Thaum nws los txog rau cov ntawv luam tawm, peb tsis tuaj yeem hnov qab lub luag haujlwm tseem ceeb ntawm cov khoom siv pabcuam.Tam sim no, feem ntau siv tin-lead solder thiab cov hlau lead-dawb solder.Qhov nto moo tshaj plaws yog 63Sn-37Pb eutectic tin-lead solder, uas yog cov khoom siv hluav taws xob tseem ceeb tshaj plaws rau ze li 100 xyoo.
Vim nws qhov zoo oxidation kuj nyob rau hauv chav tsev kub, tin yog ib tug tsawg melting point hlau nrog ib tug mos mos zoo nkauj, thiab zoo ductility.Cov hmoov txhuas tsis yog tsuas yog cov hlau mos uas muaj cov tshuaj lom neeg ruaj khov, oxidation tsis kam, thiab corrosion kuj, tab sis kuj muaj moldability zoo, thiab castability, thiab yooj yim rau txheej txheem thiab pwm.Cov hmoov txhuas thiab cov tin muaj qhov zoo sib xws.Ntxiv qhov sib txawv ntawm cov hlau lead rau tin tuaj yeem ua rau siab, nruab nrab, thiab qis kub solder.Tshwj xeeb, 63Sn-37Pb eutectic solder muaj cov khoom siv hluav taws xob zoo heev,, tshuaj lom neeg ruaj khov,, cov khoom siv hluav taws xob thiab kev ua haujlwm, cov ntsiab lus tsis tshua muaj melting thiab siab solder sib koom ua ke, yog cov khoom siv zoo tshaj plaws rau hluav taws xob soldering.Yog li ntawd, tin tuaj yeem ua ke nrog cov hlau lead, nyiaj, bismuth, indium thiab lwm yam hlau tsim los tsim cov kub, nruab nrab thiab qis kub rau ntau yam kev siv.
Cov yam ntxwv ntawm lub cev thiab tshuaj lom neeg ntawm tin
Tin yog cov nyiaj dawb-dawb cov hlau uas muaj kev tiv thaiv zoo rau oxidation ntawm chav tsev kub thiab khaws nws cov luster thaum raug huab cua: nrog rau qhov ceev ntawm 7.298 g / cm2 (15) thiab melting point ntawm 232, nws yog ib tug tsawg melting point hlau. nrog kev ntxhib los mos thiab zoo ductility.
I. Theem hloov phenomenon ntawm tin
Theem hloov point ntawm tin yog 13.2.dawb boron tin ntawm qhov kub siab tshaj qhov hloov pauv theem;thaum qhov kub thiab txias qis dua qhov hloov pauv theem, nws pib tig mus rau hauv cov hmoov.Thaum lub sijhawm hloov pauv, qhov ntim yuav nce li ntawm 26%.Tsawg kub tin theem hloov ua rau lub solder ua nkig thiab lub zog yuav luag ploj.Tus nqi ntawm theem hloov yog ceev tshaj plaws nyob ib ncig ntawm -40, thiab nyob rau hauv kub hauv qab no -50, metallic tin transforms rau hauv hmoov grey tin.Yog li ntawd, ntshiab tin tsis tuaj yeem siv rau kev sib dhos hluav taws xob.
II.Cov yam ntxwv ntawm tin
1. Tin muaj corrosion kuj zoo nyob rau hauv cov huab cua, tsis yooj yim rau poob lub luster, tsis cuam tshuam los ntawm dej, oxygen, carbon dioxide.
2. Tin tuaj yeem tiv thaiv corrosion ntawm cov organic acids thiab muaj kev tiv thaiv siab rau cov khoom nruab nrab.
3. Tin yog cov hlau amphoteric thiab tuaj yeem ua rau muaj zog acids thiab cov hauv paus, tab sis nws tsis tuaj yeem tiv taus cov tshuaj chlorine, iodine, caustic soda thiab alkali.
Corrosion.Yog li ntawd, rau cov rooj sib txoos siv nyob rau hauv acidic, alkaline thiab ntsev tshuaj tsuag ib puag ncig, yuav tsum tau siv peb zaug los tiv thaiv corrosion txheej los tiv thaiv cov pob qij txha.
Muaj qhov zoo thiab qhov tsis zoo, cov no yog ob sab ntawm cov nyiaj npib.Rau PCBA kev tsim khoom, nws yog ib qho tseem ceeb uas yuav tau xav txog yuav ua li cas xaiv txoj cai tin-lead solder lossis txawm tias tsis muaj hmoov txhuas raws li cov khoom sib txawv hauv kev tswj kom zoo.
Post lub sij hawm: Dec-21-2021