1 Kev Taw Qhia
Ceramic cov ntaub ntawv yog ib chav kawm ntawm inorganic non{0}}cov ntaub ntawv hlau tsim los ntawm ntuj los yog hluavtaws sib txuas los ntawm shaping thiab siab -kub sintering. Lawv muaj qhov zoo xws li cov ntsiab lus melting siab, siab hardness, thiab hnav tsis kam, thiab tuaj yeem siv los ua cov khoom siv thiab cov khoom siv ua haujlwm, muab cov ntawv thov dav dav [1]. Kev sintering ntawm cov ntaub ntawv ceramic feem ntau yog txheej txheem uas ib lossis ntau cov khoom siv raw cov ntaub ntawv raug thauj cov khoom hauv qab - kub cua sov, ua rau cov hmoov sib sau ua ke thiab ntom ntom. Cov txheej txheem no feem ntau siv sijhawm ob peb teev lossis txawm kaum teev. Macroscopically, sintering manifests raws li nce ceev thiab lub zog; Qhov tseem ceeb, nws yog lub zog txo qis los ntawm particle deg zog mus rau lub zog sib cuam tshuam, uas tau tsav los ntawm atomic diffusion nyob rau hauv cov tshuaj muaj peev xwm gradients ntawm ntau qhov chaw, thiab microscopically, nws manifests li tshem tawm ntawm pores ntawm nplej [2].
2 Cov txheej txheem metallization
2.1 Direct Plated Copper Metallization
Nyob rau hauv txoj kev ncaj qha plated tooj liab (DPC) metallization txheej txheem, tom qab lub substrate yog laser -drilled thiab huv si huv si, ib txheej ntawm noob yog tso rau ntawm huv si, qhuav ceramic substrate. Tom qab ntawd ib zaj duab xis qhuav yog siv, ua raws li kev txhim kho thiab raug, thiab tom qab ntawd electroplating yog ua los tsim cov hlau uas xav tau. Tom qab ntawd, cov zaj duab xis qhuav thiab cov noob txheej tau muab tshem tawm, thiab cov hlau uas tsis yog - ua haujlwm yog coated rau ntawm tooj liab los tiv thaiv txheej tooj liab rau cov txheej txheem brazing tom ntej.
Txawm hais tias DPC ceramic substrates muaj qhov zoo xws li thermal conductivity, high circuit precision, thiab txo ntim ntim los ntawm -qhov kev sib tshuam, cov txheej txheej tooj liab feem ntau txwv tsis pub ntau tshaj 150 μm vim muaj kev txwv ntawm cov txheej txheem electroplating. Tam sim no, DPC thev naus laus zis feem ntau yog siv hauv kev ntim khoom ntawm siab -faiv fab LEDs. Nyob rau hauv siab - cua sov- tiam siv xws li siab -brightness LEDs thiab sib sib zog nqus- ultraviolet LEDs, tsis tsuas yog ib tug siab -thermal- conductivity substrate yuav tsum tau nyob rau hauv lub backside rau tshav kub dissipation, tab sis pem hauv ntej - sab ntim cov ntaub ntawv kuj yuav tsum xav txog thermal stability. Cov khoom ntim cov khoom siv niaj hnub ua rau muaj kev laus thiab tsis ua haujlwm nyob rau hauv lub teeb ultraviolet thiab kub kub. Yog li ntawd, kev tshawb fawb tam sim no tseem nyiam siv cov khoom siv tsis muaj zog lossis hlau xws li kaolin, npib tsib xee, thiab tooj liab los tsim cov qauv dej ntawm DPC substrates, ua ke nrog pob tshab quartz encapsulation, txhawm rau txhim kho kev ntseeg tau ntawm cov khoom siv [3].
Tam sim no, cov txheej txheem ncaj qha plated tooj liab metallization tau siv dav, tab sis nws tseem ntsib teeb meem xws li kev ua haujlwm qis, tsis zoo ntawm - filling, thiab kev da dej tsis zoo. Ntawm cov no, tsis zoo ntawm - sau tuaj yeem cuam tshuam rau kev ua haujlwm ntawm lub cuab yeej, kev ruaj ntseg, thiab kev ntseeg siab. Yog vim li cas yog vim li cas thaum lub sij hawm electroplating, tooj liab nyiam tso nyiaj ntau nkag rau ntawm qhov chaw, ua rau lub viav vias kaw ua ntej lub sab hauv yog tag nrho, thaum kawg tsim voids hauv lub vias. Qhov zoo ntawm electroplated los ntawm filling yog cuam tshuam los ntawm plating tam sim no thiab additive formulation; optimizing lub plating tov muaj pes tsawg leeg thiab auxiliary txheej txheem tsis tuaj yeem txhim kho ntawm - ua kom zoo.
Tsis tas li ntawd, DPC ceramic substrates yuav ntsib teeb meem thaum lub sij hawm electroplating, nrog rau lub sij hawm plating ntev heev, tsis yog -coated txheej thickness, thiab macroscopic residual stresses nyob rau hauv lub txheej. Ntawm cov no, kev ntxhov siab ntau dhau tuaj yeem ua rau txheej txheej tawg lossis tawg, thiab qhov sib xyaw ntawm cov kev ntxhov siab nyob hauv cov txheej tooj liab yuav cuam tshuam rau thermal stability ntawm ceramic substrate [4].
2.2 Direct Bonded Copper Method
Txoj kev sib txuas ncaj qha tooj liab (DBC) thev naus laus zis tau ua thawj zaug los ntawm Burgess li al. xyoo 1973 [5]. Nws lub hauv paus ntsiab lus yog tias oxide txheej ntawm cov ntawv ci tooj liab ua rau Cu-O eutectic yaj ntawm qhov kub thiab txias. Cov yaj no muaj cov khoom ntub dej zoo heev thiab, ntawm eutectic kub ntawm 1065 degree, tuaj yeem ua tau zoo sib txuas cov ceramic substrate nrog cov ntawv ci tooj liab uas tsis muaj kev cuam tshuam, ua kom muaj kev ruaj ntseg tom qab txias thiab khov.
Nyob ze 1065 degree, cov ntawv Cu-O eutectic theem. Txij li thaum lub melting point ntawm ntshiab tooj liab yog 1083 degree, lub eutectic bonding yuav tsum tau nqa tawm nyob rau hauv lub kub ntawm 1065℃mus rau 1083 degree, nrog rau cov kev ua haujlwm tiag tiag feem ntau concentrated ntawm 1070℃thiab 1075 degree. Thaum lub caij txias, cov pa oxygen supersaturated hauv Cu-O eutectic precipitates li Cu₂O; Hauv Al₂O₃ lossis AlN ceramics, cov khoom siv tshuaj tiv thaiv ntxiv xws li CuAlO₂ thiab CuAl₂O₄ kuj tuaj yeem tshwm sim [5]. Kev tsim ntawm cov kua eutectic thiab nws cov ntsiab lus oxygen yog qhov tseem ceeb rau kev sib raug zoo. Muab hais tias qhov diffusion tus nqi ntawm cov pa oxygen nyob rau hauv cov tooj liab yaj yog tsawg heev (10⁻⁵ cm² / s), nws yog ib qho nyuaj rau qhia kom txaus oxygen thaum lub sij hawm sib txuas cov txheej txheem; Yog li ntawd, ua ntej-oxidation ntawm cov ntawv ci tooj liab feem ntau yog ua los ua Cu₂O ntawm cov ntawv ci tooj liab los txhawb kev tsim cov kua eutectic. Cov ntsiab lus ntawm cov pa oxygen hauv tooj liab kuj tseem cuam tshuam rau kev sib raug zoo ntawm lub zog, yog li kev tswj xyuas meej ntawm qhov ntsuas no yog qhov tseem ceeb ntawm kev ua kom muaj kev sib raug zoo [6].
Txoj kev sib txuas ncaj qha tooj liab yuav tsum muaj cov substrates tshwj xeeb rau kev siv. Ntshiab tooj liab yaj muaj tsis zoo wettability ntawm Al₂O₃, AlN, thiab Si₃N₄, nrog rau cov ces kaum sib cuag tshaj 130 degree. Los ntawm kev ua kom cov pa ib nrab siab thaum sib txuas thiab cov ntsiab lus oxygen ntawm tooj liab yaj, lub kaum sab xis ntawm Al₂O₃ qhov chaw tuaj yeem txo qis heev [7]. Txawm hais tias lub wettability ntawm AlN kuj tuaj yeem txhim kho los ntawm kev ua kom cov pa oxygen ib nrab siab thaum lub sij hawm sib txuas, kev sib koom ua ke hauv lub tshuab nqus tsev, los yog ncua sij hawm sib txuas, cov nyhuv yog txwv heev [8]. Yog li ntawd, AlN feem ntau yog ua ntej- oxidized los ua ib txheej txheej ntawm Al₂O₃, thiab tom qab ntawd sib txuas nrog cov txheej txheem saum toj no. Txawm li cas los xij, tsis muaj ib txoj hauv kev no tuaj yeem txhim kho wettability ntawm tooj liab yaj ntawm Si₃N₄, yog li DBC tsis tshua siv rau Si₃N₄.
2.3 Active Hlau Brazing Metallization
Hauv kev lag luam tsheb tshiab, SiC modules muaj nuj nqis heev. Txawm li cas los xij, thaum qhov kub thiab txias ntawm SiC cov khoom siv hluav taws xob nce mus txog 250 degree, qhov kub tsis zoo - voj voog kev ntseeg siab ntawm DBC ceramic substrates nyob rau hauv siab - qhov kub thiab txias txwv lawv daim ntawv thov. Txhawm rau daws qhov teeb meem no, cov kws tshawb fawb tau tsim AMB (Active Metal Brazed) ceramic substrates.
Ua ntej, ib txheej nyias ntawm cov solder yog siv rau hauv cov txheej txheem ceramic. Copper ntawv ci yog muab tso rau ntawm lub solder, thiab lub rooj sib txoos yog rhuab nyob rau hauv ib qho chaw nqus tsev vacuum ntawm 800℃mus rau 950℃kom yaj lub solder. Thaum txias, ib qho kev sib koom ua ke yog tsim. Tom ntej no, ntub dej etching yog siv los tsim cov qauv hlau kom tau raws li cov kev xav tau ntawm kev sib txuas hluav taws xob ntawm siab - cov khoom siv fais fab.
Vim hais tias cov pa hlau feem ntau pom cov dej tsis zoo ntawm cov khoom siv hluav taws xob, cov khoom siv hlau feem ntau yog siv los txhim kho wettability thiab txhim khu kev sib koom ua ke. Active hlau solders muaj tsawg kawg yog ib tug nquag hlau ntsiab, nrog Ti thiab lanthanide ntsiab tam sim no yog lub ntsiab active ntsiab. Cov khoom siv nquag siv hauv AMB cov txheej txheem suav nrog Sn-Ag-Ti thiab Ag-Cu-Ti systems, qhov twg Ti yog cov hlau nquag los txhim kho wettability ntawm cov solder thiab ceramic, thaum Sn thiab Ag ua kom txo cov ntsiab lus melting thiab txhim kho thermal conductivity ntawm kev sib koom ua ke.
Txawm li cas los xij, cov txheej txheem AMB yuav tsum tau ua nyob rau hauv lub tshuab nqus tsev siab lossis qhov chaw tiv thaiv, uas txwv nws txoj kev siv tau. Txhawm rau kov yeej qhov kev txwv no, cov kws tshawb fawb tau tsim Reactive Air Brazing (RAB) thev naus laus zis, uas tuaj yeem ua tau hauv huab cua. Lub brazing muab tub lim hlau siv hauv RAB feem ntau yog tsim los ntawm cov hlau tsis zoo (xws li Ag, Ag-Pd alloys) thiab hlau oxides (xws li CuO, V₂O₅ [9], Nb₂O₅, SiO₂, thiab Al₂TiO₅), yog li endowing kev sib koom tes nrog zoo oxidation. Thaum lub sij hawm RAB, cov hlau oxides tuaj yeem ua raws thiab hnov mob nrog cov txheej txheem ceramic substrate, txhim khu lub wettability ntawm ceramic substrate los ntawm kev sib koom ua ke ntawm molten muab tub lim hlau thiab qhov cuam tshuam. Lub caij no, qhov zoo ductility ntawm noble hlau pab txo cov thermal stresses nyob rau hauv lub sib koom tes, thiab ntxiv cov hlau oxides pab txo cov residual stresses tshwm sim los ntawm CTE mismatches ntawm qhov sib koom tes thiab cov ceramic matrix.
Active hlau brazing metallization muaj qhov zoo xws li cov cuab yeej siv yooj yim thiab cov txheej txheem, kev ntseeg siab, thiab tsis muaj kev txwv rau cov khoom siv ceramic substrate, ua rau nws cov txheej txheem zoo tshaj plaws metallization rau siab -cov ntaub ntawv siv hluav taws xob. Txawm li cas los xij, muab kev txhim kho sai ntawm - lub zog hluav taws xob hauv kev lag luam khoom siv hluav taws xob, cov qauv siab dua tau muab tso rau ntawm cov khoom siv kho tshuab thiab ntev - lub sijhawm ua haujlwm kev ntseeg siab ntawm AMB cov txheej txheem, xav tau kev txhim kho txuas ntxiv thiab txhim kho. Nyob rau tib lub sijhawm, AMB ceramic substrates ntsib tib qhov kev tsis sib haum xeeb ntawm qhov tsis txaus Circuit Court precision li DBC substrates. Yog tias cov thev naus laus zis tshiab tuaj yeem tsim kho kom ua tiav qhov ntsuas hluav taws xob zoo piv rau cov txheej txheem DPC, AMB ceramic substrates yuav tsum tau hloov lwm cov substrates zoo sib xws rau yav tom ntej, uas qhia tau hais tias muaj peev xwm siv tau zoo [4].
2.4 Laser-Induced Metallization
Nyob rau hauv lub laser -induced metallization txheej txheem, ib tug laser beam yog siv los xaiv irradiate ib tug txhuas-muaj ceramic substrate. Cov khoom siv irradiated ceramic yog txo mus rau activated hlau atoms. Tom qab ntawd lub substrate yog raus rau hauv ib qho electroless plating tov uas muaj Cu²⁺, qhov twg lub tshuab txais atoms txhawb qhov txo ntawm Cu²⁺ thiab nws deposition nyob rau hauv irradiated cheeb tsam, tsim metallic Circuit Court qauv [10].
Electroless plating yog cov txheej txheem autocatalytic redox uas tsis tas yuav muaj qhov tam sim no sab nraud; hlau ions raug txo kom muaj hlau los ntawm cov tshuaj txo cov neeg ua haujlwm hauv cov tshuaj [11], thiab lub zog tsav qhov kev txo qis no los ntawm cov tshuaj txo cov neeg ua haujlwm hauv cov tshuaj. Feem ntau, hlau ions nyob rau hauv lub plating da dej yog tsis yooj yim txo spontaneously, thiab ib tug catalyst feem ntau yuav tsum tau raws li ib tug nruab nrab nruab nrab los txo lub activation zog rau hlau nucleation. Thaum cov khoom siv hluav taws xob tau ua tiav tiav rau ntawm qhov chaw substrate, loj - nplai hlau tso tawm tuaj yeem tshwm sim.
Laser-induced metallization feem ntau ua rau txhuas- muaj cov substrates vim tias laser irradiation tuaj yeem ua rau Al atoms. Txawm li cas los xij, kev ua haujlwm catalytic ntawm Al atoms tsis zoo tagnrho, thiab lwm yam catalysts xav tau los txhim kho kev ua haujlwm ntawm kev tso nyiaj.
Tus tsim ntawm laser-induced metallization txheej txheem yog rhiab heev rau laser tsis, ceramic substrate yam ntxwv, thiab electroplating txheej txheem tsis. Txawm hais tias cov txheej txheem no sib txuas cov nqi kom zoo dua ntawm tooj liab electroplating nrog high Circuit Court precision ntawm LAM (laser-pab metallization) cov txheej txheem, tus nqi siab ntawm cov khoom siv laser thiab ib puag ncig muaj kuab paug los ntawm electroless plating tseem yog ib qho tseem ceeb txwv nws txoj kev loj hlob ntxiv.
2.5 Thick - Zaj duab xis Metallization
Thick- zaj duab xis metallization cuam tshuam nrog kev tshuaj ntsuam- luam cov txheej hlau rau kev sib khi, cov neeg siv hluav taws xob (circuit wiring), resistors, thiab lwm yam, mus rau ceramic substrates, tom qab ntawd los ntawm sintering los tsim cov txheej hlau brazing, circuits, thiab cov ntsiab lus txuas cov hlau lead. Thick- zaj duab xis pastes feem ntau yog tsim los ntawm cov hmoov hlau nrog qhov ntau thiab tsawg ntawm 1.5 μm, ob peb feem pua ntawm cov ntaub ntawv ruaj khov, thiab lub tsheb organic (xws li cov kuab tshuaj organic, thickeners, surfactants, thiab lwm yam), npaj los ntawm pob milling thiab sib tov. Cov kauj ruam ntawm tuab- zaj duab xis metallization feem ntau suav nrog: qauv tsim thiab kev npaj kos duab, npaj muab tshuaj txhuam, tshuaj ntsuam luam ntawv, ziab, thiab sintering [12].
Thick -film metallization siv lub hauv paus ntsiab lus ntawm kev tshuaj ntsuam luam ntawv. Ua ntej, cov txheej txheem hlau yuav tsum tau ntim los yog cov khoom siv hluav taws xob xws li cov resistors yog txuas rau aluminium nitride ceramic substrate. Tom ntej no, cov txheej hlau thiab cov khoom siv hluav taws xob tau txuas nrog rau cov khoom siv hluav taws xob los ntawm kev kub siab -kub sintering, ua tiav kev sib txuas ruaj khov ntawm txhua qhov chaw. Cov txheej txheem no muaj kev siv dav hauv kev ntim khoom siv hluav taws xob thiab kev xaim hluav taws xob. Cov tshuaj nplaum conductive yog qhov tseem ceeb cuam tshuam rau tuab -film metallization zoo; nws muaj pes tsawg leeg mas muaj hlau hmoov (1-5 μm), iav, binders, thiab ib tug organic tsheb tov los ntawm pob milling [13].
Txoj kev tuab - zaj duab xis metallization siv tau rau ntau hom ceramic thiab muaj cov txheej txheem yooj yim [14]. Txawm li cas los xij, txwv los ntawm qhov ntau thiab tsawg ntawm kev tshuaj ntsuam thiab cov khoom siv hluav taws xob, nws nyuaj rau kev tsim cov xov hlau nrog cov kab dav hauv qab 60 μm. Cov khoom siv hluav taws xob thiab lub zog adhesion ntawm cov hlau txheej yog qhov tsis zoo, ua rau nws tsuas yog tsim nyog rau cov khoom siv hluav taws xob nrog qis zog thiab qhov loj me. Conductive pastes tshwj xeeb tsim rau txhuas nitride tuab-film metallization tseem tsis tshua muaj, thiab cov khoom lag luam muab tshuaj txhuam tsis siv ncaj qha; txwv tsis pub, blistering ntawm lub interface yuav tshwm sim [15].
2.6 Nyias - Zaj duab xis Metallization
Nyias- zaj duab xis metallization yog txheej txheem uas cov ntaub ntawv hlau yog vaporized thiab tso rau hauv cov khoom siv ceramic los ntawm lub cev vapor deposition txoj kev xws li nqus evaporation los yog sputtering los ua ib tug nyias hlau zaj duab xis, ua raws li los ntawm masking, etching, thiab lwm yam kauj ruam los tsim metallized Circuit Court qauv.
Hauv txoj kev xav, cov txheej txheem no tuaj yeem tsim micron- nplai cov hlau tsis sib xws ntawm ntau yam khoom siv hauv qab ntawm evaporation lossis sputtering. Txawm li cas los xij, vim qhov sib txawv tseem ceeb hauv thermal expansion coefficients ntawm ceramics thiab metallic tooj liab, ncaj qha tooj liab deposition ntawm aluminium nitride ceramics qhia kev ntxhov siab loj ntawm cov hlau thiab ceramic txheej, cuam tshuam lub zog adhesion ntawm txheej rau ceramic thiab thermal cycling stability ntawm lub substrate. Yog li ntawd, nyob rau hauv xyoo tas los no, multilayer deposition mus kom ze tau ua nrov. Thawj txheej feem ntau yog Ti txheej, thiab txheej thib ob yog xaiv los ntawm cov hlau xws li Cu, Ag, lossis Au. Thaum dislocation plam thiab kev sib cuam tshuam hauv ib txheej yog hloov mus rau lwm txheej vim muaj kev ntxhov siab loj hauv sab hauv, cov kev ntxhov siab sab hauv hauv cov txheej hlau kuj tau txo qis.
Nyias- zaj duab xis metallization muaj cov khoom zoo, muaj zog adhesion, txheej txheej, thiab kev daws teeb meem zoo. Txawm li cas los xij, nws tsuas tuaj yeem tsim cov txheej hlau nyias nyias, thiab cov txheej txheem kev npaj yog qhov nyuaj, suav nrog ntau cov kauj ruam suav nrog kev kho saum npoo, hlau tso, thiab tom qab- kev kho mob, yuav tsum muaj kev tswj hwm nruj ntawm cov txheej txheem. Qhov no ua rau cov nqi tsim khoom siab, ua rau nws txoj kev loj hlob hnyav heev.