超细间距 LED 显示器芯片结构和倒装芯片 LED 无铅焊膏的选择

深圳市福英达工业技术有限公司/一站式锡膏解决方案供应商Ultra-Fine-PitchLEDDisplayChipStructureandSelectionofLead-FreeSolderPasteforFlip-ChipLEDsWire-bondingLEDchips,verticalLEDchips,andflip-chipLEDsarethreedifferentstructuresofLEDchips.DifferentstructuresofLEDchipsinfluencetheselectionoflead-freesolderpastes.1.LEDChipDefinitionTheLEDchipisasemiconductordevicethatrealizesthephotoelectricconversionfunction.Itismadebyprocessingsemiconductorchipsonepitaxialwafers.Thissemiconductorchipfabricationprocessistotransfermetallicorganiccompoundstoahomogeneousorheterogeneoussubstrateatasuitabletemperatureandtogrowsemiconductorthinfilmmaterialswithspecificphotoelectricpropertiesthroughchemicalreactions.2.LEDChipLightingPrincipleEachpixeloftheLEDdisplayscreeniscomposedofasetofRGB(red,green,andblue)chips,whichbelongstotheself-luminousdisplaytechnology.RGBLEDluminescentmaterialsaredifferentaccordingtothevarioussizesofthebandgapsbetweentheconductionbandsandthevalencebandsofthematerials.Thus,theenergyreleasedisdifferentwhenthematerialsareexcited,whichisreflectedbythedifferentwavelengthsofelectromagneticwaves.Thehumaneyereceivesdifferentlightcolorsofelectromagneticwaveswithdifferentwavelengths.ThecorepartoftheLEDisthep-njunction.3.LEDChipStructureTherearethreemaintypesofLEDchipstructures:wire-bondingLEDchips,verticalLEDchips,andLEDflip-chips.Thewire-bondingLEDchipelectrodesareabovethelight-emittingsurface.ThecomponentsfromtoptobottomareP-GaN,light-emittinglayer(PNjunction),N-GaN,andsubstrate.TheverticalchipstructureadoptsSi,Ge,Cu,andothermaterialstoreplacethesapphiresubstrate,improvingheatdissipationefficiency.TheverticalLEDelectrodesareonbothsidesoftheLEDepitaxiallayertoavoidlocalcurrentcongestionandhightemperature.Flip-chipstructureconsistsofN-GaN,light-emittinglayer(PNjunction),P-GaN,metalelectrodes,andbumps.

Thewire-bondingstructuremainlyusesblue-greenLEDchips.TheverticalstructureappliesredLEDchips.Theflipchipissuitableforred,blue,andgreenLEDchips.

Forthepreviousfine-pitchLED(1.0mm≤Pitch≤2.5mm)packaging,wire-bondingblue-greenLEDchips,andverticalredLEDchipsareused.Withtheriseofmini-LEDandmicro-LEDandtheshrinkingofchipsizeandpixelpitch,thewire-bondingstructureislimitedbyspaceduetotheneedforb