1.0ScopeThistestmethodistodescribetheprocedures
tobeusedforperformingdimensionalinspectionsonmicro-
sectionsofprintedboards.Thismethoddoesnotapplyto
measurementslessthan1.25μm(0.00005in).Thismethodis
intendedtosupersedeIPC-TM-650,Methods2.2.9and
2.2.11.
2.0ApplicableDocuments
IPC-TM-650Method2.1.1
IPC-TM-650Method2.1.1.2
IPC-A-600AcceptabilityofPrintedBoards
3.0TestSpecimensThetestspecimensaretobemicro-
sectionsofprintedboardsortheassociatedqualityconform-
ancetestcircuitrypreparedinaccordancewithIPC-TM-650,
Methods2.1.1or2.1.1.2.
4.0ApparatusorMaterial
4.1Metallographicequipmentandconsumablesas
describedinIPC-TM-650,Methods2.1.1or2.1.1.2.
4.2Inaddition,themicroscopeormetalllographdescribed
inMethods2.1.1or2.1.1.2shallbeequippedwithameasur-
ingreticleorfilareyepiece.
4.2.1ReticleorFilarMicrometerattachmenttoOptical
InspectionAidthatcontainsgradiationsorascale,whichwill
provideaminimummeasurementresolutionof50%ofthelast
significantdigitofthereferenceddimensionalrequirement.
TheReticleorFilarMicrometershouldbecalibratedatthe
givenmagnificationtoascertainthedistanceinμm(inches)
betweeneachdivision.
5.0Procedure
5.1Thedimensionalinspectionsaretobeperformedon
freshlypreparedandetchedmicrosections.Whenoxidation
and/orstainingarepresentthatwouldinhibittheclearviewing
oftheareastobemeasuredthemicrosections(s)shallbepre-
paredagainbeginningwiththefinestgrindingstepinthemet-
allographicpreparationsequence.
5.2Themicroscope’sormetallograph’smeasuringreticleor
filareyepieceshallbecalibratedinaccordancewiththemanu-
facturer’sinstructionsusingastagemicrometer.Thecalibra-
tionfrequencyshallbeataminimumofone(1)yearintervals
ormorefrequently,ifrequired,tomaintainaccuracyofthe
dimensionalinspections.
5.3Attributesthatcanbemeasuredusingmicrosectionsof
printedboardsincludebutarenotlimitedto:plating,coating,
orsolderresistthickness,thesizeoflaminatevoidsorcracks,
theamountofpositiveornegativeetchback,conductorthick-
ness,dielectricspacing,eitherlaterallyorvertically,annular
ringwidth,layer-to-layerregistration,ortheextentofwicking.
5.4Selectamagnificationthatallowsclearviewingofthe
areascontainingtheattributestobemeasured.Forinstance,
whenviewingmultilayerprintedboardswithplated-through
holesorviasforlayer-to-layerregistration,magnificationsof
50Xto100Xwouldbeused.Whenmeasuringplatingthick-
nessesofelectrodepositedcopperornickel,amagnification
of200Xwouldbeused.
5.5Readandrecordthedimensionsfortheattributes(s)to
bemeasuredusingthesamenumberofsignificantdigits
specifiedbythedrawing,standard,orspecificationasamini-
mumormaximumlimitingvalue.
6.0Notes
6.1Measurementslessthan1.25μm(0.00005in)cannot
accuratelybemadeusingopticaltechniques.Electronicmea-
surementtechniquesshouldbeconsideredforthesemea-
surements.
6.2IPC-A-600containsfiguresanddiagramswhichdepict
microsectionalattributesandmeasurements.
TheInstituteforInterconnectingandPackagingElectronicCircuits
2215SandersRoad?Northbrook,IL60062
IPC-TM-650
TESTMETHODSMANUAL
Number
2.2.5
Subject
DimensionalInspectionsUsingMicrosections
Date
8/97
Revision
A
OriginatingTaskGroup
RigidBoardT.M.TaskGroup,7-11d
MaterialinthisTestMethodsManualwasvoluntarilyestablishedbyTechnicalCommitteesoftheIPC.Thismaterialisadvisoryonly
anditsuseoradaptationisentirelyvoluntary.IPCdisclaimsallliabilityofanykindastotheuse,application,oradaptationofthis
material.Usersarealsowhollyresponsibleforprotectingthemselvesagainstallclaimsorliabilitiesforpatentinfringement.
EquipmentreferencedisfortheconvenienceoftheuseranddoesnotimplyendorsementbytheIPC.
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