Intego nyamukuru yo guteka PCB ni uguhumanya no gukuraho ubushuhe, no kuvanaho ubuhehere buri muri PCB cyangwa bwakuwe hanze, kuko ibikoresho bimwe na bimwe bikoreshwa muri PCB ubwabyo bikora molekile zamazi byoroshye.
Byongeye kandi, nyuma yuko PCB ikozwe kandi igashyirwa mugihe runaka, hari amahirwe yo gukuramo ubuhehere mubidukikije, kandi amazi numwe mubicanyi nyamukuru ba PCB popcorn cyangwa delamination.
Kuberako iyo PCB ishyizwe mubidukikije ubushyuhe burenze 100 ° C, nk'itanura ryongeye kugaruka, ifuru yo kugurisha imiraba, kuringaniza ikirere gishyushye cyangwa kugurisha intoki, amazi azahinduka imyuka y'amazi hanyuma yongere ubwinshi bwayo.
Iyo umuvuduko wo gushyushya PCB wihuse, umwuka wamazi uzaguka vuba; iyo ubushyuhe buri hejuru, ubwinshi bwumwuka wamazi uzaba munini; iyo umwuka wamazi udashobora guhunga PCB ako kanya, hari amahirwe menshi yo kwagura PCB.
By'umwihariko, Z icyerekezo cya PCB nicyoroshye cyane. Rimwe na rimwe, itandukaniro riri hagati yurwego rwa PCB rishobora gucika, kandi rimwe na rimwe rishobora gutera gutandukanya ibice bya PCB. Ndetse birakomeye, ndetse no kugaragara kwa PCB birashobora kugaragara. Fenomenon nko kubyimba, kubyimba, no guturika;
Rimwe na rimwe, nubwo ibintu byavuzwe haruguru bitagaragara hanze ya PCB, mubyukuri birakomeretsa imbere. Igihe kirenze, bizatera imikorere idahwitse yibicuruzwa byamashanyarazi, cyangwa CAF nibindi bibazo, kandi amaherezo bizananira ibicuruzwa.
Isesengura ryimpamvu nyayo itera PCB ningamba zo gukumira
Uburyo bwo guteka PCB mubyukuri nibibazo. Mugihe cyo guteka, ibipfunyika byumwimerere bigomba kuvaho mbere yuko bishyirwa mu ziko, hanyuma ubushyuhe bugomba kuba burenga 100 ℃ bwo guteka, ariko ubushyuhe ntibukwiye kuba hejuru cyane kugirango wirinde igihe cyo guteka. Kwaguka gukabije kwumwuka wamazi bizaturika PCB.
Muri rusange, ubushyuhe bwo guteka PCB mu nganda ahanini bushyirwa kuri 120 ± 5 ° C kugirango harebwe niba ubuhehere bushobora kuvaho mumubiri wa PCB mbere yuko bugurishwa kumurongo wa SMT kugeza ku ziko ryaka.
Igihe cyo guteka kiratandukanye nubunini nubunini bwa PCB. Kuri PCB yoroheje cyangwa nini, ugomba gukanda ikibaho hamwe nikintu kiremereye nyuma yo guteka. Ibi ni ukugabanya cyangwa kwirinda PCB Ibintu bibabaje byo guhindagurika kwa PCB bitewe no kurekura imihangayiko mugihe cyo gukonja nyuma yo guteka.
Kuberako PCB imaze guhindurwa no kugororwa, hazabaho offset cyangwa ubunini butaringaniye mugihe cyo gucapa paste yagurishijwe muri SMT, bizatera umubare munini wabagurisha imirongo migufi cyangwa inenge yo kugurisha ubusa mugihe cyo kugaruka nyuma.
Kugeza ubu, inganda muri rusange zishyiraho ibihe nigihe cyo guteka PCB kuburyo bukurikira:
1. PCB ifunze neza mugihe cyamezi 2 uhereye umunsi wakozwe. Nyuma yo gupakurura, ishyirwa mubushuhe nubushuhe bugenzurwa nubushuhe (≦ 30 ℃ / 60% RH, ukurikije IPC-1601) muminsi irenga 5 mbere yo kujya kumurongo. Guteka kuri 120 ± 5 ℃ kumasaha 1.
2. PCB ibitswe amezi 2-6 kurenza itariki yo gukora, kandi igomba gutekwa kuri 120 ± 5 ℃ mumasaha 2 mbere yo kujya kumurongo.
3. PCB ibitswe amezi 6-12 kurenza itariki yo gukora, kandi igomba gutekwa kuri 120 ± 5 ° C mumasaha 4 mbere yo kujya kumurongo.
4. PCB ibitswe amezi arenga 12 uhereye igihe yatangiriye. Ahanini, ntabwo byemewe kubikoresha, kuko imbaraga zifatika zubuyobozi bwibice byinshi bizasaza igihe, kandi ibibazo byubuziranenge nkibikorwa byibicuruzwa bidahindagurika bishobora kubaho mugihe kizaza, bikazamura isoko ryo gusana. Byongeye kandi, inzira yo kubyara nayo ifite ingaruka nko guturika amasahani no kurya amabati nabi. Niba ugomba kuyikoresha, birasabwa kuyiteka kuri 120 ± 5 ° C mumasaha 6. Mbere yumusaruro mwinshi, banza ugerageze gucapa uduce duke twa paste hanyuma ugenzure neza ko ntakibazo gihari mbere yo gukomeza umusaruro.
Indi mpamvu nuko bidasabwa gukoresha PCB zabitswe igihe kirekire kuko kuvura kwabo bizagenda binanirwa buhoro buhoro mugihe. Kuri ENIG, ubuzima bwinganda bwinganda ni amezi 12. Nyuma yiki gihe ntarengwa, biterwa no kubitsa zahabu. Umubyimba uterwa n'ubunini. Niba umubyimba ari muto, nikel irashobora kugaragara kumurongo wa zahabu kubera gukwirakwizwa no gukora okiside, bigira ingaruka ku kwizerwa.
5. PCB zose zokejwe zigomba gukoreshwa mugihe cyiminsi 5, kandi PCB idatunganijwe igomba gutekwa kuri 120 ± 5 ° C mugihe cyamasaha 1 mbere yo kujya kumurongo.