Table 4-1 typical electrostatic voltage levels, Table 4-2 static-shielding materials – Compaq V300 User Manual

Page 94

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4-6

Removal and Replacement Preliminaries

COMPAQ CONFIDENTIAL - NEED TO KNOW REQUIRED

Writer: David Calvert Saved by: The Integrity Group Saved date: 10/26/00 11:46 AM

Part Number: 128679-006 File name: Ch04

Table 4-1 shows how humidity affects the electrostatic voltage levels
generated by different activities.

Table 4-1

Typical Electrostatic Voltage Levels

Relative Humidity

Event

10%

40%

55%

Walking across carpet

35,000 V

15,000 V

7,500 V

Walking across vinyl floor

12,000 V

5,000 V

3,000 V

Motions of bench worker

6,000 V

800 V

400 V

Removing DIPS from plastic
tube

2,000 V

700 V

400 V

Removing DIPS from vinyl tray

11,500 V

4,000 V

2,000 V

Removing DIPS from Styrofoam 14,500 V

5,000 V

3,500 V

Removing bubble pack from
PCB

26,500 V

20,000 V

7,000 V

Packing PCBs in foam-lined
box

21,000 V

11,000 V

5,000 V

NOTE: 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.

Table 4-2

Static-Shielding Materials

Material

Use

Voltage Protection Level

Antistatic plastic

Bags

1,500 V

Carbon-loaded plastic Floor mats

7,500 V

Metallized laminate

Floor mats

15,000 V

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