安美特++电镀基础知识培训

Atotech(China)ChemicalsLtd.SH安美特上海青浦分公司PRESENTSELECTROPLATINGTRAINING电镀培训OUTLINE内容提要INTRODUCTION介绍ELECTROCHEMISTRY电化学CLEANING&PREPLATE清洗及预镀NICKEL镍Copper铜DECORATIVECHROMIUM装饰铬TESTING测试FILTRATION过滤TROUBLESHOOTING故障处理WHATISELECTROPLATING?什么是电镀？THEDEPOSITIONOFAMETALLICCOATINGUPONANEGATIVELYCHARGEDCATHODEBYTHEPASSINGOFANELECTRICCURRENT在电流通过时，有金属层沉积在带负电荷的阴极表面.WHATISTHEPURPOSE?电镀的目的是什么？TOOBTAINAMETALLICCOATINGHAVINGCERTAINPROPERTIESSUCHASHARDNESS,BRIGHTNESS,CORROSIONRESISTANCEANDTOREPRODUCEIDENTICALFORMSINELECTROFORMING.是为了得到具有某种特性的金属层，如：硬度、光亮度、耐腐性及在电铸方面复制同样的形状.REQUIREMENTS要求SOURCEOFDIRECTCURRENT直流电源APLATINGTANK电镀槽ASOLUTIONCONTAININGTHEDISSOLVEDSALTSOFTHEMETALTOBEPLATED含有待镀的可溶性金属盐的溶液ANODE(POSITIVEELECTRODE)阳极（正电极）APREPAREDOBJECT-CATHODE(NEGATIVEELECTRODE)准备好的待镀工件--阴极（负电极）WHATISDIRECTCURRENT?何为直流电？THEFLOWOFELECTRONSINTHESAMEDIRECTIONBETWEENPOSITIVEANDNEGATIVEELECTRODES在正负电极之间电子向同样的方向移动.WHATISAPLATINGSOLUTION?电镀液是什么？ACONDUCTINGMEDIUMFORTHEMOVEMENTOFMETALIONSINSOLUTIONBETWEENANANODEANDACATHODE溶液中在阳极与阴极间金属离子移动的导电介质.WHATISpH?什么是pH值？THEMEASUREMENTOFACIDITYORALKALINITY用来度量酸碱度的ONASCALEFROM0TO14pH值的范围处于0-14之间0TO6.9BEINGACIDICAND7.1TO14ALKALINEAND7.0BEINGNEUTRAL.小于7的为酸性，大于7且小于等于14的为碱性，7.0为中性HOWAREPLATINGSOLUTIONMAINTAINED?如何维护电镀液？CHEMICALANALYSISOFTHECONSTITUENTS持续的化学分析HULLCELLPLATINGTESTS赫氏槽电镀测试ADDITIONOFCHEMICALS添加化学品ELIMINATIONOFCONTAMINANTS去除污染物PERIODICPURIFICATION定期净化REGULARINSPECTIONOFPARTSFORDEFECTS缺陷/次品的常规检查PHYSICALTESTING物理测试WHATISAMETALION?什么是金属离子？AMETALIONISANATOMOFAMETALHAVINGAPOSITIVEELECTRICALCHARGE金属离子是带正电荷的金属原子(失去电子)WHATARETHESOURCESOFMETALIONS?金属离子来自何处？METALSALTSINPLATINGSOLUTION电镀液中的金属盐SOLUBLEMETALANODES可溶性的金属阳极WHATAREANODEBAGS?什么是阳极袋？ANODEBAGSAREPOROUSMEMBRANESPLACEDAROUNDANODESTOCOLLECTSLUDGEFORMINGONTHEDISSOLVINGANODE阳极袋是包扎在阳极外面,会将电镀过程中产生的阳极泥收集在袋内的多孔的袋。BasicELECTROCHEMISTRY基本的电化学理论ELECTROCHEMISTRY电化学PlatingCell电镀槽Ni++Ni++Cl-Cl-++_Rectifier整流器ANODE阳极CATHODE阴极ANODE阳极CATHODEREACTIONS阴极反应Cathode阴极Reductionofions离子还原反应Drawelectronsfromtheexternalcircuit从外部电路中吸收电子TYPICALREACTION典型的反应Ni+++2e-Ni(metal金属)2H++2e-H24H2O+4e-2H2+4(OH)-ANODEREACTIONS阳极反应Anode阳极Oxidationofmetaltoions金属氧化成阳离子Releaseofelectronstoexternalcircuit将电子释放至外部电路TYPICALREACTION典型的反应NiNi+++2e-4OH-O2+2H2O+4e-2H2OO2+4H++4e-RATEOFCURRENTFLOW电流速率Ohm’sLaw欧姆定律Amperes安培=Volts伏特Ohms欧姆I电流=E电压R电阻FARADAY’SLAW法拉第定律Factors要素Amperes安培Time时间EquivalentWeightofMetal金属当量FARADAY’SLAW法拉第定律Oneampereflowingforonesecondrepresentsonecoulomb.Faraday’lawstatesthat96,500coulombs(oneFaraday)willdepositonegramequivalentweightofametal.Equivalentweightistheatomicweightofthemetaldividedbyit’svalence.1安培的电流1秒的时间通过的电量等于1库仑。法拉第定律：1个法拉第即96,500库仑的电量可以沉积1克当量的金属。克当量是金属的原子量除以它的化合价.FARADAY’SLAW法拉第定律weightofmetaldeposited沉积的金属重量96,500CoulombsDepositAt.Wt.=grams96,500库仑的镀层ValenceWEIGHTOFNICKELPLATED电镀镍的重量KNOWNFACTORS已知的条件Current电流=50amps安培Time时间=15mins分钟原子量At.Wt.Ni=58.7Valence=化合价,2价CALCULATION计算96,500=45,000X=13.7GRAMS克58.7xgrams2CALCULATINGTHICKNESSFROMWEIGHT从重量计算厚度Thickness=WT1um=10-4cmdensityxarea1mil=25.4umEXAMPLE:wt=0.136grams.DensityofNi=8.9Area=4cm2Thickness=0.1368.9x4Answer=1.5milsCURRENTINCELL电镀槽中的电流Anode阳极-e=cathode阴极+eAnode阳极-e=corrosion溶解-e+Oxygen氧-eCathode阴极+e=plating所镀金属+e+hydrogen氢+eTheexchangeofelectronsattheanodeandthecathodeorthetotalflowofcurrentateachelectrodeisalwaysequal.电子在阳极和阴极上交换,在阴阳极上流动的电流总是相等的。DEPOSITIONWITHH2LIBERATION伴随着氢气释放的沉积NETRESULT最终的结果1.CathodeEfficiencyReduced阴极电流效率的降低2.pHIncreasedpH值升高Anode阳极Cathode阴极Ni+2Ni+22H+H2PLATINGEFFICIENCYANDTIMEOFPLATING电镀效率和电镀时间%Efficiency效率=ActualNiPlated实际镀的镍X100Theoretical(Faraday’sLaw)理论的（法拉第定律）FACTORSAFFECTINGPLATINGCURRENT影响电镀电流的因素HydrogenLiberation(cathode)氢气释放（阴极）OxygenLiberation(anode)氧气释放（阳极）Polarization极化ConcentrationPolarization(Diffusion)浓度极化（扩散）HydrogenOvervoltage氢过电位POLARIZATION极化E=IRE=Volts伏特(potentialdifference电位差)R=Resistance电阻(resistanceofsolutiontotheflowofcurrent溶液对电流的阻抗)I=Current电流(flowofelectricity电荷的移动)E=CURRENT电流(I)XRESISTANCE电阻(R)Ep=ChangeinpotentialdifferenceduetoPolarizationfromresistance.由于电阻升高造成的极化,极化导致的电位差的改变.POLARIZATION极化EIEpR=EIEP=PolarizationCONCENTRATIONPOLARIZATION浓度极化CONCENTRATIONOFMETALIONSBUILDONTHESURFACEOFTHEANODE阳极表面的金属离子浓度CONCENTRATIONOFTHEMETALIONSDECREASEATTHESURFACEOFTHECATHODE阴极表面的金属离子浓度减少CHANGEINANODEANDCATHODEFILMSCAUSESPOLARIZATION阳极和阴极膜层的改变导致了极化CONCENTRATIONPOLARIZATION浓度极化Ni++IonsANODE阳极CATHODE阴极++++++++++++++++++++++++++EFFECT影响Agitation打气Temperature温度HYDROGENOVERVOLTAGE氢过电位POLARIZATIONDUETOEVOLUTIONOFHYDROGENUPONASPECIFIEDELECTRODESURFACEORTHEEXCESSPOTENTIALABOVETHEEQUILIBRIUMPOTENTIALREQUIREDTOEVOLVEHYDROGENATTHECURRENTDENSITYSPECIFIED.在指定的电极表面上氢气的形成而引起的极化或在某一电流密度下氢的形成所要求的超出平衡电位后的电位.HYDROGENOVERVOLTAGE氢过电压FACTORS要素TYPEOFMETAL金属的种类SURFACEROUGHNESS表面的粗糙度TYPEOFSOLUTION溶液的类型CURRENTDENSITY电流密度TEMPERATURE温度HYDROGENOVERVOLTAGE氢过电位(1ma/cm2)ZnSnCdCuNiAgAuCPt-0.80-0.80-0.80-0.60-0.40-0.30-0.15-0.110.00ELECTROMOTIVESERIES电势序列VoltsAl3+-1.66Zn2+-0.76Cr3+-0.74Fe2+-0.44Cd2+-0.40Co2+-0.29Ni2+-0.25Sn2+-0.14Pb2+-0.13VoltsH1+0.00