01
Taw qhia
Micro LED thev naus laus zis, raws li kev txiav -ntev ntawm tom ntej- cov cuab yeej tso saib thev naus laus zis, tau txais kev saib xyuas thiab kev tshawb fawb dav dav. Piv nrog rau cov khoom siv ua kua siv lead ua kua thiab cov teeb pom kev zoo-emitting diodes (OLEDs), Micro LEDs muaj qhov ci dua, qhov sib txawv dua, thiab cov xim dav dua, thaum tseem siv zog tsawg dua thiab muaj lub neej ntev dua. Qhov no ua rau Micro LEDs muaj peev xwm tseem ceeb hauv TV, smartphones, cov khoom siv me me, hauv -cov ntxaij vab tshaus tsheb, thiab AR/VR daim ntawv thov. Kev sib piv ntawm qhov tsis sib xws ntawm Micro LED, LCD, thiab OLED.
Kev hloov pauv loj yog ib kauj ruam tseem ceeb hauv kev hloov Micro LED chips los ntawm kev loj hlob substrate mus rau lub hom phiaj substrate. Due to the high density and small size of Micro LED chips, traditional transfer methods struggle to meet the requirements for high-precision transfer. Kev ua tiav cov khoom lag luam sib txuas nrog Micro LED nrog lub voj voog tsav yuav tsum muaj ntau yam kev hloov pauv ntawm Micro LED chips (tsawg kawg los ntawm sapphire substrate → ib ntus substrate → tshiab substrate), nrog ntau cov chips pauv txhua zaus, xav tau kev ruaj ntseg thiab raug ntawm cov txheej txheem hloov. Laser huab hwm coj hloov pauv yog ib qho txheej txheem rau kev hloov Micro LED chips los ntawm haiv neeg sapphire substrate mus rau lub hom phiaj substrate. Ua ntej, cov chips raug cais los ntawm haiv neeg sapphire substrate los ntawm laser nqa-tawm; Tom qab ntawd, ablation yog ua rau ntawm lub hom phiaj substrate los pab kom cov chips raug xa mus rau lub substrate nrog cov ntaub ntawv nplaum (xws li polydimethylsiloxane). Thaum kawg, siv cov hlau sib txuas quab yuam ntawm TFT rov qab, cov chips raug xa los ntawm PDM substrate mus rau TFT backplane.
02
Laser Lift-Off Technology
Thawj kauj ruam ntawm kev hloov pauv loj ntawm laser yog laser nqa -tawm (LLO). Cov txiaj ntsig ntawm laser nqa- tawm ncaj qha txiav txim siab qhov txiaj ntsig kawg ntawm tag nrho cov txheej txheem hloov pauv laser. Micro LEDs feem ntau siv cov substrates xws li Si thiab sapphire kom loj hlob GaN epitaxial txheej rau fabrication. Muaj qhov sib txawv ntawm cov lattice mismatch thiab thermal expansion coefficient sib txawv ntawm Si thiab GaN, yog li sapphire substrates feem ntau siv rau hauv kev npaj ntawm Micro LED chips.
Lub bandgap ntawm sapphire yog 9.9eV, GaN yog 3.39eV, thiab AlN yog 6.2eV. Lub hauv paus ntsiab lus ntawm laser nqa-tawm yog siv luv luv- wavelength laser nrog photon zog ntau dua li GaN bandgap tab sis tsawg dua bandgaps ntawm sapphire thiab AlN, irradiating los ntawm sab sapphire. Lub laser hla dhau ntawm sapphire thiab AlN thiab yog absorbed los ntawm GaN txheej txheej. Thaum lub sijhawm ua haujlwm no, GaN ntog tau thermal decomposition. Txij li thaum lub melting point ntawm Ga yog hais txog 30 degree, N2 thiab kua Ga yog generated, thiab N2 khiav, yog li mechanically cais GaN epitaxial txheej los ntawm sapphire substrate. Cov tshuaj tiv thaiv decomposition tshwm sim ntawm qhov interface tuaj yeem sawv cev raws li:
Raws li cov qauv rau photon zog, qhov zoo tshaj plaws laser wavelength uas ua tau raws li cov kev mob saum toj no yuav tsum nyob rau hauv cov nram qab no ntau yam: 125 nm < 209 nm Tsawg dua los yog sib npaug rau λ Tsawg dua los yog sib npaug rau 365 nm. Kev tshawb fawb qhia tau hais tias laser pulse dav, laser wavelength, thiab laser zog ceev yog qhov tseem ceeb hauv kev ua tiav cov txheej txheem laser ablation.
Yuav kom ua tiav tag nrho -xim emission nrog Micro LEDs, nws yog ib qho tsim nyog yuav tsum tau ua kom meej thiab sib xyaw xim liab, ntsuab, thiab xiav Micro LED chips ntawm tib lub substrate los tsim me me, siab - daws teeb meem xim zaub pixels. Txawm li cas los xij, LLO tsis haum rau kev xaiv kev koom ua ke ntawm cov khoom siv tsis yog -liab, ntsuab, thiab xiav Micro LED. Ntxiv mus, kev xaiv kho me me ntawm Micro LED chips puas yog qhov tseem ceeb rau kev txhim kho cov txiaj ntsig ntawm cov khoom lag luam. Yog li ntawd, Laser Selective Lift-Off (SLLO) thev naus laus zis tau tshwm sim. Cov cuab yeej no tsim nyog rau kev sib koom ua ke thiab xaiv kev kho, tsis tas yuav tsum muaj cov txheej txheem batch nyuaj. Nws tseem tuaj yeem xaiv hloov qee qhov ua ntej - LEDs qhia thiab kho LEDs puas lawm.
SLLO yog ua tiav los ntawm kev siv lub laser los xaiv qhov sib txawv ntawm Micro LED chips thiab substrate. Lub teeb ultraviolet feem ntau yog siv los ua lub teeb ci. Luv- wavelength teeb sib cuam tshuam nrog cov khoom siv ntau dua, ua rau kev nqa tau yooj yim dua - tawm txheej txheem. Tsis tas li ntawd, cov cua kub uas tsim los ntawm ultraviolet lub teeb thaum lub sij hawm nqa tawm - txheej txheem tawm yog qhov tsawg, txo qhov kev pheej hmoo ntawm thermal puas.
Uniqarta tau npaj ib qho loj -scale parallel laser exfoliation txoj kev, raws li qhia nyob rau hauv daim duab 4. Los ntawm kev ntxiv ib tug X-Y laser scanner nyob rau hauv lub hauv paus ntawm ib tug -pulse laser, ib tug laser beam yog diffraced mus rau ntau kab teeb, enabling loj -scale nti exfoliation. Cov tswv yim no ua rau muaj txiaj ntsig ntau ntxiv ntawm cov chips exfoliated nyob rau hauv ib qho kev khiav, ua tiav tus nqi exfoliation ntawm 100 M / h, hloov qhov tseeb ntawm ± 34 μm, thiab muaj peev xwm nrhiav tau qhov tsis zoo, haum rau kev hloov pauv ntawm ntau qhov ntau thiab tsawg tam sim no.
03
Laser Hloov Technology
Cov kauj ruam thib ob ntawm kev hloov pauv loj heev yog laser hloov pauv, uas hloov cov nti delaminated los ntawm ib ntus substrate mus rau lub nraub qaum. Lub laser-induced forward transfer (LIFT) thev naus laus zis uas tau npaj los ntawm Coherent yog cov txheej txheem uas tuaj yeem tso ntau yam khoom siv thiab cov qauv hauv cov neeg siv- cov qauv uas tau hais tseg, ua kom loj - teev qhov chaw ntawm cov qauv lossis cov khoom siv nrog qhov me me. Tam sim no, LIFT thev naus laus zis tau ua tiav qhov kev hloov pauv ntawm ntau yam khoom siv hluav taws xob, nrog qhov ntau thiab tsawg ntawm 0.1 txog 6mm2. Daim duab 5 qhia txog cov txheej txheem LIFT ib txwm. Nyob rau hauv cov txheej txheem LIFT, lub laser hla dhau lub pob tshab substrate thiab yog absorbed los ntawm dynamic tso txheej. Los ntawm laser ablation los yog vapourisation, lub siab siab generated los ntawm dynamic tso tawm txheej sai sai, yog li hloov lub nti los ntawm lub stamp mus rau lub substrate tau txais.
Tom qab kev txhim kho, Uniqarta tau tsim ib lub hlwv -raws li laser-induced forward transfer technology (BB-LIFT). Raws li pom nyob rau hauv daim duab 6, qhov sib txawv nyob rau hauv hais tias thaum lub sij hawm laser irradiation, tsuas yog ib feem me me ntawm lub DRL yog ablated los tsim roj los muab kev cuam tshuam lub zog. Lub DRL tuaj yeem thaiv qhov kev poob siab yoj sab hauv los ntawm kev tsim cov hlwv nthuav dav, thawb lub nti ntau maj mam mus rau qhov tau txais substrate, uas tuaj yeem txhim kho kev hloov pauv thiab txo kev puas tsuaj.
Qhov tsis yog -reusability ntawm lub stamp yog ib qho tseem ceeb txwv tsis pub siv BB-LIFT. Txhawm rau txhim kho tus nqi-kev ua tau zoo, cov kws tshawb fawb tau tsim cov txheej txheem rov siv tau BB-LIFT cov txheej txheem raws li kev tsim cov pwm tuaj yeem siv tau, raws li pom hauv daim duab 7. Lub stamp muaj microcavity nrog txheej hlau, nrog cov kab noj hniav thiab cov kab noj hniav microstructured elastic nplaum pwm siv los ntim cov microcavity. Nyob rau hauv illumination los ntawm ib tug 808 nm laser, cov hlau txheej absorbs lub laser thiab generates tshav kub, ua rau cov huab cua nyob rau hauv lub kab noj hniav kom sai nthuav, deforming lub stamp thiab zoo heev txo nws adhesion. Nyob rau ntawm lub sijhawm no, qhov cuam tshuam los ntawm kev tsim npuas ua rau lub detachment ntawm cov nti los ntawm lub thwj.
Hauv loj -txheej hloov, yuav tsum muaj adhesion muaj zog thaum xaiv- kom ntseeg tau tias yuav tau txais kev ntseeg siab, thaum adhesion yuav tsum tsawg li tsawg tau thaum muab tso rau kom ua tiav kev hloov. Yog li ntawd, cov thev naus laus zis tseem ceeb nyob hauv kev txhim kho cov adhesion hloov piv. Cov kws tshawb fawb tau muab cov microspheres nthuav dav hauv cov nplaum nplaum thiab siv lub tshuab cua sov laser los tsim cov thermal stimulation sab nraud. Thaum lub sij hawm tuaj tos- txheej txheem, cov me me - qhov loj me me embedded expandable microspheres xyuas kom meej qhov flatness ntawm cov nplaum txheej nto, thaum cov nyhuv ntawm lub zog adhesion ntawm cov nplaum txheej tuaj yeem tsis quav ntsej. Thaum lub sij hawm hloov cov txheej txheem, lub 90℃sab nraud thermal stimulation generated los ntawm lub laser cua sov system yog sai sai hloov mus rau lub nplaum txheej, ua rau lub sab hauv microspheres nthuav dav sai, raws li pom nyob rau hauv daim duab 8. Qhov no ua rau ib tug micro- nqa qauv ntawm qhov chaw, txo qhov adhesion ntawm nto thiab ua tiav kev tso tawm txhim khu kev qha.
Txhawm rau ua tiav qhov loj- hloov pauv, cov kws tshawb nrhiav pom tias qhov hloov pauv nyob ntawm qhov sib txawv ntawm qhov sib txawv ntawm TRT thiab cov khoom siv ua haujlwm, thiab tswj tau los ntawm qhov ntsuas kub, raws li pom hauv daim duab 9. Thaum qhov kub thiab txias qis dua qhov ntsuas kub tseem ceeb Tr, lub zog tso tawm tus nqi ntawm TRT / cov khoom siv ua haujlwm tshaj qhov tseem ceeb ntawm lub zog tso tawm tus nqi ntawm cov khoom siv hluav taws xob ua rau cov khoom tawg, cov khoom siv hluav taws xob ua rau tawg. TRT/functional device interface, yog li khaws cov khoom siv ua haujlwm. Thaum lub sij hawm hloov cov txheej txheem, laser cua sov nce qhov kub siab tshaj qhov kub tseem ceeb Tr, ua rau lub zog tso tawm tus nqi ntawm TRT / functional ntaus ntawv qis dua lub zog tseem ceeb tso tawm tus nqi ntawm lub functional ntaus ntawv / lub hom phiaj substrate, yog li ntse hloov lub functional ntaus ntawv mus rau lub hom phiaj substrate.
