PCB ukufaka izintambo kubaluleke kakhulu kuwo wonke umklamo we-PCB. Ungafinyelela kanjani izintambo ezisheshayo nezisebenza kahle futhi wenze izintambo zakho ze-PCB zibukeke zinde kufanelekile ukutadisha. Kuhlelwe izici eziyisi-7 ezidinga ukunakwa kuzintambo ze-PCB, futhi uze uzohlola okushiywe futhi ugcwalise izikhala!

1. Ukucubungula okuvamile komhlaba wesekethe yedijithali kanye nesekethe ye-analog

Ama-PCB amaningi awasewona amasekhethi anomsebenzi owodwa (amasekhethi edijithali noma e-analog), kodwa akhiwe ingxube yamasekhethi edijithali nawe-analog. Ngakho-ke, kuyadingeka ukucabangela ukuphazanyiswa phakathi kwabo lapho ufaka izintambo, ikakhulukazi ukuphazamiseka komsindo ocingweni lomhlabathi. Imvamisa yesifunda sedijithali iphezulu, futhi ukuzwela kwesifunda se-analog kunamandla. Kulayini wesignali, ulayini wesignali wemvamisa ephezulu kufanele ube kude ngangokunokwenzeka kusukela kudivayisi yesekethe ye-analog ebucayi. Emgqeni ophansi, yonke i-PCB ine-node eyodwa kuphela emhlabeni wangaphandle, ngakho Inkinga ye-digital ne-analog common ground kumele kubhekwane nayo ngaphakathi kwe-PCB, futhi umhlabathi wedijithali kanye nomhlabathi we-analog ngaphakathi ebhodini empeleni kuhlukanisiwe futhi ahlukene. ayixhumekile kwenye, kodwa kusixhumi esibonakalayo (njengamapulaki, njll.) exhuma i-PCB nomhlaba ongaphandle. Kukhona ukuxhumana okufushane phakathi kwe-digital ground kanye ne-analog ground. Sicela uqaphele ukuthi kunephoyinti elilodwa kuphela lokuxhuma. Kukhona nezizathu ezingezona ezejwayelekile ku-PCB, ezinqunywa ukwakheka kwesistimu.

2. Ulayini wesiginali ubekwe kungqimba kagesi (phansi)

Ku-wiring yebhodi ephrintiwe ye-multi-layer, ngoba azikho izintambo eziningi ezisele kungqimba lomugqa wesignali ezingazange zibekwe, ukwengeza izendlalelo eziningi kuzodala imfucuza futhi kwandise umsebenzi wokukhiqiza, futhi izindleko zizokhula ngokufanele. Ukuze uxazulule lokhu kuphikisana, ungacabangela ukufaka izintambo kungqimba lukagesi (umhlabathi). Ungqimba lwamandla kufanele lucatshangelwe kuqala, futhi ungqimba lomhlabathi lwesibili. Ngoba kungcono kakhulu ukugcina ubuqotho bokwakheka.

3. Ukwelashwa kwemilenze yokuxhuma ku-conductor yendawo enkulu

Ekusekelweni kwendawo enkulu (ugesi), imilenze yezingxenye ezivamile ixhunywe kuyo. Ukwelashwa kwemilenze yokuxhuma kudinga ukucatshangelwa ngokuphelele. Ngokuphathelene nokusebenza kukagesi, kungcono ukuxhuma amaphedi emilenze yengxenye endaweni yethusi. Kunezingozi ezifihlekile ezingafuneki ekushiseleni nasekuhlanganiseni izingxenye, njengokuthi: ① Ukushisela kudinga izifudumezi ezinamandla amakhulu. ②Kulula ukubangela amajoyinti e-solder abonakalayo. Ngakho-ke, kokubili ukusebenza kukagesi kanye nezidingo zenqubo zenziwa amaphedi anephethini ephambene, abizwa ngokuthi izihlangu zokushisa, ngokuvamile ezaziwa ngokuthi ama-thermal pads (Thermal), ukuze amajoyinti e-solder abonakalayo akhiqizwe ngenxa yokushisa okukhulu kwesigaba esiphambanayo ngesikhathi sokudayiswa. Ucansi luncipha kakhulu. Ukucutshungulwa komlenze wamandla (umhlabathi) webhodi le-multilayer kuyafana.

4. Indima yesistimu yenethiwekhi kukhebula

Ezinhlelweni eziningi ze-CAD, izintambo zinqunywa ngokusekelwe ohlelweni lwenethiwekhi. Igridi iminyene kakhulu futhi indlela inyukile, kodwa isinyathelo sincane kakhulu, futhi inani ledatha ensimini likhulu kakhulu. Lokhu nakanjani kuzoba nezidingo eziphakeme zesikhala sokugcina socingo, kanye nesivinini sekhompyutha semikhiqizo ye-elekthronikhi esekelwe kukhompuyutha. Ithonya elikhulu. Ezinye izindlela azivumelekile, njengalezo ezihlala amaphedi emilenze yengxenye noma izimbobo ezifakwayo nezimbobo ezingashintshi. Amagridi amancane kakhulu namashaneli ambalwa kakhulu anomthelela omkhulu esilinganisweni sokusabalalisa. Ngakho-ke kufanele kube nesistimu yegridi enengqondo ukusekela izintambo. Ibanga eliphakathi kwemilenze yezingxenye ezijwayelekile lingu-0.1 amayintshi (2.54 mm), ngakho isisekelo sesistimu yegridi ngokuvamile simiswa ukuze sibe amayintshi angu-0.1 (2.54 mm) noma ukuphindaphinda okuhlanganisiwe okungaphansi kwamayintshi angu-0.1, njengalokhu: amayintshi angu-0.05, 0.025 amayintshi, 0.02 amayintshi njll.

5. Ukwelashwa kokunikezwa kwamandla kanye nocingo oluphansi

Ngisho noma i-wiring ebhodini lonke le-PCB igcwaliswe kahle kakhulu, ukuphazamiseka okubangelwa ukucatshangelwa okungalungile kokunikezwa kwamandla kanye nentambo yomhlabathi kuzonciphisa ukusebenza komkhiqizo, futhi ngezinye izikhathi kuthinte ngisho nezinga lokuphumelela lomkhiqizo. Ngakho-ke, izintambo zikagesi kanye nentambo yaphansi kufanele kuthathwe ngokungathi sína, futhi ukuphazamiseka komsindo okukhiqizwa amandla kagesi kanye nentambo yaphansi kufanele kuncishiswe ukuze kuqinisekiswe ikhwalithi yomkhiqizo. Wonke unjiniyela obambe iqhaza ekwakhiweni kwemikhiqizo ye-elekthronikhi uyayiqonda imbangela yomsindo phakathi kwentambo yaphansi kanye nentambo yamandla, futhi manje kuvezwa kuphela ukuncishiswa komsindo okuncishisiwe: kuyaziwa ngokungeza umsindo phakathi kokunikezwa kwamandla nomhlabathi. ucingo. I-lotus capacitor. Nweba ububanzi bamandla kanye nezintambo zaphansi ngangokunokwenzeka, okungcono intambo yaphansi ibe banzi kunentambo yamandla, ubuhlobo babo buwukuthi: intambo ephansi “yentambo yamandla” yesignali yocingo, ngokuvamile ububanzi bentambo yesiginali buthi: 0.2 ~ 0.3mm, ububanzi obuhle kakhulu bungafinyelela ku-0.05 ～0.07mm, intambo yamandla ingu-1.2–2.5mm. Ku-PCB yesifunda sedijithali, ucingo olubanzi lomhlabathi lungasetshenziswa ukwenza iluphu, okungukuthi, inetha eliphansi lingasetshenziswa (umhlabathi wesifunda se-analog awukwazi ukusetshenziswa ngale ndlela). Indawo enkulu yongqimba lwethusi isetshenziswa njengocingo oluphansi, olungasetshenziswa ebhodini eliphrintiwe. Ixhunywe phansi njengentambo yaphansi kuzo zonke izindawo. Noma ingenziwa ibhodi le-multilayer, futhi amandla kagesi kanye nezintambo zomhlabathi zithatha isendlalelo esisodwa ngasinye.

6. Ukuhlola umthetho wokuklama (i-DRC)

Ngemuva kokuthi umklamo we-wiring usuqediwe, kuyadingeka ukuhlola ngokucophelela ukuthi umklamo we-wiring uhambisana nemithetho eyakhiwe umklami, futhi ngesikhathi esifanayo, kuyadingeka ukuqinisekisa ukuthi imithetho emisiwe ihlangabezana nezidingo zenqubo yokukhiqiza ibhodi ephrintiwe. . Ukuhlola okuvamile kunalezi zici ezilandelayo: umugqa nomugqa, umugqa Ukuthi ngabe ibanga phakathi kwephedi yengxenye, ulayini kanye nembobo, iphedi lengxenye kanye nembobo, kanye nembobo kanye nembobo kunengqondo nokuthi ingabe iyahlangabezana yini nezidingo zokukhiqiza. Ingabe ububanzi bentambo yamandla kanye nentambo yaphansi bufanelekile, futhi ingabe kukhona ukuhlangana okuqinile phakathi kwentambo yamandla kanye nentambo yaphansi (i-low wave impedance)? Ingabe ikhona indawo ku-PCB lapho intambo yaphansi inganwetshwa? Ukuthi kuthathwe izinyathelo ezingcono kakhulu zemigqa yesignali engukhiye, njengobude obufushane kakhulu, ulayini wokuvikela uyengezwa, futhi ulayini wokufaka nolayini ophumayo kuhlukaniswe ngokucacile. Ukuthi kukhona izintambo zaphansi ezihlukene zomjikelezo we-analog kanye nesekhethi yedijithali. Ukuthi ihluzo (njengezimpawu nezichasiselo) ezengezwe ku-PCB zizobangela ukujikeleza okufushane kwesignali. Lungisa ezinye izimo zomugqa ezingathandeki. Ingabe ukhona umugqa wenqubo ku-PCB? Ukuthi imaski ye-solder iyahlangabezana yini nezidingo zenqubo yokukhiqiza, noma ngabe usayizi wemaski we-solder ufanelekile, nokuthi ilogo yezinhlamvu icindezelwe yini kuphedi yedivayisi, ukuze ingaphazamisi ikhwalithi yezinto zikagesi. Kungakhathaliseki ukuthi umkhawulo wefreyimu yangaphandle yesendlalelo somhlaba wamandla ebhodini lezendlalelo eziningi liyancishiswa, uma i-foil yethusi yesendlalelo somhlaba wamandla ivezwa ngaphandle kwebhodi, kulula ukubangela ukujikeleza okufushane.

7. Ngokuklama

I-Via ingenye yezingxenye ezibalulekile ze-PCB enezingqimba eziningi, futhi izindleko zokumba ngokuvamile zibalelwa ku-30% kuya ku-40% wezindleko zokukhiqiza ze-PCB. Kalula nje, yonke imbobo ku-PCB ingabizwa ngokuthi i-via. Ngokombono wokusebenza, i-vias ingahlukaniswa ngezigaba ezimbili: eyodwa isetshenziselwa ukuxhumana kukagesi phakathi kwezingqimba; enye isetshenziselwa ukulungisa noma ukubeka izinto. Ngokwenqubo, ama-vias ngokuvamile ahlukaniswe izigaba ezintathu, okuyizimpumputhe, ama-vias angcwatshwa kanye nama-vias.

Izimbobo eziyizimpumputhe zitholakala phezulu nangaphansi kwebhodi lesifunda eliphrintiwe futhi zinokujula okuthile. Zisetshenziselwa ukuxhuma umugqa ongaphezulu kanye nomugqa wangaphakathi ongaphansi. Ukujula komgodi ngokuvamile akudluli isilinganiso esithile (imbobo). Imbobo engcwatshiwe ibhekisela emgodini wokuxhuma otholakala engxenyeni yangaphakathi yebhodi lesifunda eliphrintiwe, elingadluleli ebusweni bebhodi lesifunda. Lezi zinhlobo ezimbili ezishiwo ngenhla zemigodi zitholakala kungqimba lwangaphakathi lwebhodi lesifunda, futhi zigcwaliswa ngenqubo yokwakhiwa kwembobo ngaphambi kokuba i-lamination, futhi izingqimba eziningana zangaphakathi zingase zigqitshwe ngesikhathi sokwakhiwa kwe-via. Uhlobo lwesithathu lubizwa ngokuthi i- through hole , engena kulo lonke ibhodi lesifunda futhi ingasetshenziselwa ukuxhumana kwangaphakathi noma njengengxenye yokubeka imbobo. Ngenxa yokuthi imbobo yokudlula kulula ukuyibona ohlelweni futhi izindleko ziphansi, isetshenziswa kumabhodi esekethe amaningi aphrintiwe esikhundleni sezinye izinhlobo ezimbili zokudlula izimbobo. Okulandelayo ngezimbobo, ngaphandle uma kucaciswe ngenye indlela, kuthathwa njengokudlula izimbobo.

1. Ngokombono wokuklama, i-via ngokuyinhloko yakhiwe izingxenye ezimbili, enye imbobo yokubhoboza phakathi, kanti enye iyindawo yephedi ezungeze umgodi wokubhoboza. Ubukhulu balezi zingxenye ezimbili bunquma ubukhulu be-via. Ngokusobala, ekwakhiweni kwe-PCB enesivinini esikhulu, enokuminyana okuphezulu, abaklami bahlala bethemba ukuthi i-via hole encane, kungcono, ukuze kushiywe isikhala sezintambo ebhodini. Ngaphezu kwalokho, i-via hole encane, amandla e-parasitic ayo. Uma incane, ifaneleka kakhulu kumasekhethi anesivinini esikhulu. Kodwa-ke, ukuncishiswa kosayizi wembobo nakho kuletha ukwanda kwezindleko, futhi ubukhulu be-vias abukwazi ukuncishiswa unomphela. Ivinjelwa ubuchwepheshe bezinqubo ezifana nokubhola nokucwenga: imbobo encane, ukubhoboza okwengeziwe Uma umgodi uthatha isikhathi eside, kuba lula ukuchezuka endaweni ephakathi; futhi lapho ukujula komgodi kudlula izikhathi ezingu-6 ububanzi bembobo ebhoboziwe, angeke kuqinisekiswe ukuthi udonga lwembobo lungafakwa ngokufanayo ngethusi. Isibonelo, ukujiya (ngokujula kwembobo) kwebhodi le-PCB elinezingqimba ezi-6 ezivamile lilinganiselwa ku-50Mil, ngakho-ke ubukhulu obuncane bokubhoboza obunganikezwa abakhiqizi be-PCB bungafinyelela ku-8Mil kuphela.

Okwesibili, i-parasitic capacitance ye- via hole ngokwayo inamandla e-parasitic phansi. Uma kwaziwa ukuthi ububanzi bembobo ehlukanisayo kungqimba lomhlabathi lwe-via ngu-D2, ububanzi be-pad ngu-D1, futhi ubukhulu bebhodi le-PCB ngu-T, I-dielectric constant ye-substrate yebhodi ngu-ε, futhi amandla e-parasitic we- via acishe abe: C=1.41εTD1/(D2-D1) Umthelela omkhulu wamandla e-parasitic we- via kusekethe ukunweba isikhathi sokukhuphuka kwesignali nokunciphisa Isivinini sesekhethi.

3. I-Parasitic inductance of vias Ngokufanayo, kukhona ama-parasitic inductances kanye nama-parasitic capacitances kuma-vias. Ekwakheni amasekhethi edijithali anesivinini esikhulu, umonakalo odalwe ama-parasitic inductances of vias uvamise ukuba mkhulu kunomthelela we-parasitic capacitance. Uchungechunge lwayo lwe-parasitic inductance luzokwenza buthaka umnikelo we-bypass capacitor futhi lwenze buthaka umphumela wokuhlunga walo lonke uhlelo lwamandla. Singamane sibale isilinganiso sokungena kwe-a via ngefomula elandelayo: L=5.08h[ln(4h/d)+1] lapho u-L ebhekisela ekungeneni kwe-via, h ubude be-via, futhi d iyisikhungo Ububanzi bomgodi. Kungabonakala kufomula ukuthi ububanzi be-via bunomthelela omncane ku-inductance, futhi ubude be-via bunomthelela omkhulu ku-inductance.

4. Ngokuklama ku-PCB enesivinini esikhulu. Ngokuhlaziywa okungenhla kwezici ze-vias, singabona ukuthi ekwakhiweni kwe-PCB enesivinini esikhulu, i-vias ebonakala ilula ivamise ukuletha izinto ezimbi ezinhle ekwakhiweni kwesekethe. umphumela.