Pinhole thiab porosity ob leeg sawv cev rau cov pob qij txha muaj cov pa npuas, tab sis tseem tsis tau nthuav dav rau saum npoo, feem ntau ntawm lawv tshwm sim nyob rau hauv qab ntawm lub substrate, thaum lub hauv qab ntawm cov npuas tag nrho diffuse burst ua ntej condensation, uas yog, tsim ntawm. pinhole los yog porosity. Qhov txawv ntawm pinholes thiab porosity yog tias pinholes yog me me nyob rau hauv txoj kab uas hla.
Ua rau:
Organic contaminants ntawm lub substrate los yog ntawm cov pins ntawm ib feem. Cov ntaub ntawv tsis zoo li no tuaj ntawm cov tshuab tsis siv neeg ntxig, pin sib sau tshuab thiab los ntawm yam xws li kev cia tsis zoo.
Cov substrates muaj dej vapor los ntawm cov txheej txheem plating thiab cov khoom zoo sib xws. Yog hais tias lub substrate yog ua los ntawm cov khoom pheej yig dua, nws muaj peev xwm nqus tau cov dej vapor thiab tsim kom muaj cua sov txaus thaum lub sij hawm soldering rau vaporize cov tshuaj, yog li ua rau porosity.
Substrates khaws cia ntau dhau los yog ntim tsis raug, nqus dej vapor los ntawm ib puag ncig ze.
Moisture hauv lub da dej flux.
Tshaj noo noo nyob rau hauv compressed cua siv rau foaming thiab kub cua riam.
Preheating kub yog tsawg dhau rau evaporate dej vapor los yog hnyav, thaum lub substrate nkag mus rau hauv lub cub tawg, instant contact with high temperature, thiab tawg.
Tin kub yog siab dhau lawm, ntsib nrog noo noo los yog hnyav, tam sim ntawd tawg.
Kev daws:
Kev tshem tawm cov kab mob organic los ntawm cov pins nrog cov kuab tshuaj ntau; raws li cov roj silicone thiab cov khoom zoo sib xws uas muaj silicon yog qhov nyuaj rau kev tshem tawm, yog tias qhov teeb meem tau pom los ntawm cov roj silicone, kev txiav txim siab yuav tsum tau muab rau kev hloov lub hauv paus ntawm lubricant los yog tso tawm tus neeg sawv cev.
Ci lub substrate hauv qhov cub ua ntej sib dhos kom tshem tawm cov dej noo uas muaj nyob hauv substrate.
ci lub substrate nyob rau hauv qhov cub ua ntej los ua ke.
periodic flux hloov.
qhov xav tau rau lub lim dej rau compressed cua thiab tsis tu ncua tso pa tawm.
Kho qhov kub ntawm preheating.
Tig qhov kub ntawm qhov cub solder.
Ua rau:
Lub sij hawm tsis zoo ntawm qhov kub thiab txias.
Incorrect solder composition.
Mechanical vibration ua ntej solder txias.
Tin muaj kab mob.
Kev daws:
Kho txoj siv conveyor ceev thiab kho lub solder preheat kub los tsim kom muaj kev sib raug zoo lub sij hawm-rau-kub.
Txheeb xyuas qhov sib xyaw ntawm cov khoom siv los txiav txim seb hom solder thiab qhov ntsuas kub kom zoo rau qhov muab alloy.
Kev tshuaj xyuas txoj siv conveyor kom paub meej tias lub substrate tsis tawg los yog shaken thaum soldering thiab solidification.
Tshawb xyuas hom impurity ua rau muaj kab mob thiab txo lossis tshem tawm cov kab mob sib kis hauv lub da dej los ntawm cov txheej txheem tsim nyog (dilution lossis hloov cov solder)
Ua rau:
Conveyor siv ceev ceev heev.
Vuam kub tsawg dhau.
Secondary welding waveform yog tsawg.
Tsis zoo waveform lossis tsis tsim waveform thiab phaj lub kaum sab xis thiab tsis zoo waveform ntawm qhov kawg.
Kev sib kis ntawm lub phaj nto thiab tsis zoo weldability.
Kev daws:
Ua kom qeeb ntawm txoj siv conveyor ceev; qhov tseeb point ntawm nws
Kho qhov kub thiab txias ntawm lub cub tawg.
kho qhov thib ob welding waveform.
Kho cov waveform thiab lub kaum sab xis ntawm txoj siv conveyor.
Ntxuav lub PCB board nto los txhim kho nws cov solderability.
Cheebtsam solder xaus thiab pins yog ib puag ncig los ntawm ntau dhau solder, lub wetting lub kaum sab xis yog ntau tshaj 90 °.
Ua rau:
PCB preheating kub yog tsawg dhau, cov khoom thiab CB nqus cua sov thaum soldering, kom qhov tseeb soldering kub yog txo.
Kev ua haujlwm tsis zoo ntawm flux lossis qhov tshwj xeeb me me dhau.
Tsis zoo solderability ntawm lub ncoo, lub qhov cartridge los yog tus pin, uas tsis tuaj yeem ntub dej tag nrho thiab qhov tshwm sim ntawm huab cua npuas qhwv hauv qhov sib koom ua ke.
Ib qho kev txo qis ntawm cov tin nyob rau hauv lub solder, los yog ib tug siab muaj pes tsawg leeg ntawm impurities Cu nyob rau hauv lub solder, uas tsub kom lub viscosity ntawm lub solder thiab ua rau nws tsawg dua kua.
Ntau dhau solder residue.
Qhov kub ntawm qhov vuam yog qis dhau los yog qhov siv txoj hlua siv ceev nrawm heev, ua rau cov viscosity ntawm cov molten solder loj heev.
Kev daws:
Teem lub preheating kub raws li PCB loj, board txheej, muaj pes tsawg lub Cheebtsam, seb puas muaj mounted Cheebtsam, thiab lwm yam. Qhov kub ntawm lub hauv qab ntawm lub PCB yog 90 ~ 130 ℃.
Hloov cov flux los yog kho qhov sib piv tsim nyog.
Txhim kho qhov ua tau zoo ntawm PCB, cov khoom siv ua ntej siv, tsis txhob khaws cia hauv qhov chaw ntub dej.
tin ratio ntawm tsawg dua 61.4%, ntxiv ib co ntshiab tin nyob rau hauv tsim nyog tus nqi impurities yuav tsum tau hloov thaum lub solder siab dhau lawm.
residue yuav tsum tau muab ntxuav thaum kawg ntawm txhua hnub' txoj haujlwm.
Tswj lub tin yoj kub ntawm (250 ± 5) ℃, vuam lub sij hawm 3 ~ 5s.
Ua rau:
Cov khoom tsis zoo ntawm cov hlau lead solderability, ncoo loj dhau (tshwj tsis yog qhov xav tau ntawm cov ntaub qhwv loj), lub qhov ncoo yog qhov loj heev, lub vuam lub kaum sab xis loj dhau, qhov kev sib kis ceev heev, lub lauj kaub kub kub yog siab, cov txheej txheej yog flux. tsis sib xws, lub solder tsis muaj tin txaus.
Kev daws:
daws cov hlau lead solderability, tsim kom txo tau lub ncoo thiab ncoo qhov, txo lub soldering lub kaum sab xis, kho cov kis tau tus mob ceev, kho qhov kub ntawm lub tin lauj kaub, xyuas cov pre-daim ntawv thov ntawm flux ntaus ntawv, soj ntsuam kuaj solder ntsiab lus.
