Kev teeb tsa kub nkhaus rau cov hlau lead-dawb reflow soldering ntawm SMD LED
Tam sim no, cov hlau lead-dawb reflow soldering kub nkhaus uas tau siv dav hauv kev lag luam feem ntau suav nrog trapezoidal kub nkhaus thiab maj mam kub nkhaus. Ua ke nrog qhov kub thiab txias nkhaus, cov hlau lead-dawb reflow kub nkhaus yog tsim raws li cov yam ntxwv ntawm 3014LED teeb hlaws thiab kev ua haujlwm ntawm cov hlau lead-dawb solder 95.5Sn3.8Ag0.7Cu, raws li qhia hauv daim duab.
Lead-free reflow soldering kub profile
1. Cua sov cheeb tsam rau cov hlau lead-dawb reflow soldering ntawm LED teeb hlaws
Lub preheating cheeb tsam ntawm cov hlau lead-free reflow soldering yuav muab faib ua 3 sub-zones, uas yog lub cua sov cheeb tsam, lub tshav kub preservation cheeb tsam thiab ceev ceev cua sov cheeb tsam. Hauv cheeb tsam cua sov, cov txheej txheem cua sov nrog cov cua kub ntawm 1.5 txog 2.5 ° C / sec, qhov siab tshaj plaws cua sov tsis tshaj 3 ° C / sec, thiab lub sij hawm tsis pub tshaj 90 vib nas this yog siv los ua qhov kub thiab txias. los ntawm qhov chaw ua haujlwm kub txog 130 ° C. Nyob rau theem no, LED Circuit Court board (PCB) ncav cuag qhov kub thiab txias uas yuav tsum tau siv rau reflow soldering los ntawm ambient kub, qis melting point hnyav nyob rau hauv lub solder paste volatilizes, thiab thermal shock rau cov khoom yog txo. Cov cua kub ceev yuav tsum tsis txhob ceev heev, txwv tsis pub nws yuav ua rau lub deterioration ntawm flux muaj pes tsawg leeg nyob rau hauv lub solder paste, tsim ntawm solder balls, bridging thiab lwm yam tsis xws luag, thiab nyob rau tib lub sij hawm, lub Cheebtsam yuav raug rau cov thermal stress ntau heev. thiab warp. Tsis tas li ntawd, thaum welding PCB nqa lub zog loj thiab loj-loj LED teeb hlaws, txhawm rau ua kom tag nrho PCB qhov kub thiab txias tsis xws luag xws li warpage los ntawm thermal stress, koj tuaj yeem xa mus rau cov txheej txheem kev kho cua sov thiab siv tau. kev paub, thiab maj mam nce qhov kub ntawm lub sijhawm no. Thiab preheating. Hauv thaj chaw txuag hluav taws xob, siv cov cua sov ntawm< 2="" °="" c="" sec="" los="" ua="" kom="" qhov="" kub="" thiab="" txias="" hauv="" thaj="" chaw="" khaws="" cia="" kub="" ntawm="" 140-160="" °="" c="" thiab="" khaws="" cia="" rau="" 60-90="" vib="" nas="" this.="" nyob="" rau="" hauv="" cheeb="" tsam="" no,="" cov="" flux="" pib="" ua="" haujlwm,="" thiab="" txhua="" qhov="" ntawm="" pcb="" yog="" wetted="" tusyees="" ua="" ntej="" mus="" txog="" qhov="" chaw="" reflow,="" thiab="" cov="" kuab="" tshuaj="" nyob="" rau="" hauv="" lub="" solder="" paste="" uas="" tsis="" tas="" evaporated="" yog="" ntxiv="" volatilized.="" hauv="" thaj="" chaw="" cua="" sov="" ceev,="" uas="" tseem="" hu="" ua="" flux="" infiltration="" zone,="" qhov="" kub="" sai="" sai="" nce="" mus="" rau="" qhov="" chaw="" melting="" ntawm="" cov="" tshuaj="" nplaum.="" nyob="" rau="" theem="" no,="" tus="" nqi="" cua="" sov="" yuav="" tsum="" tau="" ceev="" ceev,="" txwv="" tsis="" pub="" cov="" kev="" ua="" ntawm="" flux="" nyob="" rau="" hauv="" lub="" solder="" paste="" yuav="" raug="" txo,="" thiab="" solder="" alloy="" yuav="" oxidized="" nyob="" rau="" hauv="" high="" kub,="" tsim="" ib="" tug="" phem="" solder="" sib="" koom.="" nyob="" rau="" theem="" no,="" lub="" flux="" ntxuav="" lub="" oxide="" txheej="" ntawm="" lub="" soldering="" nto="" thiab="" tuav="" ib="" tug="" tej="" yam="" kev="" ua="" ub="" no,="" uas="" pab="" tsim="" ib="" tug="" zoo="" intermetallic="" compound="" sib="" koom="" ua="" ke="" nyob="" rau="" hauv="" lub="" soldering="" cheeb="">
2. Lead-free reflow soldering cheeb tsam rau LED teeb hlaws
Qhov chaw soldering (reflow area) solder paste muaj nyob rau hauv daim ntawv ntawm cov kua theem ntawm qhov kub siab tshaj qhov melting point. Rau cov solder 96.5% Sn / 3.0% Ag / 0.7% Cu, qhov kub siab tshaj plaws yog nyob nruab nrab ntawm 235 ~ 245 ℃, thiab lub melting point saum 225 ℃ yog tswj ntawm 40 ~ 60 vib nas this thiab lub sij hawm thaum siab tshaj 230 ℃ yog 10 ～ 20 vib nas this. Nyob rau hauv qhov kub thiab txias, cov hlau hais nyob rau hauv lub solder paste yaj, diffuse, yaj, tshuaj metallurgy, thiab daim ntawv IMC pob qij txha nyob rau hauv qhov kev txiav txim ntawm cov kua nto nro. Nyob rau tib lub sijhawm, yog tias qhov kub siab tshaj plaws yog siab dhau thiab lub sijhawm rov qab mus ntev dhau lawm, nws yuav ua rau IMC cov nplej loj dhau, thiab cov khoom siv hluav taws xob thiab hluav taws xob yuav cuam tshuam. Kev puas tsuaj thiab lwm yam. Yog tias qhov kub thiab txias qis dhau thiab lub sij hawm rov qab luv luv, lub solder thiab PCB yuav tsis ntub tag, tsim ib qho kev sib koom ua ke, uas cuam tshuam rau cov hluav taws xob conductivity. Rau cov khoom siv hluav taws xob loj, cov cua sov tsis txaus thiab cov kev sib txuas ntawm cov khoom sib txuas tsis ruaj khov. Vuam. Tus txheej txheem ntawm kev txiav txim siab qhov kub thiab txias ntawm thaj tsam soldering thiab lub sij hawm reflow yuav tsum tau tshawb fawb ntxiv rau cov teeb ci LED thiab cov PCB sib txawv.
3. Lead-free reflux txias cheeb tsam rau LED teeb hlaws
Tom qab lub teeb ci LED hlaws hluav taws xob tawm ntawm thaj chaw soldering, lub substrate nkag mus rau qhov chaw txias. Nyob rau theem no, qhov txias txias yog tsawg dua lossis sib npaug li 4 ° C / s. Yog tias qhov txias txias nrawm dhau lawm, kev ntxhov siab thermal loj yuav ua rau cov kab mob txias hauv cov pob qij txha, LED teeb hlaws, lossis txawm tias deformation ntawm PCB, thiab PCB lub teeb bar yuav raug muab pov tseg. Yog tias qhov txias txias qeeb dhau, lub sijhawm sib koom ua ke crystallization yog ntev, thiab tus nqi nucleation tsawg. Lub zog txaus yuav ua rau IMC cov nplej tuab heev, thiab nws nyuaj rau tsim IMC pob qij txha nrog cov nplej zoo, uas yuav ua rau lub zog sib koom ua ke tsis zoo, thiab txawm tias LED teeb hlaws dai. Hloov tshwm sim.
