Dab tsi yog qhov cuam tshuam ntawm kev ntxiv nitrogen rau lub qhov cub reflow?
Lub luag haujlwm tseem ceeb ntawm kev ntxiv nitrogen (N2) rau SMT reflow rauv yog txo cov oxidation ntawm vuam nto thiab txhim kho cov wettability ntawm vuam, vim nitrogen yog ib hom roj inert, thiab nws tsis yooj yim los tsim cov tebchaw nrog hlau. . Nws tseem tuaj yeem cais cov pa oxygen thiab cov hlau hauv huab cua. Kev sib cuag ntawm qhov kub siab ua kom cov tshuaj tiv thaiv oxidation.
Ua ntej, lub hauv paus ntsiab lus uas siv nitrogen tuaj yeem txhim kho qhov kev sib tw ntawm SMT yog raws li qhov tseeb tias qhov nro ntawm cov solder nyob rau hauv ib puag ncig nitrogen yuav tsawg dua li qhov cuam tshuam rau qhov chaw nyob nruab nrab, yog li qhov fluidity thiab wettability ntawm solder yuav. kho kom zoo.
Thib ob, nitrogen txo cov solubility ntawm oxygen nyob rau hauv cov huab cua thiab cov khoom uas muaj peev xwm kis tus kab mob ntawm soldering nto, zoo heev txo cov oxidation ntawm high-kub soldering, tshwj xeeb tshaj yog nyob rau hauv kev txhim kho qhov zoo ntawm lub thib ob-sab reflow soldering.
Nitrogen tsis yog panacea rau PCB oxidation. Yog tias qhov saum npoo ntawm ib feem lossis lub rooj tsavxwm tau raug oxidized hnyav, nitrogen tsis tuaj yeem coj nws rov qab mus rau lub neej, thiab nitrogen tsuas tuaj yeem muaj kev kho mob me ntsis ntawm oxidation (nws yog ib qho tshuaj, tsis yog tshuaj).
Qhov zoo ntawm reflow soldering nrog nitrogen:
Txo cov cua sov oxidation
Txhim kho vuam muaj peev xwm
Txhim kho solderability
Txo cov voids. Vim tias qhov oxidation ntawm cov tshuaj txhuam los yog cov ntaub qhwv yuav raug txo, qhov fluidity ntawm solder yuav zoo dua.
Disadvantages ntawm reflow soldering nrog nitrogen:
hlawv nyiaj
Muaj feem ntau ntawm tombstones spawning
Enhanced capillarity (cov nyhuv wicking)
Dab tsi ntawm cov laug cam lossis qhov chaw tsim nyog rau nitrogen reflow?
Lub rooj tsavxwm nrog OSP nto kho ob sab rov qab yog tsim rau siv cov pa roj nitrogen
Nws tuaj yeem siv tau thaum cov khoom siv lossis cov khoom siv hluav taws xob tsis zoo. Piv txwv li, nce lub wettability ntawm QFN tin
Cov pob loj thiab siab ceev BGA
