Reflow soldering shine mafi yadu amfani surface bangaren waldi hanya a cikin SMT masana'antu.Wata hanyar walda ita ce sayar da igiyar ruwa.Sake siyarwar ya dace da abubuwan haɗin guntu, yayin da siyar da igiyar igiyar ruwa ta dace da abubuwan lantarki na fil.
Sake yin siyar kuma tsari ne na sake kwarara.Ka'idarsa ita ce a buga ko allurar da ta dace ta manna a kan PCB pad da manna daidaitattun abubuwan sarrafa kayan aikin SMT, sannan a yi amfani da dumama wutar iska mai zafi don narkar da man siyar, sannan a ƙarshe samar da haɗin gwiwa mai aminci na solder. ta hanyar sanyaya.Haɗa abubuwan haɗin gwiwa tare da kushin PCB don kunna aikin haɗin inji da haɗin lantarki.Gabaɗaya magana, reflow soldering ya kasu kashi hudu: preheating, akai-akai zazzabi, reflow da sanyaya.
1. Yankin preheating
Yankin preheating: shine farkon dumama matakin samfurin.Manufarsa ita ce don zafi samfurin da sauri a cikin ɗaki da zafin jiki kuma kunna jujjuyawar manna mai siyarwa.Har ila yau, hanya ce ta dumama da ake buƙata don guje wa asarar ƙarancin zafi na abubuwan da ke haifar da saurin zafi mai zafi yayin nutsewar kwano na gaba.Sabili da haka, tasirin hawan zafin jiki akan samfurin yana da mahimmanci kuma dole ne a sarrafa shi a cikin kewayon da ya dace.Idan yana da sauri da sauri, zai haifar da girgizar zafi, PCB da abubuwan da aka gyara zasu shafi damuwa na thermal kuma suna haifar da lalacewa.A lokaci guda, da sauran ƙarfi a cikin solder manna zai volatilize da sauri saboda saurin dumama, haifar da splashing da samuwar solder beads.Idan yana da jinkirin sosai, ƙoshin ƙoshin ƙoshin solder ɗin ba zai canza ba kuma yana shafar ingancin walda.
2. Yankin zafin jiki na dindindin
Yankin zafin jiki na dindindin: manufarsa ita ce daidaita yanayin zafin kowane nau'i akan PCB kuma a cimma yarjejeniya gwargwadon yiwuwa don rage bambancin zafin jiki tsakanin kowane kashi.A wannan mataki, lokacin dumama na kowane sashi yana da tsayi sosai, saboda ƙananan abubuwan za su kai ga daidaito da farko saboda ƙarancin ɗaukar zafi, kuma manyan abubuwan suna buƙatar isasshen lokaci don cim ma ƙananan abubuwa saboda yawan ɗaukar zafi, da kuma tabbatar da cewa ruwan zafi yana gudana. a cikin solder manna ne cikakken volatilized.A wannan mataki, a ƙarƙashin aikin juyi, za a cire oxide akan kushin, ƙwallon solder da fil ɗin abubuwan.A lokaci guda kuma, jujjuyawar za ta cire tabon mai da ke saman sashin da pad, ƙara wurin walda kuma ya hana sashin sake yin oxidized.Bayan wannan matakin, duk abubuwan da aka gyara zasu kiyaye zafin jiki iri ɗaya ko makamancin haka, in ba haka ba za'a iya yin walda mara kyau saboda bambancin zafin jiki da ya wuce kima.
Zazzabi da lokacin zazzabi akai-akai sun dogara ne akan rikitaccen ƙirar PCB, bambancin nau'ikan kayan aiki da adadin abubuwan da aka gyara.Yawancin lokaci ana zaɓa tsakanin 120-170 ℃.Idan PCB yana da sarƙaƙƙiya musamman, yakamata a ƙayyade yawan zafin jiki akai-akai tare da zafin jiki mai laushi na rosin azaman tunani, don rage lokacin walda na yankin reflow a cikin sashe na gaba.The m zafin jiki yankin na mu kamfanin ne kullum zaba a 160 ℃.
3. Yankin Reflux
Manufar yankin reflow shine don sanya manna mai siyar ya narke ya jika kushin a saman abin da za a yi walda.
Lokacin da kwamitin PCB ya shiga yankin reflow, zafin jiki zai tashi da sauri don sanya manna mai siyar ya isa yanayin narkewa.Matsayin narkewar manna gubar gubar SN: 63 / Pb: 37 shine 183 ℃, da manna mai siyar da ba ta da gubar SN: 96.5/ag: 3 / Cu: 0. Matsayin narkewa na 5 shine 217 ℃.A cikin wannan sashe, mai zafi yana samar da mafi yawan zafi, kuma za a saita zafin wutar tander zuwa mafi girma, ta yadda yawan zafin jiki na solder zai tashi da sauri zuwa zafin jiki mafi girma.
Mafi girman zafin jiki na reflow soldering lankwasa an ƙaddara gabaɗaya ta wurin narkewar manna, allon PCB da zafin jiki mai jure zafi na ɓangaren da kansa.Matsakaicin zafin jiki na samfuran a cikin yankin sake kwarara ya bambanta dangane da nau'in manna mai siyar da aka yi amfani da shi.Gabaɗaya magana, matsakaicin matsakaicin zafin jiki na manna ba tare da gubar ba shine gabaɗaya 230 ~ 250 ℃, kuma na manna gubar gabaɗaya shine 210 ~ 230 ℃.Idan kololuwar zafin jiki ya yi ƙasa sosai, yana da sauƙi don samar da walda mai sanyi da rashin isasshen wetting na haɗin gwiwa;Idan ya yi yawa, da epoxy guduro irin substrate da filastik sassa ne yiwuwa ga coking, PCB kumfa da delamination, kuma za su kai ga samuwar wuce kima eutectic karfe mahadi, yin solder hadin gwiwa gaggautsa da waldi ƙarfi rauni, shafi inji Properties na samfurin.
Ya kamata a jaddada cewa juzu'i a cikin manna solder a cikin reflow yankin yana da taimako don inganta wetting tsakanin solder manna da bangaren walda karshen da kuma rage surface tashin hankali na solder manna a wannan lokaci, amma inganta da juyi zai. a kame saboda ragowar iskar oxygen da oxides na karfe a cikin tanderun da aka sake fitarwa.
Gabaɗaya, kyakkyawan yanayin zafin tanderu dole ne ya hadu da cewa mafi girman zafin jiki na kowane batu akan PCB yakamata ya kasance daidai gwargwadon iyawa, kuma bambancin kada ya wuce digiri 10.Ta wannan hanyar kawai za mu iya tabbatar da cewa an kammala duk ayyukan walda lafiya lokacin da samfurin ya shiga wurin sanyaya.
4. Wurin sanyaya
Manufar yankin sanyaya shine a hanzarta sanyaya ɓangarorin manna mai narkakken solder da sauri da samar da haɗin gwiwa mai haske tare da jinkirin radian da cikakken adadin tin.Saboda haka, masana'antu da yawa za su sarrafa wurin sanyaya da kyau, saboda yana da amfani don ƙirƙirar haɗin gwiwa.Gabaɗaya magana, yawan sanyaya da sauri zai sa ya yi latti don narkakkar solder manna ya yi sanyi da buffer, yana haifar da wutsiya, kaifi har ma da burar haɗin gwiwa da aka kafa.Maƙasudin sanyaya sosai zai sa tushen abu na PCB kushin saman ya haɗu a cikin manna solder, yin haɗin gwiwa mai tsauri, walƙiya mara komai da haɗin gwiwa mai solder mai duhu.Menene more, duk karfe mujallu a bangaren solder karshen zai narke a solder hadin gwiwa matsayi, sakamakon a rigar ƙi ko matalauta waldi a bangaren solder karshen, Yana rinjayar waldi quality, don haka mai kyau sanyaya kudi yana da matukar muhimmanci ga solder hadin gwiwa kafa. .Gabaɗaya magana, mai siyar da manna mai siyarwa zai ba da shawarar ƙimar sanyaya haɗin gwiwa na solder ≥ 3 ℃ / s.
Chengyuan masana'antu ne kamfani ƙware a samar da SMT da PCBA samar line kayan aiki.Yana ba ku mafita mafi dacewa.Yana da shekaru masu yawa na samarwa da ƙwarewar R & D.ƙwararrun ƙwararrun ƙwararrun ƙwararrun ƙwararrun masana suna ba da jagorar shigarwa da sabis na bayan-tallace-tallace gida-gida, don kada ku damu a gida.
Lokacin aikawa: Afrilu-09-2022