Reflow qhov cub ntsig txog kev paub
Reflow soldering yog siv rau SMT sib dhos, uas yog ib feem tseem ceeb ntawm cov txheej txheem SMT.Nws txoj haujlwm yog ua kom yaj cov nplaum nplaum, ua rau cov khoom sib dhos saum npoo thiab PCB ruaj khov ua ke.Yog tias nws tsis tuaj yeem tswj tau zoo, nws yuav muaj kev puas tsuaj rau kev ntseeg siab thiab kev pabcuam lub neej ntawm cov khoom.Muaj ntau txoj hauv kev ntawm reflow welding.Txoj kev nrov dhau los yog infrared thiab roj-theem.Tam sim no ntau lub tuam txhab siv cov cua kub reflow welding, thiab qee lub sijhawm los yog tshwj xeeb siv cov txheej txheem reflow, xws li cov tub ntxhais kub phaj, lub teeb dawb tsom, ntsug qhov cub, thiab lwm yam. Cov hauv qab no yuav ua kom luv luv rau cov cua kub nrov reflow vuam.
1. Cov cua kub reflow vuam
Tam sim no, feem ntau ntawm cov tshiab reflow soldering furnaces yog hu ua yuam convection kub cua reflow soldering furnaces.Nws siv lub kiv cua sab hauv los tshuab cua kub rau lossis ib ncig ntawm lub phaj sib dhos.Ib qho txiaj ntsig ntawm qhov cub no yog tias nws maj mam thiab tsis tu ncua muab cua sov rau cov phaj sib dhos, tsis hais xim thiab kev ntxhib los mos ntawm qhov chaw.Txawm hais tias, vim muaj cov tuab sib txawv thiab kev nqus tuab, nqus dej kub yuav sib txawv, tab sis qhov kub sib txawv ntawm tib lub pcb tsis txawv.Tsis tas li ntawd, lub tshuab hluav taws xob tuaj yeem tswj tau qhov kub thiab txias siab tshaj plaws ntawm qhov muab qhov kub thiab txias, uas muab ib qho chaw zoo dua rau cheeb tsam kev ruaj ntseg thiab cov txheej txheem tswj reflux ntau dua.
2. Kev faib khoom kub thiab ua haujlwm
Nyob rau hauv tus txheej txheem ntawm cov cua kub reflow welding, lub solder muab tshuaj txhuam yuav tsum mus los ntawm cov nram qab no theem: hnyav volatilization;flux tshem tawm oxide ntawm qhov chaw ntawm vuam;solder paste melting, reflow thiab solder paste txias, thiab solidification.Qhov kub thiab txias nkhaus (Profile: hais txog qhov nkhaus uas qhov kub ntawm qhov sib koom ua ke ntawm PCB hloov nrog lub sij hawm thaum dhau los ntawm lub qhov cub reflow) muab faib rau hauv qhov chaw ua kom sov, thaj chaw txuag hluav taws xob, thaj chaw reflow, thiab qhov chaw txias.(saib saum toj no)
① Preheating cheeb tsam: lub hom phiaj ntawm lub preheating cheeb tsam yog preheat PCB thiab Cheebtsam, ua kom muaj nuj nqis, thiab tshem tawm cov dej thiab hnyav nyob rau hauv solder paste, thiaj li yuav tiv thaiv tau solder paste collapse thiab solder spatter.Qhov kub nce siab yuav tsum tau tswj nyob rau hauv ib qho kev tsim nyog (ceev ceev heev yuav ua rau thermal shock, xws li tawg ntawm multilayer ceramic capacitor, splashing ntawm solder, tsim solder pob thiab solder pob qij txha nrog tsis txaus solder nyob rau hauv lub tsis-welded cheeb tsam ntawm tag nrho cov PCB. ; qeeb dhau yuav ua rau cov haujlwm ntawm flux tsis muaj zog).Feem ntau, qhov kub siab tshaj plaws nce siab yog 4 ℃ / sec, thiab qhov nce siab yog teem raws li 1-3 ℃ / sec, uas yog tus qauv ntawm ECs yog tsawg dua 3 ℃ / sec.
② Tshav kub preservation (active) cheeb tsam: hais txog thaj tsam ntawm 120 ℃ to 160 ℃ .Lub hom phiaj tseem ceeb yog ua kom qhov kub thiab txias ntawm txhua yam ntawm PCB yuav tsum zoo ib yam, txo qhov kub ntawm qhov sib txawv kom ntau li ntau tau, thiab xyuas kom meej tias cov solder tuaj yeem qhuav tag ua ntej mus txog qhov kub thiab txias.Thaum kawg ntawm qhov chaw rwb thaiv tsev, cov oxide ntawm cov nplaum nplaum, cov nplaum nplaum nplaum, thiab cov khoom siv tus pin yuav tsum tau muab tshem tawm, thiab qhov kub ntawm tag nrho lub rooj tsavxwm yuav tsum sib npaug.Lub sijhawm ua haujlwm yog li 60-120 vib nas this, nyob ntawm qhov xwm txheej ntawm cov khoom siv.ECS tus qauv: 140-170 ℃, max120sec;
③ Reflow cheeb tsam: qhov kub ntawm lub rhaub nyob rau hauv cheeb tsam no yog teem rau siab tshaj plaws.Qhov kub siab tshaj plaws ntawm vuam yog nyob ntawm qhov siv cov tshuaj txhuam.Nws feem ntau pom zoo kom ntxiv 20-40 ℃ rau qhov kub ntawm qhov kub ntawm cov tshuaj txhuam.Nyob rau lub sijhawm no, cov khoom siv hauv cov tshuaj txhuam hniav pib yaj thiab ntws dua, hloov cov kua dej kom ntub cov ntaub qhwv thiab cov khoom.Qee zaum, cheeb tsam kuj tau muab faib ua ob thaj tsam: thaj tsam melting thiab cheeb tsam reflow.Qhov zoo tshaj plaws kub nkhaus yog tias thaj tsam uas npog los ntawm "tib cheeb tsam" tshaj qhov melting point ntawm lub solder yog qhov tsawg tshaj plaws thiab symmetrical, feem ntau, lub sij hawm ntau tshaj 200 ℃ yog 30-40 sec.Tus qauv ntawm ECS yog qhov kub siab tshaj plaws: 210-220 ℃, lub sijhawm ntau tshaj 200 ℃: 40 ± 3sec;
④ Qhov chaw txias: txias kom nrawm li sai tau yuav pab kom tau txais cov pob qij txha ci ntsa iab nrog cov duab tag nrho thiab lub kaum sab xis sib cuag.Kev ua kom txias qeeb yuav ua rau ntau qhov decomposition ntawm lub ncoo rau hauv cov tin, ua rau cov pob qij txha grey thiab ntxhib, thiab tseem ua rau cov tin tsis zoo thiab tsis muaj zog solder sib koom ua ke.Cov cua txias feem ntau yog nyob rau hauv - 4 ℃ / sec, thiab nws tuaj yeem txias txog li 75 ℃.Feem ntau, yuam kom txias los ntawm cov kiv cua txias yog xav tau.
3. Ntau yam cuam tshuam rau kev ua haujlwm vuam
Cov yam ntxwv thev naus laus zis
Vuam pretreatment method, kho hom, txoj kev, thickness, tus naj npawb ntawm txheej.Seb nws yog rhuab, txiav los yog ua hauj lwm nyob rau hauv lub sij hawm ntawm kev kho mob mus rau vuam.
Tsim cov txheej txheem vuam
Vuam cheeb tsam: hais txog qhov loj me, qhov sib txawv, qhov sib txawv ntawm txoj siv (xaiv): cov duab, thermal conductivity, lub peev xwm kub ntawm cov khoom siv vuam: yog hais txog vuam kev taw qhia, txoj hauj lwm, siab, lub xeev kev sib txuas, thiab lwm yam.
Vuam tej yam kev mob
Nws yog hais txog vuam kub thiab lub sij hawm, preheating tej yam kev mob, cua sov, txias ceev, vuam cua sov hom, cab kuj daim ntawv ntawm tshav kub qhov chaw (wavelength, tshav kub conduction ceev, thiab lwm yam).
cov khoom siv vuam
Flux: muaj pes tsawg leeg, concentration, kev ua si, melting point, boiling point, thiab lwm yam
Solder: muaj pes tsawg leeg, qauv, impurity ntsiab lus, melting point, thiab lwm yam
Base hlau: muaj pes tsawg leeg, qauv thiab thermal conductivity ntawm lub hauv paus hlau
Viscosity, tshwj xeeb lub ntiajteb txawj nqus thiab thixotropic zog ntawm solder paste
Substrate khoom, hom, cladding hlau, thiab lwm yam.
Kab lus thiab cov duab hauv internet, yog tias muaj kev ua txhaum cai pls ua ntej hu rau peb kom tshem tawm.
NeoDen muab tag nrho SMT sib dhos kab kev daws teeb meem, suav nrog SMT reflow qhov cub, yoj lub tshuab siv lub tshuab, xaiv thiab tso tshuab, tshuab luam ntawv muab tshuaj txhuam, PCB loader, PCB unloader, nti mounter, SMT AOI tshuab, SMT SPI tshuab, SMT X-Ray tshuab, SMT sib dhos kab khoom, PCB ntau lawm Equipment SMT spare qhov chaw, thiab lwm yam yam SMT tshuab koj xav tau, thov hu rau peb kom paub ntxiv:
Hangzhou NeoDen Technology Co., Ltd
Email:info@neodentech.com
Post lub sij hawm: May-28-2020