn snug against bare skin. The ground cord must be connected and fit snugly into the banana plug connector on the grounding mat or workstation. ● Heel straps/Toe straps/Boot straps can be used at standing workstations and are compatible with most types of shoes or boots. On conductive floors or dissipative floor mats, use them on both feet with a maximum of 1 MΩ ±10% resistance between the operator and ground. Table 4-2 Static shielding protection levels Static shielding protection levels Method Voltage Antistatic plastic 1,500 30 Chapter 4 Removal and replacement procedures preliminary requirements

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Table 4-1
Static electricity occurrence based on activity and humidity
(continued)
Relative humidity
Event
55%
40%
10%
Motions of bench worker
Removing DIPs (dual in-line packages) from plastic tube
400 V
400 V
800 V
700 V
6,000 V
2,000 V
Removing DIPs from vinyl tray
Removing DIPs from polystyrene foam
Removing bubble pack from PCB (printed circuit board)
Packing PCBs in foam-lined box
2,000 V
3,500 V
7,000 V
5,000 V
4,000 V
5,000 V
20,000 V
11,000 V
11,500 V
14,500 V
26,500 V
21,000 V
Multiple electric components can be packaged together in plastic tubes, trays, or polystyrene foam.
NOTE:
As little as 700 V 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 static electricity
damage to electronic components.
To avoid hand contact, transport products in static-safe containers such as tubes, bags, or boxes.
Protect all electrostatic parts and assemblies with conductive or approved containers or packaging.
Keep electrostatic-sensitive parts in their containers until they arrive at static-free stations.
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-sensitive parts from assemblies in protective packaging or conductive foam.
Personal grounding methods and equipment
Using certain equipment can prevent static electricity damage to electronic components.
Wrist straps
are flexible straps with a maximum of 1 MΩ ²10% resistance in the ground cords. To provide
proper ground, a strap must be worn snug against bare skin. The ground cord must be connected and fit
snugly into the banana plug connector on the grounding mat or workstation.
Heel straps/Toe straps/Boot straps
can be used at standing workstations and are compatible with most
types of shoes or boots. On conductive floors or dissipative floor mats, use them on both feet with a
maximum of 1 MΩ ²10% resistance between the operator and ground.
Table 4-2
Static shielding protection levels
Static shielding protection levels
Method
Voltage
Antistatic plastic
1,500
30
Chapter 4
Removal and replacement procedures preliminary requirements