Keithley SourceMeter 2425, Руководство по обслуживанию

Страница: 86 / 141

Model 2425 Service Manual Disassembly 5-3
Static sensitive devices
CMOS devices operate at very high impedance levels. Therefore, any static that builds up
on you or your clothing may be sufficient to destroy these devices if they are not handled
properly. Use the following precautions to avoid damaging them:
CAUTION Many CMOS devices are installed in the Model 2425. Handle all
semiconductor devices as being static sensitive.
• Transport and handle ICs only in containers specially designed to prevent static
build-up. Typically, you will receive these parts in anti-static containers made of
plastic or foam. Keep these devices in their original containers until ready for
installation.
• Remove the devices from their protective containers only at a properly grounded
work station. Also, ground yourself with a suitable wrist strap.
• Handle the devices only by the body; do not touch the pins.
• Ground any printed circuit board into which a semiconductor device is to be
inserted to the bench or table.
• Use only anti-static type desoldering tools.
• Use only grounded-tip solder irons.
• Once the device is installed in the PC board, it is normally adequately protected,
and you can handle the boards normally.
Assembly drawings
Use the assembly drawings located at the end of this section to assist you as you disassem-
ble and re-assemble the Model 2425. Also, refer to these drawings for information about
the Keithley part numbers of most mechanical parts in the unit. Assembly drawings
include:
• Front panel assembly — 2430-040
• Analog board/heat sink/shield assembly — 2430-050
• Chassis assembly — 2430-051
• Chassis/analog board assembly — 2430-052
• Final chassis assembly — 2430-053