Delta Tau PMAC Pack Hardware Reference Manual Download

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PMAC-Pack

Electrostatic Discharge Control

107

APPENDIX A - ELECTROSTATIC DISCHARGE CONTROL

General

Caution:

These procedures must be followed by anyone involved in handling PMAC-Pack
components. Failure to do so may void your warranty.

This Appendix describes control measures to be taken to protect against electrostatic discharge (ESD)
damage. Many of the PMAC-Pack components and circuit assemblies are electrostatic discharge sensitive
(ESDS) and can be damaged or destroyed by ESD levels of a few hundred volts, far below the threshold
of awareness. ESD can cause total failure of electronic parts, as well as intermittent failures or erroneous
signals. Latent or delayed failures can also be caused by ESD. Items already partially damaged by ESD
can check out electrically on the repair bench, but fail when subjected to the stresses of wide temperature
ranges, mechanical shock, and high g-forces.

Whenever ESDS parts are handled outside of their protective packaging or removed from the shielding of
the outside case of a piece of equipment, they must be in a protected area. A protected area is generally an
ESD workstation consisting of a grounded workbench, a personnel wrist strap, a grounded floor mat, and
grounded tools and equipment, all connected to a common ground. A portable ESD kit, consisting of a
non-conductive tablemat, a personnel wrist strap, and a grounding cord may be adequate for field
installations.

Guidelines

1. All persons handling ESDS items should be trained in ESD precautionary procedures.

2. Any electronic part received in ESD protective packaging must be considered ESDS.

Caution:

When ESDS items are handled outside their protective packaging, they should be
handled by the shunting device, without Touching the ESDS parts or electrical
runs.

3. ESDS items must be protected from electrostatic fields and ESD with shunts such as bars, clips, or

conductive foams, or be inside conductive coverings during storage, shipping, and transporting. The
ESD protective covers and shunts should be removed at a grounded workstation immediately before
being installed into the assembly for which it is intended.

The leads or connector terminals of ESDS items should not be probed with a multimeter without first
touching the probe to ground.

5. Tools and test equipment used in ESD protected areas must be properly grounded. Hand tools with

insulated handles should be treated with topical antistat. Hand tools should be neutralized before and
during use by contact with a grounded surface.

6. Power must not be applied to equipment or assemblies while ESDS items are being removed or

installed.

7. Documents used in ESD protected areas should not be enclosed in common plastic covers.

8. Tote boxes and containers should be contacted together or grounded to a common ground before

transferring ESDS parts from one to another.

9. Technical documentation should identify ESDS items and contain cautions to require that such items

be removed from their protective packaging only in ESD protected areas.