Siemens PC 870 用户手册
Appendix B: ESD Guidelines
B-2
SIMATIC Panel PC 670 / 870 Operating Unit, Equipment Manual
Edition 07/01
Handling ESD assemblies
A general rule is that assemblies should be touched only when this cannot be avoi-
ded in the course of the work that has to performed on them. Under no circumstan-
ces should you touch device pins or circuitry when handling printed-circuit boards.
ded in the course of the work that has to performed on them. Under no circumstan-
ces should you touch device pins or circuitry when handling printed-circuit boards.
You should touch devices only if
you are grounded by permanently wearing an ESD wrist strap or
you are wearing ESD shoes or ESD shoe-grounding protection straps in con-
junction with an ESD floor.
junction with an ESD floor.
Before you touch an electronic assembly, your body must be discharged. The
simplest way of doing this is to touch a conductive, grounded object immediately
beforehand (e.g. bare metal parts of a cabinet, water pipe, etc.).
simplest way of doing this is to touch a conductive, grounded object immediately
beforehand (e.g. bare metal parts of a cabinet, water pipe, etc.).
Assemblies should not be brought into contact with charge-susceptible and highly
insulating materials such as plastic films, insulating table tops and items of clothing
etc. containing synthetic fibers.
insulating materials such as plastic films, insulating table tops and items of clothing
etc. containing synthetic fibers.
Assemblies should be deposited only on conductive surfaces (tables with an ESD
coating, conductive ESD cellular material, ESD bags, ESD shipping containers).
coating, conductive ESD cellular material, ESD bags, ESD shipping containers).
Do not place assemblies near visual display units, monitors or television sets
(minimum distance to screen > 10 cm).
(minimum distance to screen > 10 cm).
Measuring and modifying ESD assemblies
Perform measurements on ESD assemblies only if
the measuring instrument is grounded (e.g. by means of a protective
conductor) or
conductor) or
the measuring head has been briefly discharged before measurements are
made with a potential-free measuring instrument (e.g. by touching a bare metal
control cabinet).
made with a potential-free measuring instrument (e.g. by touching a bare metal
control cabinet).
When soldering, use only grounded soldering irons.
Shipping ESD assemblies
Always store and ship assemblies and devices in conductive packing,
e.g. metallized plastic boxes and tin cans.
e.g. metallized plastic boxes and tin cans.
If packing is not conductive, assemblies must be conductively wrapped before they
are packed. You can use, for example, conductive foam rubber, ESD bags, dome-
stic aluminum foil or paper (never use plastic bags or foils).
are packed. You can use, for example, conductive foam rubber, ESD bags, dome-
stic aluminum foil or paper (never use plastic bags or foils).
With assemblies containing fitted batteries, make sure that the conductive packing
does not come into contact with or short-circuit battery connectors. If necessary,
cover the connectors beforehand with insulating tape or insulating material.
does not come into contact with or short-circuit battery connectors. If necessary,
cover the connectors beforehand with insulating tape or insulating material.