[6] Handling Guide
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•
When storing printed circuit boards which have devices mounted on them, use a board
container or bag that is protected against static charge. To avoid the occurrence of static
charge or discharge due to friction, keep the boards separate from one other and do not
stack them directly on top of one another.
•
Ensure, if possible, that any articles (such as clipboards) which are brought to any location
where the level of static electricity must be closely controlled are constructed of anti-static
materials.
•
In cases where the human body comes into direct contact with a device, be sure to wear
anti-static finger covers or gloves (suggested resistance value: 10
8
Ω
or less).
•
Equipment safety covers installed near devices should have resistance ratings of 10
9
Ω
or
less.
•
If a wrist strap cannot be used for some reason, and there is a possibility of imparting
friction to devices, use an ionizer.
3.1.2
Vibration, Impact and Stress
Handle devices and packaging materials with care. To avoid damage
to devices, do not toss or drop packages. Ensure that devices are not
subjected to mechanical vibration or shock during transportation.
Ceramic package devices and devices in canister-type packages which
have empty space inside them are subject to damage from vibration
and shock because the bonding wires are secured only at their ends.
Plastic molded devices, on the other hand, have a relatively high
level of resistance to vibration and mechanical shock because their bonding wires are enveloped and
fixed in resin. However, when any device or package type is installed in target equipment, it is to
some extent susceptible to wiring disconnections and other damage from vibration, shock and
stressed solder junctions. Therefore when devices are incorporated into the design of equipment
which will be subject to vibration, the structural design of the equipment must be thought out
carefully.
If a device is subjected to especially strong vibration, mechanical shock or stress, the package or the
chip itself may crack. In products such as CCDs which incorporate window glass, this could cause
surface flaws in the glass or cause the connection between the glass and the ceramic to separate.
Furthermore, it is known that stress applied to a semiconductor device through the package
changes the resistance characteristics of the chip because of piezoelectric effects. In analog circuit
design attention must be paid to the problem of package stress as well as to the dangers of vibration
and shock as described above.
Vibration
