Ngemva kokuba PCB umklamo usuphothuliwe, konke kuzolunga? Eqinisweni, akunjalo. Enqubweni yokucubungula i-PCB, izinkinga ezihlukahlukene zivame ukuhlangatshezwana nazo, njengethayela eliqhubekayo ngemva kokufakwa kwamagagasi. Yiqiniso, akuzona zonke izinkinga “eziyibhodwe” lomklamo we-PCB, kodwa njengabaklami, kufanele siqale siqinisekise ukuthi umklamo wethu ukhululekile.

Uluhlu

I-Wave soldering

I-Wave soldering iwukwenza indawo ehlanganisiwe yebhodi le-plug-in ixhumane ngokuqondile ne-high-temperature liquid tin ukuze kuzuzwe inhloso yokudambisa. I-liquid tin enezinga eliphezulu lokushisa igcina umthambeka, futhi idivayisi ekhethekile yenza ithini eliwuketshezi libe yinto efana negagasi, ngakho ibizwa ngokuthi “i-wave soldering”. Impahla eyinhloko yimishayo ye-solder.

Kungani ibhodi le-PCB livela nethayela ngemva kokunamagagasi? Ungakugwema kanjani?

Inqubo ye-Wave soldering

Izihlanganisi ezimbili noma ngaphezulu ze-solder zixhunywe nge-solder, okuholela ekubukekeni okubi nokusebenza, okucaciswe njengezinga lesici nge-IPC-A-610D.

Kungani ibhodi le-PCB livela nethayela ngemva kokunamagagasi?

Okokuqala, sidinga ukukucacisa ukuthi ukuba khona kwethini ebhodini le-PCB akuyona inkinga yokuklama okungekuhle kwe-PCB. Kungase futhi kube ngenxa yomsebenzi ompofu wokuguquguquka, ukumanzisa okunganele, ukusetshenziswa okungalingani, ukushisa kwangaphambi kokushisa kanye nezinga lokushisa le-solder ngesikhathi se-wave soldering. Kuhle ukulinda isizathu.

Uma kuyinkinga yedizayini ye-PCB, singacabangela kusukela kulezi zici ezilandelayo:

1. Ukuthi ngabe ibanga eliphakathi kwezihlanganisi ze-solder zedivayisi ye-wave soldering lanele yini;

2. Ingabe indlela yokudlulisela ye-plug-in inengqondo?

3. Esimeni lapho i-pitch ingahlangabezani nezidingo zenqubo, ingabe ikhona iphedi lokweba ithini kanye noyinki wesikrini sikasilika okwengezwe?

4. Ukuthi ubude bezikhonkwane ze-plug-in bude kakhulu, njll.

Ungakugwema kanjani ngisho ne-tin ekwakhiweni kwe-PCB?

1. Khetha izingxenye ezifanele. Uma ibhodi lidinga i-wave soldering, isikhala esinconyiwe sedivayisi (isikhala esimaphakathi phakathi kwamaphinikhodi) sikhulu kuno-2.54mm, futhi kunconywa ukuthi sibe sikhulu kuno-2.0mm, ngaphandle kwalokho ubungozi bokuxhunywa kwethini buphezulu uma kuqhathaniswa. Lapha ungakwazi ukushintsha ngokufanelekile iphedi elungiselelwe ukuze ihlangabezane nobuchwepheshe bokucubungula kuyilapho ugwema ukuxhunywa kwe-tin.

2. Ungangeni onyaweni lwe-soldering ngaphezu kuka-2mm, ngaphandle kwalokho kulula kakhulu ukuxhuma ithini. Inani elingokomfanekiso, lapho ubude bomthofu ophuma ebhodini bungu-≤1mm, ithuba lokuxhuma ithini lesokhethi yephini eliminyene lizoncishiswa kakhulu.

3. Ibanga phakathi kwamasongo ethusi akufanele libe ngaphansi kuka-0.5mm, futhi amafutha amhlophe kufanele afakwe phakathi kwamasongo ethusi. Yingakho sivame ukubeka ungqimba lwamafutha amhlophe esikrini sikasilika endaweni yokushisela ye-plug-in lapho siklama. Ngesikhathi senqubo yokuklama, lapho i-pad ivuliwe endaweni ye-mask ye-solder, qaphela ukugwema amafutha amhlophe esikrinini sikasilika.

4. Ibhuloho likawoyela eliluhlaza akumele libe ngaphansi kuka-2mil (ngaphandle kwama-chips anamandla e-surface mount pin njengamaphakheji e-QFP), ngaphandle kwalokho kulula ukubangela ukuxhumana kwe-tin phakathi kwamaphedi ngesikhathi sokucubungula.

5. Isiqondiso sobude sezingxenye sihambisana nesiqondiso sokudlulisa ibhodi kuthrekhi, ngakho-ke inani lezikhonkwane zokuphatha uxhumano lwe-tin lizoncishiswa kakhulu. Enqubweni yokuklama ye-PCB yobungcweti, idizayini inquma ukukhiqizwa, ngakho-ke isiqondiso sokudlulisela kanye nokubekwa kwamadivayisi okuthengisa amagagasi empeleni kuhle kakhulu.

6. Faka amaphedi okuntshontsha amathini, engeza amaphedi okweba amathini ekupheleni kwendlela yokudlulisela ngokwezidingo zesakhiwo sepulaki ebhodini. Ubukhulu bephedi lokweba ithini bungalungiswa ngokufanele ngokuya ngokuminyana kwebhodi.

7. Uma kufanele usebenzise i-plug-in eminyene, singafaka ucezu lwe-solder lokudonsa endaweni engaphezulu ye-tin ukuze uvimbele ukwakheka kwe-solder futhi kubangele izinyawo zengxenye ukuthi zixhumeke kuthayela.