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高亮度LED照明技術發展與太陽能照明應用1NewEnergyCenter黃秉鈞台大機械系新能源中心民國94年8月1日高亮度LED照明之關鍵技術2NewEnergyCenter•半導體材料–發光效率:30-50Lm/W–Maxjunctiontemp:120oC•散熱技術–LED內部熱傳•與LED封裝設計與製程有關–燈具散熱設計•與燈具設計有關高亮度LED散熱之技術問題3NewEnergyCenter•LEDjunction溫度限制–Max120oC(0hrlife)–設計值:90oC(50,000hrlife@70%)•與空氣(35oC)溫差只剩55oC•不能採用風扇–自然對流散熱•散熱設計必須滿足燈具光學需求–為了容易散熱,光源分散排列,降低光學效率•散熱設計必須滿足燈具造型需求–燈具造型限制了散熱設計•成本控制–封裝製程要簡單•體積與重量限制–影響造型與成本高亮度LED照明產品發展現況•目前很少看到超過30W的LED燈具–原因猜測:1.散熱問題尚未解決2.市場尚未成熟,不想太早公開4NewEnergyCenter16W高亮度LED燈LED之熱傳機構5NewEnergyCenterTmount電路板TjTcapsuleTmountLED之上下游熱傳機構6NewEnergyCenter–LED蕊晶Tj(發光體)ÆLED底座(Tmount)•與LED封裝設計有關–LED底座(Tmount)Æ電路板(Td)Æ散熱裝置(Tb)Æ空氣(Ta)•與散熱機構(燈具)設計有關TjTmountTbTairTdlamp內部(上游)lamp外部(下游)LED下游散熱問題7NewEnergyCenter•30WLED燈具之散熱最小散熱面積需求–Tj=90oC(@50,000hrlife)ÆLED底座:Tmount=50oC@fullload–氣溫Ta=35oC;–假設Tb=Td=Tmount(LED底座至散熱板無熱阻)–熱阻Rma=(50-35)oC/30W=0.5K/W=1/hfAf–自然對流係數hf=5W/m2K(無風狀態-最壞情況)ÆAf=0.4m2(雙面)散熱面500400•條件:1.四週無障礙物2.散熱面溫度均勻分佈LED熱密度8NewEnergyCenter•熱密度(48WLED為例)–LED排列:4x4(電路板48mmx48mm)–熱密度:2.1W/cm2•CPUdieÆ20-80W/cm2(CPU需強力風扇—噪音60dB)下游散熱路徑9NewEnergyCenterTmount電路板Td•LED底座(Tmount)Æ電路板(Td)–熱接觸與面積突擴問題•電路板(Td)Æ散熱裝置(Tb)–熱接觸與面積突擴問題•散熱裝置(Tb)Æ空氣(Ta)–自然對流散熱問題2spreadresistance面積突擴熱阻問題(spreadresistance)10NewEnergyCenterLED的三重突擴熱阻•LED蕊晶Tj(發光體)ÆLED底座(Tmount)•LED底座(Tmount)Æ電路板(Td)•電路板(Td)Æ散熱裝置(Tb)•散熱裝置(Tb)Æ空氣(Ta)3spreadresistance11NewEnergyCenterLEDlampLED電路板散熱器LEDchipLED底座LED內部突擴熱阻12NewEnergyCenter48WLED電路板至散熱板之突擴熱阻13NewEnergyCenter•LED底座(Tmount)Æ空氣(Ta)之最高容許熱阻:Rma=0.5K/W•熱密度(48WLED)LED排列:4x4電路板:48mmx48mm熱密度:2.1W/cm2Tmount電路板TdLED電路板(Td)48x48Æ散熱板(Tb)500x5003WLamp間距:14mm36W結論14NewEnergyCenter•如果只用傳統散熱片散熱,48W之LED排列(電路板)至少要30x30cm以上,且散熱板(500x500)厚度要4mm以上–光學效率降低–笨重16W18W16W改善熱傳方法15NewEnergyCenter•採傳統熱管(CPU散熱用)–Spreadresistance仍高–熱管一彎曲效能便劇降•應付造型需要,必須彎曲–不彎曲又影響造型傳統熱管規格(CPU散熱用)16NewEnergyCenter傳統熱管散熱之熱阻問題17NewEnergyCenter單支熱管內部熱阻0.5K/W(壓扁後)300mm傳統熱管φ8散熱板LED燈48Spreadresistance?K/WLED照明散熱問題之解決最佳方案18NewEnergyCenter•採最先進熱管(微米熱傳科技)–迴路熱管(loopheatpipe)3WLamp間距14mm!迴路熱管LoopHeatPipe19NewEnergyCenter•合作開發:–台大新能源中心–江陵機電(陽傑)公司–俄羅斯科學院與Maidanik合作20NewEnergyCenterMaidanik之子MikhailMikhail之合夥Boris市場助理秘書MaidanikConventionalHeatPipe•Returnliquidflowsubjecttohighflowresistance–Thinwickstructure–Longliquidflowdistance•Lowrateofheattransport•Limiteddistanceofheattransport21NewEnergyCentervaporLiquidreturnthroughwickEvaporatorsectionCondensersectionadiabaticsectionwickHeatinHeatout22NewEnergyCenter迴路熱管蒸發器Evaporator冷凝板CondenserQQQ柔性毛細軟管LiquidflowwickVaporchannelHeatflowcontainer23NewEnergyCenter•Microtechnology(microwickstructure)微米科技•Long-distanceheattransport(0.3-10m)•Highrateofheattransport(30-6000W)•Againstgravity•FlexiblegeometryLHP特點24NewEnergyCenter•連通管可任意彎曲–可配合燈具造型•可長距離傳熱–降低spreadresistance•可傳送大量熱量–用於高亮度LED•缺點:太貴(太空用:15萬美元)Smallquantityproductiontest(max70sets/day)25NewEnergyCenter•量產成本:USD10(100WLHP)微米毛細材料26NewEnergyCenterMaidanik(Russia)NECKL-255-30-350NECKL-255-5-350LHPReliabilityTest27NewEnergyCenter•LHPreliability–Startupstability–Chemicalstability–Structurestrength–Durabilitytovibrationetc•Reliabilitytestwithheating1hr,non-heating1hr(12cyclesperday)at80Wor120W–athorizontalanddifferenttiltedangles•PerformancemeasurementeveryweekLHPReliabilityTest(fullyautomatic)28NewEnergyCenter•KL100-CU-10:80W(Th-Ta40oC)@Ta30oC100W(Th-Ta50oC)@Ta27oC29NewEnergyCenter30NewEnergyCenterKL100-CU-10(391days)•EvaporatorthermalresistanceRhv~0.15-0.20K/W•Overallthermalresistance:Rha~0.5K/WEvaporatorthermalresistanceLoopheatpipethermalresistanceRhv•由加熱端Th至蒸氣出口端Tv之熱阻31NewEnergyCenterThTvFanfailureduringtest(aboutonceevery4months)32NewEnergyCenterFanfailures(4/21/04)633天連續測試33NewEnergyCenterKL100-CU-07(648days)34NewEnergyCenter•Evaporatorthermalresistance:Rhv=0.05~0.09K/W•Overallthermalresistance:Rha0.6K/WKL100-07Q=101W,Th=85oC,Tv=75.5oC,Tc=65oC,Ta=24.6oCRhv=0.092K/W;Rha=0.60K/W35NewEnergyCenterKL100-23@12cycling/day•Rhv~0.1K/W•Rha0.5K/W36NewEnergyCenterPerformanceatdifferentangles37NewEnergyCenterKL100-22(testwithoutfan)38NewEnergyCenterNofanNofanHeating/coolingCyclingTest39NewEnergyCenter-60-40-200204060801001200200400600800100012001400蒸發器加熱器•Heating90min(+80℃)•Cooling90min(-40℃)LHP性能比較40NewEnergyCenterWICK種類TairLHPperformanceRhv25.9°C24.3°C0.096(KL100-37)24.1°C0.11(KL100-NC4-02)26°C24.4°C20°C0.091(KL100-Cu-23)M型WICKX型WICK0.258(KL100-NC-01)0.132(KL100-NC1-01)XX型WICKYu.F.Maydanik0.1(氨)1m長LHP性能41NewEnergyCenter標準件樣品42NewEnergyCenter43NewEnergyCenterExamples(demonstration)•SilentPC(CPUcoolingwithoutfan)0dBA•condenser:copperplate(350mm×450mm)•overallthermalresistance:around0.58K/W44NewEnergyCenterLHPwithdoubleevaporatorswithoutfan45NewEnergyCenter•overallthermalresistance(Rha)=0.3K/Wat110WLHPforcoolingofelectronicdevices46NewEnergyCenter200WLHPwithdoubleevaporators47NewEnergyCenteroverallthermalresistancewithfansRha=0.22K/Wat120W0.28K/Wat220WLHPforcoolingofserverCPU48NewEnergyCenterRhaRha0.35K/W@120W0.35K/W@120W120WLHPsamplesRha~0.35K/W49NewEnergyCenterReplacingwater-coolingdevice?(40USD,life1yr)50NewEnergyCenterLHPLHPLHP:Rha0.30K/WWater-cooled:0.27K/W高亮度LCD散熱模組51NewEnergyCent