l Cov kev cai kub tsis muaj txhuas rau cov khoom siv
Kev tsim khoom tsis muaj txhuas yuav tsum muaj cov cuab yeej siv los tiv thaiv qhov kub siab dua li cov khoom siv lead ua.Yog tias muaj teeb meem nrog cov khoom siv, cov teeb meem xws li lub tshuab hluav taws xob ua kom sov, kev deformation, thiab kev ua haujlwm tsis zoo yuav tshwm sim, uas yuav cuam tshuam rau kev tsim khoom.Yog li ntawd, txoj kev siv nyob rau hauv lub qhov cub uas tsis muaj hmoov lead-dawb reflow yuav tsum tau hardened thiab lwm yam kev kho mob tshwj xeeb, thiab cov ntaub ntawv hlau pob qij txha yuav tsum tau X-ray scan kom paub meej tias tsis muaj kab nrib pleb thiab npuas kom tsis txhob puas thiab to tom qab siv mus ntev. .
l Zoo tiv thaiv cov kab noj hniav ntawm qhov cub thiab kev tsheb nqaj hlau deformation
Cov kab noj hniav ntawm cov hlau lead-dawb reflow soldering rauv yuav tsum yog ua los ntawm tag nrho cov ntawv hlau.Yog hais tias cov kab noj hniav yog spliced nrog me me ntawm cov ntawv hlau, nws yog feem ntau ua rau warpage nyob rau hauv qhov kub tsis muaj hlau lead.
Nws yog ib qho tsim nyog los ntsuas qhov sib npaug ntawm cov ntsia hlau nyob rau hauv qhov kub thiab txias.Yog hais tias tus khiav yog deformed ntawm qhov kub thiab txias vim yog cov khoom siv thiab tsim, qhov tshwm sim ntawm jamming thiab board poob yuav raug zam.
l Tsis txhob cuam tshuam cov pob qij txha
Yav dhau los coj Sn63Pb37 solder yog ib tug eutectic alloy, thiab nws melting point thiab freezing point kub yog tib yam, ob qho tib si ntawm 183 ° C.Cov hlau lead-dawb solder sib koom ntawm SnAgCu tsis yog eutectic alloy.Nws melting point yog li ntawm 217 ° C mus rau 221 ° C.Qhov ntsuas kub qis dua 217 ° C rau lub xeev muaj zog, thiab qhov kub siab tshaj 221 ° C rau lub xeev ua kua.Thaum qhov kub ntawm 217 ° C mus rau 221 ° C Cov hlau ua rau lub xeev tsis ruaj khov.Thaum lub solder sib koom nyob rau hauv lub xeev no, cov neeg kho tshuab kev co ntawm cov cuab yeej tuaj yeem hloov tau yooj yim ntawm cov khoom sib koom ua ke thiab ua rau muaj kev cuam tshuam ntawm kev sib koom ua ke.Qhov no yog qhov tsis txaus ntseeg hauv IPC-A-610D tus qauv ntawm cov khoom siv hluav taws xob siv tau.Yog li ntawd, kev sib kis ntawm cov khoom siv lead-dawb reflow soldering yuav tsum muaj cov qauv zoo tsis muaj kev vibration kom tsis txhob cuam tshuam cov pob qij txha.
Yuav tsum tau txo cov nqi khiav haujlwm:
l Qhov nruj ntawm qhov cub kab noj hniav
Lub warpage ntawm lub cub tawg kab noj hniav thiab cov to ntawm cov cuab yeej yuav ncaj qha ua rau cov linear nce nyob rau hauv tus nqi ntawm nitrogen siv rau hluav taws xob.Yog li ntawd, kev sib khi ntawm cov khoom siv tseem ceeb heev rau kev tswj cov nqi tsim khoom.Kev xyaum tau ua pov thawj tias qhov xau me me, txawm tias lub qhov dej xau qhov loj ntawm lub qhov ntsia hlau, tuaj yeem ua kom cov nitrogen noj ntawm 15 cubic meters ib teev mus rau 40 cubic meters ib teev.
l Thermal rwb thaiv tsev kev ua tau zoo ntawm cov khoom siv
Kov qhov chaw ntawm lub qhov cub reflow (txoj hauj lwm sib thooj rau thaj tsam reflow) yuav tsum tsis txhob hnov qab (qhov kub ntawm qhov chaw yuav tsum qis dua 60 degrees).Yog tias koj xav tias kub, nws txhais tau hais tias qhov thermal rwb thaiv tsev kev ua tau zoo ntawm qhov cub reflow yog qhov tsis zoo, thiab cov hluav taws xob ntau ntawm cov hluav taws xob hloov mus rau hauv cov cua sov thiab poob, ua rau cov khoom siv hluav taws xob tsis zoo.Yog tias nyob rau lub caij ntuj sov, lub zog hluav taws xob poob hauv lub rhiav yuav ua rau qhov kub thiab txias ntawm lub rhiav, thiab peb yuav tsum siv lub tshuab cua txias kom tso cov cua sov tawm mus rau sab nraum zoov, uas ncaj qha ua rau ob lub zog pov tseg.
l Tso pa tawm
Yog tias cov cuab yeej tsis muaj kev tswj xyuas cov dej ntws zoo, thiab qhov tso tawm ntawm cov dej ntws tawm yog ua los ntawm cov pa tawm, tom qab ntawd cov cuab yeej tseem yuav tawm cov cua sov thiab nitrogen thaum rub tawm cov flux residue, uas ncaj qha ua rau muaj kev siv zog ntxiv.
l Tus nqi kho mob
Lub qhov cub reflow muaj qhov ua tau zoo heev hauv kev tsim khoom tas mus li, thiab tuaj yeem tsim ntau pua lub xov tooj ntawm tes hauv ib teev.Yog tias lub tshuab hluav taws xob muaj lub sijhawm tu ncua luv, kev saib xyuas kev ua haujlwm loj, thiab lub sijhawm ua haujlwm ntev, nws yuav ua rau lub sijhawm ntau lawm, ua rau muaj kev pov tseg ntawm kev tsim khoom.
Txhawm rau txo cov nqi txij nkawm, cov cuab yeej siv lead-dawb reflow soldering yuav tsum tau hloov kho kom ntau li ntau tau kom yooj yim rau kev tu thiab kho cov cuab yeej (Daim duab 8).
Post lub sij hawm: Aug-13-2020