Electrostatic discharge

Overview

Electrostatic discharge (ESD) (for example, caused by touching with the hand) can destroy semiconductor components. The correct operation of the complete system is then no longer assured.

ESD warning

NOTICE

ESD hazard

ESD can destroy electronic components.

Always keep circuit packs in antistatic covers. Use the original packaging if possible. Use a static ground wrist strap whenever handling circuit packs or working on the Alcatel-Lucent 1850 TSS-5 system to prevent ESD damage to sensitive components.

All semiconductor components are basically sensitive to ESD. The ESD can also affect the components indirectly.

ESD considerations

This section describes the precautions required to prevent ESD damage.

Circuit pack handling precautions

Industry experience has shown that all integrated circuit packs can be damaged by static electricity that builds up on work surfaces and personnel. The static charges are produced by various charging effects of movement and contact with other objects. Dry air allows greater static charges to accumulate. Higher potentials are measured in areas with low relative humidity, but potentials high enough to cause damage can occur anywhere.

Observe the following precautions when handling circuit packs/units to prevent ESD damage.

Assume all circuit packs contain solid-state electronic components that can be damaged by ESD.
When handling circuit packs (for example storing, installing, and removing) or when working on the backplane, always wear a grounded wrist strap or wear a heel strap and stand on a grounded, static-dissipating floor mat.
Wear working garment made of 100% cotton to avoid ESD.
Handle all circuit packs by the faceplate or latch and by the top and bottom outermost edges. Never touch the components, conductors, or connector pins.
Store and ship circuit packs and components in their shipping packing. Circuit packs and components must be packed and unpacked only at workplaces suitably protected against build-up of charge.
Observe all warning labels on bags and cartons. Whenever possible, do not remove circuit packs from antistatic packaging until ready to insert them into slots.
If possible, open all circuit packs at a static-safe work position, using properly grounded wrist straps and static-dissipating table mats.
Always store and transport circuit packs in static-safe packaging. Shielding is not required unless specified.
Keep all static-generating materials such as food wrappers, plastics, and Styrofoam® containers away from all circuit packs. When removing circuit packs from a shelf, immediately place the circuit packs in static-safe packages.
Whenever possible, maintain relative humidity above 20 percent.

Important!

Ensure that any connectors on the shelf interconnection panel that are not cabled are fitted with a plastic dust cap to provide ESD protection.

Static control wrist straps

To reduce the possibility of ESD damage, the Alcatel-Lucent 1850 TSS-5 shelf is equipped with an ESD grounding jack to enable personnel to ground themselves using wrist straps [ Figure 1-2, Static control wrist strap], while handling circuit packs or working on the shelf. Check the wrist straps periodically with a wrist strap tester to ensure that they are working properly.

Figure 1-2: Static control wrist strap

Important!

The grounding jack is located on the front of the wall-mounted and rack-mounted shelves.

Barred-hand symbol

Circuit packs containing components that are especially sensitive to ESD are identified by warning labels bearing the barred-hand symbol. The following figure shows the barred-hand symbol.