PCB ubuchwepheshe bokwelapha okungaphezulu busho inqubo yokwenza ungqimba olungaphezulu ngokwenziwa ezingxenyeni ze-PCB kanye nezindawo zokuxhuma zikagesi ezehlukile kumishini, izakhiwo zomzimba kanye namakhemikhali ze-substrate. Inhloso yawo iwukuqinisekisa ukuthi i-solderability enhle noma izakhiwo zikagesi ze-PCB. Ngenxa yokuthi ithusi livame ukuba khona ngesimo sama-oxides emoyeni, okuthinta kakhulu ukuthengiselana kanye nezakhiwo zikagesi ze-PCB, kuyadingeka ukwenza ukwelashwa okungaphezulu ku-PCB.

Njengamanje, izindlela ezijwayelekile zokwelashwa kwendawo zimi kanje:

1. Ukulinganisa komoya oshisayo

Ingaphezulu le-PCB limbozwe nge-solder ye-tin-lead encibilikisiwe futhi isicaba ngomoya ocindezelwe oshisayo (i-flat flat) ukuze kwakheke ungqimba olunamathelayo olumelana ne-oxidation yethusi futhi lunikeze ukudayiswa okuhle. Ngesikhathi sokulinganisa komoya oshisayo, i-solder nethusi yakha inhlanganisela yensimbi yethusi-tin ekuhlanganeni, futhi ubukhulu bungaba ngu-1 kuya ku-2 mils;

2. I-Organic Anti-oxidation (OSP)

Endaweni yethusi ehlanzekile engenalutho, ifilimu ye-organic itshalwa ngamakhemikhali. Lolu ngqimba lwefilimu lune-anti-oxidation, ukumelana nokushaqeka kokushisa, nokumelana nomswakama ukuze kuvikelwe indawo yethusi ekugqwaleni (i-oxidation noma i-sulfidation, njll.) endaweni evamile; ngesikhathi esifanayo, kufanele kusizwe kalula ekushiseni okulandelayo kokushisa okuphezulu I-flux isuswa ngokushesha ukuze kube lula ukushisela;

3. Igolide le-nickel elingenawo ugesi

Ungqimba olujiyile lwe-nickel-gold alloy olunezinto zikagesi ezinhle lugoqwa endaweni yethusi futhi lungavikela i-PCB isikhathi eside. Ngokungafani ne-OSP, esetshenziswa kuphela njengesendlalelo sokuvimbela ukugqwala, ingaba usizo ekusetshenzisweni kwesikhathi eside kwe-PCB futhi izuze ukusebenza okuhle kukagesi. Ngaphezu kwalokho, iphinde ibe nokubekezelela imvelo ukuthi ezinye izinqubo zokwelashwa ezingaphezulu ezingenakho;

4. Chemical Immersion Silver

Phakathi kwe-OSP ne-electroless nickel/igolide lokucwiliswa, inqubo ilula futhi iyashesha. Uma kuvezwe ukushisa, umswakama kanye nokungcola, kusengakwazi ukunikeza ukusebenza okuhle kukagesi futhi kugcine ukutholakala kahle kwe-solderability, kodwa kuzolahlekelwa ukukhanya kwayo. Ngenxa yokuthi ayikho i-nickel ngaphansi kongqimba lwesiliva, isiliva lokucwiliswa alinawo amandla angokwenyama e-electroless nickel/igolide lokucwiliswa;

5. Electroplating nickel igolide

I-conductor engaphezulu kwe-PCB ifakwe ungqimba lwe-nickel bese ihlanganiswa ngongqimba lwegolide. Inhloso eyinhloko ye-nickel plating ukuvimbela ukusabalala phakathi kwegolide nethusi. Kunezinhlobo ezimbili zegolide le-nickel elenziwe nge-electroplated: igolide elithambile (igolide elihlanzekile, igolide likhombisa ukuthi alibukeki ligqamile) kanye negolide eliqinile (indawo ebushelelezi futhi iqinile, ayigugi, iqukethe i-cobalt nezinye izakhi, kanye nengaphezulu. ibonakala ikhanya). Igolide elithambile lisetshenziselwa ikakhulukazi izintambo zegolide ngesikhathi sokupakishwa kwe-chip; igolide eliqinile lisetshenziswa kakhulu ekuxhumekeni kukagesi ezindaweni ezingadayisi (njengeminwe yegolide).

6. PCB hybrid surface treatment technology

Khetha izindlela ezimbili noma ngaphezulu zokwelashwa kwendawo yokwelapha ngaphezulu. Amafomu avamile yilawa: I-Immersion Nickel Gold + Anti-oxidation, Electroplating Nickel Gold + Immersion Nickel Gold, Electroplating Nickel Gold + Hot Air Leveling, Immersion Nickel Gold + Hot Air Leveling.

Ukulinganisa komoya oshisayo (ngaphandle komthofu/okuholayo) kuyindlela evamile futhi eshibhe kakhulu yazo zonke izindlela zokwelapha ezingaphezulu, kodwa sicela unake imithetho ye-EU ye-RoHS.

I-RoHS: I-RoHS iyindinganiso eyisibopho esungulwe umthetho we-EU. Igama layo eligcwele lithi “Ukukhawulwa Kwezinto Eziyingozi” (Ukukhawulwa Kwezinto Eziyingozi). Izinga lisetshenziswe ngokusemthethweni ngomhla ka-1 Julayi, 2006, futhi lisetshenziselwa kakhulu ukwenza amazinga okusebenza nokucubungula imikhiqizo ye-elekthronikhi kanye nekagesi, ayenze ibe wusizo empilweni yabantu nasekuvikelweni kwemvelo. Inhloso yaleli zinga ukuqeda izinto eziyisithupha okuhlanganisa umthofu, i-mercury, i-cadmium, i-hexavalent chromium, ama-polybrominated biphenyls nama-polybrominated diphenyl ethers emikhiqizweni kagesi neye-elekthronikhi, futhi ibeka ngokucacile ukuthi okuqukethwe komthofu akumele kudlule u-0.1%.