Imboni yezinto ze-PCB ichithe inani elikhulu lesikhathi ithuthukisa izinto ezinikeza ukulahleka kwesignali okuphansi kakhulu okungenzeka. Ngemiklamo yesivinini esikhulu kanye nemvamisa ephezulu, ukulahlekelwa kuzokhawulela ibanga lokusakazeka kwesignali futhi kuphazamise amasignali, futhi kuzodala ukuchezuka kwe-impedance okungabonakala kuzilinganiso ze-TDR. Njengoba siklama noma yiliphi ibhodi lesekethe eliphrintiwe futhi sithuthukisa amasekhethi asebenza ngamaza aphakeme, kungase kulingeke ukukhetha ithusi elibushelelezi kakhulu kuwo wonke amadizayini owadalayo.

Nakuba kuyiqiniso ukuthi ukuqina kwethusi kudala ukuchezuka okwengeziwe nokulahlekelwa kwe-impedance, i-foil yakho yethusi idinga ukushelela kangakanani ngempela? Ingabe zikhona izindlela ezilula ongazisebenzisa ukuze unqobe ukulahlekelwa ngaphandle kokukhetha ithusi elibushelelezi kuyo yonke imiklamo? Sizobheka lawa maphuzu kulesi sihloko, kanye nokuthi yini ongayibheka uma uqala ukuthenga izinto zesitaki ze-PCB.

Izinhlobo zeI-PCB Copper Foil

Imvamisa uma sikhuluma ngethusi ezintweni ze-PCB, asikhulumi ngohlobo oluthile lwethusi, sikhuluma kuphela ngobulukhuni bayo. Izindlela ezihlukene zokubeka ithusi zikhiqiza amafilimu anamanani ahlukene okugwedla, angahlukaniswa ngokucacile esithombeni se-electron microscope (SEM) yokuskena. Uma uzosebenza ngamaza aphezulu (ngokuvamile i-WiFi engu-5 GHz noma ngaphezulu) noma ngesivinini esiphezulu, qaphela uhlobo lwethusi olucaciswe kudatha yedatha yakho.

Futhi, qiniseka ukuthi uyaqonda okushiwo amanani ka-Dk kudatha yedatha. Buka le ngxoxo ye-podcast no-John Coonrod ovela ku-Rogers ukuze ufunde kabanzi mayelana nokucaciswa kukaDkt. Unalokho engqondweni, ake sibheke ezinye zezinhlobo ezahlukene zefoyili yethusi ye-PCB.

I-Electrodeposited

Kule nqubo, isigubhu siphothwa ngesisombululo se-electrolytic, futhi ukusabela kwe-electrodeposition kusetshenziselwa "ukukhulisa" i-foil yethusi esigubhini. Njengoba isigubhu sijikeleza, ifilimu yethusi ewumphumela igoqwa kancane kancane kurola, inikeze ishidi lethusi eliqhubekayo elingagoqeka kamuva ku-laminate. Uhlangothi lwesigubhu sekhopha luzofanelana ngokuyisisekelo nobulukhuni besigubhu, kuyilapho uhlangothi oluveziwe luzoba lukhuni kakhulu.

Electrodeposited PCB ucwecwe lwethusi

Ukukhiqizwa kwethusi kwe-Electrodeposited.
Ukuze kusetshenziswe inqubo evamile yokwenziwa kwe-PCB, uhlangothi oluqinile lwethusi luzoqala luhlanganiswe ne-glass-resin dielectric. Ikhopha esele edaluliwe (uhlangothi lwesigubhu) izodinga ukuthi yenziwe rough ngamabomu ngamakhemikhali (isb., nge-plasma etching) ngaphambi kokuthi isetshenziswe enqubweni evamile yokucwenga kwezingubo zethusi. Lokhu kuzoqinisekisa ukuthi ingahlanganiswa isendlalelo esilandelayo kusitaki se-PCB.

I-Surface-Treated Electrodeposited Copper

Angazi igama elingcono kakhulu elihlanganisa zonke izinhlobo ezahlukene zokwelashwa kwendawoizinsimbi zethusi, ngaleyo ndlela isihloko esingenhla. Lezi zinto zethusi zaziwa kakhulu ngokuthi ama-foil ahlanekezelwe, nakuba ezinye izinhlobo ezimbili zitholakala (bheka ngezansi).

Amafoyili ahlanekezelwe ahlanekezela asebenzisa ukwelapha okungaphezulu okusetshenziswa ohlangothini olubushelelezi (uhlangothi lwesigubhu) lweshidi lethusi eline-electrodeposited. Isendlalelo sokwelashwa simane siwukunamathela okuncane okwenza ngamabomu ithusi, ngakho-ke kuzoba nokunamathela okukhulu kokusebenza kwe-dielectric. Lezi zindlela zokwelapha futhi zisebenza njengesithiyo se-oxidation esivimbela ukugqwala. Lapho leli thusi lisetshenziselwa ukwakha amaphaneli e-laminate, uhlangothi oluphathwayo luhlanganiswe ne-dielectric, futhi uhlangothi olusele olubi luhlala ludaluliwe. Uhlangothi oluveziwe ngeke ludinge noma yikuphi ukuqina okwengeziwe ngaphambi kokuqoshwa; izovele inamandla anele okuhlanganisa isendlalelo esilandelayo kusitaki se-PCB.

Izinguquko ezintathu ku-foil yethusi ehlanjululwe emuva zihlanganisa:

Ucwecwe lwekhopha lokwelulwa kwezinga lokushisa eliphezulu (HTE): Lena ucwecwe lwethusi olune-electrodeposited ethobelana nokucaciswa kwe-IPC-4562 Grade 3. Ubuso obuveziwe buphinde buphathwe ngesivimbo se-oxidation ukuvimbela ukugqwala ngesikhathi sokugcinwa.
I-foil ephathwe kabili: Kule foil yethusi, ukwelashwa kusetshenziswa izinhlangothi zombili zefilimu. Le nto ngezinye izikhathi ibizwa ngokuthi i-drum-side foil ephathwayo.
I-Resistive copper: Lokhu ngokuvamile akuhlukaniswa njengethusi elifakwe phezulu. Le foil yethusi isebenzisa i-metallic coating phezu kohlangothi lwe-matte lwethusi, olube lukhuni lufike ezingeni elifunekayo.
Ukusetshenziswa kokwelashwa okungaphezulu kulezi zinto zethusi kuqondile: i-foil igoqwa ngamabhati engeziwe e-electrolyte afaka i-copper plating yesibili, elandelwa ungqimba lwembewu yokuvimbela, futhi ekugcineni ungqimba lwefilimu elwa nokungcoliswa.

PCB ucwecwe lwethusi

Izinqubo zokwelashwa kwe-surface for foil zethusi. [Umthombo: Pytel, Steven G., et al. "Ukuhlaziywa kokwelashwa kwethusi kanye nemiphumela ekusakazweni kwesignali." Ngo-2008 58th Electronic Components and Technology Conference, amakhasi 1144-1149. I-IEEE, 2008.]
Ngalezi zinqubo, unezinto ezingasetshenziswa kalula kunqubo yokwenziwa kwebhodi evamile enokucubungula okuncane okwengeziwe.

Ithusi Elijingiwe

Izindwangu zethusi ezigoqiwe zizodlulisa ucwecwe lwethusi ngepheya lamarola, azogoqa ishidi lethusi libe wugqinsi olufunayo. Ubunzima beshidi le-foil eliphumela kuzohlukahluka kuye ngokuthi imingcele yokugoqa (isivinini, ingcindezi, njll.).

Ishidi eliwumphumela lingaba bushelelezi kakhulu, futhi imigqa ibonakala ebusweni beshidi lethusi eligoqiwe. Izithombe ezingezansi zibonisa ukuqhathanisa phakathi kwecwecwe lethusi eline-electrodeposited kanye ne-rolled-annealed foil.

Ukuqhathaniswa kwe-PCB ye-copper foil

Ukuqhathaniswa kwe-electrodeposited vs. ama-foil rolled-annealed.
I-Low-Profile Copper
Lokhu akulona ngempela uhlobo lwe-foil yethusi ongalwenza ngenye inqubo. Ikhopha enephrofayili ephansi iyithusi elenziwe nge-electrodeposited eliphathwa futhi lilungiswe ngenqubo ye-micro-roughening ukuze linikeze ubuhwaba obumaphakathi obuphansi kakhulu obunokuqina okwanele kokunamathela ku-substrate. Izinqubo zokukhiqiza lezi ziphephelo zethusi ngokuvamile zingezobunikazi. Lawa ma foil avame ukuhlukaniswa njenge-ultra-low profile (ULP), iphrofayili ephansi kakhulu (VLP), kanye nephrofayili ephansi nje (LP, cishe ubuhwaba obumaphakathi be-micron eyi-1).

Izihloko ezihlobene:

Kungani i-Copper Foil isetshenziswa ekwenziweni kwe-PCB?

I-Copper Foil Esetshenziswa Ebhodini Lesifunda Eliphrintiwe