Kev lig kev cai FR-4 fiberglass boards zoo li tsim "arch" zoo tom qab reflow soldering. Qhov no yog qhov tshwm sim ntawm qhov tsis sib xws ntawm thermal stress thiab cov khoom siv lub cev. Traditional PCBs raug kev txom nyem los ntawm cov khoom siv soldering tsis xws luag thiab cov khoom siv ua haujlwm tsis zoo vim yog warping. Ib hom PCB siv ceramic ua nws cov substrate, nrog rau nws nyob ze - lub cev ruaj khov zoo, yog qhov kev xaiv tseem ceeb rau siab - lub zog lossis cov khoom siv hluav taws xob muaj kev ntseeg siab.
Vim li cas ho tsis ceramic substrates warp?
Lub hauv paus ua rau ntawm PCB warping nyob rau hauv qhov tsis sib haum xeeb ntawm thermal expansion coefficients ntawm cov ntaub ntawv thiab tso tawm ntawm kev ntxhov siab sab hauv. Ordinary FR-4 substrates yog tsim los ntawm kev sib txuas fiberglass daim ntaub thiab epoxy resin. Cov resin softens thaum rhuab thiab shrinks thaum txias. Asymmetrical tooj liab ntawv ci ntawm ob sab ntxiv exacerbates lub deformation.
Ceramic substrates muaj cov yam ntxwv sib txawv kiag li. Lawv siv siab -kub sintered ceramic ntsuab nplooj ntawv ua lub hauv paus, nthuav tawm cov qauv elastic heev thiab tsis tshua muaj coefficient ntawm thermal expansion. Thaum lub sij hawm tsim khoom, cov ntawv ci tooj liab txuas nrog rau cov nplais ceramic los ntawm kev kub siab - kub nias los yog tooj liab plating tshuab ncaj qha, ua tiav kev sib txuas sib txuas es tsis yog cov nplaum nplaum yooj yim. Qhov no tso cai rau cov qauv sib xyaw kom muaj kev ruaj ntseg zoo txawm tias nyob rau hauv qhov kub thiab txias.
Alumina ceramics: Tus Vaj Ntxwv ntawm Tus Nqi-Kev ua tau zoo
Alumina yog tam sim no siv ntau tshaj plaws ceramic substrate khoom, muaj li ntawm 75% thiab 99.5% alumina. Lub siab purity ntawm 99.5% ua rau ib tug du thiab ntom ntom nrog tsis tshua muaj dielectric poob, ua rau nws haum rau siab - zaus circuits.
Lub thermal conductivity ntawm alumina yog kwv yees li 24 txog 28 W / (m·K), ntau dua FR -4's 0.3 W / (m·K). Txawm li cas los xij, nws tseem poob qis hauv kev siv hluav taws xob ultra-siab. Nws boasts ntau raw cov ntaub ntawv, siab mechanical zog, thiab zoo heev tshuaj stability, ua rau nws yog ib tug piv txwv ntawm cov khoom uas sib npaug kev ua tau zoo thiab tus nqi, yog li tuav ib tug tseem ceeb txoj hauj lwm nyob rau hauv lub microelectronics thiab fais fab module teb.
Aluminium nitride lub siab thermal conductivity yog zoo - sib phim rau silicon wafers. Qhov tshwm sim ntawm aluminium nitride ceramics tau daws qhov teeb meem ntawm cov thermal conductivity tsis txaus hauv alumina, ua tiav cov thermal conductivity ntau tshaj 170 W / (m·K), xya npaug ntawm alumina thiab tseem tshaj ntawm cov hlau txhuas.
Qhov tseem ceeb tshaj, aluminium nitride tus coefficient ntawm thermal expansion yog heev ze rau ntawm semiconductor silicon wafers. Thaum siab - cov chips fais fab tau txuas ncaj qha rau ntawm lub substrate, qhov zoo sib xws expansion coefficient zoo zam kev ntxhov siab los ntawm thermal cycling, yog li tiv thaiv chip cracking los yog solder joint qaug zog. Nws cov txheej txheem tsim muaj cov kev xav tau siab heev rau kev tswj cov pa oxygen; Qhov qis dua cov pa oxygen impurities, lub zog thermal conductivity.
High Thermal Conductivity thiab Toxicity Limitations ntawm Beryllium Oxide
Beryllium oxide ceramics muaj qhov tshwj xeeb thermal conductivity, txawm tias dhau ntawm txhuas nitride, ncav cuag tshaj 250 W / (m·K) ntawm chav tsev kub. Nws yog ib zaug cov khoom uas nyiam nyob rau hauv cov teb uas tsis tshua muaj zog cua sov dissipation yuav tsum tau.
Txawm li cas los xij, beryllium oxide hmoov yog tshuaj lom. Yog tias cov plua plav tsim tawm thaum lub sijhawm tsim khoom thiab ua haujlwm tau nqus, nws tuaj yeem ua rau mob ntsws loj. Ib yam li ntawd, yog tias cov hmoov av tsim tawm thaum nqus tau, nws tuaj yeem ua rau mob ntsws loj. Qhov kev ua txhaum loj kawg no txwv nws txoj kev loj hlob. Tam sim no, nws tsuas yog siv nyob rau hauv ob peb qhov tshwj xeeb tub rog teb nrog kev tiv thaiv kev tiv thaiv, thiab tseem nyob rau hauv ob peb qhov tshwj xeeb aerospace teb nrog kev tiv thaiv kev tiv thaiv. Kev lag luam pej xeem tau hloov pauv los ntawm txhuas nitride.
Qhov zoo ntawm Core Ceramic PCBs
Qhov zoo tshaj plaws ntawm cov khoom siv ceramic yog lawv qhov muaj zog tam sim no - nqa lub peev xwm. Kev sim cov ntaub ntawv qhia tau hais tias thaum 100A tam sim no tsis tu ncua ntws los ntawm 1 hli tuab 0.3 hli tooj liab substrate, qhov kub nce tsuas yog nyob ib ncig ntawm 17 degree. Yog hais tias lub thickness ntawm tooj liab nce mus rau 2 hli, qhov kub thiab txias tuaj yeem tswj tau li ntawm 5 degree.
Tsis tas li ntawd, nws muaj cov rwb thaiv tsev zoo heev uas tuaj yeem tiv taus qhov hluav taws xob siab. Cov cuab yeej no ua kom muaj kev nyab xeeb ntawm cov khoom siv thiab cov neeg ua haujlwm. Vim tias nws tsis xav tau cov kua nplaum organic, nws qhov kev ua tau zoo yog qhov ruaj khov nyob rau hauv siab - kub thiab siab - av noo ib puag ncig. Tsis tas li ntawd, cov ntawv ci tooj liab adhesion muaj zog heev thiab yuav tsis tshem tawm vim qhov kub hloov pauv, ua rau nws txoj kev ntseeg tau zoo dua li PCBs zoo tib yam.
Kev tsim cov kev xaiv rau Ceramic PCBs
Txawm hais tias ceramic substrates nthuav tawm kev ua tau zoo dua, lawv qhov xwm txheej tsis yooj yim txwv lawv siv hauv kev tsim khoom loj - thaj tsam boards, thiab lawv cov nqi ntau dua FR-4. Ib qho 100mm sab aluminium nitride substrate yuav raug nqi kaum npaug ntau dua li FR-4 ntawm tib qhov loj.
Yog li ntawd, nws yog tsuas yog siv nyob rau hauv high{0}}kawg daim ntaub ntawv xws li siab- zog LEDs, automotive ignition systems, siab - zaus hloov fais fab mov, aerospace, thiab tub rog electronics. Xaiv ib lub substrate ceramic txhais tau tias xaiv qhov kawg ntawm kev ruaj ntseg thiab kev ntseeg siab. Hauv R&D tiag tiag lossis me me -batch ntau lawm, xaiv tus kws tshaj lij thiab txhim khu kev qha cov chaw tsim khoom yog qhov tseem ceeb heev. JEP PCB tau koom tes nrog kev lag luam rau ntau xyoo, muaj peev xwm ua cov txheej txheem ceramic substrate. Los ntawm prototyping mus rau ntau lawm, nws tuaj yeem muab cov lus teb sai thiab kev txhawb nqa txheej txheem ruaj khov, ua kom koj qhov kev ua tau zoo ntawm - qauv tsim tuaj yeem ua tiav.
Yog li, hauv koj tus qauv tsim khoom, koj puas yuav tsum tswj hwm tus nqi tseem ceeb, lossis koj puas yuav xaiv lub substrate ceramic vim nws qhov kub thiab txias 5℃thiab tsis muaj kev ntseeg siab thiab ruaj khov? Xav tias dawb los qhia koj cov kev xav hauv cov lus hauv nqe lus, nyiam thiab qhia cov kab lus no kom ntau tus kws tshaj lij tuaj yeem pom qhov no hauv -qhov kev tshawb fawb tob tob.