Precautions for Avoiding Static Electricity
About the handling of the device, attention for the static electricity in particular isnecessary. The precautions described below are required to prevent damage from staticelectricity.

GeneralThe basic requirements for countering static are to suppress its generation and to get ridof any charge that has built up as rapidly as possible. The environment must therefore besuch as to allow correct handling of the devices, and the person handling them musk know
about how to avoid the problems of static.
（１）Environment
Static within the work environment must be suppressed to within 100V. Materials thatgenerate static must therefore be avoided, and a humidifier used to prevent low levels ofhumidity. The effects of measures implemented to reduce static should also be reviewed
periodically.
（２）Working
In the work-place, insulating materials (notably synthetic fibers and plastics), which areprone to the build up of a charge, should as far as possible be replaced by conductive
materials. Examples are work clothes for controlling static and air ionizers.
When handling the semiconductor devices, they should be kept in materials designed tominimize static or conductive vessels (such as static shield bags or conductive mats), andcare exercised when moving them.
Measures to Prevent Static During Work
（１）Equipment
To prevent the buildup of static, all equipment including instruments and testing
devices, conveyors, workbenches, floor mats, tools, solder baths, and soldering irons
must be securely earthed. The workbench must be covered with a conductive mat(1011Ω maximum), and one placed on the floor. Both must be earthed.

（２）Human body
The worker must use a wrist or ankle strap to earth the body.
In addition, use gloves to prevent direct contact with the devices. Avoid nylon gloves orwork clothes, which tend to build up a charge. Footwear should have a resistance in therange of 100kΩ to 100MΩ. Note, however, that dirt and humidity will change theresistance.
（３）Methods of working
Use a soldering iron designed for use with semiconductors (with the low voltage of 12V

to 24V). The tip must be earthed. When mounting the device, minimize the amount ofhandling.

© ISAHAYA ELECTRONICS CORPORATION1Precautions for Avoiding Static Electricity
Post-Mounting Measures for Minimizing Static
Even after the device has been mounted on a printed circuit board (PCB), for example,
care must be taken to prevent the buildup of static.
（１）Storage

When storing or shipping printed circuit boards (with devices mounted on them), store
them in conductive bags, conductive plastic containers, or conductive racks. Avoid lacing
them in plastic boxes, vinyl bags, or polystyrene containers, which a prone to staticbuildup. When wrapping multiple printed circuit boards, use inserts to prevent theboards coming into contact with each other and from ratting around in their containers.
Short the connectors of the printed circuit board with aluminum foil or shorting bars.
For dust-proofing with sheets only, use conductive sheets or cotton sheets.
（２）Human earthing
For testing, examining, and assembling printed circuit boards with mounted devices, theworker should use the same body earthing as when handling the devices themselves.
（３）HandlingUse gloves for handling printed circuit boards. In addition, the power must always bedisconnected before connecting and disconnecting connectors (to prevent destruction ofdevices due to abnormal voltages being applied).

© ISAHAYA ELECTRONICS CORPORATION2