Lead-free Reflow Profile: Soaking type vs. Slumping type

Reflow soldering yog ib txheej txheem uas cov tshuaj txhuam hniav yog rhuab thiab hloov mus rau lub xeev molten thiaj li yuav txuas cov pins thiab PCB pads ua ke mus tas li.

Muaj plaub theem / thaj tsam rau cov txheej txheem no - preheating, soaking, reflow thiab txias.

Rau cov tsoos trapezoidal hom profile puag ntawm txhuas dawb solder paste uas Bittele siv rau SMT txheej txheem sib dhos:

1. Preheating cheeb tsam: Preheat feem ntau yog hais txog kev nce qhov kub ntawm ib txwm kub mus rau 150 ° C thiab los ntawm 150 ° C mus rau 180 C. Qhov kub ntawm qhov nruab nrab mus rau 150 ° C yog tsawg dua 5 ° C / sec (ntawm 1.5 ° C ~ 3 ° C / sec), thiab lub sij hawm ntawm 150 ° C mus rau 180 ° C yog nyob ib ncig ntawm 60 ~ 220 sec.Qhov txiaj ntsig ntawm kev ua kom sov qeeb yog cia cov kuab tshuaj thiab dej hauv cov tshuaj vapor tawm tuaj raws sijhawm.Nws kuj cia cov khoom loj tuaj yeem ua kom sov nrog rau lwm cov khoom me me.
2. Soaking cheeb tsam: Lub sij hawm preheating ntawm 150 ° C mus rau lub alloy molten point tseem hu ua lub sij hawm soaking, uas txhais tau hais tias lub flux tau txais active thiab yog tshem tawm cov oxidized hloov nyob rau hauv cov hlau nto yog li nws yog npaj los ua ib tug zoo solder sib koom. nruab nrab ntawm cov khoom siv pins thiab PCB pads.
3. Reflow zone: Qhov chaw reflow, tseem hu ua "lub sij hawm saum cov kua" (TAL), yog ib feem ntawm cov txheej txheem uas qhov kub siab tshaj plaws mus txog.Qhov kub siab tshaj plaws yog 20-40 ° C saum cov kua dej.
4. Qhov chaw txias txias: Hauv qhov chaw txias, qhov kub thiab txias tau maj mam txo qis thiab ua rau cov khoom sib txuas ua ke.Qhov siab tshaj plaws uas tso cai rau qhov txias ntawm txoj kab nqes yuav tsum tau txiav txim siab kom tsis txhob muaj qhov teeb meem tshwm sim.Qhov ntsuas cua txias ntawm 4 ° C / s tau pom zoo.

Muaj ob qhov sib txawv profile koom nrog hauv cov txheej txheem reflow - hom ntub dej thiab hom slumping.

Hom Soaking zoo ib yam li cov duab trapezoidal thaum lub slumping hom muaj cov duab delta.Yog tias lub rooj tsavxwm yooj yim thiab tsis muaj cov khoom sib txuam xws li BGAs lossis cov khoom loj ntawm lub rooj tsavxwm, qhov kev sib tsoo hom profile yuav yog qhov kev xaiv zoo dua.