Ceramic formula hmoov yog cov khoom siv tseem ceeb ntawm MLCC, suav txog 20% ~ 45% ntawm tus nqi ntawm MLCC. Tshwj xeeb, muaj peev xwm siab MLCC muaj cov kev cai nruj ntawm qhov purity, particle loj, granularity thiab morphology ntawm ceramic hmoov, thiab tus nqi ntawm cov hmoov ceramic nyiaj rau cov feem ntau dua. MLCC yog cov khoom siv hluav taws xob ceramic hmoov tsim los ntawm kev ntxiv cov tshuaj ntxiv raubarium titanate hmoov, uas tuaj yeem siv ncaj qha raws li dielectric hauv MLCC.
Tsis tshua muaj ntiaj teb oxidesyog ib qho tseem ceeb doping Cheebtsam ntawm MLCC dielectric hmoov. Txawm hais tias lawv suav txog tsawg dua 1% ntawm MLCC cov ntaub ntawv raw, lawv tuaj yeem ua lub luag haujlwm tseem ceeb hauv kev kho cov khoom siv ceramic thiab txhim kho kev ntseeg tau ntawm MLCC. Lawv yog ib qho ntawm cov khoom tseem ceeb tseem ceeb hauv kev tsim cov txheej txheem ntawm high-end MLCC ceramic hmoov.
1. Dab tsi yog cov ntsiab lus tsawg hauv ntiaj teb? Rare ntiaj teb cov ntsiab lus, tseem hu ua cov hlau tsis tshua muaj hauv ntiaj teb, yog cov ntsiab lus dav dav rau cov ntsiab lus lanthanide thiab cov pab pawg tsawg hauv ntiaj teb. Lawv muaj cov khoom siv hluav taws xob tshwj xeeb thiab lub cev thiab tshuaj lom neeg, thiab lawv cov khoom siv hluav taws xob tshwj xeeb, kho qhov muag, sib nqus, thiab thermal cov khoom raug hu ua cov khoom muaj nqis ntawm cov khoom tshiab.
Cov ntsiab lus tsis tshua muaj hauv ntiaj teb tau muab faib ua: lub teeb tsis tshua muaj lub ntiaj teb (nrog cov lej me me):scandium(Sc),yttrium(Y),lanthanum(La),cerium(Ce),praseodymium(Pr),neodymium(Nd), promethium (Pm),samarium(Sm) thiabeuropium(Eu); hnyav tsis tshua muaj ntiaj teb cov ntsiab lus (nrog cov lej loj dua atomic):gadolinium nyob rau hauv cov ntshav(Gd),terbium(Tb),dysprosium(Dy),holmium(Ho),erbium(Er),thulium(Tm),ytterbium(ywb),lutetium(Lu).
Tsis tshua muaj ntiaj teb oxides yog siv dav hauv ceramics, feem ntaucerium oxide, lanthanum oxide, neodymium oxide hmoov, dysprosium oxide, samarium oxide, holmium oxide, erbium oxide hmoov, thiab lwm yam. Ntxiv ib qho me me los yog cov lej ntawm lub ntiaj teb tsis tshua muaj rau cov ceramics tuaj yeem hloov pauv cov microstructure, theem muaj pes tsawg leeg, ntom ntom, txhua yam khoom, lub cev thiab tshuaj lom neeg thiab sintering zog ntawm cov khoom siv ceramic.
2. Kev siv lub ntiaj teb tsis tshua muaj hauv MLCCBarium titanateyog ib qho ntawm cov khoom siv tseem ceeb rau kev tsim MLCC. Barium titanate muaj piezoelectric zoo heev, ferroelectric thiab dielectric zog. Ntshiab barium titanate muaj lub peev xwm loj kub coefficient, siab sintering kub thiab loj dielectric poob, thiab tsis haum rau kev siv ncaj qha rau hauv kev tsim cov ceramic capacitors.
Kev tshawb fawb tau pom tias cov khoom dielectric ntawm barium titanate muaj feem cuam tshuam nrog nws cov qauv siv lead ua. Los ntawm doping, cov qauv siv lead ua ntawm barium titanate tuaj yeem tswj tau, yog li txhim kho nws cov khoom dielectric. Qhov no feem ntau yog vim cov nplua-grained barium titanate yuav tsim lub plhaub-core qauv tom qab doping, uas plays lub luag haujlwm tseem ceeb hauv kev txhim kho qhov kub thiab txias ntawm capacitance.
Doping tsis tshua muaj ntiaj teb cov ntsiab lus rau hauv cov qauv barium titanate yog ib txoj hauv kev los txhim kho tus cwj pwm sintering thiab kev ntseeg siab ntawm MLCC. Kev tshawb fawb txog lub ntiaj teb tsis tshua muaj ion doped barium titanate tuaj yeem taug qab rov qab mus rau thaum ntxov 1960s. Qhov sib ntxiv ntawm lub ntiaj teb tsis tshua muaj oxides txo cov kev txav mus los ntawm cov pa, uas tuaj yeem txhim kho qhov ntsuas kub ntawm dielectric thiab hluav taws xob tsis kam ntawm dielectric ceramics, thiab txhim kho kev ua haujlwm thiab kev ntseeg siab ntawm cov khoom. Feem ntau ntxiv tsis tshua muaj ntiaj teb oxides suav nrog:yttrium oxide(y2o3 ua), dysprosium oxide hmoov (Dy2O3), holmium oxide (hlo 2o3), thiab lwm yam.
Lub vojvoog loj ntawm lub ntiaj teb tsis tshua muaj ions muaj qhov cuam tshuam tseem ceeb ntawm txoj haujlwm ntawm Curie ncov ntawm barium titanate raws li ceramics. Doping ntawm lub ntiaj teb tsis tshua muaj cov ntsiab lus sib txawv nrog cov radii sib txawv tuaj yeem hloov kho cov lattice parameters ntawm crystals nrog lub plhaub core qauv, yog li hloov cov kev ntxhov siab sab hauv ntawm cov muaju. Doping ntawm lub ntiaj teb tsis tshua muaj ions nrog radii loj ua rau tsim cov pseudocubic theem nyob rau hauv cov muaju thiab residual stresses nyob rau hauv lub crystals; Kev taw qhia ntawm lub ntiaj teb tsis tshua muaj ions nrog cov hluav taws xob me me kuj ua rau muaj kev ntxhov siab tsawg dua thiab txo qis kev hloov pauv hauv lub plhaub core qauv. Txawm tias muaj me me ntawm cov khoom ntxiv, cov yam ntxwv ntawm lub ntiaj teb tsis tshua muaj oxides, xws li particle loj lossis cov duab, tuaj yeem cuam tshuam rau tag nrho cov kev ua tau zoo lossis cov khoom zoo. Kev ua tau zoo ntawm MLCC niaj hnub tsim los ntawm miniaturization, siab stacking, muaj peev xwm loj, muaj kev ntseeg siab, thiab tus nqi qis. Lub ntiaj teb cov khoom lag luam MLCC feem ntau tau nkag mus rau hauv nanoscale, thiab tsawg lub ntiaj teb oxides, raws li cov ntsiab lus tseem ceeb, yuav tsum muaj nanoscale particle loj thiab zoo hmoov dispersion.
Post lub sij hawm: Oct-25-2024