Hauv qab no, peb yuav ua tib zoo txheeb xyuas qhov kev xaiv ntawm siab - zaus pcb kho qhov chaw los ntawm plaub qhov loj me: cov txheej txheem ntawm cov nyhuv ntawm daim tawv nqaij, teeb liab cuam tshuam rau peb txheej txheem, sib piv cov ntaub ntawv ntsuas, thiab kev txiav txim siab xaiv.
Hauv qab no, peb yuav ua tib zoo txheeb xyuas qhov kev xaiv ntawm siab - zaus pcb kho qhov chaw los ntawm plaub qhov loj me: cov txheej txheem ntawm cov nyhuv ntawm daim tawv nqaij, teeb liab cuam tshuam rau peb txheej txheem, sib piv cov ntaub ntawv ntsuas, thiab kev txiav txim siab xaiv.
| zaus | Daim tawv nqaij tob ntawm tooj liab | lub ntsiab lus |
|---|---|---|
| 1 GHz | Txog 2.1 μm | Tam sim no mas propagates nyob rau hauv lub nto txheej ntawm 2.1 μ m |
| 10 GHz | 0.66m ib | Tam sim no concentration nyob rau hauv txheej txheej ntawm 0.66 μ m |
| 28 GHz | Txog 0.40 m | 5G millimeter yoj zaus band, tsis tshua muaj txheej txheej txheej |
| 77 GHz ua | Txog 0.24 m | Lub tsheb mounted radar zaus band, tsis tshua muaj siab rau qhov chaw |
2, Kev cuam tshuam ntawm ENIG ntawm cov teeb liab
Qauv thiab Txoj Cai
Cov qauv ntawm cov txheej txheem kub deposition yog: tooj liab nto + nickel txheej (3-5 μ m) + kub txheej (0.05 ~ 0.15 μ m). Cov txheej kub yog nyias nyias, thiab lub cev tseem ceeb yog cov nickel txheej.
Teeb liab cuam tshuam kev tsom xam
1. Qhov tseem ceeb nce hauv siab - zaus poob
Lub resistivity ntawm npib tsib xee yog ntau tshaj plaub npaug ntawm tooj liab, thiab lub thickness ntawm cov npib tsib xee txheej (3-5 μ m) yog ntau dua li ntawm daim tawv nqaij qhov tob ntawm 10 GHz (0.66 μ m)
High zaus tam sim no propagate yuav luag tag nrho nyob rau hauv lub nickel txheej, ntau dua li tooj liab txheej
Raws li kev ntsuam xyuas kev lag luam, ENIG nce poob los ntawm kwv yees li 19.3% piv rau liab qab tooj liab ntawm 10 GHz; Nce los ntawm kwv yees li 25.1% ntawm 20 GHz
Ntawm 28 GHz zaus band, ENIG tuaj yeem ua kom pom qhov poob ntxiv ntawm kwv yees li 0.06-0.15 dB / cm piv rau liab qab tooj liab
2. Lub℃ntawm kev cuam tshuam nyob ntawm lub thickness ntawm cov nickel txheej
Cov txheej npib tsib xee tau nce los ntawm 3 μm mus rau 6 μ m, ua rau muaj kev nce ntawm kwv yees li 15% hauv cov teeb liab poob
Cov txheej kub tau nce los ntawm 0.03 μ m mus rau 0.1 μ m, thiab qhov poob tau nce li ntawm 5% (qhov cuam tshuam tsawg dua li ntawm cov nickel txheej)
3. Lwm yam txaus ntshai
Dub solder ncoo txaus ntshai: corrosion thiab oxidation ntawm nickel txheej, tsis tshua muaj neeg kho tshuab lub zog ntawm cov pob qij txha
Lub roughness ntawm nickel txheej yog qhov siab, ntxiv rau txoj kev impedance thiab kev xav
Applicability Ciam teb
Thaum qhov kev khiav hauj lwm zaus qis dua 10 GHz thiab cov peev nyiaj poob qis, cov nqi sib tw -kev ua tau zoo yog siab
Cov xwm txheej uas xav tau ntev - lub sijhawm khaws cia (tshaj 12 lub hlis) thiab kho ntau yam
millimeter wave frequencies saum 20 GHz tsis pom zoo
3, Kev cuam tshuam ntawm Immersion Silver ntawm cov cim
Qauv thiab Txoj Cai
Sinking silver deposits ib txheej nyias nyias ntawm cov nyiaj ntshiab ntawm tooj liab nto los ntawm kev hloov pauv cov tshuaj tiv thaiv, nrog ib tug tuab feem ntau ntawm 0.1 mus rau 0.3 μ m.
Teeb liab cuam tshuam kev tsom xam
1. Kev ua tau zoo siab - zaus ua haujlwm
Lub resistivity ntawm cov nyiaj (1.59 μ Ω· cm) yog me ntsis qis dua tooj liab, ua rau nws cov hlau conductive tshaj plaws ntawm tag nrho cov hlau.
Lub thickness ntawm cov nyiaj txheej (0.1 ~ 0.3 μ m) yog thinner piv rau cov tawv nqaij qhov tob ntawm 10 GHz (0.66 μ m), thiab siab - zaus tam sim no tseem tuaj yeem nkag mus rau txheej tooj liab zoo.
Qhov kev poob ntxiv yog yuav luag tsis saib xyuas thiab yog cov txheej txheem kho mob zoo tshaj plaws rau siab - zaus cov cim
2. Zoo nto flatness
Qhov saum npoo ntawm cov nyiaj txheej yog ntom thiab du, txo qhov tawg tawg los ntawm roughness
Hauv millimeter yoj zaus band (tshaj 30 GHz), cov txiaj ntsig ntawm flatness yog qhov tseem ceeb.
Kev Sib Tw Kev Ntseeg (Tus Nqi)
1. Nyiaj Migration
Nyob rau hauv high humidity thiab bias ib puag ncig, nyiaj ions migrate raws PCB nto los tsim dendritic crystals
Kev xau lossis txawm tias luv luv yuav tshwm sim ntawm cov ntaub qhwv ntsej muag nrog qhov sib nrug zoo (tsawg dua lossis sib npaug li 0.5 hli)
High zaus sib txawv khub los yog microstrip kab muaj kev cuam tshuam tshwj xeeb
2. Sulfurization thiab oxidation
Cov rhiab heev rau sulfides, tuaj yeem hloov xim tom qab raug cua rau ob peb teev
Muaj feem cuam tshuam rau weldability thiab tiv thaiv kev ruaj ntseg
nruj nreem kaw lub ntim thiab tswj lub sij hawm raug ua ntej siv lub thaj
3. Lub neej luv luv
Feem ntau tsuas yog 6-12 lub hlis, qis dua qhov ntau tshaj 12 lub hlis ntawm immersion kub
Applicability Ciam teb
RF zaus siab tshaj 10 GHz, 5G millimeter yoj, radar, satellite kev sib txuas lus
Kev kub ceev teeb liab txuas uas yuav tsum tau tsis tshua muaj qhov ntxig poob
Siv ceev faj nyob rau hauv cov av noo, sab nraum zoov, thiab kev lag luam ib puag ncig (yuav tsum tau peb cov ntaub ntawv pov thawj xim thiab nce qhov sib txawv)
Cov khoom khaws cia ntev
4, Kev cuam tshuam ntawm Immersion Tin ntawm cov cim
Qauv thiab Txoj Cai
Deposition ntawm ntshiab tin txheej ntawm tooj liab nto, feem ntau nrog ib tug tuab ntawm 0.8-1.2 μ m.
Teeb liab cuam tshuam kev tsom xam
1. Qhov siab - zaus poob yog qhov loj dua qhov nyiaj tso nyiaj
Lub resistivity ntawm tin yog 6.4 npaug ntawm tooj liab (11.0 × 10 ⁻⁸Ω· m)
Lub thickness ntawm cov tin txheej (0.8 ~ 1.2 μ m) mus txog los yog tshaj ntawm daim tawv nqaij qhov tob (0.66 μ m) ntawm 10 GHz
High zaus tam sim no mas propagates nyob rau hauv lub siab kuj tin txheej, nrog rau qhov tseem ceeb insertion poob
2. Flatness kom zoo dua (qhov tseem ceeb nkaus xwb)
Qhov saum npoo ntawm cov tin deposited yog heev du, thiab roughness poob ntawm tus neeg xyuas pib yog me me
Qhov kom zoo dua no yuav tsum muaj qhov tseem ceeb tshaj nyob rau hauv millimeter yoj zaus band, tab sis nws tau offset los ntawm lub siab resistivity ntawm tin nws tus kheej
Kev Sib Tw Kev Ntseeg
1. Tin Whisker Loj hlob
Thaum lub sij hawm kev ntxhov siab tso tawm txheej txheem ntawm tin txheej, micrometer me me koob zoo li whiskers spontaneously loj hlob
Qhov sib nrug me me ntawm cov ntaub qhwv tuaj yeem ua rau luv luv luv
Lub sij hawm ntev kev hem thawj rau siab -frequency impedance sib xws
2. IMC txheej kev loj hlob
Copper tin intermetallic compounds (Cu ₆ Sn ₅, thiab lwm yam) tseem loj hlob txawm nyob rau hauv chav tsev kub.
Lub resistivity ntawm IMC yog ntau dua li cov ntshiab tin, thiab nws nce nrog kev laus
Qhov nce qeeb hauv kev tiv thaiv tsis tuaj yeem lees txais rau RF pem hauv ntej-kawg cov khoom siv uas yuav tsum tau muaj kev ruaj ntseg theem siab
3. Tsawg cia lub neej
Lub sij hawm ntev cia yog oxidation thiab discoloration
Applicability Ciam teb
Kev siv tsawg zaus qis dua 10 GHz
Scenarios uas yuav tsum tau siab rau flatness thiab solder compatibility, xws li automotive electronics thiab industrial tswj boards
Tsis pom zoo rau RF / millimeter wave scenarios
Cov ntawv thov uas xav tau cov theem siab ruaj khov
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6, Cov Lus Qhia Txog Kev Txiav Txim Siab
Xaiv los ntawm daim ntawv thov scenario
1. Millimeter wave/ultra-high frequency (>20 GHz, xws li 5G millimeter yoj, 77G radar)Nyiam: Silver immersion - nrog qhov qis tshaj siab - zaus poob thiab qhov ua tau zoo tshaj plaws hluav taws xob
Kev txhawb nqa kev ntsuas: lub tshuab nqus tsev ntim ntim, tswj lub sijhawm cuam tshuam ua ntej patching, daim ntawv thov ntawm peb cov pov thawj xim kom txo cov nyiaj tsiv teb tsaws
Yog tias cov txheej txheem sib dhos muaj peev xwm tswj tau muaj zog, OSP yog qhov kawg uas tsis tshua muaj kev xaiv (tab sis muaj lub sijhawm cia luv luv thiab tsis tiv taus ntau qhov rov qab)
2. High zaus RF (5-20 GHz, xws li 5G Sub-6G, WiFi 6E)
Thawj qhov kev xaiv: Sinking silver - kev ua tau zoo, thaum tseem xav txog weldability
Lwm txoj kev: Sinking kub (thaum cov nyiaj poob qis txaus), ua tib zoo saib xyuas cov thickness ntawm cov nickel txheej hauv 3-4 μ m
3. Nruab nrab qis zaus (<5 GHz)+high reliability requirements
Thawj qhov kev xaiv: Sinking kub - muaj zog oxidation tsis kam, lub neej ntev cia, ruaj khov vuam
Yog tias tus nqi rhiab heev: Tin deposition (saib qhov kev pheej hmoo ntawm tin whiskers thiab ci kom txo tau kev ntxhov siab)
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4. Cov xwm txheej xws li automotive radar uas yuav tsum tau rigidity rau flatnessTin deposition + ci txheej txheem kev ntxhov siab - qhov zoo tshaj plaws flatness, tab sis nruj tswj ntawm tin whiskers thiab IMC kev loj hlob yog yuav tsum tau
Ib qho tseem ceeb ntxiv: Tsis txhob las mees qhov roughness ntawm tooj liab ntawv ci
Txawm hais tias qhov kev kho deg twg raug xaiv, qhov roughness ntawm cov ntawv hauv qab tooj liab feem ntau muaj kev cuam tshuam ntau dua rau siab - zaus poob ntau dua li kev kho saum npoo nws tus kheej:Ntawm cov zaus siab, qhov sib txawv ntawm tus neeg xyuas pib poob los ntawm qhov sib txawv ntawm qhov sib txawv tuaj yeem ncav cuag 0.3 ~ 0.5 dB / nch
High zaus boards yuav tsum tau ua ke nrog VLP / HVLP tsawg roughness tooj liab foils thiab tsim ua ke nrog cov txheej txheem kho deg
Cov txheej txheem micro etching yav dhau los kuj tseem tuaj yeem cuam tshuam rau qhov kawg ntawm qhov roughness, thiab kev sib txuas lus meej nrog lub rooj tsavxwm Hoobkas yuav tsum
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