1、ProjectnameProjectnumberAuthorReleaseDepartmentFilenameCreationdateExecutiveSummaryTableofContents1 Introduction31.1 基本參數(shù)介紹32 Activities42.1 Theta-ja(Junction-to-Ambient42.1.1 測(cè)量方法42.1.2 節(jié)溫計(jì)算公式62.2 Theta-jc(qc)Junction-to-Case62.2.1 測(cè)量方法62.2.2 節(jié)溫計(jì)算公式62.2.3 亞與ja的關(guān)系72.3 Theta-jb(qb)Junction-to-Board72

2、.3.1 測(cè)量方法82.3.2 節(jié)溫計(jì)算公式82.3.3 .與ja的關(guān)系82.4 W的含義92.4.1 Wjb92.4.2 Wjc92.5 各種封裝的散熱效果92.5.1 TIPowerPAD封裝的使用注意事項(xiàng)103 Results123.1 關(guān)于.ejcJ乎jt使用問題124 Discussion124.1 熱仿真軟件的使用125 Conclusions125.1 126 Abbreviations,Definitiones,Glossary136.1 137 Version131Introduction1.1基本參數(shù)介紹般包括三個(gè)參數(shù)0ja.jC,Qb,三種參數(shù)所指的散熱圖示如下Ta,Tb

3、,Tc的測(cè)試點(diǎn)如下：TIteFiH汨and丁丫加加HeatF/owSolder-80%ofheatLorTpTa(ambientair)Tc。L一L1%ofheat/-20%ofheattV。已5andTtpicmHeatF加hSolderdivide。bvtctllhentiiippower佛)：applicabletoannYed-comecticpackagesTtietbeniin)e-ironmentniustbespecified.氏Rej：Jiuicrion-toCaseThenrulResistance8rsMK7WJunction-To-CaseThcnnEResistanc

4、ewithheatflowThioufhpAcknzeborrom6JrtopSjCwpKWJunction-to-CaseThenmlResiEitanctwithheatflowthroughpackagetop肌KWJuncticn-toTluidThenralResistance牝KLMJunction-to-LeadThemnRehitanice由KWJuncticn-to-LeadThenmCfcaractezarionParmieterAthem疝metrederivedfrsrntjiedfferefleeinjunctiontemperitixpe(Tj)lendTl)div

5、idertr，tetaihetinpover(Pn);applkablemostly邨kadtddevicepackage;.Tlwthemialtnusigtp?cifidSjMARsthaK7WJiuictioQ-to-lIoiigAirTherm】ResistanceG;rReJtKM，Juuctica-lo-RcfcrcnccTiiciuialRjcsaitaiiccsKNJimction-to-TapThermalClaaractenzaticmParameter.AthmnalmetncdnnTtlfioinIlirddGfeicnceinjunctiontcmpnatuzE(Tj

6、)andpackagetoptenipm.cure(Tj)-ividecbvtctalheatingpower(Ph)-Thethemudriivircmmentmustbespccifird.陛rxKMJimctiGQ-to-defmedpoin(X)TheirnaKesistance2Activities2.1 Theta-ja(Qa)Junction-to-Ambientpn節(jié)到空氣的熱阻。單位c2.1.1測(cè)量方法/WoThemeasurementof6isperformedusingthefollowingsteps(summarizedfromEIA/JESD51=1):Step1A

7、partusuallyaninteiiratedcircuitdCpackagecontainingathermaltestchipthatcanbothdissipatepowerandmeasurethernaximumchiptemperature,ismountedonatestbo白rdStepZThetemperaturesensingcomponentofthetestchipiscalibrated.Step3一Thepackage/testboardsystemisplacedineitherastiIairormovingairIaJenvironment.Step4.Ak

8、nownpowerisdissipatedinthetestchip.Step5、AftersteadystateIsreached,thejunctiontemperatureismeasured.Step6ThedifferenceinmeasuredambianttemperaturecomparedtothemeasuredjunctiontemperatureiscalculatedandIsdividedbythedissipatedpov.ergivingavaluefore,incCjW.DTItoaMkctevl器件說明書中的JA是根據(jù)JESD51標(biāo)準(zhǔn)給出的，其標(biāo)準(zhǔn)環(huán)境是指將

9、器件安裝在較大的印刷電路板上，并置于1立方英尺的靜止空氣中。&與PCB疊層結(jié)構(gòu)、芯片焊盤大小、高度等均有關(guān)系，故因此說明書中的數(shù)值（實(shí)驗(yàn)室數(shù)據(jù)）沒有太大的參考價(jià)值。但目前只能如此計(jì)算。2.1,2節(jié)溫計(jì)算公式TjunctionTambient:Tjunction:Power:=Tambient+(ja*Power)；環(huán)境溫度芯片PN節(jié)溫度芯片消耗功率2.2 Theta-jc(9=)Junction-to-Case0jc是結(jié)到管殼的熱阻，管殼可以看作是封裝外表面的一個(gè)特定點(diǎn)。此參數(shù)最是為預(yù)估有散熱器的器件設(shè)計(jì)的。2.2.1 測(cè)量方法Summarized,theprocedureis:StepLAn

10、ICpackagenormallycontainingathermaltestchipismountedonateslPCB.whichisnormallyihe1sJEDECdefinedtestboardStep2.ThepackageispressurefitinadeadbugconfigurationtnaCjcoldplate(aCublock.vithcircuitingconstanttemperaturefluid；whenthetopofthecaseistobemeasured.Otherwise,3Cucoldplatecontacttothebottomofthepa

11、ckageisprovidedthroughthePCBwhentheprimarycoolingpathofthepackageisthrough口solderedplateintothePCB.Step3.Siliconethermalgreaseorotherthermalinterlacematsnalprovidesthermalcouplingbet/jeenthecoldplateandpackage.Step4InsulationisprovkiedaroundtheteslcoupontcminimizeparasiticheatkssStep5.Powerisapplied

12、tothedevice.Step6.Thejunctiontemperatureofthetestchipismeasured.Slep1Thelemperatureofthepackagesurfaceinconlactwiththecoldp匕悔&measuredbyathermocoupleorothertemperaturesensorpre-ssedagainstthissurfaceStep88、iscalculatedbydividingtfiemeasuredtemperaturedeltabyttiedissipatedpow&r.IPiermoccupteFigure4.C

13、uColdPlateMeasurementProcess2.2.2 節(jié)溫計(jì)算公式Tjunction=Tcase+(c*Power)Tcase:芯片外殼溫度Tjunction：芯片PN節(jié)溫度Power:芯片消耗功率一般有散熱片的情況下計(jì)算公式：Tjunction=Tambient+i1也+聯(lián)+隹a)*Power)s:芯片外殼到散熱片的熱阻也a：散熱片到空氣的熱阻Tambient：環(huán)境溫度Tjunction:芯片PN節(jié)溫度Power:芯片消耗功率其中Qs的計(jì)算公式如下：2.3 丁仃日制YS用JThebestrTititliudfuitdlculalirigR”isioJLtLiallyrnidsu

14、ieIlievauebulifIhisisnotpussible.tqjJhji.LJI】。一uj1t:；，一n、二t已Ty.Nl：l山工tIf二i二fe七、-nL.mjte匚1匚tilth.：rnamtu-fjxulresistanceihatcanbdevelopedbetweendruytwosurfdcisisneglected.UgktAWhereT=Thethicknessofinterfacelayerbetweenpackageandheaisinkk二ThebulkthermalconductivityofthetiiermalinterfacenateralA-Theare

15、aoverwhicfithedermalinteifacematerialts洋plied2.2.3%與9a的關(guān)系亦可認(rèn)為存在如下公式生19c+Qa)2.3Theta-jb(00Junction-to-Board是指從結(jié)到電路板的熱阻，它對(duì)結(jié)到電路板的熱通路進(jìn)行了量化。備通常的測(cè)量位置在電路板上靠近封裝處，即L1節(jié)圖表所示。2.3.1測(cè)量方法4.1曳Measurenient期的。dTheprimarymethodtomeasuna與isasfollowsSl/p1.Alest(JMkgeoonlainiityaDermaltestdisisinauntedwimleslbu/d.Slep2At

16、mewirethermocouple(36-40gauge)isgluedorsolderedtothedevicep(ndosesitothediip.Intriecm/ofBGApiKkdgts,山匕thefiTiocuupnitsolderfdcrglu旬to(tieli冥號(hào)exlinfromnricrrhepar匕力gedgetti甫i$ctoscsttothechipStep3.Theboardisclampedinabpet.iddoubkcoldplait?fixturewithirmJdliixibt?tweenthepackage由府rhecoldplatesurfacesr

17、butwithihcrmalconmdbetweenthe8klptaieandtheboard.TheeddplalehealsinkstiePCB.Step4,Powerisdissipatedmmedie.Slep5.Theteriperalur&sofIbedieand尸。aremonitored.SipnWhen工tntf1與nrbiipvprtthpdetrbeTwrrnthenrtinnandpin，產(chǎn)eymturm*iqdividedbythelotlpowerThisptocedureisdefinedmorepredselvinEIA/JESD51SGootaminCooh

18、nlOutLeadTlermocDUpleFigurt7.fltMeasurementMethod2.3.2 節(jié)溫計(jì)算公式Tjunction=Tpcb+(fjb*Power)TPCB:PCB處溫度Tjunction:芯片PN節(jié)溫度Power:芯片消耗功率2.3.3 %與格的關(guān)系亦可認(rèn)為存在如下公式如寸jc+ebb+eba)ThemalPathr.AmbientLTCase(topofpackage二JunctionTJ-1(Heatgeneration)JAaOjRBoardbottomofpackage)BOZd(edgeofboard)AmbientNote:Intheequivalent

19、electricalcircuitPower(W)=Currant(ATemperature(CorK)=VoltageDrop(V)ThermalResistance(C/W)=Resistance(1)AT=PistheequivalentofAV=IR1.4 的含義乎和e之定義類似，但不同之處是于是指在大部分的熱量傳遞的狀況下，而e是指全部的熱量傳遞。在實(shí)際的電子系統(tǒng)散熱時(shí)，熱會(huì)由封裝的上下甚至周圍傳出，而不一定會(huì)由單一方向傳遞，因此于之定義比較符合實(shí)際系統(tǒng)的量測(cè)狀況。1.4.1 咖TJ配結(jié)到電路板的熱特性參數(shù)，單位是/Wo熱特性參數(shù)與熱阻是不同的。與熱阻ejb測(cè)量中的直接單通路不同，T

20、JB測(cè)量的元件功率通量是基于多條熱通路的。由于這些WJB的熱通路中包括封裝頂部的熱對(duì)流，因此更加便于用戶的應(yīng)用。Tjunction=Tpcb+(陰b*Power)1.4.2 WjcTjunction=Tcase+(Wjc*Power)(此時(shí)不能加散熱片)1.5 各種封裝的散熱效果PeiibnnanceofTypicalThennalSolutionsThermalSolutions由圖可見，BGA封裝的散熱效果最佳。2.5.1TIPowerPAD封裝的使用注意事項(xiàng)IntorUkilofJFrPlanoG7bormal曬口Area。&JnoAB-lcnodMQd心熊京，一一eOAunnE-n6=QUR-l加，fflun-PZB切切flMuedkn&二切In獸善一/*禽7一！uhtp，jaq石s*舌/q_!q9uLJa,JBFH-1立昌FE2恪二金七3G0s口瞿Dmuto_XI=L6(QJ到ONa邑工duao電KIF&L-CEL:ggQ%.JiddnQ.口石EQKO$OJUXJUlJEdBlm$ul.QJLDrw-口加0E&GD仁而但WDlqal邑=5-E6pusdapXJX&E-:-;MU二-:-,.二二L至Bp息8言七。15LIJ9+po_i01kc-bl-HLE50,雷旨LI.口R*urMdc-rd上d寸ll_JEDEC2-LAYERBOARDTHERMALRESI