Kuthetha ukuthini oku kwishishini lePCB elinesantya esiphezulu?
Okokuqala, xa uyila kwaye usakha izitaki zePCB, imiba yemathiriyeli kufuneka ibekwe phambili.Ii-PCB ze-5G kufuneka zihlangabezane nazo zonke iinkcukacha xa zithwala kwaye zifumana ukuhanjiswa kwesignali, ukubonelela ukudibanisa kombane, kunye nokubonelela ngokulawula imisebenzi ethile.Ukongeza, imingeni yoyilo lwePCB kuya kufuneka iqwalaselwe, njengokugcina imfezeko yesiginali kwizantya eziphezulu, ulawulo lwe-thermal, kunye nendlela yokuthintela ukuphazamiseka kwe-electromagnetic (EMI) phakathi kwedatha kunye neebhodi.
Umqondiso oxubileyo wokufumana uyilo lwebhodi yesekethe
Namhlanje, ezininzi iinkqubo zijongene ne-4G kunye ne-3G PCB.Oku kuthetha ukuba icandelo lokuhambisa kunye nokufumana uluhlu lwamaza ngama-600 MHz ukuya kwi-5.925 GHz, kunye nejenthi ye-bandwidth yi-20 MHz, okanye i-200 kHz kwiinkqubo ze-IoT.Xa uyila ii-PCBs ze-5G network systems, la macandelo aya kufuna i-millimeter wave frequencies of 28 GHz, 30 GHz okanye 77 GHz, kuxhomekeke kwisicelo.Kwiziteshi ze-bandwidth, iinkqubo ze-5G ziya kuqhuba i-100MHz ngaphantsi kwe-6GHz kunye ne-400MHz ngaphezu kwe-6GHz.
Ezi zantya eziphezulu kunye nee-frequencies eziphezulu ziya kufuna ukusetyenziswa kwezinto ezifanelekileyo kwi-PCB ukubamba ngaxeshanye kunye nokuhambisa izibonakaliso ezisezantsi neziphezulu ngaphandle kokulahlekelwa ngumqondiso kunye ne-EMI.Enye ingxaki kukuba izixhobo ziya kuba khaphukhaphu, zithwaleke ngakumbi, kwaye zibe zincinci.Ngenxa yobunzima obungqongqo, ubungakanani kunye nemiqobo yendawo, izixhobo zePCB kufuneka zibe bhetyebhetye kwaye zikhaphukhaphu ukulungiselela zonke izixhobo ze-microelectronic kwibhodi yesekethe.
Kwimikhondo yobhedu ye-PCB, iitrayisi ezincinci kunye nolawulo olungqongqo lwe-impedance kufuneka lulandelwe.Inkqubo yesiqhelo yokukhupha i-etching esetyenziselwa i-3G kunye ne-4G ye-PCB enesantya esiphezulu inokutshintshelwa kwinkqubo yokongeza i-semi-additive.Ezi nkqubo ziphuculweyo ze-semi-additive ziya kunika umkhondo ochanekileyo kunye neendonga ezichanekileyo.
Isiseko sezinto eziphathekayo sikwalungiswa ngokutsha.Iinkampani zebhodi yesekethe eprintiweyo zifunda izixhobo ezine-dielectric constant ephantsi njenge-3, kuba izinto eziqhelekileyo ze-PCB ezinesantya esiphantsi zihlala zi-3.5 ukuya kwi-5.5.I-braid ye-fiber yeglasi eqinile, ilahleko ephantsi yezinto ezilahlekileyo kunye neprofayili ephantsi yobhedu iya kuba yinto ekhethiweyo ye-PCB enesantya esiphezulu kwiimpawu zedijithali, ngaloo ndlela ikhusela ukulahleka komqondiso kunye nokuphucula imfezeko yesignali.
Ingxaki yokukhusela i-EMI
I-EMI, i-crosstalk kunye ne-parasitic capacitance ziingxaki eziphambili zeebhodi zeesekethe.Ukuze ujongane ne-crosstalk kunye ne-EMI ngenxa ye-analog kunye ne-digital frequencies ebhodini, kucetyiswa kakhulu ukuba uhlukanise umkhondo.Ukusetyenziswa kweebhodi ze-multilayer kuya kunika ukuguquguquka okungcono ukucacisa indlela yokubeka i-trace-speed traces ukwenzela ukuba iindlela ze-analog kunye ne-digital return signals zigcinwe kude komnye nomnye, ngelixa zigcina iisekethe ze-AC kunye ne-DC.Ukongeza ukhuseleko kunye nokucoca xa ubeka amacandelo kufuneka kwakhona kunciphise inani le-EMI yendalo kwi-PCB.
Ukuze kuqinisekiswe ukuba akukho ziphene kunye neesekethe ezimfutshane ezinzulu okanye iisekethe ezivulekileyo kumphezulu wobhedu, inkqubo yokuhlola i-optical optical advanced (AIO) enemisebenzi ephezulu kunye ne-2D metrology iya kusetyenziswa ukujonga umkhondo womqhubi kunye nokulinganisa.Ezi teknoloji ziya kunceda abavelisi be-PCB bajonge imingcipheko enokwenzeka yokuthotywa kophawu.
Imingeni yolawulo lobushushu
Isantya esiphezulu somqondiso siya kubangela ukuba ikhoyo ngoku ngePCB ivelise ubushushu obuninzi.Izinto ze-PCB zezinto ze-dielectric kunye ne-core substrate layers ziya kufuna ukusingatha ngokwaneleyo isantya esiphezulu esifunwa yi-teknoloji ye-5G.Ukuba izinto eziphathekayo ayanelanga, kunokubangela umkhondo wobhedu, ukuxobula, ukushwabana nokuwa, kuba ezi ngxaki ziya kubangela ukuba iPCB ibe mbi.
Ukuze ukwazi ukujamelana nala maqondo okushisa aphezulu, abavelisi baya kufuneka bagxininise ekukhethweni kwezinto ezijongene ne-thermal conductivity kunye nemiba ye-thermal coefficient.Izinto eziphathekayo ezinomgangatho ophezulu we-thermal conductivity, ukutshintshwa kobushushu obugqwesileyo, kunye ne-dielectric eqhubekayo kufuneka isetyenziswe ukwenza i-PCB efanelekileyo ukubonelela zonke iimpawu ze-5G ezifunekayo kwesi sicelo.