1, ukusebenza ngetini

Xa i-solder eshushu eshushu inyibilika kwaye ingena kumgangatho wentsimbi we PCB iyathengiswa, ibizwa ngokuba yi-metal bonding okanye i-metal bonding. Iimolekyuli zomxube we-solder kunye nobhedu zenza ingxubevange entsha eyinxalenye yobhedu nenxalenye ye-solder. Eli nyathelo lokunyibilikisa libizwa ngokuba yi-tin-bonding. Yenza ubumbano lwe-intermolecular phakathi kweendawo ezahlukeneyo ze-PCB, ukudala ikhompiyutha yensimbi. Ukusekwa kwemixokelelwane elungileyo yeemolekyuli sisiseko senkqubo ye-welding ye-PCB, emisela amandla kunye nomgangatho wamanqaku e-PCB. I-Tin inokungcoliswa kuphela ukuba umphezulu wobhedu awunangcoliseko kunye nefilimu ye-oxide eyenziweyo ngenxa yokuvezwa kwe-PCB emoyeni, kwaye i-solder kunye nomphezulu osebenzayo kufuneka ufikelele kubushushu obufanelekileyo.

2. Ukujongana komhlaba

Wonke umntu uqhelene nokuxinana komphezulu wamanzi, amandla agcina amathontsi amanzi abandayo angqukuva kwipleyiti yentsimbi ye-PCB kuba, kule meko, ukunamathela okuhlala kusasaza ulwelo kumgangatho oqinileyo kungaphantsi kobumbano lwayo. Hlamba ngamanzi ashushu kunye nesicocisi ukunciphisa uxinzelelo lomhlaba. Amanzi aya kugcwalisa ipleyiti yentsimbi ye-PCB kwaye awele ngaphandle enze umaleko omncinci, owenzekayo ukuba ukubambelela kukhulu kunokubambana.

I-tin-lead solder ibumbene ngakumbi kunamanzi, isenza ukuba i-solder eyindilinga inciphise umphezulu wayo (ngevolumu efanayo, indawo leyo inommandla omncinci kakhulu xa kuthelekiswa nezinye iijometri ukuhlangabezana neemfuno zelizwe lamandla asezantsi). Iziphumo zokuhamba ziyafana nezesepha kwityhubhu yensimbi ye-PCB egalelwe igrisi. Ukongeza, uxinzelelo lomhlaba lukwaxhomekeke kakhulu kucoceko kunye nobushushu bomphezulu wePCB. Kuphela xa amandla adhesion mkhulu kakhulu kunomphezulu wamandla (ubumbano), i-PCB inokuba ne-ad adhesion efanelekileyo.

3, kunye ne-tin Angle

I-meniscus yenziwa xa ithontsi le-solder libekwe kumphezulu we-PCB eshushu, eshushu ene-35 ° C ngaphezulu kwe-eutectic point of solder. Ukuya kwinqanaba elithile, ukubanakho komphezulu wentsimbi wePCB wokuncamathisela i-tin kunokuvavanywa ngohlobo lwe-meniscus. Isinyithi asithengiseki ukuba i-meniscus ine-cut cut ecacileyo esezantsi, ijongeka ngathi ngamathontsi amanzi kwityhubhu yensimbi ye-PCB, okanye nokuba ithande ukujikeleza. Kuphela i-meniscus yolulelwe kubungakanani obungaphantsi kwama-30. I-Angle encinci ine-weldability elungileyo.

4. Ukuveliswa kweekhompawundi zentsimbi

Iibhondi ezidibeneyo zobhedu kunye ne-tin zenza iinkozo ezimilo kunye nobukhulu bazo zixhomekeke kubude kunye namandla obushushu apho badityaniswa khona. Ubushushu obuncinci ngexesha le-welding bungenza isakhiwo esicocekileyo sekristal, esenza ifom ye-PCB indawo efanelekileyo yokuwelda ngamandla awomeleleyo. Ixesha lokuphendula ixesha elide kakhulu, nokuba kungenxa ye-PCB ye-welding yexesha elide kakhulu, iqondo lobushushu eliphezulu kakhulu okanye zombini, ziya kukhokelela kulwakhiwo lwecrystalline erhabaxa kwaye ecekeceke ngamandla ane-shear ephantsi.Ubhedu lusetyenziswa njengezinto zesiseko se-PCB, kunye ne-tin-lead isetyenziswa njenge-alloy solder. Ilothe kunye nobhedu aziyi kubumba nayiphi na ingxubevange yesinyithi, kodwa i-tin inokungena kubhedu. Ubophelelo lweemolekyuli phakathi kweetini kunye nobhedu zenza iifom ze-alloy compounds Cu3Sn kunye neCu6Sn5 kwindawo yokuhlangana kunye nesinyithi.

Umaleko wentsimbi (0.1) Kwi-PCB ye-PCB ye-welding, ubukhulu be-alloy yensimbi engu-0.5mm kwiklasi yeklasi. Kwi-soldering ye-wave kunye ne-soldering yesandla, ubukhulu be-bond edibeneyo yeendawo ezifanelekileyo ze-welding ze-PCB zingaphezulu kwe-XNUMXμm. Ngenxa yokuba amandla wokucheba kwe-PCB welds ayancipha njengoko ubungqingqwa bensimbi yentsimbi buyanda, ihlala izanywa ukugcina ubungqingqwa bentsimbi obungaphantsi kwe-1μm ngokugcina ixesha le-welding lifutshane kangangoko.

Ubunzima be-alloy yensimbi yentsimbi ixhomekeke kubushushu kunye nexesha lokwakha indawo ye-welding. Ngokufanelekileyo, i-welding kufuneka igqitywe malunga ne-220 ‘t 2s. Ngaphantsi kwezi meko, impendulo yokusasazeka kwemichiza yobhedu kunye ne-tin iya kuvelisa izinto ezifanelekileyo zokubopha isinyithi zeCu3Sn kunye neCu6Sn5 ngobukhulu obumalunga ne-0.5μm. Ukudibana okungonelanga kokuhlangana kuqhelekile kumalungu abandayo e-solder okanye amajoyini e-solder angaphakanyiswanga kubushushu obufanelekileyo ngexesha le-welding kwaye anokukhokelela ekunqunyulweni komphezulu we-PCB weld. Ngokwahlukileyo, i-alloy e-alloy e-alloy eqinileyo, eqhelekileyo kumalungu afudumeleyo okanye adibeneyo ixesha elide, iya kukhokelela kumandla obuthathaka kakhulu wamalungu e-PCB.