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3.
General Safety Precautions and Usage Considerations
This section is designed to help you gain a better understanding of semiconductor devices, so as to
ensure the safety, quality and reliability of the devices which you incorporate into your designs.
3.1
From Incoming to Shipping
3.1.1
Electrostatic Discharge (ESD)
When handling individual devices (which are not yet mounted on a printed
circuit board), be sure that the environment is protected against electrostatic
electricity. Operators should wear anti-static clothing, and containers and
other objects which come into direct contact with devices should be made of
anti-static materials and should be grounded to earth via an 0.5 to 1.0-MΩ
protective resistor.
Please follow the precautions described below; this is particularly
important for devices which are marked "Be careful of static.".
(1) Work environment
•
When humidity in the working environment decreases, the human body and other
insulators can easily become charged with static electricity due to friction. Maintain the
recommended humidity of 40% to 60% in the work environment, while also taking into
account the fact that moisture-proof-packed products may absorb moisture after unpacking.
•
Be sure that all equipment, jigs and tools in the working area are grounded to earth.
•
Place a conductive mat over the floor of the work area, or take other appropriate measures,
so that the floor surface is protected against static electricity and is grounded to earth. The
surface resistivity should be 10
7.5 × 10
•
Cover the workbench surface also with a conductive mat (with a surface resistivity of 10
8
10
this is to disperse static electricity on the surface (through resistive components) and
ground it to earth. Workbench surfaces must not be constructed of low-resistance metallic
materials that allow rapid static discharge when a charged device touches them directly.
•
Pay attention to the following points when using automatic equipment in your workplace:
(a) When picking up ICs with a vacuum unit, use a conductive rubber fitting on the end of the
pick-up wand to protect against electrostatic charge.
(b)
Minimize friction on IC package surfaces. If some rubbing is unavoidable due to the device's
mechanical structure, minimize the friction plane or use material with a small friction
coefficient and low electrical resistance. Also, consider the use of an ionizer.
(c)
In sections which come into contact with device lead terminals, use a material which
dissipates static electricity
(d) Ensure that no statically charged bodies (such as work clothes or the human body) touch the
devices
5
8
Ω
to 10
Ω/sq, for a resistance between surface and ground of 7.5 × 10
4
8
to 10
Ω/sq and the resistance between surface and ground,
96
[6] Handling Guide
5
8
Ω) . The purpose of
to 10
4
to
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