iteco esdbook 2004 eng

7/25/2019 Iteco Esdbook 2004 Eng

1/32

ESD BOOK

2004 editionISO 9001

CERTIFIEDeco

PROTECTION FROM

ELECTROSTATIC DISCHARGES

IN THE ELECTRONIC

ENVIRONMENTS


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ESDBOOK page 3

CONTENTS

References Standards 2What is ESD ? 4ESD damage 5Material classification 6ESD protections 7Labels 8Signs 9Grounding: wrist-straps, foot grounders 10Grounding: garments, gloves, chairs 11EPA ESD protected area 12Typical Workstation 13Monitoring 14

In Field working, 16

Safety 17Handling 18

Packaging General 20Packaging - Bags 21Flooring 22 - 23Humidity Control - Ionization 24Ionization 25Testing 26Testing 27Testing 28Testing 29Training - Visitors 30Check list 31

Monitoring 15tools

Carts and Shelving 19

ESD BOOK

PROTECTION FROM ELECTROSTATIC

DISCHARGES IN THE ELECTRONIC

ENVIRONMENTS


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page4 ESDBOOK

CMOS

-

--

--

- -

- - -

++

++

++

+

+ +

+

+

Electro Static Dischargelectro Static ischargewhat is it ?

Electrostatic discharge is defined as the transfer of charge between bodies atdifferent electrical potentials. The electrostatic charge occurs when two differentmaterials rub or slide together or areseparated.Examples are:

- walking over synthetic floors- rubbing of syntheticgarments- shiftingof plastic boxes- unrolling of PVCadhesivetape- moving of conveyorbelt

Static electricity can build up high voltages in modern operating environments -over 10kV is not uncommon, and with related humidity lower than 20%, over 30 kVhas been recorded.

When two objects with different chargesget closer, electrons can suddenly flowfrom oneobjectto theother.

ESD can also occur when a high

electric field develops between twoobjects in close proximity.


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ESDBOOK page 5

ESD can results in :higher costslower qualityunhappy customers

STATIC GENERATION TYPICAL VOLTAGE LEVELS

Means of generation 10-25% RH 65-90% RH

Walking across carpet

Walking across vinyl tile

Worker at bench

Poly bag picked up from bench

Chair with urethane foam

35,000 Volt

12,000 Volt

6,000 Volt

20,000 Volt

18,000 Volt

DEVICE TYPE DEVICE TYPE

VMOS

MOSFET

GaAsFET

EPROM

JFET

OP-AMP

BI-POLAR TRANSISTORS

SCHOTTKY DIODES

SCHOTTKY TTL

CMOS

1,500 Volt

250 Volt

100 Volt

1,200 Volt

1,500 Volt

ESD SUSCEPTIBILITY ESD SUSCEPTIBILITY

30 - 1,800 Volt

100 - 200 Volt

100 - 300 Volt

100 Volt

140 - 7,000 Volt

190 - 2,500 Volt

380 - 7,000 Volt

300 - 2,500 Volt

1000 - 2,500 Volt

250 - 3,000 Volt

ESD DAMAGE COST LEVELS

Catastrophic in-house failure

Latent failure

Limited costIt is the easiest type of ESDdamage normally detected

during testing

Higher cost due to:- customer support- servicing facility- replacement equipment- loss of reputation- loss of customers

Many of the common activities may generate charges harmful to components


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page 6 ESDBOOK

For ESD purposes, many materials are classified by theirresistance or resistivity characteristics.

SURFACE RESISTANCE W

SHIELDINGmaterials

Static-dissipativematerials

Conductivematerials Insulative

materials

103 105 1012

Surface resistance measurements are not always appropriate to establish the

effectiveness of the materials, where resistance is higher than 1x10 , or wherethe material is of non-homogeneous woven it is mandatory to measure the decaytime of the generated charge

providing a Faraday cage protection, limit the passage of current and attenuate theenergy resulting from an electrostatic discharge. Most static shielding materials

include a conductive (less than 1x10 ) metal or carbon element that suppressesthe field, attenuates, or reflects field energy.

characterised by a low electrical resistance (less than 1x10 ), allow the chargeto quickly distribute itselfthroughout the material.If the conductive material is connectedto ground, allchargewill flow away.Some examples of conductors are metals, carbon and the human body's sweatlayer.

are defined as those having a surface resistance greater than 1 x 10 but less

than 1 x 10 .Charges will flow to ground slower than with conductive materials, reducing itsdestroying potential.

are defined asthosehavinga surface resistanceof atleast1 x 10 .Insulative materials have a high electrical resistance and are difficult to ground.Static charges remainin place on these materials for a very long time.This property make insulators a hazard that must be controlled as part of anESD program.Some examples of insulators are common plastics, glass and air.

10

3

5

5

12

12

W

W

W

W

W

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ELECTROSTATIC SHIELDING MATERIALS

CONDUCTIVE MATERIALS

STATIC-DISSIPATIVE MATERIALS

INSULATIVE MATERIALS


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ESDBOOK page 7

ESD DAMAGE CAN OCCUR AT ANY TIME:

BASIC ESD CONTROLSGROUNDINGSHIELDINGNEUTRALIZATION (ionizers)

Four gold rules

1 all- Assume that active components are sensitive to ESD

2 only

only

- 1 Handle electronic components in the ESD protected area (EPA)

and when you are properly grounded.

3- Store and transport the ESD-sensitive items in ESD protective containers.

4-Check regularly the ESD protection system, internal and external (suppliers)

GOODS INPUTACCEPTANCE

PRODUCTIONASSEMBLY

TESTINGSTORING

PACKING

SHIPPINGMAINTENANCE

Take in evidence the principle , the elimination of chargebuild-up is obtained by using conductive and dissipative materials that have lesstendency to generate static charges.All equipment must be free of moving parts that may generate charges, e.g., rubber

rollers, plastic stoppers, etc.Things which the devices may come in contact with or get transported on must also beantistatic or conductive.The use of ionizers to neutralize newly generated charges will also prevent chargebuild-up.The minimization of movements in the work area, as well the use of ESD-safeequipment, will help in minimizing staticcharges generatedby personnel.

'No Charge/No discharge'


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page 8 ESDBOOK

min. 4mm

EARTH

BONDING POINT

EARTH BONDING POINT (EBP)ESD CAUTIONARY SYMBOL

*

BASIC SYMBOL

The basic symbol consists of a yellowhand withina black triangle. It is intended to identify devicesandassemblies which areESD sensitive.

PROTECTION SYMBOL

Used to designate all ESD protective productssuch as bags, boxes, garments.A letter is added under the symbol to indicate theprimary function:

C conductive

D dissipativeS shieldingL low charging

*

EPA LABEL

Used to designate EPA equipments such as

tables, trolleys, chairs .

ATTENTION

min. 4mm

EPA

OBSERVEPRECAUTIONS

FOR HANDLING

ELECTROSTATIC

DISCHARGESENSITIVEDEVICES


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ESDBOOK page 9

EPA WARNING SIGN

EPA WHICH CONTAIN HIGH VOLTAGE

EPA EXIT SIGN

YOU ARE LEAVINGTHE EPA

ATTENTION

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The signs are designed to attract attention and deliver a clearmessage to personneland visitors beforethey enter theEPA.Where high voltages greater than 250VAC or 500VDC arepresent, use proper warning signs.

OBSERVEPRECAUTIONS FOR

HANDLINGELECTROSTATIC

DISCHARGESENSITIVE DEVICES

ATTENTION

ESD PROTECTED AREA

OBSERVEPRECAUTIONS FOR

HANDLINGELECTROSTATIC

DISCHARGESENSITIVE DEVICES

ATTENTION

ESD PROTECTED AREA

HIGH VOLTAGE


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The elimination of charge build-up is obtained by using conductive and dissipativematerials that have less tendency to generate staticcharges.Grounding systems shall be used to ensure that components, personnel and anyother conductors areat thesame electricalpotential.For proper and safe grounding the ESD ground must be tied directly to and at thesame potential as the building or green/yellowground.

PERSONNEL GROUNDING DEVICES

The wrist strap is the most used device toground personnel, it will safely andeffectively drain static charges from thebody.

Someone offers ESD Wrist strapswithout cord (cordless), we canassure that are ineffective.

In some locations, such as stores andaround equipment, conductive shoes orfoot groundersare used.Foot grounders should be worn on bothfeet to ensure constant contact to groundfloor or floor mat.Foot grounders will not function properly if

used on surfaces which are insulative orimproperly grounded.

page 10 ESDBOOK

Earth

Earth

EarthBondingPoint

1M 1M1M

EBP

G

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people are the primary source of electrostatic charges

(earth bonding point)


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ESDBOOK page 11

Garments

Gloves

Chairs

The main purpose for wearing conductivesmocksis to suppress static fields on employeeclothing.The conductive fibers woven into the materialprovide a Faraday cage that prevents

dangerous fields from extending to anddamaging sensitive products.There shall be electrical conductivity betweenall parts of the garment.

ESD sensitive device can experience adamaging discharge if touched by a person,even if that personis properly grounded.Increasing the electrical path's contactresistance is one way to control the speed ofthe discharge.A good way to accomplish this is by wearingstaticdissipative cots and gloves.

The resistance to ground from any part of theseat which may have contact with personnel,

must belessthan1x10 .At least two castors or feet must provide apath to ground.

10W


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EPAAr

ea

E

P

r

ea An EPA (ESD Protected Area) is a defined space where noitems or activity are able to cause damage to a sensitive device.In the simplest case - a field work station - it may consist of adissipative mat, a wrist strap and common grounding facility forboth.

page 12 ESDBOOK

16

18

17

11

1

2

10

8

5

15

6

124 3

13

7

14

9

1 Groundable castors2 Groundable surface3 Wrist-strap tester4 Footwear tester

5 Footwear foot plate6 Wrist cord and wrist band7 Ground cord8 Ground9 Earth bonding point (EBP)10 Groundable point of trolley

11 Toe and heel strap (footwear)12 Ionizer13 Static-dissipative working

surface

14 Seat with groundablefeet and pads15 Static-dissipative floor16 Low charging arments17 Shelvings with grounded

surfaces18 EPA sign

g

EPA

MAXIMUM ALLOWEDELECTROSTATIC FIELD:

100V/cm


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ESDBOOK page 13

TYPICAL WORKSTATION

Ground all solder-ingiron tips.

Rgmax1x107W

Wriststrarp with coiled cord,

1M built-inW

Earth

Dissipative flooringconnected to the EBP(Earth Bonding Point)

When using thistype of groundingmethod be sure thatthe total resistance"hand to earth" is

lower than3.5x10 .7W

EarthBondingPoint

1M1M

1M

Dissipativefootwear

ATTENT

ION

ESD PRO

TECTED

AREA

EBP

OBSERV

E

PRECAU

TIONS

FOR

HANDLI

NG

ELECTR

OSTATIC

DISCHA

RGE

SENSITI

VE DEV

ICES

It is important that each bench, or work surface, is covered with the properESD material and properly connected to earth using a system of cords andEarth Bonding Points (EBPs)

Remove all extraneous materials from the workstation (food, beverages,combs, bags, clothing etc)

Clean the surfaces with purpose-made antistatic cleaner, do not usecommercial products, the cleaners may leave a residue insulative layer.

Inspect the ESDgrounding connections, the mats, the EBP, weekly.

Test the wrist strap/operator daily or install constant monitors.


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ESD protection systems as wrist straps, foot grounders, work surfaces and floorsneed to be checked on a regular basis. This is an important requirement of theESDstandard IEC 61340-5-1.

Check your ESD equipment regularly

Personnel testing

For standing operations

Garments Rs < 1 x 10Charge decay

12

2s

Glove and finger coats as worn 7.5 x 10 Rg 1x 105 12

check wrist straps and footwear twice a day

check the "footwear/flooring system" twice a year

Thepersonnelgrounding testeris a wriststrap and/or footwear tester to checkpersonnel grounding systems before enteringan EPA.

page 14 ESDBOOK

WRISTLAB TEST STATION

3) Collegare il cordone nell'ingresso "ATTACH CORD".

HOW TO TEST YOUR WRIST STRAP

5)ATTENZIONE a non alterare la misura toccando conl'altra mano il tester o il bracciale.

7) la luce rossa o gialla segnalano non-conformit.

1) Indossare il bracciale. Assicurarsi che sia aderente.

6) La luce verde ed il buzzer indicano che il braccialee l'operatore sono conformi.

8) L'indicatore "LO-BAT" segnala batteria esaurita.

4) Premere con le dita "TOUCHPLATE" .

mod.9265.026

PASS

LO BAT

LOWF AI L H IG H F AI L

ATTACH

CORD

CORD TEST

END

CORD TEST

ATTACH

PERSONNEL

CIRCUIT

TESTER

FOOTWEAR

100

TOUCHPLATE

FOOTWEAR

35

WRISTLAB

ESDflooring used with approved footwear, may be an alternative to the wrist strapsystem, in this case the standard is more restrictive and one of the followingconditions must be met:

- the resistance of the person to the ground must be less than 3.5x10- the maximum body voltage generation must be less than 100 volts.

It is easier to check the first condition, we suggest to use a Megaohmmeter withone lead attached to the ground and one electrode held by the person wearingESD footwearstanding on the factory's protective floor.

7


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check the continuous monitor functions semi-annually

check ionizers monthly (see Test method on page 29)

check workstations, floor mats, ESD ground connections ,ionizers monthly

check ESD control instruments annually

ESDBOOK page 15

Continuous Monitors can be used to constantly monitor ESDprotective items such as wrist straps, work surfaces and floors, all thesystems provide visual and audible alarms. Continuous monitoringreduces but notreplace theperiodic checks.

CONTINUOUS MONITORING METHODS

Capacitive

Dual-wire / Current loop

Wave distortion detection

affected by noise and capacitivevariations associated with personneland environmental conditions.

accurate but expensive systemrequires special wrist straps

good system not affected byinterference

EPA testing

Ionizers

Resistance to ground shouldbe:

Worksurface: 7.5 x 10 Rg 1 x 10

Floors: Rg 1 x 10

Seating: Rg 1 x 10

Tools: Rg 1 x 10

5 9

9

10

12

W W

W

W

W

Ionizers neutralize electrostatic charges with fans that blow large quantitiesof positive and negative ions. Ionizers out of balance (different quantitiesof negative and positive ions), can place a significant charge on itemsinstead of neutralizing the charges.


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Tools should not have insulating handles. Decay of charge to less than10%of initial value (1000V) within2 sec.is required.Soldering irons tips must be grounded to earth, and must beusedonly atlowvoltages (6 to 24V)

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pag.16 ESDBOOK

IN FIELD WORKS

Field work is perhaps the most risky situation of handling ESD sensitivedevices, it is also often the most neglected aspect of ESD damageprevention. The situation is risky as there are usually many potential ESDsources in the environment.Spare parts should be transported inside static shielding bags orcontainers .Where modules have to be worked on in an exposed state, static-dissipative matting should be bonded to the product's electrostatic bondingpoint,and tothe ground toact as a work surface.

Typical "field service kit"

Wriststrap with

1M resistor withcoiled cord

W

Lay ESD sensitivedevices only on the mat

Grounding cord with

1M resistor built-inW

Staticdissipative

mat

Earth Bonding Point

W1M W1MW1M


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Before we get to the key issues of ESD control, it is important to note thatpersonnel safety is paramount. In no way should an ESD control programreplace or supersede any requirements for personnel safety.

In the factory, grounding personnel around the AC power line is a possiblehazard. Personal grounding should not be used when working aroundvoltages greater than 250VAC.

Although personal grounding items must include a 1M resistor to limitcurrent to less than 0.25 mA, ground fault circuit interrupters should beused.

Where high voltages greater than 250VAC or 500VDC are present, useproper warning signs.(see page 9)

W

ESDBOOK page 17

WORKING BENCH FLOORING

EARTH BONDING POINT

GROUNDING CONNECTION

< 1x 106 W

TYPICAL EPA AREA CONFIGURATION

WRISTSTRAP

1MW

3 x 1MW

Safetymanagement isresponsible for

selectingequipment thatcomplies withapplicable lawsand regulatorycodes.

Safety

management is

responsible for

selecting

equipment that

complies with

applicable laws

and regulatory

codes.


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page 18 ESDBOOK

When transporting and storing ESD sensitive devices, use trays, racks, tote boxesandbags made of conductive, dissipative or shielding materials.

TRANSPORTATION AND STORAGE

To transport loose leaded devices,is often employed.

This prevents a potential difference ofmore than a few volts appearingacross thepins.

are used for bulksupply of dual-in-line packages.

, are used for subassembliesand printedcircuit boards.

conductive foam

Dissipative tubes

Dissipative or conductive openpart bins, tote boxes, PCB holders,trays

Store and transport ESD-sensitive items properly

Packaging used within an EPA shall be:- all with low charge generation properties- made in dissipative or conductive material

for intimate contact(see page 21 for bag specifications)

Bags

LABESTAT -A3

L

A

B

E

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T

A

T

A

044

PE-LDELD

3-LAYERS DISSIPATIVE FILM

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Movement of cartsand other wheeled equipmentthrough the facilitycan generate static charges that can transfer to products beingtransported.ESD safe carts are made from dissipative or conductive materialsand are equipped with dissipative or conductive wheels.If wheels are insulating the structure can be grounded to the floorthrough a metallic chain.If the floor of the EPA is not grounding, then the trolley should begrounded from its grounding point to an earth bonding point, whenstationary for loading or unloading.

Every surface on which ESDS are placed must be connected to ground, and have a

point-to-point resistance between 1x and 1x10 , and resistance-to-ground

between 7.5x10 and 1x10 .Surface to ground resistance values may be achieved by including discreteresistors in the ground path, or by the resistance of the material which is directlygrounded.

104W 10

5 9W

W W

RACK, CART AND SHELVING

When surfaces (example: crome plated steel) have a point to point resistance

lower than 1x10 , for housing ESD sensitive devices, use proper staticdissipative boxes or mats.

4W

Conductive wheels

ESDBOOK page 19


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page 20 ESDBOOK

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ing

The aim of ESD protective packaging is to prevent a direct electrostaticdischarge to the ESDS item contained within and allow for dissipation ofchargefrom the exterior surface. Packaging material will also often providemechanical protection and protection against contamination by dust orhumidity.

caution in purchasing:

some packaging materials may be humidity dependent and may have limited shelflife, some other may contaminate or shed particles that cause production-relatedproblems. ( example:a toobrittle hard foam)

IEC 61340-5-1 defines three levels of packaging:

in contact with the ESDS

does not make contact with the ESDS, but may encloseone or more ESDS

mainly used to give physical protection, is kept away fromESDS and is not allowed in the EPA

Intimate

proximity

secondary

Either low charging Low charging As for inside Electrostaticand and electrostatic EPA shieldingor low charging shielding or

and low charging and

(for powered ESDS only static-dissipativelow charging andstatic-dissipative

above 1xshall be used)

Dissipative or low charging No requirements

Note: Where surface resistance >1x 10 is used, the material shall be procured with aT < 2 sec

INSIDE THE EPA OUTSIDE THE EPA

Intimate Proximity Intimate Proximity

ESDS

Non ESDS

10 W

1000

conductive

static-dissipativeconductive or

109 W


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page 22 ESDBOOK

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Concrete subfloor

Lower conductive layerDissipative floor

Use dissipative shoes orfootgrounders onESD protective flooring

Static protective permanent flooring, in conjunction with conductivefootwear or heel grounding straps, drains static charge away to groundthrough the floor.It is a solid foundation for a comprehensive static control system.In addition to dissipating charges, the static-dissipative flooringreduces triboelectric charge generation in walking and minimisecharge accumulation on chairs, carts, lift trucks and other objects thatmove across the floor. However, these items require dissipative orconductive castors or wheels to make electrical contact with the floor.

Recommendations

- choose a floor covering with Rg lower than 3,5x10 , this enable thegrounding of personnel via the flooring-footwear system (see page14)in alternative with thewriststrap system.

- choose a floor covering suitable for your traffic level (frequency, weight,

typeof castors )- take in consideration the sound absorption, anti-fatigue and anti slipproperties

- ask to the supplier a guaranteethat theearth leakage resistance will bemaintained, throughout theusefullife of thefloor material.

7W

Rs 1 x 10 10W

Rg 1 x 10 9W


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page 23ESDBOOK

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With reference to the installation systems, static control flooringcan be classified into three groups:

Permanently installed floors

Vinyl tiles

Rubber tiles

Carpet

Resinous flooring

usually earthed via a strip of copper foil and bonded with conductive acrylicadhesive.

Aesthetically attractivePoor heat and chemical resistance

usually earthed via a strip of copper foil and bonded with conductive acrylicadhesive.Excellent heat and chemical resistance

Aesthetically attractive, mostly used in officesDifficult to reach a good static dissipation

(Epoxy, vinyl ester, polyurethane coating)Variable thickness for different traffic conditionChemical resistant.Easy to clean.Topcoats may get scratched or abraded

Periodically applied topical coatings on existing floor surfaces

Lower material cost, easy to applyDifficult to reach a good static dissipationWorn away easily and frequent recoating is required

Mats placed over existing floors

Vinyl mats

Rubber mats

Grid mats

Poor heat and chemical resistanceLimited coverage area

Excellent heat and chemical resistanceLimited coverage area

(polypropylene, polyethylene)

Good operator comfort, insulation from cold floorLimited coverage area

Possibility to move the mat




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ity

When humidity in the working environment decreases, the human body andother insulators can easily charge with static electricity due to friction. The airitself, being dry, becomes a part of the electrostatic build-up mechanism, everytime an air flow (wind, airconditioning, blower) come over an insulatedsurface.Relative Humidity shall be maintained over 30%.Belowthat value it is recommended the useof ionization.

Each EPA area shall be equipped with a Humidity/Temperature meter to recordthese data.These informations are useful to establish the distribution throughthetime of ESDrelated failures (needed to theFailure Process Analysis).

Environmental Monitoring

page24 ESDBOOK

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Air Ionization systems work by flooding the atmosphere with positive andnegative ions.When the ionized air comes in contact with a charged surface, the surfaceattracts ions of the opposite polarity. As a result the static electricity that has builtup on products andequipment is neutralised.Ions do remove small particles or smoke and pollens from the air, and subjectiveresearch suggest that people working in ionized area arehappier.

High maintenance required

Low discharge time when using highvolume blowersVery Low discharge time

bench Ionizers(littlearea) Ionizingbars

Ionizing guns

Manual Environmental Control(wholeroom) Automatic Environmental Control

Maximum Ozone generation accepted by law: 0.2mg perm (0.1ppm)DC Ionizers with balanced ions emission are the best solution for localprotection.

IONIZER Nuclear

AC

DC

PROTECTION Local

Complete

3

Where grounding of some equipment or parts of it throughthe traditional earthing techniques is impractical and whereit is impossible to exclude all charging materials from theworking area, the use of suitable ionizers is highly

The most significant environmental factor in ESD Control isthe relative humidity (Rh)


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page 25ESDBOOK

I

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some types of ionizers

BENCH TOPIONIZING BLOWER

OVERHEAD IONIZING BLOWER

AIR FORCEBLOW-OFF GUN

very useful to blow offcharged dust particles fromelectronic card, and other

equipment or materials.

The most common test to evaluate air ionizer performance is the static decaytime measurement (see pag. 29)


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Resistance measurement is the most common tests to verify the efficiency ofworking surfaces

RESISTANCE TO GROUND

should be measured using aMegohmeter with oneelectrode placed on the

surface and the otherterminal connected to thegroundable point.The resistance shouldmeasure between

7.5x10 and 1x105 9 W.

POINT TO POINTRESISTANCE

Is the resistance measuredbetween two points on the

surface using a Megaohmmeterwith two electrodes.

For many materials, the measuredresistance depends on the appliedvoltage; according to IEC61340-4-1 thetest voltage applied by the Megohmeteris given in the following table

Cylindrical probes with 63mm diameter and 2.3kg weight, meets IEC andANSI/ESD standards.

Rx (W)

Rx 1x10 5

1 x1 0 < R x 1 x1 05 12

100

10

Open circuittest voltage (V)

page 26 ESDBOOK

Always record:

values, as the resistancemeasurements may changewith these two parameters.

Rh (%)T (C)

RESISTANCE MEASUREMENTS


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SURFACE RESISTIVITY

Defines the electrical resistance ofthe surface of the material, it is

expressed in /square andtheoretically is 10 times greater thanthe point to point resistance.Measurements can be made using asquare probe with two parallelelectrodes or a concentric ringp r ob e , i n c o mp l ia n ce w i thIEC61340-5-1 .

W

VOLUME RESISTANCE

Is defined as the ratio of dc voltageto current passing between twoe l ec t ro d es ( o f a s p ec i fi e d

configuration) that contact oppositesides of the material of the objectunder test. Volume resistance is

measuredin .It is normal to test mats or sheetswith a cylindrical probe and a flatcounter-electrode

W

PERSON TO GROUNDRESISTANCE

Measuring Resistance through aPerson to Ground according

IEC61340-4-5 for themeasurement of a resistancethrough the combination of aperson /shoes / flooring system .

Always record:

values, as the resistancemeasurements may changewith these two parameters.

Rh (%)T (C)

RESISTANCEMETER

GIGALAB

MEASURE

PROGVtestOFF

ENTER

10V1K

100K

1M

10G

100G

500G

100V

500V

RESISTANCEMETER

GIGALAB

MEASURE

PROGVtestOFF

ENTER

10V1K

100K

1M

10G

100G

500G

100V

500V

RESISTANCEMETER

GIGALAB

MEASURE

PROGVtestOFF

ENTER

10V1K 100K

1M

10G 100G

500G

100V

500V

RESISTANCEMETER

GIGALAB

MEASURE

PROGVtestOFF

ENTER

10V1K 100K

1M

10G 100G

500G

100V

500V

RESISTANCEMETER

GIGALAB

MEASURE

PROGVtestOFF

ENTER

10V1K

100K

1M

10G

100G

500G

100V

500V

RESISTANCEMETER

GIGALAB

MEASURE

PROGVtestOFF

ENTER

10V1K

100K

1M

10G

100G

500G

100V

500V

CONCENTRIC

RING PROBE

page 27ESDBOOK

MATERIAL UNDER TEST

MATERIALUNDER TEST

COUNTER-ELECTRODE

FLOOR


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5-25mm

1 inch (25.4mm)

groundthe case

groundthe case

some hand-held electrostatic instruments useful to locatestatic charge problems

Electrostatic FIELDMETERThe accurate measurement of electrostatic fields requires the operator to be familiarwith this type of equipment.Most hand-held meters require the measure to be taken at a fixed distance from theobject (typical distance is one inch). Equipment manufacturers typically specify thatthe object being measured needs to have certain minimum dimensions. Objectssmaller than the minimum dimensions may not provide an accurate reading.

Electrostatic VOLTMETERThere exist noncontacting instruments that can provide accurate measurements at awide probe-to-surface spacing range and can inspect small charged areas on thesurface under test. The higher spot resolution capability is useful to locate charges onnon homogeneousmaterials.

choose instruments that make accuratemeasurements in ionized environments too.


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g VERIFICATION OF AIR IONIZERS

IONIZATION TEST KIT

An ionization test kit can very quickly verify the proper functioning of an ionizer.The ionization test kit should be grounded and placed in the ionized airflow tomeasure the decay time and the balance of air ionization equipment, thecharger is used to chargean isolated plate appliedon thefield-meter.

CHARGED PLATE MONITOR

Charged plate monitor tests the efficiency of ionizer's ion production bymeasuring how long it takes air ions produced to discharge a floating ioncollecting plate that has been precharged to either a positive or negativecharge level.

chargedelectrode placedin the ionizer air

stream

ionizer

digital field meter

charger( 1000Vdc )

plate voltage(adjustable)

decay time

charge plate placed in the ionized air streamplate dimensions : 150x150mmmeet IEC and ANSI/ESD standards

groundthe case


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Visitors entering the EPA shall behave properly to prevent any ESD

damageor danger.

In case of a conductive floor they shall wear ESD heel and toegrounder, which also existin theeconomic disposable version.

It is recommended to wear an antistatic overall, and also aconnectedwrist-strap in case of PCB or componentmanipulation.

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STANDARDS:

ESDTEAM:

TRAINING:

VIDEO:

SIGNALING:

DISCIPLINE:

purchase, read and get familiar with the IEC 61340-5-1Standards

establish and organise an ESD Team responsible for theESD control program.

train the operators to the use and check of personalprotection, handling, etc. Sub/contractors and visitors shallbe made aware of local ESD procedures.

some video training on ESD event, cause and effect,examples, demonstration, will get everyone aware of thisimportant problematic.

clear signs to identify the Electrostatic Protected Area orany ESD hazard, shall be widely and properly used to alertoperators, or to draw their attention over protection.

Manager and technicians shall always respect thestandards and quality procedure so as to give a goodexample to the operators.


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SimpleAuditCheck List for ESDControl Program.It is essential to implementcorrective action if deficiencies arediscovered.

- Are personnel wearing grounded wrist straps atthe ESD protective workstations?

- Are personnel checking regularly their wriststrap's continuity or using a continuous groundmonitor?

- Where ESD protective flooring is used, aredissipative footwear worn?

- Where ESD protective floors and footwear areused, do personnel check continuity to groundupon entering the area?

- When required, are ESD protective garmentscorrectly worn ?

- Is the workstation clear of all not-essentialpersonal items ?

- Are all ESD sensitive devices stored andtransported in static- shielding container ?

- Are all ESD sensitive devices correctly labelled ?

- Are visitors crossing the EPA using proper ESD

protection ?

- Do you report any ESD hazards that you noticeto your ESD responsible?

- Is the ESD equipment at the workstation properlygrounded ?

YES NO

page 31ESDBOOK


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iteco esdbook 2004 eng

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