Tam sim no,silicon carbide (SiC)yog ib yam khoom siv ceramic thermally conductive uas tau kawm txog hauv tsev thiab txawv teb chaws. Lub thermal conductivity ntawm SiC yog siab heev, thiab qee cov qauv siv lead ua tuaj yeem ncav cuag 270W / mK, uas twb yog tus thawj coj ntawm cov khoom siv tsis-conductive. Piv txwv li, daim ntawv thov ntawm SiC thermal conductivity tuaj yeem pom hauv cov ntaub ntawv substrate ntawm cov khoom siv semiconductor, cov ntaub ntawv ceramic thermal conductivity siab, cov cua sov thiab cov phaj cua sov rau kev ua semiconductor, cov ntaub ntawv capsule rau roj nuclear, thiab cov nplhaib roj sealing rau cov twj compressor.
Daim ntawv thov ntawmsilicon carbidenyob rau hauv lub teb ntawm semiconductor
Cov discs sib tsoo thiab cov khoom siv yog cov khoom siv tseem ceeb rau kev tsim cov silicon wafer hauv kev lag luam semiconductor. Yog tias lub disc sib tsoo yog ua los ntawm hlau cam khwb cia lossis carbon steel, nws lub neej ua haujlwm luv luv thiab nws cov coefficient thermal expansion loj. Thaum lub sijhawm ua cov silicon wafers, tshwj xeeb tshaj yog thaum lub sijhawm sib tsoo ceev lossis polishing, vim yog qhov hnav thiab thermal deformation ntawm lub disc sib tsoo, qhov tiaj tus thiab parallelism ntawm silicon wafer nyuaj rau lav. Lub disc sib tsoo ua los ntawmsilicon carbide ceramicsmuaj qhov hnav tsawg vim nws qhov nyuaj siab, thiab nws cov coefficient thermal expansion yeej zoo ib yam li cov silicon wafers, yog li nws tuaj yeem raug zom thiab txhuam ntawm qhov ceev ceev.
Ntxiv mus, thaum cov silicon wafers raug tsim tawm, lawv yuav tsum tau ua kom sov siab thiab feem ntau raug thauj mus los siv cov khoom siv silicon carbide. Lawv tiv taus cua sov thiab tsis ua puas tsuaj. Cov pa roj carbon zoo li pob zeb diamond (DLC) thiab lwm yam txheej txheem tuaj yeem siv rau ntawm qhov chaw kom txhim kho kev ua haujlwm, txo qhov puas tsuaj ntawm wafer, thiab tiv thaiv kev kis kab mob.
Ntxiv mus, ua tus sawv cev ntawm cov ntaub ntawv semiconductor dav dav-bandgap thib peb, cov ntaub ntawv silicon carbide ib leeg siv lead ua ke muaj cov yam ntxwv xws li qhov dav bandgap loj (kwv yees li 3 npaug ntawm Si), kev ua kom sov siab (kwv yees li 3.3 npaug ntawm Si lossis 10 npaug ntawm GaAs), kev hloov pauv ntawm cov hluav taws xob siab (kwv yees li 2.5 npaug ntawm Si) thiab lub zog hluav taws xob tawg siab (kwv yees li 10 npaug ntawm Si lossis 5 npaug ntawm GaAs). Cov khoom siv SiC ua rau cov qhov tsis zoo ntawm cov khoom siv semiconductor ib txwm muaj hauv kev siv tiag tiag thiab maj mam dhau los ua lub hauv paus ntawm cov khoom siv hluav taws xob semiconductor.
Qhov kev thov rau cov khoom siv hluav taws xob thermal conductivity silicon carbide ceramics tau nce ntxiv ntau heev
Nrog rau kev txhim kho tas mus li ntawm kev tshawb fawb thiab thev naus laus zis, qhov kev thov rau kev siv silicon carbide ceramics hauv thaj chaw semiconductor tau nce ntxiv ntau heev, thiab kev ua haujlwm thermal siab yog qhov qhia tseem ceeb rau nws daim ntawv thov hauv cov khoom siv semiconductor. Yog li ntawd, nws yog qhov tseem ceeb heev rau kev txhawb nqa kev tshawb fawb txog kev ua haujlwm thermal siab silicon carbide ceramics. Txo cov ntsiab lus oxygen hauv lattice, txhim kho qhov ceev, thiab tswj kev faib tawm ntawm theem thib ob hauv lattice yog cov txheej txheem tseem ceeb los txhim kho kev ua haujlwm thermal ntawm silicon carbide ceramics.
Tam sim no, muaj ob peb txoj kev tshawb fawb txog kev ua kom muaj cua sov siab silicon carbide ceramics hauv kuv lub tebchaws, thiab tseem muaj qhov sib txawv loj piv rau theem thoob ntiaj teb. Cov lus qhia tshawb fawb yav tom ntej suav nrog:
●Ua kom muaj zog rau kev tshawb fawb txog kev npaj cov hmoov silicon carbide ceramic. Kev npaj cov hmoov silicon carbide uas muaj cov pa oxygen tsawg thiab muaj cov khoom siv siab yog lub hauv paus rau kev npaj cov silicon carbide ceramics uas muaj cov thermal conductivity siab;
● Txhawb kom muaj kev xaiv cov khoom siv sintering thiab kev tshawb fawb txog kev xav;
●Txhawb kom muaj zog rau kev tshawb fawb thiab kev tsim cov khoom siv sintering zoo. Los ntawm kev tswj cov txheej txheem sintering kom tau txais cov qauv me me tsim nyog, nws yog ib qho tsim nyog kom tau txais cov khoom siv silicon carbide ceramics uas muaj kev ua haujlwm thermal conductivity siab.
Kev ntsuas los txhim kho qhov thermal conductivity ntawm silicon carbide ceramics
Tus yuam sij rau kev txhim kho qhov thermal conductivity ntawm SiC ceramics yog kom txo qhov zaus ntawm phonon scattering thiab nce qhov phonon mean free path. Qhov thermal conductivity ntawm SiC yuav raug txhim kho zoo los ntawm kev txo qhov porosity thiab cov ciam teb ntawm cov noob ntawm SiC ceramics, txhim kho qhov purity ntawm SiC noob ciam teb, txo SiC lattice impurities lossis lattice defects, thiab nce qhov kub ntws transmission carrier hauv SiC. Tam sim no, optimizing hom thiab cov ntsiab lus ntawm sintering aids thiab high-kub kub kho yog cov kev ntsuas tseem ceeb los txhim kho qhov thermal conductivity ntawm SiC ceramics.
① Kev txhim kho hom thiab cov ntsiab lus ntawm cov khoom siv sintering
Thaum npaj cov khoom siv SiC uas muaj cua sov zoo, ntau yam khoom siv sintering feem ntau ntxiv rau. Ntawm lawv, hom thiab cov ntsiab lus ntawm cov khoom siv sintering muaj feem cuam tshuam loj rau cov khoom siv thermal conductivity ntawm SiC ceramics. Piv txwv li, Al lossis O cov ntsiab lus hauv Al2O3 system sintering aids yooj yim yaj rau hauv SiC lattice, ua rau muaj qhov chaw khoob thiab qhov tsis zoo, uas ua rau muaj kev nce ntxiv ntawm phonon scattering zaus. Tsis tas li ntawd, yog tias cov ntsiab lus ntawm cov khoom siv sintering tsawg, cov khoom siv nyuaj rau sinter thiab densify, thaum cov ntsiab lus siab ntawm cov khoom siv sintering yuav ua rau muaj kev nce ntxiv ntawm cov khoom tsis huv thiab qhov tsis zoo. Cov khoom siv sintering theem kua ntau dhau kuj tseem yuav tiv thaiv kev loj hlob ntawm SiC noob thiab txo qhov nruab nrab ntawm txoj kev dawb ntawm phonons. Yog li ntawd, txhawm rau npaj cov khoom siv SiC uas muaj cua sov zoo, nws yog qhov tsim nyog los txo cov ntsiab lus ntawm cov khoom siv sintering ntau li ntau tau thaum ua tau raws li qhov yuav tsum tau ua ntawm sintering ceev, thiab sim xaiv cov khoom siv sintering uas nyuaj rau yaj hauv SiC lattice.
* Cov khoom siv thermal ntawm SiC ceramics thaum ntxiv cov khoom pab sintering sib txawv
Tam sim no, cov khoom siv SiC kub uas tau nias sintered nrog BeO ua ib qho kev pab sintering muaj qhov kub siab tshaj plaws hauv chav tsev (270W · m-1 · K-1). Txawm li cas los xij, BeO yog ib yam khoom lom heev thiab ua rau mob qog noj ntshav, thiab tsis haum rau kev siv dav hauv chaw soj nstuam lossis cov chaw ua haujlwm. Qhov kub qis tshaj plaws ntawm Y2O3-Al2O3 system yog 1760 ℃, uas yog ib qho kev pab sintering rau SiC ceramics. Txawm li cas los xij, txij li Al3 + yooj yim yaj rau hauv SiC lattice, thaum lub kaw lus no siv ua ib qho kev pab sintering, qhov kub hauv chav tsev ntawm SiC ceramics tsawg dua 200W · m-1 · K-1.
Cov khoom tsis tshua muaj xws li Y, Sm, Sc, Gd thiab La tsis yooj yim yaj 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 cov khoom siv thermal conductivity siab (> 200W · m-1 · K-1) SiC ceramics. Siv Y2O3-Sc2O3 system sintering aid ua piv txwv, tus nqi ion deviation ntawm Y3 + thiab Si4 + yog loj, thiab ob qho tsis dhau cov tshuaj khov. Qhov solubility ntawm Sc hauv SiC ntshiab ntawm 1800 ~ 2600 ℃ yog me me, txog (2 ~ 3) × 1017 atoms · cm-3.
② Kev kho cua sov kub siab
Kev kho cua sov siab ntawm SiC ceramics yog qhov zoo rau kev tshem tawm cov qhov tsis zoo ntawm lattice, dislocations thiab cov kev ntxhov siab seem, txhawb kev hloov pauv ntawm qee cov khoom siv amorphous rau cov siv lead ua, thiab ua rau lub zog ntawm phonon scattering effect. Tsis tas li ntawd, kev kho cua sov siab tuaj yeem txhawb kev loj hlob ntawm SiC noob, thiab thaum kawg txhim kho cov khoom thermal ntawm cov khoom. Piv txwv li, tom qab kev kho cua sov siab ntawm 1950 ° C, qhov coefficient thermal diffusion ntawm SiC ceramics nce ntawm 83.03mm2·s-1 mus rau 89.50mm2·s-1, thiab chav tsev thermal conductivity nce ntawm 180.94W·m-1·K-1 mus rau 192.17W·m-1·K-1. Kev kho cua sov siab zoo txhim kho lub peev xwm deoxidation ntawm cov khoom siv sintering ntawm SiC nto thiab lattice, thiab ua rau kev sib txuas ntawm SiC noob nruj dua. Tom qab kev kho cua sov siab, chav tsev thermal conductivity ntawm SiC ceramics tau zoo dua.
Lub sijhawm tshaj tawm: Lub Kaum Hli-24-2024