Compaq Evo N150 Maintenance And Service Manual page 66

Non-conductive plastic bags, tubes, or boxes


Metal tote boxes


Electrostatic voltage levels and protective materials


Table 4-1 shows how humidity affects the electrostatic voltage
levels generated by different activities.
Walking across carpet
Walking across vinyl floor
Motions of bench worker
Removing DIPS from plastic tube
Removing DIPS from vinyl tray
Removing DIPS from Styrofoam
Removing bubble pack from PCB
Packing PCBs in foam-lined box
A product can be degraded by as little as 700 volts.


Table 4-2 lists the shielding protection provided by antistatic bags
and floor mats.
Material
Antistatic plastic
Carbon-loaded plastic
Metallized laminate
Maintenance and Service Guide
Typical Electrostatic Voltage Levels
Event
Static-Shielding Materials
Use
Bags
Floor mats
Floor mats
Removal and Replacement Preliminaries
Table 4-1
10%
35,000 V
12,000 V
6,000 V
2,000 V
11,500 V
14,500 V
26,500 V
21,000 V
Table 4-2
Voltage Protection Level
1,500 V
7,500 V
5,000 V
Relative Humidity
40%
15,000 V
5,000 V
800 V
700 V
4,000 V
5,000 V
20,000 V
11,000 V
55%
7,500 V
3,000 V
400 V
400 V
2,000 V
3.500 V
7,000 V
5,000 V
4–7