Kusho ukuthini lokhu ngemboni ye-PCB enesivinini esikhulu?
Okokuqala nje, lapho uklama futhi wakha izitaki ze-PCB, izici ezibonakalayo kufanele zibekwe phambili. Ama-PCB e-5G kufanele ahlangabezane nakho konke ukucaciswa lapho ephethe futhi ethola ukudluliswa kwesignali, ehlinzeka ngoxhumo lukagesi, futhi enikeza ukulawula kwemisebenzi ethile. Ngaphezu kwalokho, izinselele zokuklama i-PCB kuzodingeka zixazululwe, njengokugcina ubuqotho besignali ngesivinini esiphezulu, ukuphathwa kwe-thermal, kanye nendlela yokuvimbela ukuphazamiseka kwe-electromagnetic (EMI) phakathi kwedatha namabhodi.
Isignali exubile ethola umklamo webhodi lesifunda
Namuhla, amasistimu amaningi asebenzelana ne-4G ne-3G PCB. Lokhu kusho ukuthi ingxenye yokudlulisa nokwamukela imvamisa ingu-600 MHz kuya ku-5.925 GHz, futhi isiteshi somkhawulokudonsa singu-20 MHz, noma u-200 kHz wezinhlelo ze-IoT. Lapho udizayina ama-PCB wezinhlelo zenethiwekhi ye-5G, lezi zingxenye zizodinga amaza amaza ama-millimeter angu-28 GHz, 30 GHz noma angu-77 GHz, kuye ngohlelo lokusebenza. Eziteshini zomkhawulokudonsa, amasistimu e-5G azocubungula u-100MHz ngaphansi kuka-6GHz no-400MHz ngaphezu kuka-6GHz.
Lezi zivinini eziphezulu kanye namaza aphakeme azodinga ukusetshenziswa kwezinto ezifanele ku-PCB ukuze kuthathwe kanyekanye futhi kudlulise amasignali aphansi naphezulu ngaphandle kokulahlekelwa kwesignali kanye ne-EMI. Enye inkinga ukuthi amadivaysi azolula, aphatheke kalula, futhi abe mancane. Ngenxa yesisindo esiqinile, usayizi kanye nezingqinamba zesikhala, izinto ze-PCB kufanele zibe nezimo futhi zingasindi ukuze kufakwe wonke amadivaysi e-microelectronic ebhodini lesekethe.
Ukuze uthole imikhondo yethusi ye-PCB, imikhondo emincane kanye nokulawula okuqinile kwe-impedance kufanele kulandelwe. Inqubo yendabuko yokufaka i-subtractive etching esetshenziselwa i-3G kanye ne-4G ye-PCB enesivinini esiphezulu ingashintshelwa kunqubo eguquliwe yokwengeza ingxenye. Lezi zinqubo ze-semi-additive ezithuthukisiwe zizohlinzeka ngemikhondo enembe kakhudlwana nezindonga eziqondile.
Isisekelo sezinto ezibonakalayo siphinde siklanywe kabusha. Izinkampani zamabhodi esekethe eziphrintiwe zifunda izinto ezisebenza ngokuguquguquka kwe-dielectric eziphansi njengo-3, ngoba izinto ezijwayelekile zama-PCB anesivinini esiphansi ngokuvamile zingu-3.5 kuya ku-5.5. I-braid ye-fiber yengilazi eqinile, ukulahlekelwa kwesici esiphansi kanye nethusi lephrofayili ephansi nakho kuzoba ukukhetha kwe-PCB enesivinini esikhulu kumasignali edijithali, ngaleyo ndlela kuvinjwe ukulahlekelwa kwesignali nokuthuthukisa ubuqotho besignali.
Inkinga yokuvikela i-EMI
I-EMI, i-crosstalk kanye ne-parasitic capacitance yizinkinga eziyinhloko zamabhodi wesifunda. Ukuze ubhekane ne-crosstalk ne-EMI ngenxa yamafrikhwensi e-analog nedijithali ebhodini, kunconywa kakhulu ukuhlukanisa imikhondo. Ukusetshenziswa kwamabhodi ezendlalelo eziningi kuzonikeza ukuguquguquka okungcono kakhulu kokunquma indlela yokubeka imikhondo yesivinini esiphezulu ukuze izindlela zezimpawu zokubuya kwe-analog nedijithali zigcinwe ziqhelelene, kuyilapho kugcinwa amasekhethi e-AC ne-DC ehlukene. Ukwengeza ukuvikela nokuhlunga lapho ubeka izingxenye kufanele futhi kwehlise inani le-EMI yemvelo ku-PCB.
Ukuze kuqinisekiswe ukuthi azikho iziphambeko namasekhethi amafushane angathi sína noma amasekhethi avulekile endaweni yethusi, isistimu yokuhlola ezenzakalelayo ye-othomathikhi (i-AIO) enemisebenzi ephakeme kanye ne-2D metrology izosetshenziswa ukuhlola ukulandelelwa komqhubi nokukala. Lobu buchwepheshe buzosiza abakhiqizi be-PCB ukuthi babheke izingozi ezingaba khona zokuwohloka kwesignali.
Izinselele zokuphatha okushisayo
Isivinini sesignali esiphezulu sizobangela ukuthi okwamanje nge-PCB kukhiqize ukushisa okwengeziwe. Izinto ze-PCB zezinto ze-dielectric kanye nezendlalelo ze-substrate eziyinhloko zizodinga ukuphatha ngokwanele isivinini esiphezulu esidingwa ubuchwepheshe be-5G. Uma impahla inganele, ingabangela imikhondo yethusi, ukuxebuka, ukushwabana nokuwa, ngoba lezi zinkinga zizodala ukuthi i-PCB yonakale.
Ukuze ubhekane nalawa mazinga okushisa aphezulu, abakhiqizi bazodinga ukugxila ekukhethweni kwezinto ezibhekana ne-thermal conductivity kanye nezindaba ze-coefficient ezishisayo. Izinto ezinokusebenza okuphezulu kwe-thermal, ukudluliswa kokushisa okuhle kakhulu, kanye nokungaguquki kwe-dielectric kufanele kusetshenziselwe ukwenza i-PCB enhle ukuhlinzeka ngazo zonke izici ze-5G ezidingekayo kulolu hlelo lokusebenza.