Tam sim no,silicon carbide (SiC)yog cov khoom siv thermally conductive ceramic uas nquag kawm hauv tsev thiab txawv teb chaws. Lub theoretical thermal conductivity ntawm SiC yog siab heev, thiab qee cov ntaub ntawv siv lead ua tuaj yeem ncav cuag 270W / mK, uas twb yog tus thawj coj ntawm cov khoom siv tsis zoo. Piv txwv li, daim ntawv thov ntawm SiC thermal conductivity tuaj yeem pom nyob rau hauv cov ntaub ntawv substrate ntawm cov khoom siv semiconductor, cov khoom siv thermal conductivity ceramic, cov cua sov thiab cov phaj cua sov rau kev ua cov khoom siv hluav taws xob, cov khoom siv tshuaj ntsiav rau cov roj nuclear, thiab cov roj sealing nplhaib rau compressor twj.
Daim ntawv thov ntawmsilicon carbidenyob rau hauv lub semiconductor teb
Sib tsoo discs thiab fixtures yog cov txheej txheem tseem ceeb cov cuab yeej siv rau silicon wafer ntau lawm hauv kev lag luam semiconductor. Yog tias qhov sib tsoo disc yog ua los ntawm cov hlau cam khwb cia lossis carbon hlau, nws lub neej kev pabcuam luv luv thiab nws cov thermal expansion coefficient loj. Thaum lub sij hawm ua cov silicon wafers, tshwj xeeb tshaj yog thaum lub sij hawm high-speed sib tsoo los yog polishing, vim hnav thiab thermal deformation ntawm kev sib tsoo disc, lub flatness thiab parallelism ntawm silicon wafer yog ib qho nyuaj rau lav. Kev sib tsoo disc ua los ntawmsilicon carbide ceramicsmuaj tsawg hnav vim nws siab hardness, thiab nws thermal expansion coefficient yeej ib yam li cov silicon wafers, yog li nws yuav ua tau hauv av thiab polished ntawm kev kub ceev.
Tsis tas li ntawd, thaum silicon wafers raug tsim, lawv yuav tsum tau mus rau qhov kub thiab txias kev kho mob thiab feem ntau thauj siv silicon carbide fixtures. Lawv yog cov cua sov-resistant thiab tsis muaj kev puas tsuaj. Pob zeb diamond zoo li cov pa roj carbon (DLC) thiab lwm yam txheej txheej tuaj yeem siv rau ntawm qhov chaw los txhim kho kev ua tau zoo, txo qhov kev puas tsuaj ntawm wafer, thiab tiv thaiv kom tsis txhob kis kab mob.
Tsis tas li ntawd, raws li ib tug neeg sawv cev ntawm peb-tiam dav-bandgap semiconductor cov ntaub ntawv, silicon carbide ib leeg siv lead ua cov ntaub ntawv muaj zog xws li loj bandgap dav (li 3 npaug ntawm Si), siab thermal conductivity (li 3.3 npaug ntawm Si los yog 10 npaug ntawm Si. uas ntawm GaAs), siab electron saturation migration rate (li 2.5 npaug ntawm Si) thiab siab tawg hluav taws xob teb (li 10 npaug ntawm Si los yog 5 npaug ntawm GaAs). SiC cov cuab yeej ua rau qhov tsis xws ntawm cov khoom siv semiconductor ib txwm siv hauv cov ntawv thov thiab tau maj mam dhau los ua lub ntsiab ntawm lub zog semiconductors.
Qhov kev thov rau siab thermal conductivity silicon carbide ceramics tau nce ntau heev
Nrog rau kev txhim kho txuas ntxiv ntawm kev tshawb fawb thiab thev naus laus zis, qhov kev thov rau daim ntawv thov ntawm silicon carbide ceramics hauv cov khoom siv hluav taws xob tau nce ntau, thiab cov thermal conductivity siab yog qhov qhia tau tseem ceeb rau nws daim ntawv thov hauv cov khoom siv semiconductor. Yog li ntawd, nws yog ib qho tseem ceeb kom ntxiv dag zog rau cov kev tshawb fawb ntawm high thermal conductivity silicon carbide ceramics. Txo cov ntsiab lus ntawm lattice oxygen, txhim kho qhov ntom ntom, thiab tsim nyog tswj kev faib khoom ntawm theem ob hauv cov lattice yog cov txheej txheem tseem ceeb los txhim kho cov thermal conductivity ntawm silicon carbide ceramics.
Tam sim no, muaj ob peb txoj kev tshawb fawb txog cov thermal conductivity silicon carbide ceramics hauv kuv lub teb chaws, thiab tseem muaj qhov sib txawv loj piv nrog rau qib ntiaj teb. Cov lus qhia kev tshawb fawb yav tom ntej muaj xws li:
● Txhim kho cov txheej txheem kev tshawb fawb ntawm silicon carbide ceramic hmoov. Kev npaj ntawm high-purity, qis-oxygen silicon carbide hmoov yog lub hauv paus rau kev npaj ntawm high thermal conductivity silicon carbide ceramics;
● Ntxiv dag zog rau kev xaiv cov khoom siv sintering thiab lwm yam kev tshawb fawb theoretical;
● Txhim kho txoj kev tshawb fawb thiab kev tsim cov khoom siv sintering high-end. Los ntawm kev tswj cov txheej txheem sintering kom tau txais qhov tsim nyog microstructure, nws yog ib qho tsim nyog yuav tau txais cov thermal conductivity silicon carbide ceramics.
Kev ntsuas los txhim kho thermal conductivity ntawm silicon carbide ceramics
Tus yuam sij rau kev txhim kho cov thermal conductivity ntawm SiC ceramics yog txo cov phonon tawg zaus thiab ua rau kom lub phonon txhais tau tias dawb txoj kev. Lub thermal conductivity ntawm SiC yuav ua tau zoo dua los ntawm kev txo cov porosity thiab grain ciam ciam ceev ntawm SiC ceramics, kev txhim kho lub purity ntawm SiC lis ciam teb, txo SiC lattice impurities los yog lattice defects, thiab ua rau kom lub tshav kub khiav kis tau tus mob cab kuj nyob rau hauv SiC. Tam sim no, optimizing hom thiab cov ntsiab lus ntawm sintering pab thiab high-temperature kho cua sov yog lub ntsiab ntsuas los txhim kho cov thermal conductivity ntawm SiC ceramics.
① Optimizing hom thiab cov ntsiab lus ntawm sintering pab
Ntau yam kev pabcuam sintering feem ntau ntxiv thaum npaj siab thermal conductivity SiC ceramics. Ntawm lawv, hom thiab cov ntsiab lus ntawm sintering aids muaj kev cuam tshuam zoo rau cov thermal conductivity ntawm SiC ceramics. Piv txwv li, Al lossis O cov ntsiab lus hauv Al2O3 system sintering pab tau yooj yim yaj rau hauv SiC lattice, ua rau muaj qhov tsis txaus thiab qhov tsis xws luag, uas ua rau muaj kev nce hauv phonon tawg zaus. Tsis tas li ntawd, yog tias cov ntsiab lus ntawm sintering aids tsawg, cov khoom siv nyuaj rau sintering thiab densify, thaum cov ntsiab lus siab ntawm sintering aids yuav ua rau muaj kev nce hauv impurities thiab tsis xws luag. Cov kua theem sintering ntau dhau kuj tseem tuaj yeem cuam tshuam qhov kev loj hlob ntawm SiC nplej thiab txo qis txoj hauv kev dawb ntawm phonons. Yog li ntawd, txhawm rau npaj siab thermal conductivity SiC ceramics, nws yog ib qho tsim nyog los txo cov ntsiab lus ntawm sintering aids kom ntau li ntau tau thaum ua tau raws li qhov yuav tsum tau ua ntawm sintering ntom, thiab sim xaiv cov khoom siv sintering uas nyuaj rau yaj hauv SiC lattice.
* Cov khoom cua sov ntawm SiC ceramics thaum sib txawv sintering pab ntxiv
Tam sim no, kub nias SiC ceramics sintered nrog BeO ua sintering pab muaj qhov siab tshaj plaws chav-kub thermal conductivity (270W·m-1·K-1). Txawm li cas los xij, BeO yog cov khoom siv tshuaj lom neeg thiab cov kab mob carcinogenic, thiab tsis haum rau kev siv dav hauv cov chaw sim lossis cov chaw lag luam. Qhov qis tshaj eutectic point ntawm Y2O3-Al2O3 system yog 1760 ℃, uas yog ib qho kev pab ua kua-theem sintering rau SiC ceramics. Txawm li cas los xij, txij li Al3+ tau yooj yim yaj rau hauv SiC lattice, thaum lub kaw lus no siv los ua kev pabcuam sintering, chav tsev kub thermal conductivity ntawm SiC ceramics tsawg dua 200W·m-1·K-1.
Cov ntsiab lus tsis tshua muaj hauv ntiaj teb xws li Y, Sm, Sc, Gd thiab La tsis yooj yim soluble hauv SiC lattice thiab muaj cov pa oxygen siab, uas tuaj yeem txo cov pa oxygen ntawm SiC lattice. Yog li ntawd, Y2O3-RE2O3 (RE = Sm, Sc, Gd, La) system yog ib qho kev pab sintering rau kev npaj siab thermal conductivity (> 200W·m-1·K-1) SiC ceramics. Noj Y2O3-Sc2O3 system sintering pab ua piv txwv, ion deviation tus nqi ntawm Y3+ thiab Si4+ yog qhov loj, thiab ob qho tib si tsis dhau kev daws teeb meem. Solubility ntawm Sc hauv ntshiab SiC ntawm 1800 ~ 2600 ℃ yog me me, txog (2 ~ 3) × 1017atoms · cm-3.
② Kub kub kev kho mob
Kev kho cua sov kub ntawm SiC ceramics yog qhov tsim nyog rau kev tshem tawm cov teeb meem ntawm lattice, dislocations thiab residual stresses, txhawb cov kev hloov pauv ntawm qee cov ntaub ntawv amorphous rau cov muaju, thiab ua rau cov phonon tawg ua rau tsis muaj zog. Tsis tas li ntawd, kev kho cua sov kub tuaj yeem txhawb kev loj hlob ntawm SiC nplej, thiab thaum kawg txhim kho cov khoom thermal ntawm cov khoom. Piv txwv li, tom qab kev kho cua sov kub ntawm 1950 ° C, thermal diffusion coefficient ntawm SiC ceramics tau nce los ntawm 83.03mm2·s-1 txog 89.50mm2·s-1, thiab chav tsev kub thermal conductivity nce ntawm 180.94W·m. -1·K-1 to 192.17W·m-1·K-1. Kev kho cua kub kub ua haujlwm tau zoo txhim kho lub peev xwm deoxidation ntawm sintering pab ntawm SiC nto thiab lattice, thiab ua rau kev sib txuas ntawm SiC nplej nruj dua. Tom qab kev kho cua sov siab, chav tsev kub thermal conductivity ntawm SiC ceramics tau zoo dua.
Post lub sij hawm: Oct-24-2024