01 Taw Qhia
Nrog rau kev nce qib ntawm kev tshawb fawb thiab thev naus laus zis tsis tu ncua thiab kev siv dav dav ntawm cov ntaub ntawv tshiab, kev tsim khoom niaj hnub no tau txhim kho sai sai rau lub teeb yuag, me me, thiab siab - cov lus qhia meej. Hauv thaj chaw xws li microelectronics, optoelectronics, thiab micro-electromechanical systems (MEMS), kev sib txuas thiab kev koom ua ke ntawm micro-nano qauv yog qhov tseem ceeb tshwj xeeb. Kev ua cov txheej txheem ib txwm ua, xws li ntev -pulse laser ua lossis hluav taws xob machining, feem ntau tuaj nrog cov cua sov tseem ceeb- thaj chaw cuam tshuam (HAZ), uas tuaj yeem yooj yim ua rau cov khoom deformation, microcracks, los yog cov txheej txheem rov ua dua, ua rau nws nyuaj kom ua tau raws li qhov siab -txheej txheem kev sib txuas ntawm micro{{8.}} thiab nanoscale. Ultrafast lasers, feem ntau yog xa mus rau lasers nrog pulse widths nyob rau hauv lub femtosecond (fs) los yog picosecond (ps) ntau yam, muab ib tug tshiab kev daws teeb meem rau precision manufacturing vim lawv tsis tshua muaj siab ncov hwj chim ceev thiab ultra{10}}lub sij hawm sib cuam tshuam. Tshwj xeeb, ultrafast laser micro-nano welding (Nano Vuam) tuaj yeem kov yeej cov thermal diffusion txwv ntawm cov vuam tsoos thiab ua tiav cov kev sib txuas meej ntawm micro-nano nplai. Cov thev naus laus zis no siv cov teebmeem nonlinear ntawm ultrafast laser kev sib cuam tshuam nrog cov ntaub ntawv kom ua tiav cov melting thiab kev sib txuas hauv cov cheeb tsam me me thaum tsis txhob muaj kev puas tsuaj rau cov khoom nyob ib puag ncig. Raws li qhov kev nce qib tshiab tshaj plaws hauv kev ua haujlwm ultrafast laser microstructure, daim ntawv no tsom mus rau kev piav qhia cov hauv paus ntsiab lus ntawm ultrafast laser micro-nano vuam, cov txheej txheem tseem ceeb, thiab nws cov kev siv hauv cov khoom siv sib txawv.
02 Ultra-Fast Laser Vuam Txoj Cai
Cov txheej txheem tseem ceeb ntawm ultrafast laser micro-nano welding yog nyob rau hauv cov txheej txheem thermodynamic thiab cov nyhuv hauv cheeb tsam. Lub hauv paus ntsiab lus yog tias los ntawm kev sib cuam tshuam ntawm ultrafast laser thiab cov khoom, kev sib cuag ntawm microstructures yuav tsum tau welded undergoes lub zos melting, yog li tshem tawm qhov sib txawv thiab tsim ib tug ruaj khov kev twb kev txuas. Nyob rau hauv cov txheej txheem vuam rau cov txheej txheem subwavelength xws li nanowires, femtosecond laser irradiation tuaj yeem ua rau cov plasma resonance hauv zos, uas ua rau thaj chaw siab - qhov kub thiab txias ntawm cov ntsiab lus sib txuas lossis thaj chaw sib cuag ntawm nanowires, ua kom muaj kev sib txuas, txiav, lossis rov ua dua ntawm nanowires. Ib qho txiaj ntsig tseem ceeb ntawm cov thev naus laus zis no yog nws cov thermal localization siab heev. Vim lub ultrashort mem tes dav ntawm lub ultrafast laser (feem ntau nyob rau hauv femtosecond scale), tshav kub diffusion yog heev suppressed, cia lub zuag qhia tag nrho kub mus txog equilibrium nyob rau hauv 10⁻¹² vib nas this. Qhov no ultrafast thermal so mechanism ua kom ntseeg tau tias qhov kub thiab txias tsuas yog nyob rau hauv cheeb tsam hauv cheeb tsam uas cov plasma resonance tshwm sim, thaum cov cheeb tsam ntawm cov qauv nanowire sab nraum thaj tsam resonance tsis puas los ntawm qhov kub siab, yog li tswj tag nrho cov qauv kev ncaj ncees ntawm cov cuab yeej. Tsis tas li ntawd, qhov kev xaiv ntawm cov txheej txheem vuam tsis muaj qhov cuam tshuam rau qhov zoo ntawm vuam. Cov kev tshawb fawb tau pom tias kev siv lub siab mem tes rov qab ua ke nrog lub zog pulse qis tuaj yeem txo qhov tsim ntawm nkig intermetallic tebchaw, txo qhov tshwm sim ntawm weld defects, thiab tiv thaiv ntau dhau ablation ntawm cov khoom hlau.
Daim duab 1. Schematic daim duab ntawm nonlinear ionization, plasma evolution, thiab thermodynamic mechanisms ntawm ultrafast laser kev cuam tshuam nrog silicon.
Daim duab 2. Kev sib piv ntawm lub zog deposition mechanisms thiab theem transformation txheej txheem ntawm hlau thiab non-cov ntaub ntawv hlau nyob rau hauv ultrafast laser micro-nano vuam.
03 Ultrafast Laser Vuam daim ntaub ntawv
Tam sim no, ultrafast laser micro-nano vuam tshuab tau dav siv rau kev sib txuas ntawm ntau yam conductive micro-nano qauv. Nyob ntawm cov yam ntxwv ntawm cov khoom, nws tuaj yeem raug faib ua hlau micro-nano qauv vuam, semiconductor nanomaterial vuam, thiab heterojunction vuam ntawm cov khoom sib txawv. Hauv peb daim ntawv thov no, ultrafast lasers tau pom qhov zoo ntawm cov txheej txheem ib txwm muaj.
Hais txog kev sib cuam tshuam ntawm cov hlau micro-nano cov qauv, tsoos micro- vuam thev naus laus zis feem ntau ntsib cov teebmeem thermal overflow thaum tuav micron- lossis nanometer- nplai hlau xaim, vim qhov nyuaj ntawm kev tswj cov cua sov kom raug. Qhov no thermal load tsis tau tsuas yog yooj yim melts zoo hlau hlau, tab sis kuj nyhav tsim nkig intermetallic tebchaw nyob rau hauv lub junctions ntawm dissimilar hlau, uas ua rau cov neeg kho tshuab tsis muaj zog thiab nquag welding tsis xws luag. Nyob rau hauv sib piv, ultrafast laser welding, los ntawm kev siv ib tug tshwj xeeb txheej txheem zoo combining siab mem tes repetition tus nqi nrog tsawg mem tes zog, zoo overcomes cov kev cov nyom. Qhov kev sib koom ua ke ntawm kev rov ua dua ntau zaus thiab tsis muaj zog ua kom muaj zog txaus txaus rau vuam thaum txo qis ntau dhau ntawm cov khoom siv hlau, yog li tiv thaiv kev tsim cov nkig intermetallic tebchaw thiab txo qis qhov tsis xws luag.
Hauv cov ntawv thov tshwj xeeb, cov kws tshawb fawb yog thawj zaug siv cov thev naus laus zis no kom ua tiav cov vuam ntawm Ag micro-cov xaim rau Cu substrates, ua kom pom nws lub peev xwm hauv microelectronic interconnections. Tsis tas li ntawd, rau nanoscale Ag-Ag homogeneous hlau nanowires, cov kws tshawb fawb tau ua tiav cov nanowires siv 35 fs ultrashort pulses ntawm lub zog ceev ntawm kwv yees li 90 mJ / cm². Cov pob qij txha tshwm sim tsis yog tsuas yog cov txheej txheem zoo nkaus xwb tab sis kuj tseem muaj cov khoom siv hluav taws xob zoo heev thiab lub zog txhua yam.
Nyob rau hauv qhov tsis muaj kev sib txuas ntawm cov khoom siv semiconductor nanomaterials, cov cua sov thoob ntiaj teb los yog kev sib cuag vuam tuaj yeem ua rau cov qauv siv lead ua ntawm nanowires yooj yim puas los yog ua rau thermal puas nyob rau hauv tsis yog -weld cheeb tsam vim lub siab brittleness thiab thermal rhiab heev ntawm cov ntaub ntawv semiconductor. Ultrafast laser welding daws qhov teeb meem no los ntawm nws qhov tshwj xeeb hauv zos plasma resonance mechanism. Thaum femtosecond laser irradiation yog siv rau nanowires, localized plasma resonance yog induced ntawm kev sib tshuam los yog junctions, generating localized high kub kom ua tau vuam, txiav, los yog reshaping. Vim tias lub sijhawm ua haujlwm ntawm lub laser ultrafast yog luv heev, kub diffusion mus txog qhov sib npaug ntawm picosecond range (10^-12 vib nas this), txhais tau tias qhov kub thiab txias generated yog nruj me ntsis txwv rau hauv cheeb tsam resonant cheeb tsam, tawm hauv nanowire lug sab nraum lub resonant cheeb tsam kiag li undamaged.
Raws li txoj cai no, cov kws tshawb fawb tau ua tiav kev vuam ntawm ZnO-ZnO homogeneous semiconductor nanowires. Nyob rau hauv 35 fs mem tes dav thiab lub zog ceev ntawm 77.6 mJ / cm², tom qab 30 vib nas this ntawm irradiation, cov nanowires tau ruaj khov thiab tsis muaj kev sib txuas. Qhov kev rhuav tshem no muab qhov ua tau zoo thiab meej tsis yog-txoj kev ua haujlwm sib cuag rau kev sib dhos ntawm tag nrho -oxide photodetectors thiab sensors.
Ultrafast laser micro-nano vuam thev naus laus zis, nrog nws qhov dav dav dav dav dav dav thiab lub zog siab kawg nkaus, tau kov yeej cov kev txwv ntawm cov txheej txheem vuam ib txwm siv los tswj cov teebmeem thermal, dhau los ua cov cuab yeej tseem ceeb hauv kev lag luam micro-nano manufacturing. Los ntawm cov plasma resonance thiab nonlinear absorption mechanisms, cov cuab yeej no tuaj yeem ua tiav cov txheej txheem melting thiab kev sib txuas ntawm cov ntaub ntawv ntawm cov nplai me me thiab lub cev ntawm lub cev, kom tsis txhob muaj kev puas tsuaj thermal rau ib puag ncig micro-nano cov qauv. Los ntawm cov hlau microwires mus rau semiconductor nanowires, thiab txawm tias nyuaj heterogeneous cov ntaub ntawv junctions, ultrafast laser welding tau pom dav cov khoom adaptability thiab zoo heev ua. Nyob rau hauv lub neej yav tom ntej, nrog kev tshawb fawb tob rau hauv cov txheej txheem ntawm laser- teeb meem kev sib cuam tshuam thiab kev txhim kho ntxiv hauv laser kev ua tau zoo, ultrafast laser micro-nano vuam yuav tsum ua lub luag haujlwm tseem ceeb hauv kev tsim cov khoom siv hluav taws xob hloov tau yooj yim, nano- cov khoom siv optoelectronic, thiab cov sensors sib xyaw ua ke, tsav tsheb micro{9} rau kev ua haujlwm siab dua thiab siab dua.
