l Izidingo zokushisa eziphezulu ezingenamthofu zezinto zemishini
Ukukhiqizwa okungenamthofu kudinga okokusebenza ukumelana namazinga okushisa aphezulu kunokukhiqizwa okunomthofu.Uma kunenkinga ngempahla yemishini, uchungechunge lwezinkinga ezifana ne-warpage yomgodi wesithando somlilo, ukuwohloka kwethrekhi, nokusebenza kabi kokuvala kuzokwenzeka, okuzogcina kuthinte kakhulu ukukhiqizwa.Ngakho-ke, ithrekhi esetshenziswa kuhhavini ogeleza kabusha ongenamthofu kufanele wenziwe lukhuni kanye nezinye izindlela zokwelapha ezikhethekile, futhi amalunga ensimbi yeshidi kufanele askeniwe nge-X-ray ukuze kuqinisekiswe ukuthi akukho mifantu namabhamuza ukuze kugwenywe umonakalo nokuvuza ngemva kokusetshenziswa isikhathi eside. .
l Vimbela ngempumelelo i-warpage yomgodi wesithando somlilo kanye nokuguqulwa kwesitimela
Imbobo yesithando somlilo esingaholeli kabusha esigeleza umthofu kufanele senziwe ngocezu lonke lweshidi lensimbi.Uma umgodi uhlanganiswe nezingcezu ezincane zeshidi lensimbi, uthambekele ekubeni ne-warpage endaweni yokushisa engenamthofu.
Kudingeka kakhulu ukuhlola ukufana kwama-rails ngaphansi kokushisa okuphezulu nokushisa okuphansi.Uma ithrekhi ikhubazekile ngezinga lokushisa eliphezulu ngenxa yento esetshenziswayo kanye nomklamo, ukwenzeka kokuminyana nokwehla kwebhodi ngeke kugwemeke.
l Gwema ukuphazamisa amalunga e-solder
I-solder ye-Sn63Pb37 ehamba phambili ehamba phambili iyingxube ye-eutectic, futhi indawo yayo yokuncibilika kanye nezinga lokushisa lendawo yokuqandisa kuyafana, kokubili ku-183°C.Ijoyini ye-lead-free solder ye-SnAgCu ayiyona i-eutectic alloy.Izinga layo lokuncibilika lisukela ku-217°C kuya ku-221°C.Izinga lokushisa lingaphansi kuka-217°C esimweni esiqinile, futhi izinga lokushisa lingaphezu kuka-221°C esimweni samanzi.Uma izinga lokushisa liphakathi kuka-217°C kuya ku-221°C Ingxubevange ibonisa isimo esingazinzile.Uma i-solder joint ikulesi simo, ukudlidliza kwemishini kwemishini kungashintsha kalula ukuma okuhlangene kwe-solder futhi kubangele ukuphazamiseka kwe-solder joint.Lokhu iphutha elingamukelekile kuzinga le-IPC-A-610D lemibandela eyamukelekayo yemikhiqizo kagesi.Ngakho-ke, uhlelo lokudlulisela lwemishini yokudayiswa kwe-reflow engenamthofu kufanele ibe nomklamo omuhle wesakhiwo esingenawo ukudlidliza ukuze kugwenywe ukuphazamisa amalunga e-solder.
Izidingo zokunciphisa izindleko zokusebenza:
l Ukuqina kwe-oven cavity
I-warpage yesikhala somlilo kanye nokuvuza kwezinto zokusebenza kuzobangela ngokuqondile ukwanda okuqondile kwenani le-nitrogen elisetshenziselwa ugesi.Ngakho-ke, ukubekwa uphawu kwemishini kubaluleke kakhulu ekulawuleni izindleko zokukhiqiza.Ukuzijwayeza kufakazele ukuthi ukuvuza okuncane, ngisho nembobo evuzayo elingana nembobo eyisikulufa, kungase kwenyuse ukusetshenziswa kwe-nitrogen kusuka ku-cubic metres angu-15 ngehora kuya ku-40 cubic metres ngehora.
l Ukusebenza kwe-thermal insulation yemishini
Thinta ingaphezulu lehhavini lokugeleza kabusha (isikhundla esihambisana nendawo yokugeleza kabusha) akufanele sizwe kushisa (izinga lokushisa elingaphezulu kufanele libe ngaphansi kwama-degree angu-60).Uma uzizwa ushisa, kusho ukuthi ukusebenza kwe-thermal insulation ye-oven reflow impofu, futhi inani elikhulu lamandla kagesi liguqulwa libe ukushisa futhi liyalahleka, libangele ukuchithwa kwamandla okungadingekile.Uma ehlobo, amandla okushisa alahlekile endaweni yokusebenzela azokwenza ukuthi izinga lokushisa le-workshop likhuphuke, futhi kufanele sisebenzise idivayisi ye-air-conditioning ukukhipha amandla okushisa ngaphandle, okuholela ngokuqondile ekulahlekeni kwamandla okuphindwe kabili.
l Khipha umoya
Uma imishini ingenalo uhlelo oluhle lokuphathwa kwe-flux, futhi ukukhishwa kwe-flux kwenziwa ngokukhipha umoya, khona-ke imishini izophinde ikhiphe ukushisa ne-nitrogen ngenkathi ikhipha insalela ye-flux, okubangela ngokuqondile ukwanda kokusetshenziswa kwamandla.
l Izindleko zesondlo
I-ovini yokugeleza kabusha inokukhiqiza okuphezulu kakhulu ekukhiqizeni okuqhubekayo ngobuningi, futhi ingakhiqiza amakhulukhulu amabhodi esekethe omakhalekhukhwini ngehora.Uma isithando somlilo sinesikhathi esifushane sokulungisa, umthwalo omkhulu wokulungisa, kanye nesikhathi eside sokusilungisa, nakanjani sizothatha isikhathi esengeziwe Sokukhiqiza, okuholela ekumoshweni kokusebenza kahle kokukhiqiza.
Ukuze kuncishiswe izindleko zokulungisa, okokusebenza kwe-lead-free reflow soldering okungenayo umthofu kufanele kwenziwe imodular ngangokunokwenzeka ukuze kuhlinzekwe lula ukugcinwa nokulungiswa kwemishini (Umfanekiso 8).
Isikhathi sokuthumela: Aug-13-2020