Inhloso eyisisekelo kakhulu ye PCB ukwelashwa surface ukuqinisekisa solderability ezinhle noma izakhiwo kagesi. Njengoba ithusi lemvelo livame ukuba khona ngesimo sama-oxides emoyeni, akunakwenzeka ukuthi lihlale liyithusi langempela isikhathi eside, ngakho-ke ezinye izindlela zokwelapha ziyadingeka ngethusi.

1. Ukulinganisa komoya oshisayo (ukufafaza ngethini) ukulinganisa komoya oshisayo, okubuye kwaziwe ngokuthi ukuleveliswa kwe-hot air solder (okuvame ukwaziwa ngokuthi ithini lokufafaza), kuyinqubo yokumboza i-solder encibilikisiwe yethayela (lead) ebusweni be-PCB kanye nokulinganisa (ukuvuthela) it ngomoya ocindezelwe oshisayo. Yakha isendlalelo sokumboza esingamelani kuphela ne-oxidation yethusi, kodwa futhi sinikeza i-solderability enhle. Ngesikhathi sokulinganisa komoya oshisayo, i-solder nethusi zakha i-copper-tin intermetallic compound ekuhlanganyeleni. Lapho i-PCB ilinganiswe ngomoya oshisayo, kufanele icwiliswe ku-solder encibilikisiwe; ummese womoya uphephetha i-solder ewuketshezi ngaphambi kokuba i-solder iqine; ummese womoya unganciphisa i-meniscus ye-solder endaweni yethusi futhi uvimbele i-solder ekubhubhiseni.

2. I-Organic Solderability Preservative (OSP) I-OSP iyinqubo yokwelashwa okungaphezulu kwe-printed circuit board (PCB) ucwecwe lwethusi oluhlangabezana nezimfuneko zomyalelo we-RoHS. I-OSP isifinyezo se-Organic Solderability Preservatives, esihunyushwa ngokuthi i-Organic Solderability Preservatives ngesi-Chinese, eyaziwa nangokuthi i-Copper Protector, noma i-Preflux ngesiNgisi. Kalula nje, i-OSP iwukukhulisa ngamakhemikhali ungqimba lwefilimu ephilayo endaweni ehlanzekile yethusi engenalutho. Lesi singqimba sefilimu sine-anti-oxidation, ukumelana nokushisa okushisayo, nokumelana nomswakama ukuze kuvikelwe indawo yethusi ekugqwaleni (i-oxidation noma i-sulfidation, njll.) endaweni evamile; kodwa ekushiseleni okwalandela izinga lokushisa eliphezulu, lolu hlobo lwefilimu yokuzivikela kufanele lube kakhulu Kulula ukususwa ngokushesha yi-flux, ukuze indawo yethusi ehlanzekile eveziwe ingahlanganiswa ngokushesha ne-solder encibilikisiwe ibe yinhlanganisela eqinile ye-solder endaweni enkulu. isikhathi esifushane.

3. Ipuleti lonke lihuqwe nge-nickel negolide

I-nickel-gold plating yebhodi iwukuba unamathisele ungqimba lwe-nickel ebusweni be-PCB bese kuba ungqimba lwegolide. I-nickel plating ihlose ukuvimbela ukuhlukaniswa phakathi kwegolide nethusi. Kunezinhlobo ezimbili zegolide le-nickel elenziwe nge-electroplated: igolide elithambile (igolide elihlanzekile, indawo yegolide ayibukeki ikhanya) kanye negolide eliqinile (indawo ebushelelezi futhi iqinile, ayigugi, iqukethe i-cobalt nezinye izakhi, kanye nendawo yegolide. ibonakala ikhanya). Igolide elithambile lisetshenziselwa ikakhulukazi izintambo zegolide ngesikhathi sokupakishwa kwe-chip; igolide eliqinile lisetshenziselwa ikakhulukazi ukuxhumana kukagesi ezindaweni ezingashiselwe.

4. Ukucwiliswa kwegolide Ukucwiliswa kwegolide ungqimba oluwugqinsi lwengxube ye-nickel-golide enezici ezinhle zikagesi endaweni yethusi, engavikela i-PCB isikhathi eside; ngaphezu kwalokho, iphinde ibe nokubekezelelana kwemvelo ukuthi ezinye izinqubo zokwelashwa ezingaphezulu ezingenakho. Ngaphezu kwalokho, ukucwiliswa kwegolide kungavimbela futhi ukuchithwa kwethusi, okuzozuzisa umhlangano ongenamthofu.

5. Ithini lokucwiliswa Njengoba wonke ama-solder amanje asekelwe ku-tin, ungqimba lukathayela lungafaniswa nanoma yiluphi uhlobo lwe-solder. Inqubo yokucwiliswa kwethini ingakha inhlanganisela ye-copper-tin intermetallic eyisicaba. Lesi sici senza ukucwiliswa kwe-tin kube nokudayiswa okuhle okufanayo nokulingana komoya oshisayo ngaphandle kwenkinga yokuqina kwekhanda yokulinganisa komoya oshisayo; amabhodi e-tin-immersion awakwazi ukugcinwa isikhathi eside kakhulu , Umhlangano kufanele wenziwe ngokohlelo lwethini lokucwila.

6. Ukucwiliswa kwesiliva Inqubo yesiliva yokucwiliswa iphakathi kokumboza okuphilayo kanye ne-electroless nickel/igolide lokucwiliswa. Inqubo ilula futhi iyashesha; ngisho noma evezwe ukushisa, umswakama kanye nokungcoliswa, isiliva lisengakwazi ukugcina i-solderability enhle. Kodwa izolahlekelwa ukucwebezela kwayo. Isiliva lokucwiliswa alinawo amandla angokomzimba we-nickel engenawo ugesi/igolide lokucwiliswa ngoba ayikho i-nickel ngaphansi kongqimba lwesiliva.

7. Uma kuqhathaniswa negolide lokucwiliswa, ikhemikhali ye-nickel palladium gold inongqimba olwengeziwe lwe-palladium phakathi kwe-nickel negolide. I-Palladium ingavimbela ukugqwala okubangelwa ukusabela kokushintsha futhi yenze amalungiselelo aphelele egolide lokucwiliswa. Igolide limbozwe ngokuqinile ku-palladium, linikeza indawo enhle yokuxhumana.

8. Igolide eliqinile elifakwe ngogesi ukuze kuthuthukiswe ukumelana nokugqokwa komkhiqizo futhi kwandiswe inani lokufakwa nokususwa.