柔性铰链相关外文翻译.docx

柔性铰链相关外文翻译.docx

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柔性铰链相关外文翻译

外文翻译

毕业设计题目：

柔性铰链微运动的测量与控制方法

原文1：

APrecisionCapacitanceCellforMeasurementofThinFilmOut-of-PlaneExpansion–PartIII:

ConductingandSemiconductingMaterials

译文1：

一种精密电容测量薄膜平面扩张的第三部分：

导体和半导体材料

原文2：

Circularareflexiblehingestiffnesscharacteranalysis

译文2：

圆弧型柔性铰链刚度特性分析

APrecisionCapacitanceCellforMeasurementofThinFilmOut-of-PlaneExpansion–PartIII:

ConductingandSemiconductingMaterials

Abstract—Thispaperdescribestheconstruction,calibration,anduseofaprecisioncapacitance-basedmetrologyforthemeasurementofthethermalandhygrothermal（swelling）expansionofthinfilms.Itisdemonstratedthatwiththisversionofourcapacitancecell,materialsranginginelectricalpropertiesfrominsulatorstoconductorscanbemeasured.Theresultsofourmeasurementsonp-type<100>-orientedsinglecrystalsiliconarecomparedtotherecommendedstandardreferencevaluesfromtheliteratureandareshowntobeinexcellentagreement.

IndexTerms—Capacitancecell,coefficientofthermalexpansion（CTE）,guardedelectrode,highsensitivitydisplacement,innerlayerdielectrics,polymers,thinfilms.

I.INTRODUCTION

THEcoefficientofthermalexpansion（CTE）isakeydesignparameterinmanyapplications.Itisusedforestimatingdimensionaltolerancesandthermalstressmismatches.Thelatterisofgreatimportancetotheelectronicsindustry,wherethermalstressescanleadtodevicefailure.Foraccuratemodelingofthesesystems,reliablevaluesareneededfortheCTE.

Traditionally,displacementgaugetechniquessuchasthermomechanicalanalysis（TMA）havebeenutilizedfordeterminingtheCTE.However,standardtestmethodsbasedonthesetechniquesarelimitedtodimensionsgreaterthan100

m[1-2].Thisisproblematicformaterialswhichcanbeformedonlyasthinlayers（suchascoatingsandcertaininnerlayerdielectrics）.Additionally,thereissomequestionastowhethervaluesobtainedonlargersamples（bulkmaterial）arethesameasthoseobtainedforthinfilms,evenwhentheeffectsoflateralconstraintsareincludedinthecalculations.

Ithaslongbeenrecognizedthatcapacitance-basedmeasurements,inprinciple,canofferthenecessaryresolutionforthesefilms.Forapairofplane-parallelplatecapacitors,ifthesampleisusedtosetthespacingoftheplates

whilebeingoutsideofthemeasurementpath,thenforaconstanteffectiveareaoftheplates

thecapacitanceinavacuum

isgivenbythewell-knownequation

（1）

where

isthepermittivityoffreespace（

）.Withthesampleoutsideofthemeasurementpathandonlyairetweentheelectrodes,thevacuumcapacitanceisobtainedromthemeasuredcapacitance

by

（2）

where

isthedielectricconstantofair.

Inthreepreviouspapers,thedesignanddatareductiontechniqueswerepresentedforourthree-terminalcapacitance-basedmetrologyforthinpolymerfilmmeasurements.Thefirstpaper（I）describedtheinitialdesignbasedongold-coatedZerodur.However,severalproblemswereencountered.ItwasdiscoveredthatZerodurdisplaysferroelectricbehavior,withanapparentCurietemperatureof206℃asdeterminedbyfittingwithaCurie–Weisslaw.TherapidchangeinthedielectricconstantoftheZeroduralongwithacouplingfromthecentralcontactthroughtheguardgaptothehighelectrodecreatedanapparentnegativethermalexpansion.Thesecondproblemwiththeinitialdesignwaswiththegoldcoating.Thiscoatinghadthetendencyto“snowplow”whenscratchesformedinthesurfacecreatingraisedareaswhichwouldresultinshortswhenmeasurementswereperformedonthinsamples.Thesecondproblemwiththegoldwasthatitunderwentmechanicalcreepunderloading.

Toresolvetheseproblems,anewelectrodewasdesignedfromfusedquartzcoatedwithnichrome.Agroovefilledwithconductivesilverpaintwasaddedtothebacksideofthebottomelectrodearoundthecentralcontacttointerceptanyfieldlinesbetweenthecentralwirecontactthroughtheguardgaptothehighelectrode.Thenewdesignwasdescribedinthesecondpaper（II）alongwiththermalexpansionmeasurementson<0001>-orientedsinglecrystalsapphire（

）anda14-

thickinnerlayerdielectricmaterial[10].ItwasrecognizedinIIthatthedatareductionwassimpleaslongastheairfillingthegapbetweenthecapacitorplateswasdry.However,toexpandtheutilityofthecapacitancecelltohygrothermalexpansion（i.e.,swellinginahumidenvironment）,thethirdpaper（III）describedthedatareductiontechniquesnecessaryforuseofthecapacitancecellunderhumidconditions.

Fig.1.Schematicoftheelectrodes.Notethattheshadedareascorrespondtothenichromecoating.

TheresolutionoftheinstrumentwasdeterminedinIIandIII.Fordry,isothermalconditions,thecapacitancecellcanmeasurerelativechangesinthicknessontheorderof

fora0.5-mmthicksample;thiscorrespondstoaresolutionontheorderof

.Underdryconditionsinwhichthetemperatureischanged,thereproducibilityofarelativethicknesschange（e.g.,forCTEmeasurement）isontheorderof

.Finally,underhumidconditions,theultimateresolutionisprimarilyafunctionoftemperature—theactualvaluesofwhicharegiveninIII.

InII,adeficiencywasrecognizedinthedesign.Neithersemiconductingorconductingmaterialscouldbeusedasthematerialfortesting.Thiswasespeciallythecaseforsilicon,whichformsaSchottkybarrierwithnichromeandactsasavoltagerectifier.Additionally,becauseofthenatureoftheinterface,the1kHzmeasurementfrequencygeneratesultrasoundwhichresultsintheepoxycontactsbeingshakenloose.WementionedbrieflyinIIthatifthetopelectrodehadaguardringadded,thesamplecouldbeheldatzeropotentialandthiswouldnolongerbeaproblem.Todemonstratethis,weconstructedsuchacapacitancecell—thedesignandtestingofwhicharedescribedinthispaper.

II.CAPACITANCECELLDESIGN

A.ElectrodeDesign

BecausetheconstructionoftheelectrodeswasthoroughlydescribedinII,alessdetaileddescriptionwillbegivenwithemphasisonthechangesinthedesign.Theelectrodeswereconstructed,asbefore,inthefollowingmanner（seeFig.1）.

cylindricalblanksoffusedquartzweregroundandpolishedtoopticalflatness.Smallholesweredrilledthroughthecenterofeachblanksothat16gaugewirecouldbeinsertedintothem.Thewireswerethencementedwithaconductingepoxy（resistivityof

at25℃）.Asecondholeandwirewerethenaddedtoeachblankapproximately0.75cmfromtheedgeoftheblanks.Acoatingofnichromewasthenaddedsuchthatitcoveredallsurfacesexceptforasmallareaaroundthebackoftheblanks.Aguardgapwasscribedonboththetopandbottomelectrodessuchthatnomaterialwasraisedwhichcouldcauseashort.Onthebottomelectrode,theguardgapwasscribedona3cmdiameter,andonthetopelectrodeitwasscribedona6cmdiameter.Inthebottomelectrode,a1cmdiameterwellwascutintothebackoftheblankwhichextendedtowithin5mmofthefrontsurface.Thiswellwasthenfilledwithathinconductivesilverpaint.Thepaintconnectedtheouterguardring’smetallizationtotheedgeofthewell.

Fig.2.Schematicoftheassembledcapacitancecell.

B.CellAssemblyandCapacitanceMeasurements

TheholderdescribedinIIwasemployedforthemodifiedcell.Inthisversionofthecapacitancecell,bothconductorsofthesemirigidcoaxiallinewereconnectedtothetopelectrode.Thecenterconnectorandbraidwereconnectedtothecenterareaandouterguardring,respectively,byfine30gaugewirecoils.Thecoilswereterminatedwithcenterfemalecontactsfrom50

BNCconnectors,whichcouldbeeasilyconnected/disconnectedtothe16gaugetinnedcopperwirethatwasepoxiedintotheelectrodes.AschematicoftheassembledcellisshowninFig.2.ThefemaleBNCconnectoronthebrassholder（bottomelectrode）wasconnectedtothelowterminal,andthefemaleBNCconnectoronthesemirigidcoaxiallinewasconnectedtothehighterminal.AllconnectionsfromthecapacitancecelltothebridgewereperformedusingTefloninsulatedlownoisecables.

Thecapacitancemeasurementswereobtainedusingacommercialautomatedthree-terminalcapacitancebridgewhichusesanoven-stabilizedquartzcapacitorandhasacitedguaranteedrelativeresolutionofbetterthan

pF/pFfortherangeofcapacitancesusedwiththiscell（Andeen–Hagerling2500A1kHzUltra-PrecisionCapacitanceBridgewithOptionE）.（Notethatthe“useful”relativeresolutionissuggestedbythemanufacturertobetypicallyafactorof10ormorebetterthatthecitedrelativeresolution.）Thecapacitancebridge’scalibrationwasverifiedagainstaNationalInstituteofStandardsandTechnology（NIST）calibratedstandardreferencecapacitor—thedifferencebetweenthetwowaswithinthecapacitor’suncertainty.

Allmeasurementswereperformedinatemperature/humiditychamberequippedwitha90℃dewpointairpurge.Thecellwasequilibratedateachtemperatureuntiltherelativefluctuationsinthevacuumcorrectedcapacitancewerenomorethan

10pF/pF.Barometricpressurewasmonitoredusingadigitalpressuresensorwithamanufacturer’sstateduncertaintyof0.1mmHg（13Pa）.AsstatedpreviouslyinII,thetemperatureofthecellwascalibratedintermsofthechambertemperaturewitharesistancetemperaturedevice（RTD）mountedtothecellwiththermallyconductingpaste.TheRTDwascalibratedagainstaNISTcertifiedITS-90standardreferencethermometer.AsinII,becauseweareusingadryairpurge,wecanusetheidealgaslawcorrectiontodeterminethemolarvolumeoftheair

tocalculate

（3）

Where

T---absolutetemperature;

P---pessure;

R---gasconstan