Lake Shore Cryotronics Measure Ready M91 FastHall, Руководство пользователя

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1.11.1 Electrostatic
Discharge Electrostatic discharge (ESD) may damage electronic parts, assemblies, and equip-
ment. ESD is a transfer of electrostatic charge between bodies at different electro-
static potentials caused by direct contact or induced by an electrostatic field. The
low-energy source that most commonly destroys electrostatic discharge sensitive
devices is the human body, which generates and retains static electricity. Simply
walking across a carpet in low humidity may generate up to 35,000 V of
static electricity.
Current technology trends toward greater complexity, increased packaging density,
and thinner dielectrics between active elements, which result in electronic devices
with even more ESD sensitivity. Some electronic parts are more ESD sensitive than
others. ESD levels of only a few hundred volts may damage electronic components
such as semiconductors, thick and thin film resistors, and piezoelectric crystals
during testing, handling, repair, or assembly. Discharge voltages below 4000 V cannot
be seen, felt, or heard.
1.11.2 Identification of
Electrostatic Discharge
Sensitive Components The following are various industry symbols used to label components as
ESD sensitive.
FIGURE 1-16
Symbols indicating ESD sensitivity
1.11.3 Handling
Electrostatic Discharge
Sensitive Components Observe all precautions necessary to prevent damage to ESDS components before
attempting installation. Bring the device and everything that contacts it to ground
potential by providing a conductive surface and discharge paths. As a minimum,
observe these precautions:
D
De-energize or disconnect all power and signal sources and loads used with unit
D
Place unit on a grounded conductive work surface
D
Technician should be grounded through a conductive wrist strap (or other device)
using 1 M series resistor to protect operator
D
Ground any tools, such as soldering equipment, that will contact unit. Contact
with operator's hands provides a sufficient ground for tools that are otherwise
electrically isolated.
D
Place ESD sensitive devices and assemblies removed from a unit on a conductive
work surface or in a conductive container. An operator inserting or removing a
device or assembly from a container must maintain contact with a conductive
portion of the container. Use only plastic bags approved for storage of
ESD material.
Do not handle ESD sensitive devices unnecessarily or remove them from the packages
until they are actually used or tested.