Nyob rau hauv lub hnub nyoog ntawm cov ntaub ntawv ceev ceev, qhov ceev thiab kev cia siab ntawm cov ntaub ntawv kis tau tus mob yog lub neej ntawm cov khoom siv technology. Txawm hais tias nws yog daim npav duab xa tawm kaum tawm gigabits ib ob, cov servers ua kom siab - nrawm sib txuas, lossis sai sai no -rau -be-nrov 5G / 6G cov khoom siv sib txuas lus, ib qho ntawm lawv cov pob zeb tseem ceeb yog cov qauv tsim kom zoo, siab -PCB ceev luam tawm). Nws tsis yog ib qho yooj yim xaim txuas ntxiv lawm; nws yog ib txoj kev loj uas muaj siab - zaus cov cim. Nws tsim ncaj qha txiav txim siab qhov kev ua tau zoo qab nthab ntawm tag nrho cov system.
I. Core Challenge: Thaum Cov Hlau Tsis Muaj Cov Hlau Ntau Lawm
Hauv ib txwm qis-ntau zaus PCB tsim, cov xov hlau tuaj yeem suav tias yog cov neeg siv hluav taws xob zoo tshaj plaws, tso cai rau cov teeb liab hla yuav luag tam sim ntawd. Txawm li cas los xij, nyob rau hauv qhov siab - nrawm nrawm (feem ntau yog xa mus rau lub sijhawm nce lub sijhawm hauv nanosecond lossis txawm tias picosecond ntau), PCB cov kab mob nthuav tawm cov yam ntxwv "hloov kab" nyuaj. Cov teeb meem tseem ceeb suav nrog:
Cov Teeb Meem Kev Ncaj Ncees (SI): Siab -frequency signals muaj kev cuam tshuam, distortion, thiab attenuation hauv cov kab sib kis. Impedance discontinuities (xws li tam sim no kab dav hloov, vias, thiab connectors) tuaj yeem ua rau qee lub teeb liab lub zog los cuam tshuam rov qab mus rau qhov chaw, cuam tshuam cov waveform thiab ua rau muaj qhov yuam kev.
Lub Hwj Chim Kev Ncaj Ncees (PI): Siab - cov chips ceev yuav tsum muaj cov tam sim no loj heev thaum hloov. Yog tias lub zog faib hluav taws xob (PDN) tsis teb tam sim ntawd, nws tuaj yeem ua rau lub zog hloov hluav taws xob hloov pauv (suab nrov), zoo li lub tsheb thauj mus los, cuam tshuam ncaj qha rau cov teeb liab zoo thiab txawm tias ua rau nti ua haujlwm tsis zoo.
Electromagnetic cuam tshuam (EMI): Cov hluav taws xob hloov pauv tau tsim hluav taws xob hluav taws xob, uas tuaj yeem tsis tsuas cuam tshuam nrog lwm cov circuits hauv lub rooj tsavxwm tab sis kuj tseem ua rau lub cuab yeej ua tsis tau daim ntawv pov thawj electromagnetic compatibility. Tsis tas li ntawd, kev cuam tshuam sab nraud tuaj yeem cuam tshuam rau qhov siab siab - cov cim ceev.
Poob: Raws li qhov zaus nce, tus neeg xyuas pib poob (vim cov nyhuv ntawm daim tawv nqaij) thiab dielectric poob (vim cov yam ntxwv ntawm cov khoom siv PCB) nce ntau, ua rau lub teeb liab amplitude attenuation thiab txwv kev sib kis deb.
II. Tsim Qhov Tseem Ceeb: Los ntawm "Kev Sib Txuas" mus rau "Control"
Txhawm rau daws cov teeb meem no, lub hom phiaj ntawm siab -kev tsim PCB ceev tau hloov pauv los ntawm kev ua tiav kev sib txuas hluav taws xob mus rau kev tswj cov teeb liab, lub zog, thiab tus cwj pwm electromagnetic. Cov ntsiab lus tseem ceeb ntawm kev tsim qauv yog raws li hauv qab no:
Kev tswj hwm impedance yog qhov tseem ceeb: Kev tuav tus yam ntxwv tsis tu ncua impedance (xws li 50Ω rau ib zaug - xaus circuits thiab 100Ω rau qhov sib txawv circuits) hauv txoj kev teeb liab yog qhov tseem ceeb. Qhov no yuav tsum tau muab xam thiab tswj cov kab dav dav, dielectric thickness, thiab cov dielectric tas li ntawm cov khoom siv hauv lub rooj tsavxwm, thiab kev siv nruj heev thaum tsim khoom.
Stacking lub tswv yim thiab cov dav hlau siv: Siv cov txheej txheem ntau txheej txheej tsim los muab lub dav hlau ua tiav, tsis sib faib (feem ntau yog lub dav hlau hauv av lossis lub dav hlau fais fab) rau siab - cov cim ceev. Qhov no tsis yog tsuas yog muab kev tswj hwm impedance rov qab txoj hauv kev rau cov kab sib kis, tab sis kuj tsim lub hauv paus rau kev tiv thaiv zoo thiab ruaj khov zog.
Kev taw qhia sib txawv thiab sib npaug -ntev routing: Rau siab dua- cov cim ceev (xws li PCIe, USB, thiab DDR), qhov sib txawv ntawm kev sib kis yog feem ntau siv. Qhov no ua rau muaj txiaj ntsig zoo tshaj - hom suab nrov thiab txo EMI. Qhov ntev ntawm cov kab nyob rau hauv cov khub sib txawv yuav tsum nruj me ntsis sib npaug (sib npaug ntev) kom ntseeg tau tias cov teeb liab sib npaug tuaj txog thiab zam lub sijhawm yuam kev.
Ceev faj los ntawm kev tuav: Vias yog qhov tseem ceeb ntawm kev sib txuas ntawm interlayer, tab sis lawv tuaj yeem qhia txog kev cuam tshuam ntawm impedance thiab teeb liab cuam tshuam. Rau qhov tseem ceeb siab - cov cim ceev ceev, cov txheej txheem siab heev xws li backdrilling thiab dig muag / faus vias yuav tsum tau txo qis kev cuam tshuam ntawm cov stubs thiab tswj lawv tus lej.
Fais Fais Fais Fais Fab (PDN) Decoupling: Decoupling capacitors ntawm qhov sib txawv capacitance yog cov tswv yim muab tso rau ze ntawm lub nti lub hwj chim pins los ua ib tug "reservoir" uas muab cov nti nrog ruaj khov tam sim no nyob rau hauv tag nrho cov ntau zaus, los ntawm tsawg mus rau high zaus. Optimizing tus tsim ntawm lub dav hlau fais fab kuj tseem ceeb heev.
Kev xaiv cov khoom: Ordinary FR-4 cov ntaub ntawv pov thawj poob siab ntawm cov zaus siab. Rau ultra- siab- daim ntawv thov ceev tshaj 10 Gbps, tshwj xeeb qis- poob (Low-Df) laminates, xws li Rogers thiab Taconic, feem ntau xav tau. Txawm tias kim dua, cov ntaub ntawv no yog qhov tseem ceeb rau kev ua kom lub teeb pom kev zoo.
3. Simulation Ua ntej: Npaj cov teeb meem ua ntej kev tsim khoom
Niaj hnub nimno siab -ceev PCB tsim cia siab rau cov cuab yeej simulation muaj zog. Cov neeg tsim qauv ua haujlwm nruj SI / PI / EMI simulations ua ntej thiab tom qab layout thiab routing los kwv yees cov teeb liab qhov muag daim duab, lub hwj chim mov suab nrov, thiab hluav taws xob kev ua tau zoo. Los ntawm kev rov ua kom zoo dua qub, cov teeb meem muaj peev xwm tuaj yeem daws tau ua ntej lub rooj tsav xwm kos duab txawm tias npaj tau, zam kom tsis txhob raug nqi ntau dua ntawm cov ntaub ntawv pov thawj- ntawm- kev tsim kho thiab kev debugging, thiab ua kom lub voj voog R&D luv.
Xaus
High -Kev xa xov hluav taws xob ceev PCB tsim yog ib qho kev kos duab uas muaj kev sib txuas ntawm electromagnetic field theory, microwave engineering, thiab material science. Nws yuav tsum tau engineers kom muaj kev xav thiab ua tib zoo npaj txhua yam ntawm no "cov ntaub ntawv superhighway." Raws li cov ntaub ntawv tus nqi nce mus rau 112Gbps thiab dhau mus, cov kev xav tau rau PCB tsim yuav dhau los ua nruj zuj zus, tsis tu ncua tsav tsheb tshiab thiab kev tawg ntawm cov ntaub ntawv, txheej txheem, thiab cov qauv tsim.