Ireflow ovenisetyenziselwa ukuthengisa amacandelo etshiphu ye-SMT kwibhodi yesekethe kwinkqubo ye-SMT yokuvelisa izixhobo zokuvelisa.I-oven reflow ixhomekeke ekuhambeni komoya oshushu eziko ukubrasha intlama ye-solder kumalungu e-solder paste yebhodi yesekethe, ukuze intlama ye-solder iphinde inyibilike ibe yitoti yolwelo ukuze amacandelo etshiphu ye-SMT kunye nebhodi yesekethe. I-welded kunye ne-welded, kwaye emva koko i-reflow soldering Isithando somlilo sipholile ukwenza i-solder joints, kwaye i-colloidal solder paste ifumana ukusabela komzimba phantsi kobushushu obuthile obuphezulu bokuhamba komoya ukuphumeza umphumo we-solder yenkqubo ye-SMT.
I-soldering kwi-oven reflow ihlukaniswe kwiinkqubo ezine.Iibhodi zesekethe ezinamacandelo e-smt zithuthwa ngeereyile zesikhokelo se-oven reflow ngokusebenzisa indawo yokufudumeza, indawo yokugcina ubushushu, indawo yokuthambisa, kunye nendawo yokupholisa ye-oveni yokuphinda iphinde iphinde iphinde iphinde iphinde iphinde ifakwe.Imimandla emine yokushisa yesithando somlilo yenza i-welding point epheleleyo.Emva koko, i-Guangshengde i-reflow soldering iya kuchaza imigaqo yeendawo ezine zokushisa ze-oven yokubuyisela ngokulandelelana.
Ukufudumeza kuqala kukwenza i-solder paste isebenze, kunye nokuphepha ukufudumeza okukhawulezileyo kobushushu obuphezulu ngexesha lokuntywiliselwa kwetoti, esisenzo sokufudumeza esenza ukuba kubangele iindawo ezineziphene.Injongo yale ndawo kukutshisa i-PCB kwiqondo lokushisa ngokukhawuleza, kodwa izinga lokushisa kufuneka lilawulwe ngaphakathi koluhlu olufanelekileyo.Ukuba ikhawuleza kakhulu, ukutshitshiswa kwe-thermal kuya kwenzeka, kwaye ibhodi yesekethe kunye namacandelo anokonakala.Ukuba icotha kakhulu, isinyibilikisi asiyi kumka ngokwaneleyo.Umgangatho wokuwelda.Ngenxa yesantya sokufudumeza ngokukhawuleza, ukuhluka kweqondo lokushisa kwisithando somlilo sikhulu kwinxalenye yokugqibela yendawo yokushisa.Ukuze kuthintelwe ukothuka kwe-thermal ekonakalisa amacandelo, umlinganiselo ophezulu wokufudumeza uchazwe ngokubanzi njenge-4℃/S, kwaye izinga lokunyuka lihlala libekwe kwi-1 ~ 3℃/S.
Injongo ephambili yenqanaba lokugcinwa kobushushu kukuzinzisa ubushushu becandelo ngalinye kwisithando somlilo sokufudumeza kunye nokunciphisa ukuhluka kweqondo lokushisa.Nika ixesha elaneleyo kule ndawo ukwenza ubushushu becandelo elikhulu ukubamba kunye necandelo elincinci, kwaye uqinisekise ukuba i-flux kwi-solder paste iguquguquke ngokupheleleyo.Ekupheleni kwecandelo lokugcinwa kobushushu, i-oxides kwi-pads, iibhola ze-solder kunye nezikhonkwane zecandelo zisuswa phantsi kwesenzo se-flux, kwaye ukushisa kwebhodi yesekethe yonke kulinganiswe.Kufuneka kuqatshelwe ukuba onke amacandelo kwi-SMA kufuneka abe nobushushu obufanayo ekupheleni kweli candelo, kungenjalo, ukungena kwi-reflow section kuya kubangela i-solder ezahlukeneyo ezimbi ngenxa yobushushu obungalinganiyo becandelo ngalinye.
Xa i-PCB ingena kwindawo yokubuyisela kwakhona, ubushushu bukhuphuka ngokukhawuleza ukuze i-solder paste ifikelele kwimo etyhidiweyo.Indawo yokunyibilika ye-lead solder paste 63sn37pb yi-183 ° C, kunye ne-melting point ye-lead solder paste 96.5Sn3Ag0.5Cu yi-217 ° C.Kule ndawo, ukushisa kwe-heater kubekwe phezulu, ukwenzela ukuba ukushisa kwecandelo kukhuphuke ngokukhawuleza kwiqondo lokushisa.Ukushisa kwexabiso le-curve reflow ngokuqhelekileyo kunqunywe yiqondo lokunyibilika kwe-solder kunye nobushushu bokumelana nobushushu be-substrate edibeneyo kunye namacandelo.Kwicandelo le-reflow, ukushisa kwe-solder kuyahluka ngokuxhomekeke kwi-solder paste esetyenzisiweyo.Ngokubanzi, ubushushu obuphezulu belothe ngama-230-250℃, kwaye ubushushu belothe yi-210-230℃.Ukuba ubushushu buphantsi kakhulu, kulula ukuvelisa amajoyina abandayo kunye nokumanzisa okwaneleyo;ukuba iqondo lobushushu liphezulu kakhulu, i-coking kunye ne-delamination ye-epoxy resin substrate kunye neenxalenye zeplastiki zinokuthi zenzeke, kwaye iikhompawundi ze-eutectic zetsimbi ezigqithisileyo ziya kubumba, eziya kukhokelela kwi-brittle solder joints, okuya kuchaphazela amandla e-welding.Kwindawo ye-reflow soldering, hlawula ingqalelo ekhethekileyo kwixesha lokubuyisela kwakhona ukuba lingabi lide kakhulu, ukuthintela umonakalo kwisithando somlilo, kunokubangela ukuba imisebenzi engafanelekanga yamacandelo e-elektroniki okanye ibangele ukuba ibhodi yesekethe itshiswe.
Kweli nqanaba, ubushushu bupholisiwe ukuya ngaphantsi kobushushu besigaba esiqinileyo ukuze kuqiniswe amalungu e-solder.Izinga lokupholisa liya kuchaphazela amandla e-solder joint.Ukuba izinga lokupholisa licotha kakhulu, liya kubangela ukuba kuveliswe iikhompawundi zetsimbi eutectic ezigqithisileyo, kwaye izakhiwo ezinkulu eziziinkozo ziyakwazi ukwenzeka kumalungu e-solder, okuya kunciphisa amandla amalunga e-solder.Izinga lokupholisa kwindawo yokupholisa liba malunga ne-4℃/S, kwaye izinga lokupholisa yi-75℃.unako.
Emva kokuxubha i-solder paste kunye nokunyuka kwamacandelo e-smt chip, ibhodi yesekethe ihanjiswa ngomzila wesikhokelo somlilo we-reflow solder, kwaye emva kwesenzo semimandla emine yobushushu ngaphezu kwesithando somlilo sokujikeleza, ibhodi yesekethe edibeneyo yenziwa.Lo ngumgaqo opheleleyo wokusebenza kwe-oven yokubuyisela kwakhona.
Ixesha lokuposa: Jul-29-2020