Solder tsis ib txwm sib raug zoo rau cov khoom, ua rau muaj kev sib txuas tsis zoo, txuas tus pins, lossis tsis muaj kev sib koom ua ke. Siv tus neeg sawv cev flux thiab qhov kub thiab txias kom kov yeej cov teeb meem no.
Flux yog dab tsi?
Thaum solder melts thiab tsim kev sib koom ua ke ntawm ob qhov chaw hlau, nws tsim ib daim ntawv cog lus metallurgical los ntawm chemically reacting nrog rau lwm qhov chaw hlau. Daim ntawv cog lus zoo yuav tsum muaj ob yam:
- Ib lub tshuab uas yog metallurgically sib haum nrog cov hlau uas raug khi.
- Cov hlau zoo tsis muaj oxides, plua plav, thiab grime uas tiv thaiv kev sib raug zoo.
Tshem tawm cov grime thiab plua plav los ntawm kev ntxuav qhov chaw lossis tiv thaiv cov no nrog cov txheej txheem khaws cia zoo. Oxides, ntawm qhov tod tes, xav tau lwm txoj hauv kev.
Oxides thiab Flux
Oxides tsim ntawm yuav luag txhua cov hlau thaum cov pa oxygen hauv huab cua cuam tshuam nrog cov hlau. Ntawm hlau, oxidation feem ntau hu ua xeb. Txawm li cas los xij, oxidation cuam tshuam rau tin, aluminium, tooj liab, nyiaj, thiab yuav luag txhua cov hlau siv hauv hluav taws xob. Oxides ua rau soldering nyuaj los yog tsis yooj yim sua, tiv thaiv ib tug metallurgical daim ntawv cog lus nrog lub solder. Oxidization tshwm sim txhua lub sijhawm. Txawm li cas los xij, nws tshwm sim sai dua ntawm qhov kub thiab txias dua-raws li thaum soldering flux cleans hlau nto thiab reacts nrog oxide txheej, tawm hauv ib tug nto primed rau ib tug zoo solder bond.
Flux tseem nyob rau saum npoo ntawm cov hlau thaum koj tab tom soldering, uas tiv thaiv cov oxides ntxiv los ntawm kev tsim vim qhov kub ntawm cov txheej txheem soldering. Raws li nrog solder, muaj ntau ntau hom flux, txhua tus siv tseem ceeb thiab qee qhov kev txwv.
Type of Flux
Rau ntau daim ntawv thov, cov flux suav nrog hauv cov tub ntxhais ntawm cov hlau nplaum yog txaus. Txawm li cas los xij, ntxiv flux muaj txiaj ntsig zoo hauv qee qhov xwm txheej, xws li nto-mount soldering thiab desoldering. Nyob rau hauv txhua rooj plaub, qhov zoo tshaj plaws flux siv yog qhov tsawg tshaj plaws acidic (tsawg aggressive) flux uas yuav ua hauj lwm ntawm oxide ntawm cov khoom thiab ua rau ib tug zoo solder bond.
Rosin Flux
Qee yam ntawm cov laus tshaj plaws ntawm flux yog raws li ntoo thuv sap-refined thiab purified-hu ua rosin. Rosin flux tseem siv niaj hnub no, tab sis niaj hnub rosin flux muab sib txawv fluxes los ua kom nws qhov kev ua tau zoo.
Qhov zoo tshaj plaws, cov dej ntws tau yooj yim thaum kub, tshem tawm cov oxides sai sai, thiab pab tshem tawm cov khoom txawv teb chaws los ntawm qhov chaw ntawm cov hlau raug soldered. Rosin flux yog acid thaum ua kua. Thaum nws txias, nws yuav khov thiab inert. Vim tias rosin flux yog inert thaum muaj zog, nws tuaj yeem tso rau ntawm lub rooj tsav xwm luam tawm yam tsis muaj kev puas tsuaj rau lub voj voog tshwj tsis yog lub voj voog sov so rau qhov chaw uas cov rosin tuaj yeem ua kua thiab noj tam sim ntawm qhov kev sib txuas.
Nws yog txoj cai zoo kom tshem tawm rosin flux residue los ntawm PCB. Tsis tas li ntawd, yog tias koj npaj siab yuav siv cov txheej txheem sib xws lossis yog tias PCB cov tshuaj pleev ib ce tseem ceeb, cov khoom seem yuav tsum raug tshem tawm nrog cawv.
YOrganic Acid Flux
Ib qho ntawm cov fluxes ntau dua yog dej-soluble organic acid flux. Cov kua qaub tsis muaj zog feem ntau yog siv rau hauv cov organic acid flux, suav nrog citric, lactic, thiab stearic acids. Cov organic acids tsis muaj zog yog ua ke nrog cov kuab tshuaj xws li isopropyl cawv thiab dej.
Organic acid fluxes muaj zog dua rosin fluxes thiab ntxuav cov oxides tawm sai dua. Tsis tas li ntawd, cov dej-soluble xwm ntawm cov organic acid flux tso cai rau PCB kom yooj yim ntxuav nrog dej tsis tu ncua-tsuas yog tiv thaiv cov khoom uas yuav tsum tsis txhob ntub. Vim tias OA residue yog cov khoom siv hluav taws xob thiab cuam tshuam rau kev ua haujlwm thiab kev ua haujlwm ntawm lub voj voog, tshem tawm cov khoom seem thaum koj ua tiav soldering.
Inorganic Acid Flux
Inorganic acid flux ua haujlwm zoo dua nrog cov hlau muaj zog xws li tooj liab, tooj dag, thiab stainless hlau. Nws yog ib qho kev sib xyaw ntawm cov kua qaub uas muaj zog xws li hydrochloric acid, zinc chloride, thiab ammonium chloride. Inorganic acid flux yuav tsum tau ua kom tiav tu tom qab siv los tshem tawm cov corrosive residues ntawm qhov chaw, uas tsis muaj zog los yog ua puas lub solder sib koom yog tias nyob rau hauv qhov chaw.
Inorganic acid flux yuav tsum tsis txhob siv rau kev ua haujlwm hauv hluav taws xob los yog hluav taws xob ua haujlwm.
Solder Fumes
Cov pa luam yeeb thiab fumes tso tawm thaum soldering suav nrog ntau cov tshuaj lom neeg los ntawm cov kua qaub thiab lawv cov tshuaj tiv thaiv nrog cov oxide txheej. Lwm cov tshuaj xws li formaldehyde, toluene, cawv, thiab acidic fumes feem ntau muaj nyob rau hauv cov pa taws. Cov fumes no tuaj yeem ua rau mob hawb pob thiab nce rhiab heev rau cov pa taws. Xyuas kom muaj qhov cua txaus thiab, yog tias tsim nyog, siv lub tshuab ua pa.
Kev mob qog noj ntshav thiab cov hlau lead txaus ntshai los ntawm cov pa hluav taws xob tsawg vim tias qhov kub ntawm cov khoom siv hluav taws xob yog ob peb zaug kub dua li qhov kub ntawm qhov kub thiab txias ntawm cov solder. Qhov kev pheej hmoo loj tshaj plaws ntawm cov hlau lead yog kev tuav ntawm lub solder. Kev saib xyuas yuav tsum tau ua thaum siv cov solder, nrog rau kev tsom mus rau kev ntxuav tes thiab tsis txhob noj, haus, thiab haus luam yeeb nyob rau hauv cov cheeb tsam uas muaj cov solder kom tsis txhob muaj cov kab mob nkag mus rau hauv lub cev.
