Lub tshuab hluav taws xob laser diode, hom uas siv lub tshuab txiav laser lossis cov cuab yeej kho mob, ua kom muaj cua sov zoo kawg los ntawm thaj chaw microscopic nti. Qhov kub siab, tsom ntsoov rau qhov kub yuav tsum tau nthuav tawm sai thiab sib npaug, lossis lub nti yuav ua kom puas nws tus kheej hauv ib feem ntawm ib pliag. Tooj liab yog cov khoom siv hluav taws xob zoo tshaj plaws, tab sis rau cov ntawv thov huab cua no, txawm tias tooj liab tsis nrawm txaus. Qhov kev daws teeb meem kawg yog lub tshuab hluav taws xob ua kom sov ua los ntawm cov khoom siv hluavtaws, cov pob zeb dawb huv- cov khoom siv hluav taws xob ua kom sov zoo dua li lwm yam hauv ntiaj teb.
Thermal Management Challenge nyob rau hauv High-Power Laser Diodes
Lub laser diode ua haujlwm nrog cov hluav taws xob tam sim no muaj zog heev nyob rau thaj tsam nquag feem ntau me dua 100 µm × 1 mm. Cov hluav taws xob pov tseg uas tsim los ntawm qhov chaw me me no tuaj yeem tshaj 1 kW / cm². Yog tias tsis muaj qhov sib kis tau zoo heev, qhov kub ntawm qhov sib txuas tau nce siab tshaj qhov ntsuas qhov siab tshaj plaws (feem ntau yog 50-85℃rau kev ua haujlwm nthwv dej tas li), ua rau muaj kev hloov pauv, lub zog yob tawm, thiab kev puas tsuaj rau qhov muag pom tshwm sim.
Lub tshuab hluav taws xob cua sov- tseem hu ua sub-mount lossis platen (chuck) uas tuav lub laser diode- yuav tsum ua ob txoj haujlwm ib txhij:
Tshaj tawm cua sov tom qablos ntawm microscopic kub qhov chaw mus rau thaj chaw loj dua qhov uas nws tuaj yeem raug tshem tawm los ntawm lub thermoelectric txias los yog dej-txias txias phaj.
Hluav taws xob caislub laser diode cov hluav taws xob tiv tauj los ntawm grounded platen, vim hais tias feem ntau laser diodes yog hluav taws xob tsav.
Copper tau ntev ua cov khoom siv rau cov khoom siv hluav taws xob vim nws cov thermal conductivity (≈400 W / m·K) thiab yooj yim ntawm fabrication. Txawm li cas los xij, tooj liab yog cov khoom siv hluav taws xob zoo heev thiab yog li ntawd yuav tsum muaj txheej txheej insulating ntxiv (piv txwv li, nyias nyias los yog dielectric txheej) thaum siv los ua platen. Cov txheej ntxiv no qhia txog kev tiv thaiv thermal, negating ib feem ntawm tooj liab kom zoo dua.
CVD Pob zeb diamond ua lub tshav kub Spreader: Cov khoom thiab kev tsim khoom
Chemical Vapor Deposition (CVD) pob zeb diamond yog tsim los ntawm kev loj hlob ntawm polycrystalline los yog ib leeg-crystal pob zeb diamond films los ntawm hydrocarbon-hydrogen plasma mus rau lub substrate. Tom qab kev loj hlob, lub pob zeb diamond txheej raug tshem tawm ntawm lub substrate raws li ib tug dawb-standing phaj, uas yuav polished mus rau ib tug du, tiaj tus nto (Ra < 10 nm) thiab txiav mus rau qhov yuav tsum tau qhov ntev.
Lub thermal conductivity ntawm CVD pob zeb diamond nyob ntawm nws cov crystalline zoo:
Polycrystalline CVD pob zeb diamond- Cov thermal conductivity yog li ntawm 1000 txog 1500 W / m·K, nrog rau qhov muaj nuj nqis nyob ib ncig ntawm 1200–1300 W / m·K yog ib qho ntawm cov khoom siv kho qhov muag. Lub conductivity yog txwv los ntawm phonon scattering ntawm grain ciam teb thiab impurities.
High-quality, isotopically ntshiab CVD pob zeb diamond- Los ntawm kev siv carbon-12 (¹²C) enrichment thiab txo nitrogen thiab boron impurities, thermal conductivities tshaj 2000 W / m·K tau tiav. Qhov no mus txog qhov theoretical txwv ntawm ntuj pob zeb diamond (≈2200 W / m·K ntawm chav tsev kub).
Rau kev sib piv, ntshiab tooj liab (annealed, 99.99%) muaj thermal conductivity ntawm kwv yees li 401 W / m·K ntawm 25 degree. Txawm tias qib qis tshaj plaws CVD pob zeb diamond (≈800 W / m·K) ua tau zoo tshaj tooj liab los ntawm ib qho ntawm ob. Standard polycrystalline CVD pob zeb diamond (1200 W / m·K) yog peb zaug zoo dua tooj liab, thaum isotopically txhim kho pob zeb diamond yog tsib zaug zoo dua.
Kev sib piv ncaj qha: CVD Pob Zeb Diamond vs. Copper Heat Spreader rau Laser Diode Platen
CovCVD pob zeb diamond vs tooj liab tshav kub kis laser diode platenKev ntsuam xyuas muaj ntau yam kev ntsuas kev ua tau zoo tshaj li cov thermal conductivity. Cov lus hauv qab no qhia txog cov kev sib piv tseem ceeb:
| Khoom | Copper (Ntshiab, Annealed) | Polycrystalline CVD pob zeb diamond |
|---|---|---|
| Thermal conductivity (W / m·K) ntawm 25 degree | ≈400 | 1000–1500 (typical); >2000 (isotopically ntshiab) |
| Hluav taws xob tiv taus (Ω·cm) | ≈1.7 × 10⁻⁶ (tus neeg xyuas pib) | >10¹⁴ (insulator) |
| Coefficient ntawm thermal expansion (CTE, ppm / K) | ≈16.5 | ≈1.0–2.5 (nyob ntawm crystallinity) |
| Qhov ceev (g / cm³) | 8.96 | 3.52 |
| Young tus modulus (GPa) | 110–130 | 1000–1200 |
| Fracture toughness (MPa·m¹/²) | ≈80-100 (ductile) | ≈3-5 (ntxuav ceramic) |
| Tus nqi (xws li tooj liab) | 1× | 100–500× |
Pob zeb diamond yog ib qho zoo meej, crystalline txoj kev loj rau cua sov, qhov twg tooj liab tsuas yog txoj kev nrawm, tab sis tsis zoo, txoj kev hlau.
Thermal Spreading Resistance
Ib qho tseem ceeb ntawm kev tsim nyog rau lub tshuab hluav taws xob yog qhov thermal kis tsis kam- qhov kub siab nce vim qhov tsis sib haum ntawm qhov chaw sov me me thiab lub dab dej loj dua. Rau ib square tshav kub qhov chaw ntawm sab ntev �a ntawm ib tug semi-infinite spreader, qhov kis tsis kam ���Rsp yog inversely proportional rau ��⋅�πa⋅k, qhov twg �k yog thermal conductivity. Yog li, ob npaug k halves qhov kev sib kis tsis kam. Rau 1 hli × 0.1 hli laser diode bar, tooj liab kis tau tus mob (k = 400 W/m·K) nthuav tawm kev sib kis tsis zoo li peb zaug siab dua li CVD pob zeb diamond spreader (k = 1200 W/m·K). Qhov no txhais tau ncaj qha rau hauv qhov kub ntawm qhov sib txuas qis dua -feem ntau 20-40℃txias dua rau cov pob zeb diamond spreader nyob rau hauv tib lub txias txias.
Hluav taws xob cais Advantage
Because diamond is an electrical insulator (resistivity >10¹⁴ Ω·cm), CVD pob zeb diamond tshav kub kis tau tuaj yeem tso ncaj qha ntawm lub laser diode cov hluav taws xob tiv tauj thiab cov hlau platen yam tsis muaj txheej txheej dielectric ntxiv. Piv txwv li, tooj liab yuav tsum tau cais cov hluav taws xob insulating txheej (xws li Al₂O₃, AlN, los yog nyias pob zeb diamond zoo li txheej). Cov txheej ntawd ntxiv cov thermal kuj-feem ntau 0.5–2℃·cm²/W- uas txo cov kev ua tau zoo ntawm cov tooj liab kis. CVD pob zeb diamond sib txuas ua ke sib txuas hluav taws xob thiab hluav taws xob sib cais hauv ib qho khoom siv monolithic.
Kev koom ua ke hauv Platen Assembly
Lub CVD pob zeb diamond hluav taws kub tsis yog tsuas yog hloov rau tooj liab siv tib txoj kev txhim kho. Cov khoom siv yog cov tawv tawv, nkig ceramic nrog cov coefficient tsawg heev ntawm thermal expansion (CTE) ntawm kwv yees li 1-2.5 ppm / K, piv rau tooj liab 16.5 ppm / K. Yog hais tias lub pob zeb diamond phaj yog ncaj qha soldered los yog brazed mus rau ib tug tooj liab heatsink, qhov loj CTE mismatch induces siab thermal stresses thaum kub cycling, uas yuav tawg lub pob zeb diamond.
Kev sib koom ua tiav yuav tsum:
Cov khaubncaws sab nraud povtseg- Ib txheej nyias, ua raws (xws li mos kub-tin (AuSn) solder lossis graphite-raws li thermal interface khoom) yog siv los ua kom haum rau kev ntxhov siab. Cov txheej tuab yog khaws cia me me (5-20 µm) kom txo cov thermal tsis kam thaum tso cai rau strain nyem.
Matched CTE heatsinks- Xwb, lub pob zeb diamond spreader txuas nrog lub heatsink ua los ntawm cov khoom siv qis-CTE xws li tooj liab-tungsten (CuW, CTE ≈ 8 ppm / K) lossis tooj liab-molybdenum (CuMo, CTE ≈ 7 ppm / K). Qhov no txo qhov mob ntawm pob zeb diamond.
Metallization- Lub pob zeb diamond nto yog metallized (piv txwv li, nrog Ti / Pt / Au lossis Ti / W / Ni / Au multilayer) kom muaj kev sib tw. Lub metallization yuav tsum ua raws li cov pob zeb diamond, uas yog chemically inert. Carbide-forming hlau (titanium los yog chromium) yog siv los ua thawj txheej.
Thaum tsim tau zoo, CVD pob zeb diamond hluav taws xob muaj sia nyob ntau txhiab lub voj voog thermal yam tsis muaj kev puas tsuaj.
Kev siv tswv yim thiab kev txwv
CVD pob zeb diamond tshav kub kis tau siv rau hauv:
High-power laser diode tuav thiab arraysrau kev lag luam txiav, vuam, thiab siv cov khoom lag luam lasers.
Laser diode modules rau kev sib txuas lus kho qhov muag(telecom thiab datacom) yuav tsum tau nruj wavelength stability.
Kev kho mob laser tshuab(piv txwv li, dermatology, phais) qhov kev ntseeg siab thiab kev ntim khoom yog qhov tseem ceeb.
Xov tooj cua zaus (RF) fais fab transistorsthiab monolithic microwave integrated circuits (MMICs), qhov twg muaj kev sib tw thermal zoo sib xws.
Cov kev txwv ntawm CVD pob zeb diamond suav nrog:
Nqi- Ib qho 10 hli × 10 hli × 0.3 hli CVD pob zeb diamond spreader raug nqi ntau pua las, piv rau ob peb xees rau ib daim tooj liab ntawm tib qhov loj. Yog li ntawd, pob zeb diamond yog tshwj tseg rau cov ntawv thov uas tooj liab tsis tuaj yeem ua tau raws li qhov xav tau thermal.
Fabrication complexity- Txiav, lapping, polishing, thiab metallizing pob zeb diamond xav tau cov cuab yeej tshwj xeeb (laser txiav lossis pob zeb diamond-impregnated sib tsoo cov cuab yeej) thiab kev txawj ntse.
Mechanical fragility- Pob zeb diamond daim hlau yog nkig thiab tuaj yeem tawg los ntawm kev siv tsis raug lossis los ntawm kev quab yuam ntau dhau.
Kev txhim kho yav tom ntej
Kev tshawb fawb txuas ntxiv txo tus nqi ntawm CVD pob zeb diamond los ntawm kev tso nyiaj ntau dua, thaj chaw loj hlob, thiab txhim kho cov txiaj ntsig. Isotopically ntshiab pob zeb diamond (³⁰ C) tseem kim thiab txwv rau kev tshawb fawb, tab sis polycrystalline pob zeb diamond nrog conductivities ntawm 1500-1800 W / m·K tau dhau los ua lag luam. Tsis tas li ntawd, pob zeb diamond-composite heat spreaders (piv txwv li, pob zeb diamond-tooj liab lossis pob zeb diamond-silver composites) tau tsim los ua ke cov pob zeb diamond siab conductivity nrog hlau ductility thiab CTE txuam, txawm hais tias qhov tshwm sim conductivities (600-800 W / m·K) yog qis dua pob zeb diamond.
Xaus
CVD pob zeb diamond yog qhov kawg, tsis muaj kev cuam tshuam cov khoom siv hluav taws xob sib kis, ci ntsa iab, thermally super-conductive siv lead ua uas tawm txawm tias cov hlau zoo tshaj plaws nyob deb, tshwj tseg rau cov tseem ceeb tshaj plaws thermal tswj kev cov nyom. Nrog rau cov thermal conductivity ntau tshaj 1000 W/m·K-thiab feem ntau tshaj 1200 W/m·K hauv qib lag luam-CVD pob zeb diamond outclasses tooj liab los ntawm ib qho ntawm peb lossis ntau dua. Thaum ua ke nrog nws cov hluav taws xob rwb thaiv tsev, pob zeb diamond tshem tawm qhov xav tau rau cov txheej txheem dielectric ntxiv uas txo cov kev ua tau zoo ntawm cov hlau nplaum. Txawm hais tias tus nqi thiab nkig ntawm pob zeb diamond yuav tsum tau ceev faj kev koom ua ke rau hauv lub laser diode platen, qhov ua rau txo qis hauv qhov kub thiab txias ncaj qha txhais mus rau hauv lub zog laser ntau dua, lub neej ntev dua, thiab kev tswj lub wavelength nqaim. Qhov kub tshaj plaws, muaj zog tshaj lasers ntawm lub neej yav tom ntej yuav txias los ntawm lub phaj ntawm ntshiab, hluavtaws pob zeb diamond.
