6] handling guide – Toshiba Semiconductor User Manual
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[6] Handling Guide
97
(e) Make sure that sections of the tape carrier which come into contact with installation devices
or other electrical machinery are made of a low-resistance material.
(f) Make sure that jigs and tools used in the assembly process do not touch devices.
(g) In processes in which packages may retain an electrostatic charge, use an ionizer to
neutralize the ions.
•
Make sure that CRT displays in the working area are protected against static charge, for
example by a VDT filter. As much as possible, avoid turning displays on and off. Doing so
can cause electrostatic induction in devices.
•
Keep track of charged potential in the working area by taking periodic measurements.
•
Ensure that work chairs are protected by an anti-static textile cover and are grounded to
the floor surface by a grounding chain. (Suggested resistance between the seat surface and
grounding chain is 7.5
× 10
5
to 10
12
Ω.)
•
Install anti-static mats on storage shelf surfaces. (Suggested surface resistivity is 10
4
to 10
8
Ω/sq; suggested resistance between surface and ground is 7.5 × 10
5
to 10
8
Ω.)
•
For transport and temporary storage of devices, use containers (boxes, jigs or bags) that are
made of anti-static materials or materials which dissipate electrostatic charge.
•
Make sure that cart surfaces which come into contact with device packaging are made of
materials which will conduct static electricity, and verify that they are grounded to the floor
surface via a grounding chain.
•
In any location where the level of static electricity is to be closely controlled, the ground
resistance level should be Class 3 or above. Use different ground wires for all items of
equipment which may come into physical contact with devices.
(2) Operating
environment
•
Operators must wear anti-static clothing and conductive
shoes (or a leg or heel strap).
•
Operators must wear a wrist strap grounded to earth via a
resistor of about 1 M
Ω.
•
Soldering irons must be grounded from iron tip to earth,
and must be used only at low voltages (6 V to 24 V).
•
If the tweezers you use are likely to touch the device terminals, use anti-static tweezers and
in particular avoid metallic tweezers. If a charged device touches a low-resistance tool,
rapid discharge can occur. When using vacuum tweezers, attach a conductive chucking pat
to the tip, and connect it to a dedicated ground used especially for anti-static purposes
(suggested resistance value: 10
4
to 10
8
Ω).
•
Do not place devices or their containers near sources of strong electrical fields (such as
above a CRT).