产品的热设计(Thermal introduction)(精品).ppt

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1、IntroductionofThermalGGT/REEnvironmentTestTeamPrimaryMechanicofHeatTransferThermalenergytransport:causebytemperaturedifference,highT-lowTConductionHeattransferringbysolidmediumConvectionTransferringenergybetweensolidsurfaceandfluidMasstransportNatural(free)convectionForcedconvectionRadiationHeattran

2、sferringbyelectromagneticwavesConductionFouriersLawQ=-KAT/LQ:heattransferrateA:cross-sectionalareaofheatflux T/L:temperaturegradientK:thermalconductivity(W/mk)Ex.Al=230Cu=380Mylar=1.8ConvectionNewtoniancoolingLawQc=hcAs(TsTa)Qc:convectionheattransferrateAs:surfaceareaTs:surfacetemperatureofsolidTa:t

3、mperatureofambienthc:heattransfercoefficient,f(flowtype,bodygeometry,physicalproperty,temperature,velocity,viscosity)Naturalconvection&Forcedconvctionhc of air,natural convection:0.00150.015 W/in2 forced convection:0.0150.15 W/in2RadiationQa=AF1-2(Ts4Ta4)Qa:radiationheattransferrate:emissivity,01:St

4、efan-BoltzmannconstantA:surfaceareaF1-2:viewfactorTs:temperatureofbodysTa:temperatureofbodyaThermalResistanceR=V/IV:voltage=T:temperaturedifferenceI:current=Q:heatConductionRk=L/KAkConvectionRs=1/hcAsRadiationRa=(TsTa)/AF1-2(Ts4Ta4)BasicConceptsforNBThermalDesignThermalDesignTargetThermaldesignmustm

5、eetthermalspec.ofCPU,allkeycomponents(HDD,FDD,CD-ROM,PCMCIA),andallICchips(Chipset,VGA,RAM,PCMCIA),andallICchips(Chipset,VGA,RAM,Audio)ineachuserconditionsThermalResistancej-a=(TjTa)/Pcpu j-a:CPUjunctiontoambientthermalresistanceTj:CPUjunctiontemperatureTa:ambienttemperaturePcpu:CPUpowerBasicConcept

6、sforNBThermalDesignSystemThermalCouplingeffectj-a=(TjTaTsys)/PcpuTsys:systemtemperature=Psys*=Pi*i,(i:DRAM,Chipset,HDD,FDD,CD-ROM)R:thermalcouplingfactorbetweenPcpuandPsysTj:CPUspec.forIntel:100Ta:OEMspec.,35j-a,Tsys:OEMdesigndependent,Tsys=1015BasicConceptsforNBThermalDesignThermalSolutionsPassivet

7、hermalsolutionActivethermalsolutionHybridthermalsolutionRHERemoteHeatExchangerBasicConceptsforNBThermalDesignCharacteristicofagoodpassivecomponents1.SpreaderplateconnectedtoCPUshouldbeaslargeaspossible2.TemperaturevariationonspreaderplateshouldbeminimalCharacteristicofagoodactivecomponent1.Airinleta

8、ndoutletshouldbeclearlydefined2.LengthofairpassagethroughNBshouldbesmalltokeeppressuredroplow,flowratehigh3.Possiblereducenoiselevelofthefan4.DesignmustbecapableofventingaportionofhotairfromNBinsideImportantComponentsForThermalDesignHeatSinkHeatPipeFanTIM(ThermalInterfaceMaterial)Combinationofaforem

9、entionedcomponentsHeatSinkMaterialMaterial:A1050A6063ADC12C1100K(W/mk):230210192384Specificgravity:2.712.692.70 8.92ProductionDie-castingExtrudedQ=-KAT/LFin,Q=hATDie-casting,extrusion,folder,stack,solderingfinsHeatPipeBasicconfigurationandcharacteristicBasicspecificationMaterial:copperWorkingfluid:p

10、urewaterStandardworkingtemperature:0100Size:3,4,5,6,8TypicalheatpipewickstructuresFiber,mesh,groove,powderTypicalmodificationofheatpipeFlatteningBendingHeatPlateFanStructureRotator:magneticblade,shaftStator:bearing,wire,stainlessplateControlcircuitTheoryTypeAxialfanBlowerfanSelectionTotalcoolingrequ

11、irementQ=Cp*m*T=*Cp*CFM*TTotalsystemresistance/systemcharacteristiccurveSystemoperatingpointFanParallelandseriesoperationAcousticalnoiselevel(dB)ToachievelownoiseshouldconsiderSystemimpedanceFlowdisturbanceFanspeedandsizeTemperatureriseVibrationVoltagevariationDesignconsiderationsTIMThermalInterface

12、MaterialToreducecontactthermalresistancebetweenCPUdieandthermalmoduleImportantofTIMMaterialVariousmaterial:silicon-base,carbonNon-phasechangePhasechangePressureeffectPressurespec.onCPUspec.100psiThermalDesignProcedureClarifyClarify Thermal Specification Thermal SpecificationDesign Thermal SolutionDe

13、sign Thermal SolutionAnalytic ApproachEvaluate Solution PerformanceNumerical ApproachExperiment ApproachVerifyDesign Thermal SolutionDesign Thermal SolutionEvaluate heat generationAllowable thermal resistanceAllowable design spaceEvaluate Chassis heat dissipationEvaluate heat exchange areaEvaluate f

14、an flow ratePassFailInspect Structure.Production method.CostRecommend Thermal SolutionThermal Test in Working SampleVerify Overall SystemMeeting Thermal SpecificationThermal Design OK!Examine and ModifyThermal SolutionPassFailThermalDesignGuidesDesign guide for thermal (Ver.0.2)ThankYou!fiberMesh細絲(

15、銅絲)螺旋彈片銅网groove直接加工而成Powder類型:金屬粉末燒結在HeatPipe內壁,形成毛細結構NNNNSSSS無刷馬達轉動原理無刷馬達轉動原理有HallIC感應其磁鐵N.S.極,經由電路控制其線圈之導通產生內部激磁使轉子部旋轉CFM(ft3/min)StaticpressureSystemresistancecurveFancurveSystemoperatingpoint1.ThermalModule1)Reservespaceforthermalmodule(Intelrecommendation)Coppermine:70*50*11.5mmTualatin:75*55*1

16、1.5mmNorthwood:85*60*19mm2)Itshouldreserveagapbetweenthermalmoduleandtopcover(keyboardcover)1.ThermalModule3)ThegapbetweenthermalmoduleexitandNBcaseventshouldbesealedwellsothehotaircouldntflowbacktosystem.Ifleaveanopengapalongairflowpath,itwillaffectthermalefficiencyandacousticnoise.1.ThermalModule4

17、)ThethermalmoduleandCPUshouldcontactwell.a)ThemaxpressureofthethermalmoduleonCPUis100psi.WithinSPEC,efficiencyofthermalmoduleincreaseswithpressure.b)ItsbettertofixmoduleonM/Bbyfourscrews(avoidingthreescrews)andspringdesign.2.Fan1)Faninletconstraints:gap35mmisneeded.3mm80%performance4mm90%performance

18、5mm100%performance2)Configurationofairinlet&outletventscanmakedramaticallyflowresistance;thereforehighopenrateisbetter.2.Fan3)Dontplaceblocks(largeICsorconnector)nearorbelowthefantoaffectairflowinducedintofan.4)Itisbetterforfixingfanbyrubberinsteadofmetalscrewstoavoidvibration.2.Fan5)Thefanspacedesi

19、gnhassomerestrictions.a)Forefficiencyandacoustic,thegapbetweenfinsandfanbladeshouldkeepadistanceofL=510mm.b)ThedistanceWisbettertokeepaslargeaspossibleforgoodefficiency.c)Fanbladeshouldclosetofantongueforbetterefficiency.3.PCMCIACard1)DontplacePCMCIAonlowersideofM/B,nearhotterICs,andstackedupkeycomp

20、onents(HDD,CD-ROM,DVD,FDD).2)IfitneedstoplacePCMCIAnearheatsource,itisnecessarytoinduceairflowtocoolit.(Ex.ForJ2I+,L1R,itisremovedmetalplateonPCMCIAslotandmakesholesabovePCMCIAifthereisanAlplateuponit.Bythisway,aircanflowthroughthisareatocoolPCMCIAcard.)3.PCMCIACard3)Duetoaforementionedsolution,PCMC

21、IAshouldplacenearfaninordertoinduceairflowtocool.4.KeyComponents1)BecauseHDD,CD-ROM,FDDthermalSPCEislow,thesekeycomponentsneedtobeplacedincolderregion.(AvoidplacingtheminthemiddleofthesystemanduponM/BwithhotICs,andstackingupeachother).2)ItsbettertoplaceFDDalone,nottoputon/beneathCD-ROMorHDD.5.Palm-R

22、estandGlidPad1)ItshouldavoidplacinghotcomponentsandICsbelowpalm-restandglidpad.2)Itshouldreserveagaptomakeathermalresistancebetweenpalm-restandthehotcomponentsortoaddametalplateforspreadingheat.6.LCDInverterItshouldreserveagapbetweenInverterandLCDcovertomakeathermalresistanceortoaddametalplateforspr

23、eadingheat.7.BottomcaseandDimmDoor1)ItshouldreserveagapbetweenICchipsandbottomcase(gap3mmisbetter).2)ItmighthavealargeAl-plateonbottomcaseforspreadingheat.3)M/BhasaholebelowfaninordertoinduceairflowunderM/B.4)ItsbettertoplacehotterchipsonuppersideofM/B.5)ItshouldreserveagapbetweenMemorychipsanddimmd

24、oor(gape1.5mmisbetter).8.M/BLayout1)IftheresthermalissueofICs,itshouldreservespaceforthermalsolutions(Ex.DontplacehighercomponentsbesidetheseICs,soitcouldputmetalplateonICsinfuture)2)DontplacelowtemperaturespecICsandcomponentsnearhotterregionorhightemperaturespecICsandcomponents.9.Others1)Itsbettert

25、ousethethinnerorphasechangeTIM(thermalinterfacematerial)Ex.28WCPU(phasechange)Powerstrate0.08mm 75(phasechange)T-pcm0.25mm83T-pcm0.50mm86(phasechangewithAl)T-mate0.50mm83(non-phasechange)Tx0.25mm90Tx0.5mm969.Others1)Heatpipesonthermalmodulehavesomerestrictions2)Thethicknessshouldntbelessthan2mmwhenb

26、emadeflat.3)Thecurveradiusshouldbelargerthantriplediameteratleastwhenbebended.4)ItmightneedsomeholesonbottomcaseandsidewallofNBinordertoinduceairflowtodissipateheat.35mmAirflowFan3mm80%performance4mm90%performance5mm100%performanceFanBlocksBaddesignLWTongue該縫隙越小該縫隙越小Fan 效效率越高率越高,但但Noise 也會隨之上升也會隨之上升

27、L:太大太大,Fan效率效率下降下降;太小太小,噪音上升噪音上升.W:作為風道作為風道,盡盡量大量大SinglefanDoublefanParallelCFMPressurePressureCFMSinglefanDoublefanSeriesTIM:thermalinterfacematerial考慮將散熱器固定於發熱器件的方法時,重要的是要使二者之間界面熱傳到處效率最大.也應考慮其他要求,如介電特性,電導性,附著強度和再次安裝的可能性.發熱組件和散熱器之間界面的熱傳輸效率取決於空氣殘留,填充物類型和黏合曾的厚度等參數.方法優點缺點機械安裝有助於散熱;可即時安裝空氣間隙導致較差的傳導率;緊固件導致壓應力帶矽樹脂的機械安裝(有/無雲母墊片)好的導熱率流程控制困難;由移植和灰塵造成的污染會引起接觸不良帶可壓縮墊片和墊料的機械安裝較好的導熱率;無移植問題嚴重的扭矩變化會導致難以防止緊固件鬆動帶還氧樹脂黏合劑的黏合良好的導熱率;壓力均衡(可避免鬆動);無移植問題要求混合;罐裝壽命有限;熱固性不允許在線安裝相變化材料良好的導熱率重複性使用差