物質(zhì)本身或當(dāng)物質(zhì)與物質(zhì)接觸時(shí)

Introduction

of

TemperatureMeasurementbyR&DRETeamMarch3rd,2002GGTinc.1PresentationOutlinePrimaryMechanicofHeatTransferProcessorThermalSolutionDesignThermalMeasurementEquipmentThermalProfileTestProcedureSummary 2PrimaryMechanicofHeatTransfer

Conduction

物質(zhì)本身或當(dāng)物質(zhì)與物質(zhì)接觸時(shí),能量傳遞的最基本形式

Convection

流體因加熱而流動(dòng)的傳遞熱能的方式

Radiation

熱輻射是一種可以在沒(méi)有任何介質(zhì)(空氣)的情況下,不需要靠接觸,就能夠達(dá)成熱交換的傳遞方式

3ConductionQ=K˙A˙ΔT/ΔL

Q

為熱量,就是熱傳導(dǎo)所能帶走的熱量

K

為材料的熱傳導(dǎo)系數(shù)值(Conductivity)

A

代表傳熱的面積(或是兩物體的接觸面積)

ΔT

代表兩端的溫度差;ΔL則是兩端的距離.

熱傳導(dǎo)后溫度分布示圖

4ConvectionQc=hc

˙

As

˙(Ts-Ta)

Qc

:熱量,就是熱對(duì)流所能帶走的熱量

As

:固體的表面積Ts

:固體的表面溫度

Ta

:環(huán)境溫度

hc

:傳熱系數(shù),f(flowtype,bodygeometry,physical,property,temperature,velocity,viscosity……)

hc

ofair,naturalconvection:0.0015~~0.015W/in2℃

forcedconvection:0.015~~0.15W/in2℃

5RadiationQ=e˙s˙F˙Δ(T4

)

Q

為物體表面熱輻射的熱交換量

e

物體表面的熱輻射系數(shù)(Emissivity),其值介于0~1之間,是屬于物體的表面材料特性

S

是波次曼常數(shù)5.67*10-8

F(ExchangeViewFactor)

輻射熱交換的視角關(guān)系,它其實(shí)是一個(gè)函數(shù),一個(gè)跟兩個(gè)表面所呈角度,

面積,及熱輻射系數(shù)有關(guān)的函數(shù)

Δ(T4)=(Ta

4--Tb4),其中Ta是表面a的溫度,而Tb

是表面b的溫度

6ProcessorThermalSolutionDesign

HeatSink

HeatPipe

Fan

TIM(ThermalInterfaceMaterial)7HeatSink

Thethermalresistanceofaheatsinkisdeterminedbytheheatdissipationsurfacearea,thematerialand

shapeoftheheatsink,andtheairflowvolumethroughtheheatsink.

ΘJ-A=(TJ-TA)/PCPU℃/W

ΘJ-A

:CPUJunctiontoambientthermalresistance

TJ:CPUJunctiontemperature(specforIntel:100℃)

TA

:ambienttemperature(OEMspec:35℃)

PCPU:CPUpower

inanintegritythermaldesignsystem

ΘJ-A=ΘJ-hp+

Θhp-hs

+

Θhs-A8HeatPipe&FanHeatPipeMaterial:銅Workingfluid:純水

Standardworkingtemperature:0-100

℃Size:Φ3,Φ4,Φ5,Φ6,Φ8

Typicalheatpipewickstructures:纖維(fiber),

絲網(wǎng)

(mesh),凹槽(groove)Fan轉(zhuǎn)速

噪音

(Fansareneededtomovetheairthroughthechassis,theairflowrateofafanisusuallydirectlyrelatedtotheacousticnoiselevelofthefanandsystem.)9TIM(ThermalInterfaceMaterial)ImportantofTIMMaterial

油脂(grease),蠟(wax),thermalpads/taps,環(huán)氧樹(shù)脂(epoxy)Thermalresistanceofthesematerial

0.15~~0.3℃/W

10ThermalProfileTestIntroductionThermalMeasurementEquipmentThermalProfileTestProcedure11Thermocouple:OMEGAT-type,-270℃~~900℃,accuracy=+/-1.0℃ThermalEpoxy:OMEGABOND101ThermocouplesConnector:OMEGAT-typeWelder:TC50WRecorder:YOKOGAWAHybridRecorderDR230KaptonChamber:KSONBurnInRoomP2000H+

ThermalMeasurementEquipment12ThermalProfileTestProcedure裁剪適當(dāng)長(zhǎng)度的熱偶線(xiàn),約2米

焊接熱偶線(xiàn)量測(cè)端的兩端點(diǎn)

在另一端接上轉(zhuǎn)接頭

選擇量測(cè)點(diǎn)

固定熱偶線(xiàn)

將轉(zhuǎn)接頭連接到recorder

Continued13ThermalProfileTestProcedure14將待測(cè)機(jī)放入chamber中

運(yùn)行測(cè)試軟件

開(kāi)啟chamber,設(shè)置其目標(biāo)溫度為35℃,讓其運(yùn)行大約半小時(shí)待溫度穩(wěn)定后stop之,讓待測(cè)機(jī)在無(wú)風(fēng)環(huán)境下進(jìn)行測(cè)試

開(kāi)啟recorder,并開(kāi)始記錄

3~4小時(shí)后,待溫度曲線(xiàn)平穩(wěn)再讀取測(cè)試結(jié)果.ChoosemeasuringpointAmbienttemperature(Ta)BottombaseBeneathCPUBeneathchargerBeneathLANBeneathmemoryBeneathnorthbridgeBatterytopcase&bottomLCDinverterThreespindlesVGABIOSAudiocodecPalmRest(left&right)PMU07AdapterFloppydiskettePCMCIAambientPCMCIAcontrollerNorthbridgeSouthbridgeK/BcontrollerMiniPCICPULVDSCLKgeneratorSDRAMLAN……15Summary隨著NoteBook的處理器頻率越來(lái)越高,體積越來(lái)