TFT-LCD制造流程及光學(xué)規(guī)格介紹-080527

TFT-LCD模組結(jié)構(gòu)組成

TFT-LCD工作原理

TFT-LCD製作流程簡介

TFT-LCD光學(xué)規(guī)格介紹TFT-LCD簡介及光學(xué)規(guī)格介紹ThinFilmTransistorLiquidCrystalDisplay薄膜電晶體液晶顯示器What’sTFT-LCDThethin-filmtransistorliquidcrystaldisplay(TFT-LCD)isacutting-edgedisplay,whichscreenspictureinformationbyadjustingtheamountoflightpermitted.

TFTisacircuitformedwithsemiconductorfilmsonathinglasssubstratetocontrolliquidcrystals.Thiscircuitplaysavitalroleincontrollingeachpixel,thebasicunitofapictureimage.

Thecolorfilterdisplaysacolorimagebycoatingthepixel(red,greenandblue)onaglasssubstrate.

DriverICCellTFT-LCDpanelBacklightFrontviewBackviewX-PCBLampConnectorDriverICTimingControllerSignalInterfaceY-PCBLVDSreceiverTFT-LCD模組結(jié)構(gòu)組成關(guān)于液晶

1888年，澳大利亞植物學(xué)者萊尼茨爾（Reinitzer）研究膽甾醇在植物中的作用時，用膽甾基苯進(jìn)行試驗，無意間發(fā)現(xiàn)了液晶，但液晶的實際應(yīng)用直到二十世紀(jì)五十年代才開始。顧名思義，液晶是固液態(tài)之間的一種中間類狀態(tài)。液晶是一種有機(jī)化合物，在一定的溫度范圍內(nèi)，它既具有液體的流動性、粘度、形變等機(jī)械性質(zhì)，又具有晶體的熱（熱效應(yīng)）、光（光學(xué)各向異性）、電（電光效應(yīng)）、磁（磁光效應(yīng)）等物理性質(zhì)。光線穿透液晶的路徑由構(gòu)成它的分子排列所決定。人們發(fā)現(xiàn)給液晶充電會改變它的分子排列，繼而造成光線的扭曲或折射。

液晶按照分子結(jié)構(gòu)排列的不同，分為三種：晶體顆粒粘土狀的稱為近晶相（Smectic）液晶、類似細(xì)火柴棒的稱為向列相（Nematic）液晶、類似膽固醇狀的稱為膽甾相（Cholestic）液晶。這三種液晶的物理特性都不盡相同，用于液晶顯示器的是第二類的向列相（Nematic）液晶

TFT-LCD工作原理Apixel,thesmallestunittoindicateapictureimage,isformedbythreesub-pixelsconsistingofred,green,andblue.ThenumberofpixelsarrangedinadisplaydeterminestheresolutionoftheTFT-LCD.TFTiscomposedofthedataline(imagesignaltransfer)andgateline(TFTon/offsignaltransfer).

TFTexistingineachsub-pixelcontrolsthevoltagedifferencebetweentheTFTglasselectrodeandthecolorfilterglasselectrodeinordertoadjustthemoleculararrayofliquidcrystals.Suchachangeinthemoleculedirectionofliquidcrystalsalterstheamountoflightpenetratingtheliquidcrystallayer.Consequently,theTFT-LCDdisplayshowspictureimageinformation.

TFT-LCD工作原理液晶是一種有機(jī)復(fù)合物，由長棒狀的分子構(gòu)成。在自然狀態(tài)下，這些棒狀分子的長軸大致平行。LCD第一個特點是必須將液晶灌入兩個列有細(xì)槽的平面之間才能正常工作。這兩個平面上的槽互相垂直(90度相交)，也就是說，若一個平面上的分子南北向排列，則另一平面上的分子?xùn)|西向排列，而位于兩個平面之間的分子被強(qiáng)迫進(jìn)入一種90度扭轉(zhuǎn)的狀態(tài)。由于光線順著分子的排列方向傳播，所以光線經(jīng)過液晶時也被扭轉(zhuǎn)90度。但當(dāng)液晶上加一個電壓時，分子便會重新垂直排列，使光線能直射出去，而不發(fā)生任何扭轉(zhuǎn)。LCD的第二個特點是它依賴極化濾光片和光線本身，自然光線是朝四面八方隨機(jī)發(fā)散的，極化濾光片實際是一系列越來越細(xì)的平行線。這些線形成一張網(wǎng)，阻斷不與這些線平行的所有光線，極化濾光片的線正好與第一個垂直，所以能完全阻斷那些已經(jīng)極化的光線。只有兩個濾光片的線完全平行，或者光線本身已扭轉(zhuǎn)到與第二個極化濾光片相匹配，光線才得以穿透。LCD正是由這樣兩個相互垂直的極化濾光片構(gòu)成，所以在正常情況下應(yīng)該阻斷所有試圖穿透的光線。但是，由于兩個濾光片之間充滿了扭曲液晶，所以在光線穿出第一個濾光片后，會被液晶分子扭轉(zhuǎn)90度，最后從第二個濾光片中穿出。另一方面，若為液晶加一個電壓，分子又會重新排列并完全平行，使光線不再扭轉(zhuǎn)，所以正好被第二個濾光片擋住?？傊与妼⒐饩€阻斷，不加電則使光線射出。當(dāng)然，也可以改變LCD中的液晶排列，使光線在加電時射出，而不加電時被阻斷。但由于液晶屏幕幾乎總是亮著的，所以只有"加電將光線阻斷"的方案才能達(dá)到最省電的目的。TFT-LCD工作原理TFT-LCD工作原理TFT-LCD製作流程

TFT-LCD製作流程TFTProcess

TFT-LCD製作流程TFTProcess

TFT-LCD製作流程TFTProcess

processandprocessingstepsarequitesimilartothatofthesemiconductorindustry.Deposition,photolithographyandetchingstepsarecommontobothindustries.ThekeydifferencesarethattheTFTisbuiltonaglasssubstrateinsteadofasiliconwafer.Inaddition,theTFTrequiresaprocessingtemperaturerangingfromapproximately300to500??comparedtoabout1,000??requiredforsemiconductorfabrication..

1.PECVD(PlasmaEnhancedChemicalVaporDeposition)Process

Beforegasentersthechamber,thestateofthevacuumismaintainedandtheglassplateisheatedtoaspecifictemperature.Whengasflowsintothechamber,theRFvoltageisappliedfromelectrodesinsidethechamber,whichtransformgasintoaplasmastate.Fromthisplasma,precursorsareformedanddepositedontheglasssubstrate.

2.SputteringProcess

Sputteringistheprocesswhereinthegasion,whichisthehighenergyinsidetheplasmacreatedbyRFpowerorDCpowercollideswiththetargetsurface,resultinginthedepositionofthetargetmaterialontheplate.Generally,thetargetmaterialsaremountedonthenegativeelectrodesurface.Then,thesputteredtargetmaterialsaredepositedontheplate,whichisputonthepositiveelectrode.Forsputtering,inactivegasesareused,suchasheliumandargon,sothatdepositionmaterialchemistryisnotaffected.3.PhotolithographyProcess

Photolithographyisthetransferofapatternfromthephotomaskontoasubstrate.Thephotolithographyprocessbeginswhenthesubstrateiscoatedwithanextremelythinliquidfilmofphotosensitivematerial,calledphotoresis.Thelightthenexposesthephotoresist,someofwhichisdestroyedwhenexposedtothelight.Theunnecessaryportionofthematerialisthencleanedfromthesurfacethroughanotherprocess,leavinganextremelyfinepatternbehind.Anotherlayerofthephotoresististhendepositedtothesubstrate,exposed,cleaned,untilallthelayershavebeenprintedorimagedontothesurface.ThephotolithographyprocessisacriticalstepwithintheLCDmanufacturingprocessbecausepanelqualitydependsontheentirepatternformation.Assuch,itisextremelysensitivetoparticlesandotherformsofcontamination.Thus,thisprocessrequiresaspecialcleanenvironment,commonlyreferredtoasacleanroom,andprecisecontrolofequipment,chemicalsandmaterials.Inthefuture,thiswillproveincreasinglyimportantasadvanceddisplaysthatoffergreaterfunctionalityandhigherperformancewillrequireincreasinglycomplexandstringentmanufacturingcapabilities.

4.DryetchProcessThedryetchprocessusesreactivespecies,suchasatomsorradicalsfromthegasplasma,toetchawayaportionoftheobjectmaterial.Whenthesespeciesreactwiththemateriallocatedontheplate,theopenregionofmaterialtransformsintoavolatilestateandisremovedfromthematrix.Inthisprocess,thereactionvelocityisfastandfinepatternscanbeformeduniformly.TFT-LCD製作流程ColorFilterProcess

TFT-LCD製作流程CellProcess

LCDproductionprocesscanbedescribedasfollows:

(1)theorientationlayeronthelowerandupperplateisformed;

(2)thelayerisproperlypositionedsothattheliquidcrystalcanproperlyalign;

(3)thespacerisdispensed,thesealisprinted,andthetwoplatesareassembled;

(4)theliquidcrystalisinjectedintothecellthroughthecapillaryeffect;and

(5)theinjectionholeissealed.

1.PrintingtheOrientationLayer

Theorientationlayerisevenlyspreadonthepixelareaoftheupperandlowerplate.Thepolyimideisspreadonthedrumthinlyandevenlyandiscoatedontherubberplate,whichhasbeenpatternedinadvance.Inturn,thepolyimideisprintedontheuppercolorfilterorthelowerTFT-arrayplate.Afterprinting,thepolyimideishardenedthroughtheprocessofannealing.

2.Rubbing

Rubbingistheprocessthatformsthestraightgrooveonthehardenedpolyimideinafixeddirectioninordertomaketheliquidcrystalorientinafixeddirection.Thestraightgroovecanbeformedbyrubbingthepanelinacertaindirectionwiththerubbingvelvetattachedtotherotatingdrum.3.DispensingSpacers

Thespacersaredispensedevenlyinordertosecurethefixedcellgapwhenassemblingtheupperandlowerplate.Afterthespacersaremixedintheliquidwiththeproperconcentration,theyarethentransportedtothespraynozzlethroughthepump,andsubsequentlysprayedonthesurfaceoftheplatefromthenozzlewithhighpressure.Heatingdriestheliquid,andthedensityofthespacerisadjustedbetween100ea/and200ea/accordingtothedisplaysize.Thespacershapeislikeaballwithadiametersizebetween4and5whichdeterminesthecellgapbetweentheplates.

4.InjectingtheLiquidCrystal

Theliquidcrystalisinjectedbetweentheupperandlowerplateusingcapillaryactionandpressuredifferencesaftertheupperandlowerplateareassembled.Theprocesssystemconsistsofavacuumpump,vacuumchamber,anup/downmovingdevice,ajig,whichcontainstheliquidcrystal,and,anNsystem.Atfirst,theinternalcellvacuumlevelismaintainedatabout10-3Torrfromtheoriginalvacuumstate.Theliquidcrystalisthenpulledintothecellbythecapillaryeffect.Whenthecellisfilledwithliquidcrystaluptoabout80percent,N??sthenpurgedintothevacuumchamberslowlyandtheliquidcrystalfillstheremainingspaceinthecellasaresultofthedifferenceinpressurefrominsideandoutsidethecell.TFT-LCD製作流程ModuleProcess

Themoduleprocessisthestepthatdeterminesthefinalqualityoftheproducttobedeliveredtothecustomer.Thestepiscompletedoncethepolarizer,thedriveIC,PCB,backlightunitandtheframeareassembled.亮度Luminance(cd/m2)TFT-LCD重要光學(xué)規(guī)格10mm10mm10mm10mm1/4H1/2H3/4H1/4V1/2V3/4VY1Y11Y5Y4Y2Y12Y13Y8Y7Y6Y3Y9Y10a.規(guī)格條件：(1)中心點(2)五點平均b.影響亮度的因素

(1)Cell穿透率(開口率)(2)GammaCurve(3)BL發(fā)光效率

(4)燈管電流2.對比度ContrastRatio(CR)

TFT-LCD重要光學(xué)規(guī)格LuminanceofallpixelsWhite(L255)LuminanceofallpixelsDark(L0)L255(orL63)L0CR=3.分辨率

TFT-LCD重要光學(xué)規(guī)格LCD的最大分辨率就是它的真實分辨率，也就是最佳分辨率。4.ViewingAngle(可視角)TFT-LCD重要光學(xué)規(guī)格CR>10(W/B)

液晶顯示器的可視角度包括水平可視角度和垂直可視角度兩個指標(biāo)：

水平可視角度表示以顯示器的垂直法線(即顯示器正中間的垂直假想線)為準(zhǔn)，在垂直于法線左方或右方一定角度的位置上仍然能夠正常的看見顯示圖像，這個角度范圍就是液晶顯示器的水平可視角度；同樣如果以水平法線為準(zhǔn)，上下的可視角度就稱為垂直可視角度。一般而言，可視角度是以對比度變化為參照標(biāo)準(zhǔn)的。當(dāng)觀察角度加大時，該位置看到的顯示圖像的對比度會下降，而當(dāng)角度加大到一定程度，對比度下降到10∶1時，這個角度就是該液晶顯示器的最大可視角。一般主流LCD的可視角度為120~160度。比較理想的可視角度應(yīng)在175度以上（水平).TFT-LCD重要光學(xué)規(guī)格

帶寬是指每秒鐘掃描過的圖像點的個數(shù)，以MHz(兆赫茲)為單位，表明了顯示器電路可以處