Amabhodi esekethe aphrintiwe (ama-PCB) awumgogodla wemishini yesimanje kagesi. Kusukela kuma-smartphone kuya kumishini yezokwelapha, amabhodi e-PCB adlala indima ebalulekile ekuxhumaniseni nasekunikezeni ukusebenza ezingxenyeni ezihlukahlukene ze-elekthronikhi. Ukuqinisekisa ukusebenza kahle, abaklami be-PCB kumele bacabangele izici ezimbalwa, okuhlanganisa nokuvinjelwa okulawulwayo. Kulokhu okuthunyelwe kwebhulogi, sizocubungula umqondo wokuphazamiseka okulawulwayo kumabhodi e-PCB futhi siqonde ukubaluleka kwawo ekuzuzeni imiklamo yesekethe esebenza kahle nethembekile.
Yini i-impedance elawulwayo ku-PCB?
I-impedance ingachazwa njengokumelana okuhlangatshezwana nayo ngokushintshashintsha kwamanje (AC) kugeleza kusekethe. I-impedance elawulwayo isho ngokuqondile inani le-impedance elingaguquki ngamabomu kumkhondo othize noma ulayini wokudlulisela ebhodini le-PCB.
Ukulawulwa kokuphazamiseka kubalulekile lapho kucutshungulwa amasiginali edijithali yemvamisa ephezulu ngoba kusiza ukugcina ubuqotho besignali, ukunciphisa ukubonakaliswa kwesignali, nokunciphisa ukuphazamiseka kwe-electromagnetic (EMI). Uma i-impedance ingalawulwa, ingacekela phansi izici zokudlulisela zesiginali, ibangele ukuhlanekezela, izinkinga zesikhathi, kanye nokuwohloka kokusebenza okupheleleyo.
Izinto ezithinta impedance elawulwayo:
Ukuze kuzuzwe ukuphazamiseka okulawulwayo kwebhodi le-PCB, kunezici ezimbalwa ezidinga ukucatshangelwa. Lezi zici zihlanganisa:
1. Landelela ijiyomethri: Ububanzi, ukujiya kanye nesikhala sokulandela umkhondo kanye nemigqa yokudlulisela ku-PCB kunomthelela omkhulu enanini lokuvimba. Ubukhulu kufanele bubalwe kahle kusetshenziswa isibali se-impedance noma buhlinzekwe ngumkhiqizi we-PCB.
2. Impahla ye-Dielectric: Izinto ze-dielectric ezisetshenziswa ku-PCB nazo zithinta i-impedance elawulwayo. Izinto ezihlukene zinezimo ezihlukahlukene ze-dielectric, ezithinta ukuthi amasignali asakazeka ngokushesha kangakanani.
3. Ibanga lokulandelelwa okuncikene: Ukuba seduze kokudlulisa nokwamukela imikhondo kuzodala amandla afanayo kanye ne-inductance, ngaleyo ndlela kuguqule inani lokuvimba. Ukugcina ibanga eliphephile phakathi kokulandelelwa kusiza ukugcina i-impedance elawulwayo.
4. Ukupakishwa kwesendlalelo: Ukuhlelwa nokulandelana kwezingqimba ze-PCB kudlala indima ebalulekile ekulawulweni kwe-impedance. Ukungaguquguquki kokunqwabelaniswa kwesendlalelo kubalulekile ekuvimbeleni ukungahambisani kwe-impedance.
Ukubaluleka kokuphazamiseka okulawulwayo ekwakhiweni kwe-PCB:
1. Ubuqotho besignali: I-impedance elawulwayo iqinisekisa ukuthi amasignali edijithali adluliselwa ngempumelelo ku-PCB ngaphandle kokuhlanekezela. Ukugcina isilawuli se-impedance kunciphisa ukubonakaliswa, ukulahlekelwa kwesignali, kanye ne-crosstalk, ngaleyo ndlela kuthuthukisa ubuqotho besignali jikelele.
2. Yehlisa ukuthikamezeka kazibuthe kagesi (EMI): Njengoba izinto zikagesi ziqhubeka nokukhula ngobunkimbinkimbi namafrikhwensi amasignali eba phezulu, i-EMI isibe yinkinga ebalulekile. I-impedance elawulwayo isiza ukunciphisa i-EMI ngokunciphisa ukubonakaliswa kwesignali nokuqinisekisa ukubeka phansi nokuvikela okufanele.
3. Ukusebenza okungaguquki: Ama-PCB ane-impedance elawulwayo ahlinzeka ngezici zikagesi ezingaguquki ngisho nangaphansi kokushintsha kwezimo zemvelo ezifana nezinga lokushisa nomswakama. Lokhu kuvumelana kuhumusha ekusebenzeni okuthembekile nokuphila okunwetshiwe kwamadivayisi akho kagesi.
4. Ukuvumelana: I-impedance elawulwayo iphinde iqinisekise ukuhambisana nezinye izingxenye nezinhlelo. Amabhodi e-PCB anokufaniswa kwe-impedance angaxhuma kalula futhi axhumane namanye amadivaysi, okuvumela ukuhlanganiswa okungenamthungo.
I-impedance elawulwayo iyisici esibalulekile sokuklama kwe-PCB, ikakhulukazi kuma-high frequency nezinhlelo zokusebenza ezibucayi. Ngokugcina amanani e-impedance angaguquki, abaklami bangakwazi ukuthuthukisa ubuqotho besignali, banciphise i-EMI, futhi baqinisekise ukuhambisana. Ukuqonda izici ezithinta i-impedance elawulwayo, njenge-trace geometry, izinto ze-dielectric, kanye ne-stackup yesendlalelo, kubalulekile ekuzuzeni imiklamo ye-PCB ephumelelayo nethembekile. Ngokubeka phambili ukulawulwa kwe-impedance, abaklami bangavula amandla aphelele wezinto zikagesi ngenkathi beletha ukusebenza okuphakeme nokuphila isikhathi eside.
Isikhathi sokuthumela: Sep-15-2023