Inhloso enkulu yokubhaka kwe-PCB ukukhipha umswakama nokususa umswakama oqukethwe ku-PCB noma omuncwe emhlabeni wangaphandle, ngoba ezinye izinto ezisetshenziswa ku-PCB ngokwayo zakha kalula ama-molecule amanzi.
Ngaphezu kwalokho, ngemva kokukhiqizwa kwe-PCB futhi ibekwe isikhathi esithile, kunethuba lokumunca umswakama endaweni, futhi amanzi angomunye wababulali abakhulu be-PCB popcorn noma i-delamination.
Ngoba uma i-PCB ibekwe endaweni lapho izinga lokushisa lidlula u-100°C, njenge-oven yokugeleza kabusha, i-wave soldering oven, ukulinganisa komoya oshisayo noma ukusoda ngesandla, amanzi azophenduka abe umhwamuko wamanzi bese andisa ivolumu yawo ngokushesha.
Lapho ukushisa kusetshenziswa ngokushesha ku-PCB, umhwamuko wamanzi uzokhula ngokushesha; lapho izinga lokushisa liphakeme, umthamo omkhulu womhwamuko wamanzi uyanda; lapho umhwamuko wamanzi ungakwazi ukuphuma ku-PCB ngokushesha, kunethuba elihle lokunweba i-PCB .
Ikakhulukazi, i-Z direction ye-PCB iyona entekenteke kakhulu. Ngezinye izikhathi i-vias phakathi kwezingqimba ze-PCB ingase iphulwe, futhi ngezinye izikhathi ingase ibangele ukuhlukaniswa kwezingqimba ze-PCB. Okubi nakakhulu, ngisho nokubukeka kwe-PCB kungabonakala. Isenzakalo esinjengokuqhuma, ukuvuvukala, nokuqhuma;
Kwesinye isikhathi ngisho noma lezi zinto ezingenhla zingabonakali ngaphandle kwe-PCB, kulimala ngaphakathi. Ngokuhamba kwesikhathi, izodala imisebenzi engazinzile yemikhiqizo kagesi, noma i-CAF nezinye izinkinga, futhi ekugcineni ibangele ukwehluleka komkhiqizo.
Ukuhlaziywa kwembangela yangempela yokuqhuma kwe-PCB nezinyathelo zokuvimbela
Inqubo yokubhaka ye-PCB empeleni inzima kakhulu. Ngesikhathi sokubhaka, amaphakheji okuqala kufanele asuswe ngaphambi kokuthi afakwe kuhhavini, bese izinga lokushisa kufanele libe ngaphezu kuka-100℃ ukubhaka, kodwa izinga lokushisa akufanele libe phezulu kakhulu ukugwema isikhathi sokubhaka. Ukunwetshwa ngokweqile komhwamuko wamanzi kuzoqhumisa i-PCB.
Ngokuvamile, izinga lokushisa lokubhaka le-PCB embonini livame ukusethwa ku-120±5°C ukuze kuqinisekiswe ukuthi umswakama ungasuswa ngempela emzimbeni we-PCB ngaphambi kokuthi udayiswe kulayini we-SMT uye esithandweni sokugeleza kabusha.
Isikhathi sokubhaka siyahlukahluka ngobukhulu nobukhulu be-PCB. Kuma-PCB azacile noma amakhulu, kufanele ucindezele ibhodi ngento esindayo ngemva kokubhaka. Lokhu okokunciphisa noma ukugwema i-PCB Isigameko esidabukisayo sokuguquguquka kwe-PCB ngenxa yokukhululwa kwengcindezi phakathi nokupholisa ngemva kokubhaka.
Ngoba uma i-PCB isikhubazekile futhi igobile, kuzoba khona ukujiya noma ukushuba okungalingani lapho uphrinta unamathisele i-solder ku-SMT, okuzodala inani elikhulu lamasekethe amafushane we-solder noma amaphutha angenalutho wokunamathisela ngesikhathi sokugeleza kabusha okulandelayo.
PCB ukubhaka isimo setting
Njengamanje, imboni ngokuvamile ibeka izimo kanye nesikhathi sokubhaka kwe-PCB ngale ndlela elandelayo:
1. I-PCB ivalwe kahle phakathi nezinyanga ezi-2 kusukela ngosuku lokukhiqiza. Ngemva kokukhipha impahla, ibekwa endaweni elawulwa izinga lokushisa nokuswakama (≦30℃/60%RH, ngokusho kwe-IPC-1601) izinsuku ezingaphezu kwezingu-5 ngaphambi kokungena ku-inthanethi. Bhaka ku-120±5℃ ihora elingu-1.
2. I-PCB igcinwa izinyanga ezingu-2-6 ngemva kosuku lokukhiqiza, futhi kufanele ibhakwe ku-120±5℃ amahora angu-2 ngaphambi kokungena ku-inthanethi.
3. I-PCB igcinwa izinyanga ezingu-6-12 ngaphezu kosuku lokukhiqiza, futhi kufanele ibhakwe ku-120±5°C amahora angu-4 ngaphambi kokungena ku-inthanethi.
4. I-PCB igcinwa isikhathi esingaphezu kwezinyanga eziyi-12 kusukela ngosuku lokukhiqiza, ngokuyisisekelo ayinconywa, ngoba amandla okubopha amabhodi amaningi azoguga ngokuhamba kwesikhathi, futhi izinkinga zekhwalithi ezifana nemisebenzi engazinzile yomkhiqizo ingase yenzeke esikhathini esizayo, okuzokwenza ukwandisa imakethe yokukhandwa Ngaphezu kwalokho, inqubo yokukhiqiza nayo inezingozi ezifana nokuqhuma kwamapuleti kanye nokungadli kahle kwamathini. Uma kufanele uyisebenzise, kutuswa ukuthi uyibhake ku-120±5°C amahora angu-6. Ngaphambi kokukhiqiza ngobuningi, qala uzame ukuphrinta izingcezu ezimbalwa ze-solder unama futhi uqiniseke ukuthi ayikho inkinga ye-solderability ngaphambi kokuqhubeka nokukhiqiza.
Esinye isizathu ukuthi akunconywa ukusebenzisa ama-PCB agcinwe isikhathi eside kakhulu ngoba ukwelashwa kwawo okungaphezulu kuzohluleka kancane kancane ngokuhamba kwesikhathi. Ku-ENIG, impilo yeshalofu yomkhakha yizinyanga eziyi-12. Ngemva kwalo mkhawulo wesikhathi, kuya ngediphozithi yegolide. Ubukhulu buncike ekugqineni. Uma ubukhulu buncane, ungqimba lwe-nickel lungase luvele kungqimba lwegolide ngenxa yokusabalalisa kanye ne-oxidation yefomu, ethinta ukwethembeka.
5. Wonke ama-PCB abhakiwe kufanele asetshenziswe zingakapheli izinsuku ezi-5, futhi ama-PCB angakacutshungulwa kufanele abhakwe futhi ku-120±5°C elinye ihora elingu-1 ngaphambi kokungena ku-inthanethi.