Ukwelashwa kwendawo jikelele ye PCB kufaka phakathi ukufutha ngothayela, i-OSP, ukucwiliswa kwegolide, njll. “Ubuso” lapha bubhekisela ezindaweni zokuxhuma ku-PCB ezihlinzeka ngoxhumano lukagesi phakathi kwezingxenye ze-elekthronikhi noma ezinye izinhlelo kanye nesekhethi ye-PCB, njengamaphedi. Noma indawo yokuxhumana. I-solderability yethusi engenalutho ngokwayo inhle kakhulu, kodwa kulula ukuyi-oxidize lapho ivuliwe emoyeni, futhi kulula ukungcoliswa. Yingakho i-PCB kufanele iphathwe ngaphandle.

1. Futha ithini (HASL)

Lapho amadivaysi anezimbobo ebusa, i-wave soldering iyindlela engcono kakhulu yokuhlanganisa. Ukusetshenziswa kwe-hot-air solder leveling (i-HASL, i-Hot-air solder leveling) ubuchwepheshe bokwelashwa kwendawo yanele ukuhlangabezana nezidingo zenqubo ye-wave soldering. Yiqiniso, ngezikhathi ezidinga amandla aphezulu okuhlangana (ikakhulukazi uxhumano lokuxhumana), i-electroplating ye-nickel/igolide ivame ukusetshenziswa. . I-HASL iwubuchwepheshe bokwelapha obuphezulu obusetshenziswa emhlabeni wonke, kodwa kunamandla amathathu amakhulu okushayela aqhuba imboni yezogesi ukuthi icabangele obunye ubuchwepheshe be-HASL: izindleko, izidingo zenqubo entsha kanye nezidingo ezingenamthofu.

Ngokombono wezindleko, izakhi eziningi ze-elekthronikhi ezifana nokuxhumana kwamaselula namakhompyutha omuntu siqu seziba yizimpahla zabathengi ezidumile. Kuphela ngokuthengisa ngezindleko noma amanani aphansi lapho singakwazi khona ukunqotshwa endaweni enokuncintisana enonya. Ngemuva kokuthuthukiswa kobuchwepheshe bokuhlanganisa ku-SMT, amaphedi e-PCB adinga ukuphrinta kwesikrini kanye nezinqubo zokuphinda zigeleze ngesikhathi somhlangano. Endabeni ye-SMA, inqubo yokwelashwa kwendawo ye-PCB isasebenzisa ubuchwepheshe be-HASL ekuqaleni, kodwa njengoba amadivaysi e-SMT eqhubeka nokuncipha, ama-pads kanye nokuvuleka kwe-stencil nakho kuye kwaba kuncane, futhi ukungaphumeleli kobuchwepheshe be-HASL kuye kwadalulwa kancane kancane. Amaphedi acutshungulwe ubuchwepheshe be-HASL awasicaba ngokwanele, futhi i-coplanarity ayikwazi ukuhlangabezana nezidingo zenqubo yamaphedi we-fine-pitch. Ukukhathazeka kwemvelo kuvame ukugxila emthelela ongaba khona womthofu endaweni ezungezile.

2. I-Organic Solderability Protective Layer (OSP)

I-Organic solderability preservative (i-OSP, i-Organic solderability preservative) iwukunamathela okuphilayo okusetshenziselwa ukuvimbela i-oxidation yethusi ngaphambi kokudayiswa, okungukuthi, ukuvikela ukudayiswa kwamaphedi e-PCB emonakalweni.

Ngemva kokuba indawo ye-PCB iphathwe nge-OSP, kwakheka isakhi semvelo esincanyana phezu kwethusi ukuze kuvikelwe ithusi ku-oxidation. Ugqinsi lwe-Benzotriazoles OSP luvamise ukuba ngu-100 A°, kuyilapho ubukhulu be-Imidazoles OSP bushubile, ngokuvamile bungu-400 A°. Ifilimu ye-OSP isobala, akulula ukuhlukanisa ubukhona bayo ngeso lenyama, futhi kunzima ukuyibona. Ngesikhathi senqubo yokuhlanganisa (i-reflow soldering), i-OSP iyancibilika kalula ku-solder paste noma i-Acidi Flux, futhi ngesikhathi esifanayo indawo yethusi esebenzayo ivezwa, futhi ekugcineni ama-Sn / Cu intermetallic compounds akhiwa phakathi kwezingxenye namapads. Ngakho-ke, i-OSP inezici ezinhle kakhulu lapho isetshenziselwa ukwelapha indawo yokushisela. I-OSP ayinayo inkinga yokungcoliswa komthofu, ngakho-ke ihambisana nemvelo.

Imikhawulo ye-OSP:

①. Njengoba i-OSP isobala futhi ingenambala, kunzima ukuyihlola, futhi kunzima ukuhlukanisa ukuthi i-PCB ihlanganiswe ne-OSP.

② I-OSP ngokwayo ivalekile, ayiwuhambisi ugesi. I-OSP ye-Benzotriazoles incane kakhulu, engase ingathinti ukuhlolwa kukagesi, kodwa ku-OSP ye-Imidazoles, ifilimu yokuzivikela eyakhiwe iwugqinsi, okuzothinta ukuhlolwa kukagesi. I-OSP ayikwazi ukusetshenziselwa ukuphatha izindawo zokuthintana zikagesi, njengezindawo zekhibhodi zokhiye.

③ Ngesikhathi senqubo yokushisela ye-OSP, i-Flux enamandla iyadingeka, ngaphandle kwalokho ifilimu yokuzivikela ayikwazi ukuqedwa, okuzoholela ekushiyekeni kwe-welding.

④ Phakathi nenqubo yokugcina, ingaphezulu le-OSP akumele livezwe ezintweni ezine-acidic, futhi izinga lokushisa akufanele libe phezulu kakhulu, ngaphandle kwalokho i-OSP izoshintshashintsha.

3. Igolide lokucwiliswa (ENIG)

Indlela yokuvikela ye-ENIG:

I-Ni/A igxunyekwa endaweni yethusi ngendlela yamakhemikhali. Ugqinsi lwe-deposition yongqimba lwangaphakathi lwe-Ni ngokuvamile luyi-120 kuya ku-240 μin (cishe u-3 kuya ku-6 μm), futhi ugqinsi lwe-deposition yongqimba lwangaphandle lwe-Au luncane kakhulu, ngokuvamile lu-2 kuya ku-4 μin (0.05 kuya ku-0.1 μm). I-Ni yakha isendlalelo sokuvimbela phakathi kwe-solder nethusi. Ngesikhathi se-soldering, i-Au engaphandle izoncibilika ngokushesha ku-solder, futhi i-solder ne-Ni izokwakha i-Ni / Sn intermetallic compound. Ukufakwa kwegolide ngaphandle ukuvikela i-Ni oxidation noma i-passivation ngesikhathi sokugcinwa, ngakho-ke ungqimba lwegolide lokucwenga kufanele lube lukhuni ngokwanele futhi ukujiya akufanele kube mncane kakhulu.

Igolide lokucwiliswa: Kule nqubo, inhloso ukubeka ungqimba oluvikelayo lwegolide oluncane noluqhubekayo. Ubukhulu begolide eliyinhloko akufanele bube bukhulu kakhulu, ngaphandle kwalokho amalunga e-solder azoba brittle kakhulu, okuzothinta kakhulu ukuthembeka kwe-welding. Njenge-nickel plating, igolide lokucwiliswa linezinga lokushisa eliphezulu lokusebenza kanye nesikhathi eside. Ngesikhathi senqubo yokucwilisa, ukusabela kokufuduka kuzokwenzeka-ebusweni be-nickel, igolide lithatha indawo ye-nickel, kodwa lapho ukufuduka kufinyelela ezingeni elithile, ukusabela kokufuduka kuzoma ngokuzenzakalelayo. Igolide linamandla amakhulu, ukumelana nokuhuzuka, ukumelana nokushisa okuphezulu, futhi akulula ukwenza i-oxidize, ngakho-ke ingavimbela i-nickel kusuka ku-oxidation noma i-passivation, futhi ifaneleka ukusebenza kuzinhlelo zokusebenza zamandla aphezulu.

Indawo ye-PCB ephathwa yi-ENIG iphansi kakhulu futhi inokubumbana okuhle, okuyiyona kuphela esetshenziselwa indawo yokuxhumana yenkinobho. Okwesibili, i-ENIG ine-solderability enhle kakhulu, igolide lizoncibilika ngokushesha ku-solder encibilikisiwe, ngaleyo ndlela lidalule i-Ni entsha.

Imikhawulo ye-ENIG:

Inqubo ye-ENIG iyinkimbinkimbi kakhulu, futhi uma ufuna ukuzuza imiphumela emihle, kufanele ulawule ngokuqinile imingcele yenqubo. Into ekhathaza kakhulu ukuthi indawo ye-PCB ephathwa yi-ENIG ijwayele ukuba namaphedi amnyama ngesikhathi se-ENIG noma i-soldering, okuzoba nomthelela oyinhlekelele ekuthembekeni kwamalunga e-solder. Indlela yokukhiqiza yediski emnyama iyinkimbinkimbi kakhulu. Kwenzeka ekuxhumaneni kwe-Ni negolide, futhi kubonakaliswa ngokuqondile njenge-oxidation eyeqile ye-Ni. Igolide eliningi lizohlanganisa amalunga e-solder futhi lithinte ukwethembeka.

Inqubo ngayinye yokwelashwa kwendawo inezici zayo ezihlukile, futhi ububanzi bokusebenza buhlukile. Ngokusetshenziswa kwamabhodi ahlukene, izidingo ezihlukene zokwelashwa kwendawo ziyadingeka. Ngaphansi komkhawulo wenqubo yokukhiqiza, ngezinye izikhathi senza iziphakamiso kumakhasimende ngokusekelwe kuzici zamabhodi. Isizathu esiyinhloko siwukuba nokwelashwa kwendawo okunengqondo okusekelwe esicelweni somkhiqizo wekhasimende kanye nekhono lenqubo yenkampani. s Ukukhetha.