1, ithini lokufaka umphumela

Lapho i-liquid solder eshisayo incibilika futhi ingena ebusweni bensimbi ye- PCB kuthengiswa, kubizwa ngokuthi yi-metal bonding noma i-metal bonding. Ama-molecule enhlanganisela ye-solder nethusi akha ingxubevange entsha eyingxenye yethusi nengxenye ye-solder. Lesi senzo se-solvent sibizwa ngokuthi yi-tin-bonding. Kwakha isibopho se-intermolecular phakathi kwezingxenye ezahlukahlukene ze-PCB, kwakha inhlanganisela yensimbi. Ukwakheka kwezibopho ezinhle ze-intermolecular kungumgogodla wenqubo ye-PCB welding, enquma amandla nekhwalithi yamaphoyinti wokushisela we-PCB. I-Tin ingamenyezelwa kuphela uma indawo yethusi ingenakho ukungcoliswa nefilimu ye-oxide eyakhiwe ngenxa yokuchayeka kwe-PCB emoyeni, futhi i-solder nendawo yokusebenza idinga ukufinyelela izinga lokushisa elifanele.

2.Ukuqina kwesimo

Wonke umuntu ujwayelene nokungezwani kwamanzi, amandla agcina amaconsi amanzi abandayo eyindilinga kungcwecwe wensimbi we-PCB ngoba, kulokhu, ukunamathela okuvame ukusabalalisa uketshezi endaweni eqinile kuncane kunokuhlangana kwawo. Geza ngamanzi afudumele kanye nensipho yokunciphisa ukungezwani komhlaba. Amanzi azogcwalisa ipuleti lensimbi eligcotshiswe nge-PCB bese egelezela ngaphandle akha ungqimba oluncane, olwenzeka uma ukunamathela kukhulu kunokuhlangana.

I-tin-lead solder ihlangana kakhulu kunamanzi, okwenza i-solder eyindilinga ukunciphisa indawo yayo (ngevolumu efanayo, indawo inendawo encane kunazo zonke uma iqhathaniswa namanye amajometri ukuhlangabezana nezidingo zombuso wamandla aphansi). Umphumela wokufuduka ufana nowokuhlanza epuletini lensimbi le-PCB eligcotshiswe ngamafutha. Ngaphezu kwalokho, ukungezwani kobuso nakho kuncike kakhulu ekuhlanzekeni nasekushiseni kobuso be-PCB. Kuphela lapho amandla wokubambelela makhulu kakhulu kunamandla angaphezulu (ukuhlangana), i-PCB ingaba nokunamathela okuhle kothini.

3, nge-Angle yethini

I-meniscus yakhiwa lapho ithonsi le-solder lifakwa ebusweni be-PCB eshisayo, eshubile cishe ngama-35 ° C ngaphezulu kwephuzu le-eutectic le-solder. Ngokwezinga elithile, ikhono lobuso bensimbi be-PCB lokunamathisela i-tin lingahlolwa ukwakheka kwe-meniscus. Insimbi ayithengiseki uma i-meniscus ine-cut engezansi ecacile, ibukeka njengamaconsi amanzi epuletini lensimbi ye-PCB, noma ivame ukuba yindilinga. I-meniscus kuphela enwebeke ngosayizi ongaphansi kuka-30. I-Angle encane ine-weldability enhle.

4. Isizukulwane samakhemikhali wensimbi alloy

Izibopho ezihlanganiswayo zethusi nethini zakha okusanhlamvu ukwakheka nosayizi wazo kuncike ebudaleni nasemandleni okushisa lapho afakwa khona. Ukushisa okuncane ngesikhathi sokushisela kungakha isakhiwo esihle se-crystal, okwenza ifomu le-PCB libe yindawo enhle kakhulu yokushisela ngamandla amahle kakhulu. Isikhathi eside kakhulu sokuphendula, kungaba ngenxa yesikhathi sokushisela se-PCB eside kakhulu, izinga lokushisa eliphakeme kakhulu noma zombili, kuzoholela esakhiweni esinamakhristali amabi ashubile futhi aqhekeka ngamandla aphansi okushefa.Ithusi lisetshenziswa njenge-base yensimbi ye-PCB, ne-tin-lead isetshenziswa njenge-solder alloy. Umthofu nethusi ngeke kwakheke izakhi zensimbi, kepha ithini lingangena ethusi. Isibopho semolekyuli phakathi kukathayela nethusi sakha ingxubevange yensimbi i-Cu3Sn ne-Cu6Sn5 enhlanganweni yokuhlangana neyensimbi.

Isendlalelo sensimbi (isigaba se-n + ε) kufanele sibe mncane kakhulu. Ngo-PCB laser Welding, ukushuba wensimbi ingxubevange ungqimba kuyinto 0.1mm ekilasini inombolo. Ku-wave soldering kanye ne-soldering yesandla, ubukhulu besibopho esiphakathi kwamaphuzu amahle wokushisela we-PCB angaphezu kuka-0.5μm. Ngoba amandla okuphuca ama-welds e-PCB ancipha njengoba ubukhulu bensimbi yensimbi benyuka, kuvame ukuzama ukugcina ubukhulu bensimbi yensimbi engaphansi kwe-1μm ngokugcina isikhathi sokushisela sifushane ngangokunokwenzeka.

Ubukhulu besendlalelo sensimbi sixhomeke ekushiseni nesikhathi sokwakha indawo yokushisela. Ngokufanelekile, i-welding kufanele igcwaliswe cishe ku-220 ‘t 2s. Ngaphansi kwalezi zimo, ukusabela kwamakhemikhali okusakazwa ngethusi nethini kuzokhiqiza izinto ezihlanganayo ezihlanganisa insimbi i-Cu3Sn ne-Cu6Sn5 ngobukhulu obucishe bube ngu-0.5μm. Ukuhlangana okunganele kwe-intermetal kuvamile emalungeni e-solder abandayo noma amalunga we-solder angakhuliswanga ezingeni lokushisa elifanele ngesikhathi sokushisela futhi angaholela ekunqanyulweni kwendawo ye-PCB weld. Ngokuphambene nalokho, izingqimba zengxubevange yensimbi ejiyile kakhulu, ejwayelekile kumajoyini ashubile noma ashiselwe isikhathi eside kakhulu, izophumela emandleni abuthaka kakhulu wokuqina kwamalunga we-PCB.