Dab tsi yog Wave Soldering Flux?

Wave soldering fluxyog tus neeg sawv cev tshuaj siv rau cov ntawv luam tawm hauv Circuit Court ua ntej lawv hu rau cov molten solder yoj, ua haujlwm kom tshem tawm cov hlau oxides los ntawm cov khoom siv tau yooj yim thaum txhawb kev ntub dej kom zoo thiab sib xyaw ua ke. Cov flux muaj cov activators, tsheb, thiab cov kuab tshuaj-txhua qhov khoom ua haujlwm sib txawv ntawm cov tshuaj thermochemical uas txiav txim siab seb daim ntawv sib koom ua ke puas raug lossis dhau los ua lwm qhov nkag hauv koj lub log tsis raug.

saib ntxiv

Txhua qhov chaw hlau raug rau huab cua loj hlob ib txheej oxide. Tooj liab oxidizes. Tin oxidizes. Cov khoom xyaw ua rau zaum hauv lub raj ntawd rau rau lub hlis hauv koj chav tsev khaws khoom- tau oxidized tiag tiag. Cov oxidation tshwm sim tsis tu ncua, pib lub caij liab liab pom huab cua, accelerating ntawm siab kub.

Solder tsis ntub oxides. Nws ntub dej huv huv.

Qhov tseem ceeb incompatibility no tsim tag nrho vim li cas flux tshwm sim. Koj tsis tau ntxiv flux vim qee daim ntawv qhia tshwj xeeb qhia rau koj. Koj tab tom ntxiv nws vim tias tsis muaj tshuaj lom neeg cuam tshuam, qhov 260℃nthwv dej ntawm SAC305 yuav yob hla koj lub rooj tsavxwm ua tiav tsis muaj dab tsi. Cov pob khaus tuaj, tsis kam sib kis, thiab koj li ntawm - qhov tshwm sim zoo li ib tus neeg sim ua kom muaj mercury.

Kuv tau saib cov neeg ua haujlwm ntsia ntawm cov pob qij txha tsis zoo rau cov pob qij txha tsis zoo, liam lub sijhawm nyob, cem cov dej nitrogen-txhua yam tshwj tsis yog qhov pom tseeb. Tshawb xyuas koj qhov kev pab cuam flux ua ntej. Cuaj caum feem pua ntawm cov dej tsis ua hauj lwm rov qab mus rau qhov tsis txaus flux mus txog qhov sib koom ua ke.

Rosin{0}}raws li fluxes dominate yoj soldering rau cov laj thawj uas rov qab mus rau ntau pua xyoo. Cov khoom xyaw nquag -abietic acid, C19H29COOH- muab los ntawm ntoo thuv resin los ntawm distillation thiab purification. Qhov no tsis yog sophisticated chemistry. Ancient metalworkers siv ntoo thuv pitch. Cov txheej txheem niaj hnub no tsuas yog tswj cov kev hloov pauv zoo dua.

Abietic acid melts nyob ib ncig ntawm 172-175 degree, yooj yim hauv qab ib txwm tin -lead eutectic ntawm 183℃. Lub sijhawm tseem ceeb. Koj xav tau kev ua kom muaj zog ua ntej kev sib cuag los ntawm cov feem ntawm cov vib nas this- ntev txaus los strip oxides, luv txaus uas cov khoom ntxuav tsis rov oxidize ua ntej solder tuaj txog.

Lub tshuab ua kom muaj cov kua qaub- puag ncig ntawm pawg carboxylic thiab hlau oxides:

RCOOH + CuO → RCOO-Cu + H2O

Cov tooj liab ua khi rau hauv rosin -soluble ntsev. Cov tshuaj tiv thaiv cov khoom yaj mus rau hauv molten flux thiab tau nqa tawm ntawm qhov sib koom ua ke. Cov hlau huv si. Solder wets.

Lead- dawb hloov txhua yam txog lub sijhawm no. SAC305 liquidus zaum ntawm 217-220℃. Qhov ntawd ntxiv 35-40 degrees txhais tau hais tias koj cov flux yuav tsum tau nyob twj ywm chemically nquag ua ntej thermal decomposition ua rau nws tsis muaj txiaj ntsig. Cov tshuaj rosin cov qauv tsim los rau 63/37 cov txheej txheem feem ntau ua tsis tau zoo ntawm cov hlau lead- qhov kub thiab txias-lawv tau tso lawv lub peev xwm tshem tawm oxide ua ntej lub solder txawm tuaj txog.

"Tsis yog- huv" tsis txhais hais tias "tsis muaj residue." Nws txhais tau hais tias cov seem theoretically yuav tsis ua teeb meem kev ntseeg tau yog tias sab laug ntawm lub rooj tsavxwm.

Kev xav.

Qhov kev muaj tiag suav nrog cov tuam txhab ua lag luam ua haujlwm SIR kuaj ntawm 85℃/ 85% txheeb ze av noo ntawm IPC-B-24 zuag cov qauv, ua kom pom tias lawv cov residues tuav 100 megohm rwb thaiv tsev tiv thaiv rau 168 teev nyob rau hauv kev tswj cov chaw kuaj mob. Seb qhov ntawd txhais tau li cas rau koj cov khoom muaj sia nyob kaum xyoo nyob rau hauv lub tsheb cav compartment lossis ib puag ncig kev lag luam nrog kev sib kis tiag tiag yog lwm lo lus nug tag nrho.

Tsis muaj- cov dej huv huv muaj 1-5% cov ntsiab lus ntawm cov khoom sib xyaw- feem ntau cov organic acids tsis muaj zog nrog tej zaum qee cov rosin lossis hluavtaws cob. Cov formulations txhob txwm txi kev ua si rau residue benignity. Kev lag luam ua haujlwm thaum koj cov khoom muaj cov khoom tshiab, solderable nto. Nws ua tsis tau zoo heev thaum kev yuav khoom oxidized qhov chaw los ntawm tus neeg muag khoom hauv Shenzhen uas khaws cov khoom muag hauv ib lub tsev khaws khoom uas tsis muaj kev nyab xeeb.

Txhua lub chaw tsim khoom cog lus uas kuv tau ua haujlwm nrog khaws cov dej- cov kua dej soluble ntawm tes rau cov laug cam uas tsis muaj - ntxuav tsis kam ua kom zoo. Cov ntaub ntawv txheej txheem raug cai yuav qhia tau tias ORL0 tsis yog- huv rau txhua yam. Cov khoom hauv pem teb kev muaj tiag yuav hloov chemistry thaum cov nqi tsis raug nce.

Cov dej- cov kua dej soluble muaj cov organic acids-adipic, citric, succinic- ntawm cov kev ua ub no uas ua rau cov qauv rosin saib maj mam. Cov kua qaub ntau dua tawm tsam oxides aggressively. Wetting tshwm sim sai. Lub qhov filling txhim kho. Cov pob qij txha zoo li ci.

Cov residues kuj corrosive txaus los rhuav tshem koj cov khoom.

Tsis yog thaum kawg. Tsis yog theoretically. Active corrosive. Cia cov dej-soluble residue rau ntawm lub rooj tsavxwm uas muaj zog thaum hmo ntuj thiab saib dendrites loj hlob ntawm cov kab. Cov kab mob ionic tsim cov kab hluav taws xob los ntawm kev nqus dej. Electrochemical migration nram qab no. Cheebtsam ua tsis tiav.

Dej- cov txheej txheem soluble yuav tsum tau ntxuav. Aqueous tu, feem ntau ntawm 140℃F nrog DI dej, tshem tawm cov dej ntsev ua ntej lawv ua kev puas tsuaj. Txhua lub rooj tsavxwm. Txhua lub sijhawm. Tsis muaj kev zam.

Cov kauj ruam tu ntxiv cov nqi- khoom siv, kev kho dej, ziab, kuaj kab mob ionic. Manufacturing engineers ntxub nws. Tab sis rau cov laug cam uas muaj qhov ntev ntev, los yog cov khoom uas muaj oxidized hnyav heev, los yog txhua qhov xwm txheej uas lub qhov ntim xav tau kev ua haujlwm siab tshaj plaws, dej -soluble tseem yog tib txoj kev siv tshuaj lom neeg uas ua haujlwm tau zoo.

IPC J-STD-004 faib cov no raws li ORH lossis txawm INH hom. Qhov "H" txhais tau tias muaj kev ua haujlwm siab. Cov txheej txheem kev faib tawm muaj tshwj xeeb los ceeb toom rau tib neeg txog kev muaj peev xwm corrosion.

Foam fluxing ua haujlwm los ntawm bubbling compressed cua los ntawm ib tug ntxeem tau pob zeb submerged nyob rau hauv flux, tsim ib tug sawv taub hau ntawm ua npuas ncauj uas hu rau lub rooj tsavxwm underside. Cov txheej txheem tau muaj txij li xyoo 1970s. Nws yog qhov yooj yim, pheej yig, thiab txhim khu kev qha thaum khaws cia zoo.

Nws kuj faib cov flux tsis sib xws.

Lub taub hau ua npuas dej tawg thaum cov laug cam nrog qhov tsis xwm yeem hauv qab topography hla dhau. Cov Cheebtsam loj glued rau sab solder tsim duab ntxoov ntxoo. Flux noj txawv nrog ambient humidity. Lub pob zeb ntxeem tau clogs nrog qhuav residue yog tias leej twg tsis nco qab tso lub reservoir ua ntej kaw.

Kuv tau siv tag nrho cov kev hloov pauv daws teeb meem ua npuas ncauj fluxer. Cov pob zeb thaiv yog cov classic- manifests raws li qhov txo npuas qhov siab, cov neeg ua haujlwm them nyiaj los ntawm kev ua kom huab cua siab, uas ua rau cov npuas tsis ruaj khov uas tawg thaum lub caij tsheb thauj mus los, uas ua rau muaj qhov tsis zoo uas tshwm sim raws li kev hla hla dhau. Kev kho yuav tsum tau ntws, ntxuav, qee zaum hloov lub pob zeb tag nrho. Meanwhile ntau lawm nres.

Spray fluxing atomizes kua flux los ntawm nozzles, depositing tswj kom muaj nuj nqis raws nraim qhov programmed. Kev pab them nqi uniformity zoo heev. Flux noj tee vim tias koj tsis tau tswj xyuas lub evaporating ua npuas ncauj reservoir. Cov txheej txheem tsis tau- txau ntim, traverse ceev, cua riam siab- teb kwv yees rau kev hloov kho.

Txau tshuab raug nqi ntau dua. Lawv txhaws yog tias ib tug neeg siv flux nrog cov ntsiab lus siab uas tsis muaj kev kho cov sijhawm tu. Tab sis rau ib qho kev tsim khoom ntim pov thawj cov peev txheej, tshuaj tsuag ua npuas dej.

Cov tshuab ultrasonic atomization tshiab tshiab tawg tawg rau hauv cov tee dej zoo dua li huab cua -pab tshuaj tsuag, txhim kho kev nkag mus rau hauv qhov chaw nruj. Txawm hais tias qhov ntawd tseem ceeb rau koj tus qauv tsim tshwj xeeb yog nyob ntawm geometry nkaus xwb.

Lead- dawb solder tsis sau qhov zoo li tin - lead ua.

Lub physics muaj qhov nro saum npoo thiab ntub dej ceev. SAC305 nthuav tawm qhov nro siab dua 63/37-kwv yees 500 mN / m piv rau 470 mN / m. Lub molten alloy resists ntws mus rau hauv cov thoob nqaim. Capillary sawv raug kev txom nyem. Sab saum toj fillets tawm nyias los yog tsis tuaj kiag li.

Flux tuaj yeem them nyiaj ib nrab. Cov txheej txheem ua haujlwm siab dua txo qhov nro ntawm qhov zoo los ntawm kev tshem tawm oxide zoo dua, txhim kho capillary kev ua. Extended preheat kom ntseeg tau tias flux volatiles tau tag nrho evaporated ua ntej nthwv dej sib cuag, ua kom cov residual activator concentration ntawm lub sijhawm tseem ceeb. Slower conveyor speeds nce lub sij hawm sib cuag, muab solder ntau lub sijhawm rau wick upward.

Tab sis muaj kev txwv.

Cov Boards tuab dua 0.093 ntiv tes nrog qhov sib piv ntau dua 8: 1 kev sib tw txawm tias muaj kev sib tw hnyav heev. Lub thoob qhov ntev tsuas yog tshaj li qhov kev txiav txim capillary tuaj yeem ua tiav hauv lub sijhawm nyob. Koj tuaj yeem nce lub sijhawm sib cuag kom txog thaum thermal puas hem cov khoom, lossis lees txais cov ntawv tsis tiav raws li kev txwv tsis pub dhau.

Qee cov tuam ntxhab hais qhov no nrog kev xaiv soldering rau cov teeb meem pob qij txha. Lwm tus redesign pad geometry. Tsis muaj leej twg tau pom ib qho flux- tsuas yog kev daws teeb meem rau siab -yam- piv nrog cov hlau lead- dawb alloys. Lub physics yuav tsis tso cai rau nws.

Volatile organic compound cov cai yuam kev hloov pauv hloov pauv thoob plaws kev lag luam. Ib txwm haus cawv-raws li fluxes tawm isopropanol vapor thaum lub sij hawm thov thiab preheat- txaus los ua rau muaj teeb meem kev ua raws li ib puag ncig hauv cheeb tsam nrog cov huab cua nruj.

VOC-dawb formulations siv dej raws li cov cab kuj hnyav. Lawv ua haujlwm. Lawv kuj coj txawv txawv.

Dej evaporates qeeb dua isopropanol. Preheat zones yuav tsum tau txuas ntxiv lossis siab dua kom ua tiav qhov sib npaug ntawm cov kuab tshuaj tshem tawm. Kev ziab qeeb qeeb cuam tshuam li cas flux faib thoob plaws qhov chaw tsis zoo. Cov yam ntxwv residue hloov vim txawv cov cab kuj evaporation kinetics hloov qhov seem tom qab thermal raug.

Hloov los ntawm cawv-raws li VOC-dawb flux yeej tsis poob - hloov. Cov txheej txheem tsim nyog yog qhov yuav tsum tau ua. Tus neeg twg uas qhia rau koj txwv tsis pub sim ua qhov hloov pauv ntawm - cov khoom muaj kev ntseeg siab.

Solders

IPC's flux classification scheme hloov cov qub tub rog QQ-S-571 cov qauv nrog cov qauv ntawm cov qauv tsim: muaj pes tsawg leeg (RO rau rosin, RE rau resin, LOSSIS rau organic, IN rau inorganic) ua ke nrog qib kev ua haujlwm (L / M / H rau qis / nruab nrab / siab) thiab cov ntsiab lus halide (0 lossis 1).

Yog li ROL0 qhia rosin-raws li, qis-kev ua, halide- dawb flux. ORM1 txhais tau hais tias cov organic muaj pes tsawg leeg, kev ua haujlwm nruab nrab, halides tam sim no.

Lub kaw lus pab sib piv cov khoom thoob plaws manufacturers. Nws tsis qhia koj seb qhov flux tshwj xeeb yuav ua haujlwm rau koj daim ntawv thov. Ob lub ROL0 fluxes los ntawm cov chaw muag khoom sib txawv tuaj yeem pom qhov sib txawv ntawm cov dej ntub dej vim qhov kev faib tawm ntsuas qhov ntsuas qhov ntsuas tshwj xeeb - iav tooj liab, SIR, corrosion- tsis yog tag nrho cov txheej txheem muaj peev xwm.

Siv qhov kev faib tawm rau kev kuaj thawj zaug. Cia siab rau koj tus kheej qhov kev xeem tsim nyog rau kev txiav txim siab ntau lawm.

Halide activators-feem ntau yog cov tshuaj chloride lossis bromide cov tshuaj xws li diethylammonium chloride-ua kom ntub dej ceev ceev heev. Lawv tawm tsam oxides sai dua cov organic acid lwm txoj kev. Rau oxidized Cheebtsam los yog liab qab OSP tiav, halide-activated flux feem ntau ua rau qhov sib txawv ntawm cov txheej txheem tau txais yields thiab rework tas li.

Cov residues nyob twj ywm ionic. Nyob rau hauv cov av noo, halide residues nqus noo noo thiab ua conductive. Electrochemical migration accelerates. Kev ntseeg tau engineers sau cov kev ua tsis tiav ntawm qhov kev loj hlob ntawm dendritic xyoo tom qab sib dhos.

Siab- daim ntawv thov kev ntseeg siab-aerospace, kev kho mob, tub rog-feem ntau txwv tsis pub halide- muaj flux tag nrho tsis hais txog kev faib ua haujlwm. Cov neeg siv khoom siv hluav taws xob tiv thaiv halides vim tias cov khoom lag luam lifespans tsis txuas mus rau ntau xyoo thiab qhov chaw ua haujlwm tsis tshua muaj cov av noo nrog lub zog tas li.

Qhov kev xaiv no suav nrog kev lees paub qhov txaus ntshai. Halides txhim kho manufacturability ntawm tus nqi ntev - lub sij hawm corrosion muaj peev xwm. Tsis muaj- cov qauv huv huv nrog halides (L1, M1 tus tsim) xav tau kev tshuaj xyuas tshwj xeeb vim tias cov seem tau tsim los nyob hauv pawg thawj coj mus tas li.

Cov kua dej tuaj txog los ntawm cov neeg muag khoom ntawm cov ntsiab lus ntawm cov khoom sib cais -tej zaum 2% rau cov tshuaj tsuag tsis muaj - huv, 15% rau cov npuas dej rosin. Thaum siv, hnyav evaporates. Ceev nce. Kev ua ib chav tsev ntim nce.

Tsis muaj kev saib xyuas, flux uas pib ntawm 2% cov khoom nkag mus rau 3% lossis 4%. Daim ntawv thov ntim nyob twj ywm vim tsis muaj leej twg hloov cov tshuaj tsuag. Boards tau txais cov khoom siv tseem ceeb tshaj li cov txheej txheem tsim nyog rau. Cov qib residue tshaj qhov kev cia siab. Kev ua raws li SIR yuav muaj lus nug.

Txhua txoj haujlwm yoj soldering yuav tsum ntsuas flux ceev txhua hnub. Refractometers ua haujlwm, txawm hais tias mob siab rau flux density meters muab qhov tseeb dua. Qhov ntsuas yuav siv peb caug vib nas this. Lwm txoj hauv kev yog tshawb pom thaum lub sij hawm cov neeg siv khoom tsim nyog tshawb xyuas tias koj cov txheej txheem drifted sab nraud specification rau lub hlis dhau los.

Rosin-raws li flux muaj cov tshuaj sib xyaw nrog ob daim ntawv cog lus ua rau oxidative polymerization. Khaws cia kom sov, muab tso rau hauv lub teeb, tawm hauv cov thawv unsealed - cov flux degrades. viscosity nce. Wetting kev ua tau zoo poob. Dab tsi ua haujlwm lub hli dhau los ua tsis tiav hnub no.

Cov neeg tsim khoom hais kom khaws cia ntawm 15-25 degree. Lawv txhais tau tias.

Kuv tau pom cov kab ntau lawm daws teeb meem phantom soldering tsis xws luag rau lub lis piam ua ntej ib tug neeg xyuas seb cov flux drums tau khaws cia ntawm ib sab ntawm lub preheat pa duct. Lub flux tseem tseem tau siav thaum khaws cia. Cov khoom tshiab los ntawm tib tus lej ntau tau ua ib txwm ua.

Kev xaiv Flux suav nrog kev ntsuas kev ua si tiv thaiv qhov kev txhawj xeeb ntawm qhov seem, sib piv chemistry rau koj cov khoom tshwj xeeb solderability thiab board tiav, tom qab ntawd ua tiav kev ua tau zoo los ntawm kev sim ntau lawm. Datasheet specifications muab cov ntsiab lus pib, tsis lav. Cov txheej txheem kev faib tawm muaj cov ntsiab lus rau kev sib tham txog kev xaiv, tsis yog kev kwv yees ntawm kev vam meej.

Txoj hauj lwm tseem ceeb- tshem tawm cov oxides kom cov hlau ntub dej - tsis tau hloov txij li cov neeg ua haujlwm qub pom tias cov ntoo thuv tau pab koom nrog tooj liab. Cov txheej txheem niaj hnub ua kom zoo nyob ib puag ncig cov kev txwv niaj hnub no: txhuas- qhov kub thiab txias, kev tswj hwm ib puag ncig, siab -cov duab geometry, kev cia siab rau cov khoom lag luam.

Thaum soldering tsis ua hauj lwm, xyuas cov flux ua ntej. Tshawb xyuas qhov kev pab cuam, tshawb xyuas kev ua kom muaj zog, xyuas seb cov chemistry puas sib phim koj cov txheej txheem. Cov lus teb feem ntau yog yooj yim dua li leej twg xav lees.