Ngokufika kwesikhathi solwazi, ukusetshenziswa kwamabhodi e-pcb kuya ngokuya kunwebeka, futhi ukuthuthukiswa kwamabhodi e-pcb kuya kuba nzima nakakhulu.Njengoba izingxenye ze-elekthronikhi zihlelwa ngokuminyene kakhulu ku-PCB, ukuphazamiseka kukagesi sekuyinkinga engenakugwenywa.Ekuklanyeni nasekusetshenzisweni kwamabhodi anezingqimba eziningi, ungqimba lwesignali kanye nongqimba lwamandla kufanele kuhlukaniswe, ngakho ukuklama nokuhlelwa kwesitaki kubaluleke kakhulu.Uhlelo oluhle lokuklama lunganciphisa kakhulu umthelela we-EMI kanye ne-crosstalk kumabhodi we-multilayer.
Uma kuqhathaniswa namabhodi avamile anongqimba olulodwa, ukuklanywa kwamabhodi anezingqimba eziningi kwengeza izendlalelo zesignali, izendlalelo zezintambo, futhi kuhlele izingqimba zamandla ezizimele nezingqimba zomhlabathi.Izinzuzo zamabhodi anezingqimba eziningi ziboniswa ngokuyinhloko ekunikezeni i-voltage ezinzile yokuguqulwa kwesignali yedijithali, nokwengeza ngokulinganayo amandla engxenyeni ngayinye ngesikhathi esifanayo, kunciphisa ngokuphumelelayo ukuphazamiseka phakathi kwamasignali.
Ukunikezwa kwamandla kusetshenziswa endaweni enkulu yokubeka ithusi kanye nongqimba lomhlabathi, okunganciphisa kakhulu ukumelana kwesendlalelo samandla kanye nongqimba lomhlabathi, ukuze i-voltage isendlalelo samandla izinzile, kanye nezici zomugqa wesiginali ngamunye. ingaqinisekiswa, okuzuzisa kakhulu ekunciphiseni i-impedance kanye ne-crosstalk.Ekwakheni amabhodi esekethe asezingeni eliphezulu, kubekwe ngokucacile ukuthi ngaphezu kwe-60% yezinhlelo zokupakisha kufanele zisetshenziswe.Amabhodi anezingqimba eziningi, izici zikagesi, nokucindezelwa kwemisebe kagesi konke kunezinzuzo ezingenakuqhathaniswa ngaphezu kwamabhodi anengqimba ephansi.Mayelana nezindleko, ngokujwayelekile, uma kunezingqimba eziningi, intengo ibiza kakhulu, ngoba izindleko zebhodi le-PCB zihlobene nenani lezingqimba, kanye nokuminyana kwendawo ngayinye yeyunithi.Ngemuva kokunciphisa inani lezendlalelo, isikhala sezintambo sizoncishiswa, ngaleyo ndlela sikhulise ukuminyana kwezintambo., futhi uhlangabezane nezidingo zedizayini ngokunciphisa ububanzi bomugqa nebanga.Lokhu kungase kwenyuse izindleko ngendlela efanele.Kungenzeka ukunciphisa ukupakisha nokunciphisa izindleko, kodwa kwenza ukusebenza kukagesi kubi nakakhulu.Lolu hlobo lomklamo ngokuvamile aluzuzisi lutho.
Uma ubheka izintambo ze-PCB microstrip kumodeli, ungqimba lomhlabathi lungabuye luthathwe njengengxenye yolayini wokudlulisela.Isendlalelo sethusi esiphansi singasetshenziswa njengendlela yeluphu yomugqa wesignali.Indiza yamandla ixhunywe endizeni yaphansi ngokusebenzisa i-decoupling capacitor, esimweni se-AC.Zombili ziyalingana.Umehluko phakathi kwefrikhwensi ephansi kanye nezihibe zamanje zamanje yilokho.Kumafrikhwensi aphansi, amandla okubuya alandela indlela yokumelana okuncane.Kumafrikhwensi aphezulu, i-return current isendleleni ye-inductance encane.Izimbuyiselo zamanje, zigxiliswe futhi zisatshalaliswa ngokuqondile ngaphansi kokulandelelwa kwesignali.
Endabeni yefrikhwensi ephezulu, uma ucingo lubekwe ngokuqondile kungqimba lomhlabathi, ngisho noma kukhona ama-loops amaningi, ukubuyisela kwamanje kuzogeleza kubuyele emthonjeni wesignali kusukela kungqimba lwezintambo ngaphansi kwendlela yokuqala.Ngoba le ndlela ine-impedance encane.Lolu hlobo lokusetshenziswa kwe-capacitive coupling enkulu ukucindezela inkambu kagesi, kanye ne-capacitive coupling encane yokucindezela isitshalo kazibuthe ukuze sigcine ukusabela okuphansi, sikubiza ngokuthi ukuzivikela.
Kungabonakala kufomula ukuthi lapho i-current igeleza ibuyela emuva, ibanga ukusuka kumugqa wesignali liphambene ngokulingana nokuminyana kwamanje.Lokhu kunciphisa indawo ye-loop kanye ne-inductance.Ngesikhathi esifanayo, kungaphetha ngokuthi uma ibanga eliphakathi komugqa wesignali kanye ne-loop liseduze, ama-currents amabili afana nobukhulu futhi aphikisana nendawo.Futhi insimu kazibuthe eyenziwe yisikhala sangaphandle ingasuswa, ngakho-ke i-EMI yangaphandle nayo incane kakhulu.Ekwakhiweni kwesitaki, kuhle kakhulu ukuba umkhondo wesignali ngamunye uhambisane nongqimba oluseduze kakhulu lomhlabathi.
Enkingeni ye-crosstalk kungqimba lomhlabathi, i-crosstalk ebangelwa yiziyingi ze-high-frequency ikakhulukazi ngenxa yokuhlanganisa inductive.Kusukela kufomula yeluphu engenhla yamanje, kungaphethwa ngokuthi ama-loop currents akhiqizwa imigqa yesignali emibili esondelene izokweqa.Ngakho kuzoba nokuphazanyiswa kazibuthe.
U-K kufomula uhlobene nesikhathi sokukhuphuka kwesignali nobude bomugqa wesignali yokuphazamiseka.Esimisweni sesitaki, ukufinyeza ibanga phakathi kongqimba lwesignali kanye nongqimba lomhlabathi kuzonciphisa ngempumelelo ukuphazamiseka okuvela kungqimba lomhlabathi.Lapho ubeka ithusi kungqimba lokunikezela kwamandla kanye nongqimba lomhlabathi kuzintambo ze-PCB, kuzovela udonga oluhlukanisayo endaweni yokubeka ithusi uma unganaki.Ukuvela kwalolu hlobo lwenkinga kungenzeka kakhulu kungenxa yokuminyana okuphezulu kwezimbobo, noma idizayini engenangqondo yendawo ehlukaniswayo.Lokhu kunciphisa isikhathi sokukhuphuka futhi kwandisa indawo ye-loop.I-inductance iyanda futhi idala i-crosstalk ne-EMI.
Kufanele sizame konke okusemandleni ethu ukumisa izinhloko zezitolo ngababili.Lokhu kucatshangelwa izidingo zesakhiwo sebhalansi kule nqubo, ngoba isakhiwo esingalingani singabangela ukuguqulwa kwebhodi le-pcb.Kusendlalelo ngasinye sesignali, kuhle ukuba nedolobha elijwayelekile njengesikhawu.Ibanga phakathi kokunikezwa kwamandla aphezulu kanye nedolobha lethusi lihambisana nokuzinza nokwehliswa kwe-EMI.Ekwakhiweni kwebhodi lesivinini esikhulu, izindiza zaphansi ezingafuneki zingangezwa ukuze zihlukanise izindiza zesignali.
Isikhathi sokuthumela: Mar-23-2023