Lokacin zayyana PCB, ɗaya daga cikin mahimman tambayoyin da za a yi la'akari da su shine aiwatar da buƙatun ayyukan da'irar da ake buƙata na nawa na'ura mai walƙiya, jirgin ƙasa da jirgin sama mai ƙarfi, da bugu na wiring na allo, jirgin ƙasa da iko. Ƙayyadewar jirgin sama na adadin yadudduka da aikin kewayawa, amincin sigina, EMI, EMC, farashin masana'anta da sauran buƙatu.
Don yawancin ƙira, akwai buƙatu masu cin karo da juna da yawa akan buƙatun aikin PCB, farashin manufa, fasahar masana'anta, da sarkar tsarin. Tsarin laminated na PCB yawanci yanke shawara ne na sulhu bayan la'akari da dalilai daban-daban. Yawancin da'irori na dijital masu saurin sauri da da'irorin wutsiya galibi ana tsara su tare da allunan multilayer.
Anan akwai ƙa'idodi takwas don ƙirar cascading:
1. Delamination
A cikin PCB multilayer, yawanci ana samun sigina Layer (S), jirgin sama mai ba da wutar lantarki (P) da jirgin ƙasa (GND). Jirgin wutar lantarki da jirgin GROUND galibi jirage ne masu ƙarfi waɗanda ba a raba su waɗanda za su ba da kyakkyawar hanyar dawowar ƙarancin ƙarancin ƙarfi na halin yanzu na layin sigina da ke kusa.
Yawancin siginar yadudduka suna tsakanin waɗannan hanyoyin samar da wutar lantarki ko filayen jirgin sama na ƙasa, suna samar da layukan madaidaici ko asymmetric banded. Ana amfani da manyan yadudduka na sama da ƙasa na PCB multilayer don sanya abubuwan haɗin gwiwa da ƙaramin adadin wayoyi. Wayoyin waɗannan sigina bai kamata su yi tsayi da yawa ba don rage radiation kai tsaye da ke haifar da wayoyi.
2. Ƙayyade jirgin sama mai ƙarfi guda ɗaya
Yin amfani da na'urori masu rarrabawa shine ma'auni mai mahimmanci don warware daidaiton wutar lantarki. Za a iya sanya capacitors na gyarawa a sama da kasa na PCB. Hanyar sarrafa capacitor, solder pad, da ramuka wucewa za su yi tasiri sosai ga tasirin decoupling capacitor, wanda ke buƙatar ƙira dole ne a yi la'akari da cewa hanyar da ake amfani da shi na decoupling capacitor ya zama gajere da faɗi sosai, kuma wayar da aka haɗa da rami ya kamata. kuma zama gajere kamar yadda zai yiwu. Alal misali, a cikin da'irar dijital mai sauri, yana yiwuwa a sanya capacitor na decoupling a saman Layer na PCB, sanya Layer 2 zuwa babban da'irar dijital mai sauri (kamar processor) a matsayin Layer na wutar lantarki, Layer 3. a matsayin siginar siginar, da kuma Layer 4 a matsayin ƙasa mai sauri na dijital.
Bugu da kari, ya zama dole a tabbatar da cewa siginar da ke tafiyar da na'urar dijital mai sauri ta dauki nau'in wutar lantarki iri daya kamar na jirgin sama, kuma wannan Layer wutar lantarki shine Layer samar da wutar lantarki na na'urar dijital mai sauri.
3. Ƙayyade jirgin sama mai ƙarfi da yawa
The Multi-power reference jirgin sama za a raba zuwa da dama m yankuna da daban-daban voltages. Idan siginar siginar yana kusa da layin wutar lantarki mai yawa, siginar halin yanzu akan siginar siginar da ke kusa zai ci karo da hanyar dawowa mara gamsarwa, wanda zai haifar da raguwa a hanyar dawowa.
Don siginar dijital mai sauri, wannan ƙirar hanyar dawowa mara ma'ana na iya haifar da matsala mai tsanani, don haka ana buƙatar cewa manyan siginar siginar dijital ya kamata a nisanta daga jirgin sama mai ƙarfi da yawa.
4.Ƙayyade manyan jiragen sama na ƙasa
Jiragen sama masu yawa na ƙasa (jirgin ƙasa) na iya samar da kyakkyawar hanyar dawowar rashin ƙarfi na yanzu, wanda zai iya rage yanayin gama-gari na EML. Ya kamata a haɗa jirgin ƙasa da jirgin sama mai ƙarfi sosai, kuma a haɗa siginar siginar tam tare da jirgin da ke kusa. Ana iya samun wannan ta hanyar rage kauri na matsakaici tsakanin yadudduka.
5. Haɗin haɗin wayoyi a hankali
Yadudduka biyun da aka zagaya ta hanyar sigina ana kiran su “haɗin wiring”. An ƙera mafi kyawun haɗin wayoyi don guje wa dawowar halin yanzu da ke gudana daga jirgin sama zuwa wancan, amma a maimakon haka yana gudana daga aya ɗaya (fuskar) na jirgin sama zuwa wancan. Domin kammala hadaddun wayoyi, jujjuyawar haɗin keɓaɓɓen wayoyi ba makawa. Lokacin da aka canza siginar tsakanin yadudduka, ya kamata a tabbatar da dawowar halin yanzu yana gudana cikin sauƙi daga wannan jirgin sama zuwa wancan. A cikin ƙira, yana da kyau a yi la'akari da yadudduka da ke kusa azaman haɗin waya.
Idan hanyar sigina tana buƙatar tazarar yadudduka da yawa, yawanci ba ƙira ce mai ma'ana ba don amfani da ita azaman haɗin wayoyi, saboda hanyar da ke cikin yadudduka da yawa ba ta da lahani don magudanar ruwa. Ko da yake ana iya rage lokacin bazara ta hanyar sanya capacitor decoupling kusa da rami ko rage kauri na matsakaici tsakanin jiragen sama na tunani, ba kyakkyawan zane ba ne.
6.Saitin hanyar waya
Lokacin da aka saita hanyar wayoyi akan siginar sigina iri ɗaya, yakamata ya tabbatar da cewa yawancin hanyoyin haɗin waya sun daidaita, kuma yakamata su kasance daidai da kwatancen layin siginar da ke kusa. Misali, ana iya saita hanyar wayoyi na siginar siginar ɗaya zuwa ga “Y-axis”, kuma ana iya saita hanyar wiring na wani layin siginar da ke kusa da hanyar “X-axis”.
7. Adopted da ko da Layer tsarin
Ana iya samuwa daga ƙirar PCB ɗin da aka ƙera cewa ƙirar lamination na gargajiya kusan duk ko da yadudduka ne, maimakon yadudduka mara kyau, wannan al'amari yana faruwa ne ta hanyoyi da yawa.
Daga tsarin masana'anta na allon da'ira da aka buga, zamu iya sanin cewa duk abin da ke gudana a cikin allon kewayawa an ajiye shi a kan babban Layer, kayan core Layer gabaɗaya allo mai gefe biyu ne, lokacin da cikakken amfani da core Layer. , da conductive Layer na buga kewaye allon ne ko da
Hatta allunan da'ira da aka buga Layer suna da fa'idodin farashi. Saboda rashin wani Layer na kafofin watsa labarai da jan karfe, farashin kayan albarkatun PCB masu ƙima ya ɗan yi ƙasa kaɗan fiye da farashin ko da yadudduka na PCB. Koyaya, farashin sarrafawa na ODd-Layer PCB a bayyane yake ya fi na PCB-Layer saboda ODd-Layer PCB yana buƙatar ƙara tsarin haɗin gwiwa wanda ba a daidaita shi ba bisa tushen tsarin tsarin Layer. Idan aka kwatanta da tsarin gama gari na yau da kullun, ƙara cladding tagulla a waje da ainihin tsarin Layer zai haifar da ƙarancin samarwa da kuma tsawon lokacin samarwa. Kafin laminating, babban Layer na waje yana buƙatar ƙarin aiki, wanda ke ƙara haɗarin ɓarna da ɓarna na waje. Ƙarfafa sarrafa waje zai haɓaka farashin masana'antu sosai.
Lokacin da aka sanyaya yadudduka na ciki da na waje na allon da'irar da aka buga bayan tsarin haɗin gwiwar da'ira mai yawa, nau'in lamination daban-daban zai haifar da nau'i daban-daban na lanƙwasa akan allon da aka buga. Kuma yayin da kaurin allon ke ƙaruwa, haɗarin lanƙwasa allon da'ira da aka haɗa tare da sifofi daban-daban guda biyu yana ƙaruwa. Allolin da'ira masu ƙima suna da sauƙin lanƙwasa, yayin da kwalayen da'irar da'irar maɗaukaki na iya guje wa lankwasawa.
Idan an ƙera allon da'irar da aka buga tare da adadi mara kyau na yadudduka na wutar lantarki da ma adadin siginar sigina, ana iya ɗaukar hanyar ƙara matakan wutar lantarki. Wata hanya mai sauƙi ita ce ƙara ƙirar ƙasa a tsakiyar tarin ba tare da canza sauran Saitunan ba. Wato, PCB ana yin waya a cikin wani adadi mara kyau na yadudduka, sa'an nan kuma ana kwafin Layer na ƙasa a tsakiya.
8. La'akarin Kuɗi
Dangane da farashin masana'anta, allunan kewayawa da yawa sun fi tsada fiye da allunan kewayawa guda ɗaya da ninki biyu tare da yanki ɗaya na PCB, kuma ƙarin yadudduka, ƙimar mafi girma. Duk da haka, lokacin da ake la'akari da fahimtar ayyukan da'ira da miniaturization na hukumar, don tabbatar da amincin siginar, EMl, EMC da sauran alamun aiki, ya kamata a yi amfani da allunan kewayawa da yawa kamar yadda zai yiwu. Gabaɗaya, bambance-bambancen farashi tsakanin allunan kewayawa da yawa da allunan kewayawa mai Layer Layer da Layer Layer biyu ba su da yawa fiye da yadda ake tsammani.