Tako Thailand-Manufacturer ESD-rubber,tape,antistatics

Triboelectric effect.

Field induction.

TRIBOELECTRIC

the Charges that generated when two kind of material come into contracted and then separation, two objects
become charged by gained electrons from the other, the magnitude and polarity of the charges depends upon
the characteristics to those two kind of materials and affected by several factors like surface condition, size of
contract area, speed of separation and humidity. (See Triboelectric series)
Once the charged that have been build up on the objects can be accumulated and then discharged through
the ESD sensitive devices when it become to contract to the Charged objected.

FIELD INDUCTION

Most of High voltages equipments like Computer Monitors, CRT oscilloscope that always generate of high
intensity of electronic field, the Strong E Field that extend to surrounding can induce the charge on the objects
that place nearby and caused them to become charged.
Once it come to contact to the ESD senilities, devices, the amount of unbalance charges will immediately
through the devices to ground, that so call ESD damage by induction.

HOW STATIC ELECTROSTATIC SENSITIVE DEVICES HISTORY

INTEGRATED CIRUIT MR HEAD

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The recently technology such submicron technology IC fabrication, Magneto Resistive Head all
fabricated with very thin of insulative layer and metalic elecments in few angstrom thinickness, So all of these
devices will become highly ESD sensitive devices, The thin insulation can be repture and thin metallic or silicon
element can be melt and caused short circuit by very low static potential, Some can not be withstand in 5 volts
static potentials environment (Potential different) Such as MR Head, Giant MR Head technolgy ETC.

VACUUM TUBE
MONOLITHIC HEAD

BIPOLAR TRANSISTOR
COMPOSITE HEAD

MOSFET
THINFILM HEAD

HOW TO PREVENT ESD DAMAGE

ESD Awareness Training program.

Reduce Risk of static charges generation
build the ESD Safe work station, eliminate all non ESD Safe
Packaging (Plastic, insulative Materials), Use conductive or
dissipative flooring, Dissipative table top, ionization will be the
other solution but need very good maintenance otherwise it will be very dangerouse. Grounding all conductive path are necessary, to provide Zero potentials environment.

HOW TO PROTECT ESD SENSITIVE DEVICES

Use protective material with FARADAY CAGE Sheilding effect during storage and transportation (Conductive bag, Sheilding Bag, conductive IC Table, conductive container, conductive IC foams).

ESD Material Classification

the Materials classified by Surface Resistivity (ASTM D257)

Surface Resistivity range

Conductive good shielding, allow changes to drain quickly, eliminates charges buildup.
Static Dissipative drains a charge to ground slowly, minimal shielding, minimizes charge buildup.
Antistatic minimizes charge buildup up via trboelectricity.

ESD Sensitive Device Classification
Class   1    0 v   to   1,000 v                    MR Head, MOSFET, Thinfilm Head, Thinfilm Resistor, VMOS
Class   2     1,000 v to 4,000 v                Protected MOSFET & IC, Schottky Diodes, OP Amp.
Class   3     4,000 v to 15,000 v              Silicon Transistor, Bipolar IC, Power TR, SCR, Piezoelectric Crystals

The recently magnetic recording head like MR and giant MR Head Technology have been considered as the most
ESD sensitive devices, it can be blow out when exposured to less than 10 volt potential different environment so,
all concern material being use must be sellected to prevent tribocharge at very low level (production equipment,
room facilities, packing, storage and transportation material)

Introduction to ESD How static charge is generated How static electrostatic devices How to prevent esd damage How to protect esd sensitive devices

Introduction to ESD
How static charge is generated How static electrostatic devices
How to prevent esd damage How to protect esd sensitive devices