SMT thaj yog hais txog cov ntawv luv ntawm cov txheej txheem txheej txheem raws li PCB. PCB (Printed Circuit Board) yog lub rooj tsav xwm luam tawm.
SMT yog cov ntawv luv ntawm Surface Mounted Technology, uas yog cov cuab yeej siv nrov tshaj plaws thiab cov txheej txheem hauv kev lag luam hluav taws xob sib dhos. Hluav taws xob Circuit Court nto sib dhos tshuab (Surface Mount Technology, SMT) yog hu ua nto mount lossis nto mounting tshuab. Nws yog ib txoj hauv kev txhim kho cov khoom siv lead ua tsis muaj txhuas lossis luv-luv-dawb nto-mounted Cheebtsam (hu ua SMC / SMD, hu ua chip Cheebtsam hauv Suav) rau saum npoo ntawm cov ntawv luam tawm Circuit Board (PCB) lossis lwm yam substrate. Lub tshuab hluav taws xob sib dhos uas tau sib sau ua ke los ntawm kev siv cov txheej txheem xws li reflow soldering lossis dip soldering.
Nyob rau hauv cov txheej txheem SMT vuam, nitrogen yog tsis tshua muaj tsim nyog raws li ib tug tiv thaiv roj. Qhov laj thawj tseem ceeb yog tias nws lub zog cohesive yog siab, thiab tshuaj lom neeg cov tshuaj tiv thaiv tsuas yog tshwm sim nyob rau hauv qhov kub thiab txias (> 500C,> 100bar) lossis nrog kev sib ntxiv ntawm lub zog.
Nitrogen generator yog tam sim no cov khoom siv nitrogen tsim nyog tshaj plaws siv hauv kev lag luam SMT. Raws li cov khoom siv nitrogen hauv chaw tsim khoom, lub tshuab hluav taws xob nitrogen yog tag nrho tsis siv neeg thiab tsis muaj neeg saib xyuas, muaj lub neej ntev, thiab muaj qhov tsis ua haujlwm tsawg. Nws yog qhov yooj yim heev kom tau txais nitrogen, thiab tus nqi kuj yog qhov qis tshaj ntawm txoj kev siv nitrogen tam sim no!
Nitrogen ntau lawm Manufacturers - Tuam Tshoj Nitrogen ntau lawm Hoobkas & lwm (xinfatools.com)
Nitrogen tau siv nyob rau hauv reflow soldering ua ntej inert gases tau siv nyob rau hauv yoj soldering txheej txheem. Ib feem ntawm qhov laj thawj yog tias kev lag luam hybrid IC tau ntev siv nitrogen hauv reflow soldering ntawm nto-mount ceramic hybrid circuits. Thaum lwm lub tuam txhab pom cov txiaj ntsig ntawm hybrid IC manufacturing, lawv tau siv txoj cai no rau PCB soldering. Hauv hom vuam no, nitrogen kuj hloov cov pa oxygen hauv lub cev. Nitrogen tuaj yeem nkag mus rau hauv txhua qhov chaw, tsis yog hauv thaj chaw reflow xwb, tab sis kuj ua kom txias ntawm cov txheej txheem. Feem ntau cov tshuab reflow tam sim no yog npaj txhij; qee lub tshuab tuaj yeem hloov kho tau yooj yim los siv roj txhaj tshuaj.
Siv nitrogen hauv reflow soldering muaj cov hauv qab no zoo:
‧ Fast wetting ntawm cov terminals thiab pads
‧ Kev hloov me me hauv kev sib tw
‧ Txhim kho qhov tsos ntawm cov dej ntws tawm thiab cov khoom sib koom ua ke
‧ Ua kom txias sai yam tsis muaj tooj liab oxidation
Raws li kev tiv thaiv roj, nitrogen lub luag haujlwm tseem ceeb hauv kev vuam yog tshem tawm cov pa oxygen thaum lub sij hawm vuam, ua kom muaj kev sib txuas, thiab tiv thaiv rov oxidation. Rau kev txhim khu kev qha vuam, ntxiv rau kev xaiv qhov tsim nyog solder, kev koom tes ntawm flux feem ntau yuav tsum tau ua. Cov flux feem ntau tshem tawm oxides los ntawm vuam ib feem ntawm SMA tivthaiv ua ntej vuam thiab tiv thaiv rov oxidation ntawm vuam ib feem, thiab cov ntaub ntawv zoo wetting tej yam kev mob rau lub solder los txhim kho solderability. . Kev ntsuam xyuas tau ua pov thawj tias ntxiv formic acid nyob rau hauv kev tiv thaiv nitrogen tuaj yeem ua tiav cov teebmeem saum toj no. Lub nplhaib nitrogen yoj soldering tshuab uas siv lub qhov taub-hom vuam tank qauv yog feem ntau yog lub qhov taub-hom vuam ua lub tank. Lub hau sab saud yog tsim los ntawm ob peb daim iav qhib kom ntseeg tau tias oxygen tsis tuaj yeem nkag mus rau hauv lub tank ua haujlwm. Thaum nitrogen tau nkag rau hauv vuam, siv qhov sib txawv ntawm cov pa tiv thaiv thiab huab cua, nitrogen yuav cia li tsav cov cua tawm ntawm qhov chaw vuam. Thaum lub sij hawm vuam txheej txheem, PCB lub rooj tsavxwm yuav txuas ntxiv nqa oxygen mus rau hauv qhov chaw vuam, yog li nitrogen yuav tsum tau txuas ntxiv mus rau hauv qhov chaw vuam kom cov pa oxygen tsis tu ncua mus rau qhov hluav taws xob.
Nitrogen ntxiv rau formic acid technology feem ntau yog siv nyob rau hauv qhov-hom reflow furnaces nrog infrared enhanced convection mixing. Lub qhov hluav taws xob thiab qhov hluav taws xob feem ntau yog tsim los qhib, thiab muaj ntau lub qhov rooj ntaub thaiv sab hauv nrog kev sib khi zoo, uas tuaj yeem ua kom sov thiab preheat Cheebtsam. Qhuav, reflow soldering thiab txias yog tag nrho cov tiav nyob rau hauv lub qhov. Nyob rau hauv cov huab cua sib xyaw no, cov tshuaj nplaum siv tsis tas yuav muaj cov activators, thiab tsis muaj qhov seem seem ntawm PCB tom qab soldering. Txo oxidation, txo qhov tsim ntawm cov khoom siv solder, thiab tsis muaj kev sib txuas, uas yog qhov zoo heev rau kev vuam ntawm cov khoom siv zoo-pitch. Nws txuag cov cuab yeej ntxuav thiab tiv thaiv lub ntiaj teb ib puag ncig. Cov nqi ntxiv uas tshwm sim los ntawm nitrogen tau yooj yim recouped los ntawm cov nqi txuag tau los ntawm kev txo qis thiab kev ua haujlwm.
Wave soldering thiab reflow soldering nyob rau hauv kev tiv thaiv nitrogen yuav dhau los ua cov thev naus laus zis hauv kev sib dhos saum npoo. Lub nplhaib nitrogen yoj soldering tshuab yog ua ke nrog formic acid technology, thiab lub nplhaib nitrogen reflow soldering tshuab yog ua ke nrog tsis tshua muaj kev ua haujlwm solder paste thiab formic acid, uas tuaj yeem tshem tawm cov txheej txheem ntxuav. Nyob rau niaj hnub no txoj kev loj hlob sai ntawm SMT vuam tshuab, qhov teeb meem tseem ceeb tau ntsib yog yuav ua li cas tshem tawm cov oxides, tau txais ib qho chaw ntshiab ntawm cov khoom siv hauv paus, thiab ua tiav kev sib txuas zoo. Feem ntau, flux yog siv los tshem tawm oxides, moisten qhov chaw yuav tsum tau soldered, txo qhov nro ntawm lub solder, thiab tiv thaiv re-oxidation. Tab sis tib lub sijhawm, flux yuav tawm cov khoom seem tom qab soldering, ua rau muaj kev cuam tshuam tsis zoo rau PCB Cheebtsam. Yog li ntawd, lub rooj tsav xwm Circuit Court yuav tsum tau muab ntxuav kom huv si. Txawm li cas los xij, qhov loj ntawm SMD yog me me, thiab qhov sib txawv ntawm qhov tsis-solding qhov chaw tau txais me me thiab me. Kev tu kom huv tsis tuaj yeem ua tau lawm. Qhov tseem ceeb tshaj yog kev tiv thaiv ib puag ncig. CFCs ua rau muaj kev puas tsuaj rau cov huab cua ozone txheej, thiab CFCs ua tus neeg saib xyuas tseem ceeb yuav tsum raug txwv. Ib txoj hauv kev zoo los daws cov teeb meem saum toj no yog siv cov cuab yeej tsis huv hauv kev sib dhos hluav taws xob. Ntxiv ib qho me me thiab ntau npaum li cas ntawm formic acid HCOOH rau nitrogen tau ua pov thawj tias yog cov txheej txheem tsis huv uas tsis tas yuav tsum tau ntxuav tom qab vuam, tsis muaj kev phiv lossis kev txhawj xeeb txog cov khoom seem.
Post lub sij hawm: Feb-22-2024
