In high-speed HDI PCB design, nge design kuyisici esibalulekile. Iqukethe imbobo, indawo ye-pad ezungeze umgodi, kanye nendawo ehlukanisiwe ye-POWER layer, evame ukuhlukaniswa ngezinhlobo ezintathu: izimbobo ezingaboni, izimbobo ezigqitshiwe kanye nezimbobo. Enqubweni yokuklama ye-PCB, ngokuhlaziywa kwe-parasitic capacitance kanye ne-parasitic inductance ye-vias, ezinye izinyathelo zokuqapha ekwakhiweni kwe-PCB ngesivinini esikhulu ziyafingqwa.

Njengamanje, idizayini ye-PCB enesivinini esikhulu isetshenziswa kabanzi kwezokuxhumana, amakhompiyutha, ihluzo nokucubungula izithombe neminye imikhakha. Yonke imiklamo yemikhiqizo ye-elekthronikhi ene-value ephezulu yobuchwepheshe obuphezulu ilandela izici ezifana nokusetshenziswa kwamandla okuphansi, imisebe ye-electromagnetic ephansi, ukwethembeka okuphezulu, i-miniaturization, nesisindo esincane. Ukuze kuzuzwe lezi zinhloso ezingenhla, ngokuklama kuyisici esibalulekile ekwakhiweni kwe-PCB enesivinini esikhulu.

1. Nge
I-Via iyisici esibalulekile ekwakhiweni kwe-PCB enezingqimba eziningi. A via ngokuyinhloko yakhiwa izingxenye ezintathu, eyodwa imbobo; enye indawo yephedi ezungeze umgodi; kanti eyesithathu indawo eyedwa yongqimba lwaMANDLA. Inqubo ye- via hole iwukuba ucwebezelise ungqimba lwensimbi endaweni eyicylindrical yodonga lwembobo yembobo ngokufaka amakhemikhali ukuxhuma ucwecwe lwethusi oludinga ukuxhunywa kuzendlalelo ezimaphakathi, kanye nezinhlangothi ezingaphezulu nezingezansi i-via hole yenziwe ibe amaphedi ajwayelekile Ukuma kungaxhunyaniswa ngokuqondile nemigqa ezinhlangothini ezingenhla nezingezansi, noma zingaxhunywanga. I-Vias ingadlala indima yokuxhuma ugesi, ukulungisa noma ukubeka amadivaysi.

Ama-Vias ngokuvamile ahlukaniswe izigaba ezintathu: imigodi eyimpumputhe, imigodi egqitshiwe kanye nemigodi.

Izimbobo eziyizimpumputhe zitholakala phezulu nangaphansi kwebhodi lesifunda eliphrintiwe futhi zinokujula okuthile. Zisetshenziselwa ukuxhuma umugqa ongaphezulu kanye nomugqa wangaphakathi ongaphansi. Ukujula komgodi nobubanzi bomgodi ngokuvamile akudluli isilinganiso esithile.

Imbobo engcwatshiwe ibhekisela emgodini wokuxhuma otholakala engxenyeni yangaphakathi yebhodi lesifunda eliphrintiwe, elingadluleli ebusweni bebhodi lesifunda.

I-vias eyimpumputhe kanye ne-vias engcwatshwe zombili zitholakala kungqimba lwangaphakathi lwebhodi lesifunda, eliphothulwa ngenqubo yokubumba imbobo ngaphambi kokuba i-lamination, futhi izingqimba eziningana zangaphakathi zingase zigqitshwe ngesikhathi sokwakhiwa kwe-vias.

Ngezimbobo, ezidlula kulo lonke ibhodi lesifunda, zingasetshenziselwa ukuxhumana kwangaphakathi noma njengembobo yokubeka ingxenye. Njengoba ngokusebenzisa izimbobo kulula ukuqalisa inqubo kanye nezindleko eziphansi, ngokuvamile ephrintiwe amabhodi wesifunda asebenzisa ngokusebenzisa izimbobo.

2. I-Parasitic capacitance ye-vias
I-via ngokwayo inamandla e-parasitic phansi. Uma ububanzi bembobo ehlukanisiwe kungqimba lomhlabathi lwe-via kungu-D2, ububanzi be-via pad ngu-D1, ubukhulu be-PCB bungu-T, futhi i-dielectric constant ye-substrate yebhodi ingu-ε, khona-ke amandla e-parasitic i-via ifana ne:

C =1.41εTD1/(D2-D1)

Umthelela oyinhloko we-parasitic capacitance ye- via hole kusekethe ukunweba isikhathi sokukhuphuka kwesignali nokunciphisa isivinini sesekhethi. I-capacitance value encane, umphumela uba mncane.

3. I-Parasitic inductance ye-vias
I-via ngokwayo ine-parasitic inductance. Eklanyweni yamasekhethi edijithali anesivinini esikhulu, umonakalo odalwe i-parasitic inductance ye-via ngokuvamile mkhulu kunethonya lamandla e-parasitic. Uchungechunge lwe-parasitic inductance ye-via luzokwenza buthaka umsebenzi we-bypass capacitor futhi lwenze buthaka umphumela wokuhlunga walo lonke uhlelo lwamandla. Uma u-L ebhekisela ekungeneni kwe-via, u-h ubude be-via, futhi u-d uwububanzi bembobo emaphakathi, ukungeniswa kwe-via kufana nokuthi:

L=5.08h［ln(4h/d) 1］

Kungabonakala kufomula ukuthi ububanzi be-via bunomthelela omncane ku-inductance, futhi ubude be-via bunomthelela omkhulu ku-inductance.

4. Ukungadlulisi ngokusebenzisa ubuchwepheshe
Ama-vias angadlulisi ahlanganisa ama- blind vias kanye nama- vias angcwatshwa.

Ku-non-through ngokusebenzisa ubuchwepheshe, ukusetshenziswa kwe-vias eyimpumputhe kanye nama-vias angcwatshwe kunganciphisa kakhulu usayizi nekhwalithi ye-PCB, kunciphise inani lezendlalelo, kuthuthukise ukuhambisana kwe-electromagnetic, kwandise izici zemikhiqizo ye-elekthronikhi, kunciphise izindleko, futhi umsebenzi wokuklama Ulula futhi uyashesha. Ekwakhiweni nasekusetshenzisweni kwe-PCB yendabuko, ngokusebenzisa izimbobo kungaletha izinkinga eziningi. Okokuqala, athatha indawo enkulu yesikhala esisebenzayo, futhi okwesibili, inqwaba yezimbobo zigcwele endaweni eyodwa, okudala isithiyo esikhulu ku-wiring yongqimba yangaphakathi ye-PCB ye-multilayer. Lezi zimbobo zithatha isikhala esidingekayo ukuze kufakwe izintambo, futhi zidlula ngamandla kugesi naphansi. Ingaphezulu lesendlalelo socingo lizophinde licekele phansi izici zokuthibela zesendlalelo sentambo yaphansi yamandla futhi kwenze isendlalelo sentambo yamandla ephansi singasebenzi. Futhi indlela evamile yomshini wokumba izoba izikhathi ezingu-20 kunomsebenzi wobuchwepheshe obungewona umgodi.

Ekwakhiweni kwe-PCB, nakuba ubukhulu bamapads kanye ne-vias buye bancipha kancane kancane, uma ukushuba kongqimba lwebhodi bungancishiswa ngokulinganayo, isilinganiso se-aspect ratio ye- through hole sizokhula, futhi ukwanda kwe-aspect ratio ye- through hole kuzonciphisa. ukwethembeka. Ngokuvuthwa kobuchwepheshe be-laser drilling obuthuthukisiwe kanye nobuchwepheshe bokufaka okomile kwe-plasma, kungenzeka ukusebenzisa izimbobo ezincane eziyizimpumputhe ezingangeni kanye nezimbobo ezincane ezingcwatshiwe. Uma ububanzi balawa ma-vias angangeni bungu-0.3mm, imingcele ye-parasitic izoba Mayelana ne-1/10 yembobo yasekuqaleni evamile, okuthuthukisa ukwethembeka kwe-PCB.

Ngenxa yokungadlulisi ngokusebenzisa ubuchwepheshe, kukhona ama-vias amakhulu ambalwa ku-PCB, anganikeza isikhala esiningi sokulandela umkhondo. Isikhala esisele singasetshenziselwa izinjongo zokuvikela indawo enkulu ukuze kuthuthukiswe ukusebenza kwe-EMI/RFI. Ngesikhathi esifanayo, isikhala esiningi esisele singasetshenziswa ukuze ungqimba lwangaphakathi luvikele kancane idivayisi kanye nezintambo ezibalulekile zenethiwekhi, ukuze zibe nokusebenza okuhle kakhulu kukagesi. Ukusetshenziswa kwe-vias engadluli kwenza kube lula ukukhipha izikhonkwane zedivayisi, okwenza kube lula ukusebenzisa amaphinikhodi asondelene kakhulu (njengamadivayisi apakishwe e-BGA), ukunciphisa ubude bezintambo, kanye nokuhlangabezana nezidingo zesikhathi zamasekhethi anesivinini esikhulu. .

5. Ngokukhetha ku-PCB evamile
Ekwakhiweni okuvamile kwe-PCB, amandla e-parasitic kanye ne-parasitic inductance ye- via anomthelela omncane ekwakhiweni kwe-PCB. Ngomklamo we-PCB wengqimba engu-1-4, 0.36mm/0.61mm/1.02mm (indawo yokuhlukanisa imbobo/iphedi/AMAMANDLA ngokuvamile ikhethwa) ) I-Vias ingcono. Olayini besignali abanezidingo ezikhethekile (njengezintambo zikagesi, izintambo zaphansi, izintambo zewashi, njll.), 0.41mm/0.81mm/1.32mm vias zingasetshenziswa, noma ama-vias obunye osayizi angakhethwa kuye ngokwesimo sangempela.

6. Ngokuklama ku-PCB enesivinini esikhulu
Ngokuhlaziywa okungenhla kwezici ze-vias, singabona ukuthi ekwakhiweni kwe-PCB enesivinini esikhulu, ama-vias abonakala elula ngokuvamile aletha imiphumela emibi kakhulu ekwakhiweni kwesifunda. Ukuze unciphise imiphumela emibi ebangelwa imiphumela ye-parasitic ye-vias, okulandelayo kungenziwa ekwakhiweni:

(1) Khetha okunengqondo ngosayizi. Ekwakheni i-PCB enezingqimba eziningi ezijwayelekile, kungcono ukusebenzisa u-0.25mm/0.51mm/0.91mm (izimbobo ezibhobhile/amaphedi/Indawo yokuhlukanisa AMANDLA) ngokusebenzisa; kwamanye ama-PCB anobukhulu obukhulu, i-0.20mm/0.46 ingasetshenziswa nge-mm/0.86mm nge-vias, ungaphinda uzame ukudlula okungadluli; ukuze uthole amandla noma i-vias yomhlabathi, ungacabangela ukusebenzisa usayizi omkhulu ukuze unciphise i-impedance;

(2) Uma inkulu indawo ehlukanisiwe YAMANDLA, iba ngcono, uma kucatshangelwa ukuminyana ku-PCB, ngokuvamile okuthi D1=D2 0.41;

(3) Zama ukungaguquki izingqimba zezimpawu zesignali ku-PCB, okusho ukunciphisa i-vias;

(4) Ukusetshenziswa kwe-PCB ezacile kusiza ekwehliseni amapharamitha amabili e-parasitic we-via;

(5) Amandla nezikhonkwane zomhlabathi kufanele zenziwe ngezimbobo eziseduze. Ukuthi umthofi omfushane phakathi kwe- via hole nephini, kuba ngcono, ngoba azokwandisa i-inductance. Ngesikhathi esifanayo, amandla kanye nemikhondo yomhlabathi kufanele ibe nkulu ngangokunokwenzeka ukuze kuncishiswe i-impedance;

(6) Beka ama-vias aphansi eduze kwe-vias yongqimba lwesignali ukuze unikeze iluphu yebanga elifushane yesiginali.

Yebo, izindaba ezithile zidinga ukucutshungulwa ngokuningiliziwe lapho kuklanywa. Uma kucatshangelwa kokubili izindleko kanye nekhwalithi yesiginali ngokugcwele, ekwakhiweni kwe-PCB enesivinini esikhulu, abaklami bahlale bethemba ukuthi i- via hole ibancane, kungcono, ukuze kushiywe isikhala esengeziwe sezintambo ebhodini. Ngaphezu kwalokho, i-via hole encane, eyayo I-capacitance encane ye-parasitic, ifaneleka kakhulu kumasekhethi anesivinini esikhulu. Ekwakhiweni kwe-PCB enokuminyana okuphezulu, ukusetshenziswa kwama-vias okungadluli kanye nokuncipha kosayizi we-vias nakho kubangele ukwanda kwezindleko, futhi ubukhulu be-vias abukwazi ukuncishiswa unomphela. Ithintwa izinqubo zokubhoboza kanye ne-electroplating yabakhiqizi be-PCB. Imikhawulo yobuchwepheshe kufanele icatshangwe ngokulinganayo ekwakhekeni kwama-PCB anesivinini esikhulu.