Yadda ake saita zazzabi mai sake kwarara mara gubar

Hannun Sn96.5Ag3.0Cu0.5 alloy gargajiya gubar-free reflow soldering kwana kwana.A shine wurin dumama, B shine wurin daɗaɗɗen zafin jiki (yankin jika), kuma C shine wurin narkewar kwano.Bayan 260S shine yankin sanyaya.

Sn96.5Ag3.0Cu0.5 alloy gargajiya gubar-free sake kwarara yawan zafin jiki lankwasa

Manufar dumama yankin A shine don ɗora zafi sama da allon PCB zuwa zafin jiki na kunnawa.Yanayin zafin jiki yana tashi daga zafin jiki zuwa kimanin 150 ° C a cikin kimanin 45-60 seconds, kuma gangaren ya kamata ya kasance tsakanin 1 zuwa 3. Idan yanayin zafi ya tashi da sauri, zai iya rushewa kuma ya haifar da lahani irin su beads na solder da bridging.

Yanayin zafin jiki na dindindin B, zafin jiki yana tashi a hankali daga 150 ° C zuwa 190 ° C.Lokacin yana dogara ne akan takamaiman buƙatun samfur kuma ana sarrafa shi a kusan daƙiƙa 60 zuwa 120 don ba da cikakkiyar wasa ga ayyukan ƙoshin ƙarfi da cire oxides daga saman walda.Idan lokacin ya yi tsayi da yawa, kunnawa da yawa na iya faruwa, yana shafar ingancin walda.A wannan mataki, wakili mai aiki a cikin jujjuyawar ruwa ya fara aiki, kuma rosin resin ya fara yin laushi da gudana.Wakilin mai aiki yana yaduwa kuma yana kutsawa tare da rosin guduro akan kushin PCB da farfajiyar ƙarshen ɓangaren, kuma yana hulɗa tare da oxide na saman kushin da ɓangaren siyar da farfajiyar.Reaction, tsaftace saman da za a welded da cire datti.A lokaci guda kuma, rosin resin yana faɗaɗa cikin sauri don samar da fim mai kariya a saman Layer na waje na farfajiyar walda kuma ya keɓe shi daga haɗuwa da iskar gas na waje, yana kare farfajiyar walda daga iskar oxygen.Manufar saita isasshen lokacin zafin jiki na yau da kullun shine don ba da damar PCB kushin da sassan su isa zafin jiki iri ɗaya kafin sake dawo da siyarwar da rage bambancin zafin jiki, saboda ƙarfin ɗaukar zafi na sassa daban-daban da aka ɗora akan PCB sun bambanta sosai.Hana ingantattun matsalolin da rashin daidaituwar zafin jiki ke haifarwa yayin sake kwarara, kamar dutsen kaburbura, siyar da karya, da sauransu. Idan yawan zafin jiki na yau da kullun ya yi zafi da sauri, motsin da ke cikin faifan solder zai yi saurin faɗaɗa kuma ya canza, yana haifar da matsaloli iri-iri kamar pores, busa. tin, da tin beads.Idan akai-akai lokacin zafin jiki ya yi tsayi da yawa, jujjuyawar ƙanƙara za ta ƙafe da yawa kuma ta rasa ayyukanta da aikinta na kariya a lokacin sayar da wutar lantarki, wanda ke haifar da jerin munanan sakamako kamar siyarwar kama-da-wane, ragowar haɗin gwiwa mai baƙar fata, da haɗin gwiwar solder.A cikin samarwa na ainihi, ya kamata a saita lokacin zazzabi akai-akai bisa ga halaye na ainihin samfurin da manna mai siyar da mara gubar.

Lokacin da ya dace don siyar da yankin C shine 30 zuwa 60 seconds.Matsakaicin lokacin narkewar gwangwani na iya haifar da lahani kamar rauni mai rauni, yayin da tsayin daka zai iya haifar da wuce gona da iri na ƙarfe ko sanya duhu ga haɗin gwiwa.A wannan mataki, foda na alloy a cikin manna mai siyar ya narke kuma ya amsa da karfe a saman da aka sayar.Maganin juye-juye yana tafasa a wannan lokacin kuma yana haɓaka volatilization da kutsawa, kuma yana shawo kan tashin hankali a yanayin zafi mai yawa, yana ba da damar solder na ruwa ya gudana tare da juzu'i, yada a saman kushin kuma ya nannade ƙarshen farfajiyar na sashin don samar da shi. wani sakamako mai wetting.A ka'ida, mafi girman zafin jiki, mafi kyawun tasirin wetting.Koyaya, a aikace-aikace masu amfani, dole ne a yi la'akari da matsakaicin haƙurin zafin zafi na hukumar PCB da sassa.Daidaita yanayin zafin jiki da lokacin yankin reflow na siyarwa shine neman ma'auni tsakanin zafin jiki kololuwa da tasirin siyarwar, wato, don cimma ingantacciyar ingancin siyarwar a cikin madaidaicin zafin jiki da lokaci.

Bayan yankin waldawa shine yankin sanyaya.A cikin wannan mataki, mai siyar yana kwantar da ruwa daga ruwa zuwa daskararru don samar da haɗin gwiwar saida, kuma ana samun hatsin crystal a cikin mahaɗin solder.Saurin sanyaya na iya samar da abin dogara ga haɗin gwiwa mai sheki mai haske.Wannan shi ne saboda saurin sanyaya na iya sa haɗin gwiwa na solder ya zama gami tare da tsari mai tsauri, yayin da saurin sanyi zai samar da adadi mai yawa na tsaka-tsakin kuma ya samar da hatsi mafi girma a kan haɗin gwiwa.Amintaccen ƙarfin injin na irin wannan haɗin gwiwa yana da ƙasa, kuma Fuskar kayan haɗin gwal ɗin zai zama duhu da ƙarancin haske.

Saita zazzabi mai sake kwarara mara gubar

A cikin tsarin sake kwararar dalma ba tare da gubar ba, yakamata a sarrafa kogon tanderun daga duk wani nau'in karfe.Idan kogon tanderan an yi shi da ƙananan ƙarfe na takarda, warping na kogon tanderun zai iya faruwa cikin sauƙi a ƙarƙashin yanayin zafi mara gubar.Yana da matukar mahimmanci don gwada daidaiton waƙa a ƙananan yanayin zafi.Idan waƙar ta lalace a yanayin zafi mai yawa saboda kayan aiki da ƙira, cunkushewa da faɗuwar allon ba zai yuwu ba.A da, Sn63Pb37 mai siyar da gubar siyar ce ta gama gari.Alloys crystalline suna da wurin narkewa iri ɗaya da zafin jiki mai daskarewa, duka 183 ° C.Ƙungiyar SnAgCu mara siyar da gubar ba kayan haɗaɗɗiyar eutectic bane.Matsayinsa na narkewa shine 217 ° C-221 ° C.Yanayin zafi yana da ƙarfi lokacin da zafin jiki ya ƙasa da 217 ° C, kuma zafin jiki yana yin ruwa lokacin da zafin jiki ya wuce 221 ° C.Lokacin da zafin jiki ya kasance tsakanin 217 ° C da 221 ° C Alloy yana nuna rashin kwanciyar hankali.