Ta hanyar rami (VIA) muhimmin sashi ne na PCB mai yawa, kuma farashin ramukan hakowa galibi yana lissafin kashi 30% zuwa 40% na farashin yin katako na PCB. A taƙaice, kowane rami akan PCB ana iya kiransa ramin wucewa. Dangane da aiki, ramin za a iya raba shi gida biyu: ana amfani da ɗaya don haɗin wutar lantarki tsakanin yadudduka; Ana amfani da ɗayan don gyara na’urar ko sakawa.

Dangane da tsarin, waɗannan ramukan rabe-raben sun kasu kashi uku, wato makafi ta hanyar, binne ta hanyar ta. Makafi ramuka suna kan saman da kasa saman allon da aka buga na PRINTED kuma suna da wani zurfin don haɗa farfajiyar ƙasa zuwa da’irar ciki a ƙasa. Zurfin ramukan yawanci baya wuce wani rabo (buɗewa). Ramukan da aka binne ramukan haɗin gwiwa ne a cikin ɓoyayyen ciki na allon da’irar da aka buga wanda baya kaiwa zuwa saman allon da’irar da aka buga. Nau’ikan ramukan guda biyu suna cikin layin ciki na allon da’irar, wanda tsarin gyaran ramin ya cika kafin lamination, kuma ana iya yin rufi da dama a ciki yayin samuwar ramin. Nau’i na uku, wanda ake kira ramuka, yana gudana ta cikin dukkan allon kewaye kuma ana iya amfani dashi don haɗin haɗin ciki ko azaman hawa da gano ramuka don abubuwan haɗin. Saboda ramin rami ya fi sauƙin aiwatarwa a cikin tsari, farashin ya yi ƙasa, don haka yawancin allon allon da aka buga ana amfani da shi, maimakon sauran nau’ikan biyu ta rami. Abubuwan da ke biyowa ta cikin ramuka, ba tare da bayani na musamman ba, za a ɗauke su a matsayin ramuka.

Nawa kuka sani game da ramin ƙirar PCB

Daga mahangar ƙira, ramin rami galibi ya ƙunshi sassa biyu, ɗaya shine ramin rami a tsakiya ɗayan kuma shine yanki kushin kusa da ramin ramuka, kamar yadda aka nuna a cikin adadi na ƙasa. Girman waɗannan sassa biyu yana ƙaddara girman ramin. A bayyane yake, a cikin ƙirar babban sauri, PCB mai yawa, mai zanen koyaushe yana son ramin a matsayin ƙarami kamar yadda zai yiwu, wannan samfurin na iya barin ƙarin sararin wiring, ƙari, ƙaramin rami, ƙarfin ikon sa na parasitic shine ƙarami, ƙari dace da madaidaicin gudu. Amma girman ramin yana raguwa a lokaci guda yana kawo hauhawar farashi, kuma ba za a iya rage girman ramin ba tare da iyakancewa ba, an iyakance shi ta hanyar hakowa (rami) da sanya (plating) da sauran fasaha: ƙaramin rami, ya fi tsayi yana yin hakowa, mafi sauƙin shine karkacewa daga tsakiya; Lokacin da zurfin ramin ya ninka diamita na rami fiye da sau 6, ba shi yiwuwa a tabbatar da suturar tagulla ta bangon ramin. Misali, kauri na yau da kullun na yau da kullun (ta zurfin rami) na allon PCB 6-Layer yana kusan 50Mil, don haka ƙaramin ramin hakowa wanda masana’antun PCB zasu iya bayarwa zai iya kaiwa 8Mil kawai. Ƙarfin parasitic na ramin da kansa ya wanzu zuwa ƙasa, idan diamita na ramin kadaici shine D2, diamita na kushin rami shine D1, kaurin allon PCB shine T, kuma madaidaicin madaidaicin substrate shine ε, karfin parasitic na ramin shine kusan: C = 1.41εTD1/ (D2-D1)

Babban tasirin parasitic capacitance akan da’irar shine tsawaita lokacin tashin siginar da rage saurin kewaye. Misali, ga allon PCB mai kauri 50Mil, idan diamita na cikin ramin shine 10Mil, diamita na kushin shine 20Mil, kuma tazara tsakanin kushin da bene na jan ƙarfe shine 32Mil, zamu iya kimanta ƙarfin parasitic capacitance na rami ta amfani da dabarar da ke sama: C = 1.41 × 4.4 × 0.050 × 0.020/ (0.032-0.020) = 0.517pF, canjin lokacin tashi wanda wannan ɓangaren ƙarfin ya haifar shine: T10-90 = 2.2C (Z0/ 2) = 2.2 × 0.517x (55/ 2) = 31.28ps. Daga waɗannan ƙimar, a bayyane yake cewa kodayake tasirin ƙarfin parasitic capacitance daga rami ɗaya akan jinkirin tashi ba a bayyane yake ba, masu zanen kaya yakamata suyi taka tsantsan idan ana amfani da ramuka da yawa don sauyawa Layer-to-Layer.

A cikin ƙirar da’irar dijital mai saurin gudu, ɓarkewar ɓarna na ɓarna na ɓarna ta cikin rami galibi ya fi tasirin ƙarfin parasitic capacitance. Tsarin shigar sa na parasitic zai raunana gudummawar wuce gona da iri da rage tasirin tace dukkan tsarin wutar lantarki. Za mu iya lissafin raunin parasitic na kusancin rami ta amfani da dabara mai zuwa: L = 5.08h [ln (4h/d) +1] inda L ke nufin shigarwar rami, h shine tsawon hanyar- rami, kuma D shine diamita na tsakiyar rami. Ana iya gani daga lissafin cewa diamita na ramin ba shi da tasiri a kan shigarwar, yayin da tsawon ramin yana da babban tasiri a cikin shigar. Har yanzu ta amfani da misalin da ke sama, ana iya ƙididdige fitowar daga cikin rami azaman L = 5.08 × 0.050 [ln (4 × 0.050/0.010) +1] = 1.015nh. Idan lokacin tashin siginar shine 1ns, to girman girman impedance shine: XL = πL/T10-90 = 3.19 ω. Ba za a iya yin watsi da wannan ƙarancin ba a gaban babban ƙarfin halin yanzu. Musamman, dole ne mai wucewa mai wucewa ya ratsa ramuka biyu don haɗa layin samarwa zuwa samuwar, don haka ya ninka raunin raunin rami.

Ta hanyar binciken da ke sama na halayen parasitic na ramin, zamu iya ganin cewa a cikin ƙirar PCB mai saurin gudu, rami da alama mai sauƙi sau da yawa yana kawo babban mummunan sakamako ga ƙirar kewaye. Domin rage munanan illolin parasitic na ramin, za mu iya yin iya gwargwado a cikin ƙira: 1. Daga ɓangarorin biyu na farashi da ingancin sigina, zaɓi girman ramin da ya dace. Misali, don 6-10 yadudduka na ƙirar PCB na MEMORY module, yana da kyau a zaɓi 10/20mil (hakowa/kushin) ta cikin rami, don wasu ƙananan ƙananan ƙananan jirgi, Hakanan kuna iya ƙoƙarin amfani da 8/18mil ta ramin. Tare da fasaha na yanzu, zai yi wuya a yi amfani da ƙananan ramuka. Don samar da wutar lantarki ko waya ta ƙasa ta cikin ramuka ana iya ɗaukar yin amfani da girman da ya fi girma don rage rashin ƙarfi.

2. Tsarin dabaru guda biyu da aka tattauna a sama sun nuna cewa amfani da allon PCB mafi kauri yana taimakawa rage rabe -raben ƙwayoyin cuta guda biyu ta cikin ramuka.

3. siginar siginar da ke kan allon PCB bai kamata ta canza layin kamar yadda zai yiwu ba, wato a gwada kada a yi amfani da ramukan da ba dole ba.

4. Ya kamata a haƙa fil ɗin wutar lantarki da ƙasa kusa. The guntu gubar tsakanin fil da ramuka, mafi alh betterri, domin za su kai ga wani karuwa a inductance. A lokaci guda, ikon da ke ƙasa yakamata ya zama mai kauri sosai don rage ƙarancin ƙarfi.

5. Sanya wasu ramuka na ƙasa kusa da ramukan canjin siginar siginar don samar da madauki mafi kusa don siginar. Hakanan kuna iya sanya ƙarin ramuka na ƙasa da yawa akan PCB. Tabbas, kuna buƙatar zama masu sassauƙa a cikin ƙirar ku. Samfurin ramin da aka tattauna a sama shine halin da ake ciki inda ake samun gammaye a kowane Layer. Wani lokaci, zamu iya rage ko ma cire gammaye a wasu yadudduka. Musamman a yanayin yawan ramin yana da girma ƙwarai, yana iya haifar da samuwar yanke tsagewar da’ira a cikin bututun tagulla, don warware irin wannan matsalar ban da matsar da wurin ramin, mu ma muna iya duba ramin a cikin jan ƙarfe don rage girman kushin.