IPC-1601PRINTEDCIRCUITBOARDHANDLINGANDSTORAGE

GUIDELINES

StrawmanDraft–September2007

1INTRODUCTION

1.1BackgroundHistorically,theprintedcircuitboard(pcb)industryreliedonmilitary

specificationsandguidelinestodefinepackagingmethodstopreservethequalityand

reliabilityofpcbsandassembliesduringshipmentandstorage.Mostofthese

specificationsandguidelinesarenowirrelevant,obsoleteoroutdated,leavingthe

industrywithoutanycurrentlyeffectiveguidelines.Additionally,theproliferationofnew

alternativefinalfinisheshasproducednewconcernsandneeds.Overwhelming

attendanceatapaneldiscussionheldattheIPCFallWorksmeetinginMinneapolisin

2004producedmanyrequeststodevelopaguidelinethatourindustrycoulduseto

achieveeffectivehandling,packaging,andstoragepractices.Thisguidelineistheresult

ofthoseinputs.

1.2PurposeThisguidelineisintendedtoprovideusefulinformationonhandling,

packagingmaterials,environmentalconditionsandstoragemethods,forpcbsand

assemblies.Thescopeofcoveragewillbefromthemanufactureofthebarepcballthe

waytopossiblereturnoftheassembledpcbforwarrantyrepair.Asaguideline,this

informationistobeusedwith,andissecondaryto,establishedrequirementsinsuch

documentsastheIPC-455X(aseriesofdocumentsforalternatefinalfinishes)seriesof

documents.Effectiveuseofthisguidelineshouldpreventdamageandmaintain

reliabilityofpcbsandassemblies.

1.3TargetAudienceThetargetaudienceincludesallphasesofpcbdesign,manufacture,

assembly,shipping,storage,andpossiblewarrantyactivities.Resourcesforthis

informationincludeallofthesefunctions,aswellasthematerialandequipment

suppliers.

1.4TermsandDefinitionsThedefinitionofalltermsusedhereinshallbeasspecifiedin

IPC-T-50andasdefinedbelow.

2APPLICABLEDOCUMENTS

2.1IPC

IPC-T-50

3BOARDFABRICATIONANDPACKAGING(HANDLING)

3.1BoardMaterialsAllmaterialsusedinthemanufacturingofprintedboardsmustbe

protectedfromenvironmental,handlingandstoragedamage.Itiscustomaryfor

manufacturerstohaveFODprocedures(spellout)ISO,OEMflowdowntosuppliersin

placethatoutlinethesepreventivepractices.Primaryareasofconcernforprintedboard

materialsare:

3.1.1Bondingmaterials,pre-pregandfoils

3.1.1.1EnvironmentalconcernsThesematerialsaresensitivetodamagefromexposure

tomoistureandhumidity.Theymusthaveadegreeofprotectionstartingfrommaterial

manufactureandstorage,throughtransportationtotheusingfacility,andwithintheusing

facility.Typically,thesematerialsarestoredandusedinacontrolledenvironmentwhere

thetemperatureandhumiditycontrolledwithinlimitsspecifiedbythemanufacturersof

thesematerials.ThenormalrangesareXX-XX%humidityandXX-XXtemperature.

Temperatureandhumidityrecordersareanormalpartofthecontrolprocessforthe

storageanduselocations,andmayalsobeusedduringthetransportationofthese

materials.Pleaserefertoyourmaterialmanufacturer’srecommendationsforguidanceon

yourmaterials.

3.1.1.2HandlingandprocessingconcernsTheinfrastructureofthemanufacturing

location,aswellastheequipmentusedtomanufacturethesematerials,mustbedesigned

andevaluatedtoprovideprotectionfromdamageandtheintroductionofforeign

materialsthatmaybedetrimentaltothefinishedproduct.Boxes,trays,andcartscanbe

designedtoprotectthesematerialsduringtransportationanduse.Processingequipment

mustbeevaluatedtoassurethatitiscapableofprocessingthesematerialsreliably

withoutcausingdamagetothesematerialsorthefinishedproduct.

3.2INNERLAYERPRODUCTIONCONCERNS

3.2.1Phototooling

3.2.1.1TemperatureandHumidityThetemperatureandhumidityintheareathatthe

phototoolsareusedandstoredmustbeinthesamerangesthattheareathatthephoto

toolsaremanufactured.Thiswillensurethatthescalingoftheimagedproductmatches

theintendedscalingofthephototooling.Temperatureandhumidityrecordersare

typicallyusedintheseareastoassistincontrollingthisenvironment.

3.2.1.2HandlingandStoragePhototoolsareusuallyplacedintoprotectiveenvelopes,

andstoredinamannerthatprovidesareasonableamountofairmovementaroundthe

phototooltoprevententrapmentofmoisture.Thismoisturemaydegradethephototool

prematurely.Theseprotectiveenvelopesalsoprovideprotectionfromabrasionandthe

introductionofforeignmaterials.Protectivecarriersmaybedesignedtoprotectphoto

toolsduringtransportationfromthemanufacturingareatotheareaofusewherethis

transportationisrequired.

3.2.2ProcessEquipment

3.2.2.1CapabilityEquipmentusedforprocessinginnerlayersmustbedesignedfor

handlingtheinnerlayersizes,thicknesses,andmaterialtypesused.Processingequipment

mustbeverifiedcapableofprocessingthesematerialswithoutincurringdamage.

3.2.2.2PreventiveMaintenanceApreventivemaintenanceprogramshouldbe

developedandimplementedtopreventtheequipmentfrombecomingin-capableof

processingproductreliably.

3.3HandlingoftheFinishedBoard-Assignee-TomKemp-Rockwell(Vegas)

3.3.1Handlingduringsub-processes(betweenfacilities)

3.3.2MarkingoftheBoard

3.3.3HandlingforBareBoardTest

3.3.4ESD(EmbeddedComponents?)

3.3.5CustomerReturns

4Marking–BareBoardand/OrPackaging-Assignee-JoeKane-BAE

4.1LeadFree/RoHScompliance

Whererequiredbystatuteorbytheuser,packagingshallbemarkedinaccordancewith

RoHSDirective2002/95/EC,withexceptionsnotedintheAnnex,orotherapplicable

statutes.ThisappliestoPCB’sthatonlycontainpermissiblelevelsoflead,mercury,

cadmium,hexavalentchromium,polybrominatedbiphenyls,andpolybrominated

diphenylethers.

Asuitableidentificationsymbolsuchasthefollowingmaybeusedonpackagingor

packaginglabels:

RoHS

Whererequiredbytheuser,surfacefinishandotherattributesofPCB’sandpackaging

shallbemarkedinaccordancewithJ-STD-609.

4.2ESD

PackagingforESD-sensitivePCB’sshallbemarkedperANSI/ESDS20.20,including

theESDprotectivesymbol:

EOS/ESD

Protective

S8.1

Symbol

4.3Moisture

PCB’senclosedindrypackagingmaybemarkedwithasuitablewarningormoisture

sensitivitycautionsymbolinasimilarfashiontothemarkingrequirementsofJ-STD-

033:

Moisture

Sensitivity

Symbol

Caution

4.4Notgreaterthan97%Tin:

PCB’sthatincludetin(Sn)platingthatismorethan97%puretinmaybeatriskfor

developingtinwhiskers.Whererequiredbytheuser,packagingmayincludeasuitable

warning,suchasthefollowing:

Warning:ContainsPureTin,WhichMayBeSusceptibleToGrowthOfTinWhiskers.

Notethattinfinishescontainingmorethan97%tinmaybeconsidered“pure”according

tosomemilitaryorindustryspecificationsforthepurposeofassessingtheriskoftin

whiskergrowth,butthisdefinitiondoesnotnecessarilyassurecompliancewiththeRoHS

Directive(seeParagraph4.1).

4.5Othermarkings

Othermarkings(e.g.datecodes,U.L.)shallbeasspecifiedbytheuser.

ReferencedDocuments:(MovetoSection2.0?)

ANSI/ESDS20.20ProtectionofElectricalandElectronicParts,Assembliesand

Equipment(ExcludingElectricallyInitiatedExplosiveDevices)

Directive2002/95/ECoftheEuropeanParliamentandoftheCouncilof27January2003

ontherestrictionoftheuseofcertainhazardoussubstancesinelectricalandelectronic

equipment(RoHSDirective)

EOS/ESDS8.1

ESDAwareness

ProtectionofElectrostaticDischargeSusceptibleItems-Symbols-

IPC/JEDECJ-STD-033

Handling,Packing,ShippingandUseofMoisture/Reflow

SensitiveSurfaceMountDevices

J-STD-609MarkingandLabelingofComponents,PCBsandPCBAstoIdentifyLead,

LeadFreeandOtherAttributes

5ShipmentofBareBoard–Assignee-MikePaddack-Boeing

5.1MarkingofthePackage

5.2PackagingMaterials/Testing(Bags,SealTestofBags,etc.)

5.3PackagingMethods

5.3.1RigidBoards

5.3.2FlexibleBoards(Fixturing)

5.3.3BoardCleanliness

5.3.4Baking

5.3.4.1Time

5.3.4.2Temperature

5.3.4.3UseLife

5.3.4.4UseofVacuum

5.3.5CustomerReturns

6StoragePriortoAssembly–Assignee-DonYoungblood-Honeywell

6.1StorageConditions(Temperature,Humidity,Atmosphere)

6.1.1StorageContainers

6.1.2StorageLocation

6.1.3ShelfLife

6.1.4Desiccant/HumidityIndicators(BagSize,NumberRequired,etc.)

7AssemblyProcesses

7.1HandlingPriortoAssembly–Assignee-DaveHillman-RockwellCollins

7.1.1BoardTypeConsiderations

7.1.2SurfaceFinishConsiderations

7.2HandlingduringAssembly

7.2.1EquipmentConsiderations

Printers

Considerationofstress,strainandESDmustbemaintainedatthesametimeasthatof

cleanliness.Theprinteranditsassociatedstencilsmustbecleanedsothatneitherfresh

solderpasteordried,oldpastearedepositedwherenotrequired/needed.The

preventativemaintenance(PM)scheduleofthemachineshouldbesuchthatthereisno

dangerofmachineoilsorgreasescomingincontactwiththeprintedcircuitboard;the

solderpaste;stencil;supportblocks,pins,grid,orplates(dependinguponthemachine

type);orstencilcleaningequipment/cloth.

Theplacementofthesupportingaccessoriesintheprintermustbesuchastoprevent

boardwarpageandsubsequentsolderpastebleedonapplication.Thepressureofthe

squeegeemustbesuchastonotexacerbatethesituation.

Conveyors

Allconveyorbeltsandconveyoredgefingersmustbekeptfreeoftheabove-mentioned

contaminants.ThePMschedulemustbesuchtomaintaintheequipmentinanessentially

pristineconditionwithregardstopotentialcontaminationoftheprintedcircuitboardasit

traversesthemanufacturingprocess.Similarstatementsaboutthesametypesof

materialscanbemadefortheplacementequipmentandreflowoven.

Thewidthandparallelismoftheconveyorizedsystemmustbecheckedregularlytomake

surethattheboarddoesnotfalloutofthesystembindorbow.Inextremecasesofthe

latter,thepotentialexists,althoughrare,thatcoppertracesand/orcarboninks,etc.could

becracked,resultinginintermittentsorcompleteopens.

PlacementEquipment

Theplacementequipmentneedstobecheckedfortwoadditionalitems:component

placementforceandthepresenceofloosecomponentsinsidethemachine.Excessive

placementforcecouldresultinsolderpasteshorts,misplacementofcomponents,

componentcracking,componentsbouncingofftheboardorcrackingoftheboarditself.

Thelatterwouldbeanextremecase.Examplesofsmallchipcomponentsfoundunder

largerPQFPsandarraydevicesareembarrassingandnotunheardofandcanbeavoided

bymaintainingpropermachinecleanliness.

Twoconcernsforboardhandlinginthereflowovenhavenotbeenaddressedyet.These

arefluxresiduesandorphansolderballs.ReflowovensPMsshouldpre-emptcasesof

evaporated/sublimedsolderpasteflux/flux/glue/underfillmaterialfallingfromtheroofor

ductingoftheovenontotheprintedcircuitboard.Internalovencleanlinessisespecially

importantforconvectionreflowovens.Smallorphansolderballscanbeejectedfromthe

solderpasteandpotentiallykeptaloftbyair/nitrogencurrentsintheoven.Appropriate

wipingdownandvacuuming(withaHEPAfilterequippedvacuum)willeliminatethis

possiblecontaminationproblem.

Depaneling

Saw,routersandotherdepanelingequipmentmustbechosenfortheprocessand

maintainedsuchthatthecircuitpacksarenotsubjectedtoundoforcesorcontamination.

Duringprocessqualificationattheveryleastvisualinspectionoftheboardsexcisedfrom

thepanelshouldbecompleted.Betteryet,acousticmicroscopyinspectionofchip

componentsandthesolderjointsofleadedcomponentsshouldbedone.Ideallystrain

gagesshouldbeusedduringtheexcisingprocesstocheckthatthestressesapplieddonot

reachlevelsabovelimitssetbythecompanyandthecomponentsupplier.

7.2.2HandlingduringCleaning

Handlingofbarecircuitboardsandprintedcircuitpackscansometimesbeblaséright

beforecleaning.Personnelmayassumethatthecleaningprocesswillremoveany

contaminationthattheymayhavecontributedtotheboardorthepack.However,the

cleaningprocessmaybesetuptoonlyremoveaparticulartypeortypesofcontamination

andmaynotremovethematerialsaddedbythehandler.Therefore,itisstrongly

suggestedthathandlingprotocolsusedinotherpartsoftheprocessbymaintained.

7.2.3CleanlinessofReusableContainers

Reusablecontainercleanlinessshouldbecheckedregularly.Threeofthemostimportant

contaminantstocheckforarefiberglassfilaments,solderballsanddirtysolvents.The

firstcouldbecomelodgedinconnectorsandnotallowproperconnectormating.Solder

balls