以CuSO4·5H2O作主盐,乙二胺四乙酸二钠盐(Na2EDTA)作主络合剂,三乙醇胺(TEA)作辅助络合剂,2,2′_联吡啶(dipyridine)作添加剂,组成化学镀铜液体系,研究络合剂、添加剂对该镀液电化学极化性能的影响,并结合化学沉积速率考察TEA和2,2′_联吡啶对镀液性能的影响.
In this study, ethylenediaminetetraacetic acid disodium salt (Na_2EDTA), triethanolamine(TEA), and 2,2′-dipyridine were adopted as chelating agents or additives in the electrolyte for electroless copper plating, and formaldehyde (HCHO) was as the reducting agent. Linear sweep voltammetry was applied to analyze the polarization behavior. The peak current of formaldehyde oxidation which increased by the addition of 2,2′-dipyridine is beneficial to formaldehyde oxidation in a specific range of concentration, While TEA decreased the peak current of formaldehyde oxidation. Two cathodic peaks due to copper(Ⅱ)reduction of TEA chelatation and copper(Ⅱ)reduction of EDTA chelatation were examined. EDTA increased the reduction peak current of Cu-EDTA and decreases that of Cu-TEA, While TEA increased the reduction peak current of Cu-TEA, and it decreased that of Cu-EDTA. The addition of 2,2′-dipyridine also decreases the reduction peak current of Cu-TEA. The experimental results are in agreement with the results obtained by weight gain measurement.
[1] MatsuokaM,YoshidaY,IwakuraC,etal.Theeffectsofaerationandaccumulationofcarbonateionsonthemechanicalpropertiesofelectrolesscoppercoatings[J].JElectrochemSoc.,1995,142(1):87~91.
[2] LinWH,ChangHF.Effectofchelatingagentsonthestructureofelectrolesscoppercoatingonaluminapowder[J].Surf.andCoatingsTech.,1998,107:48~54.
[3] KouS_C,HungA.Effectof2,2′_dipyridineonborate_bufferedelectrolesscopperdeposition[J].Plat&SurfFinish,2003,90(3):44~47.
[4] LinYM,YenSC.Effectsofadditivesandchelatingagentsonelectrolesscopperplating[J].Appl.Surf.Sci.,2001,178:116~126.
[5] KouSC,HungA.Effectofbufferonelectrolesscopperdeposition[J].Plat&SurfFinish,2002,89(2):48~52.
[6] DongC,DongGL,ZhouWZ,etal.Polarizationcharacteristicsofelectrolesscopperplaingbathscontainingcomplexingagents[J].MaterialsProtection,1996,29(9):7~9.
[7] DongC,DongGL,ZhouWZ,etal.Astudyontheeffectsoftheadditiveselectrolesscopperdepositionbyelectrochemicalmethod[J].MaterialsProtection,1997,30((1):8_10.
[8] Kondo,Koji,Murakawa,etal.Electrolesscopperplatingsolutionandprocessforelectrolesslyplatingcopper[P].U.S.Pat.4834796,1989.
[9] Kondo,Koji,Amakusa,etal.Electrolesscopperplatingsolutionandprocessforformationofcopperfilm[P].U.S.Pat.5039338,1991.
[10] NuzziFJ.Acceleratingtherateofelectrolesscopperplating[J].Plat&SurfFinish,1983,70(1):51~54.
[11] HungA.Effectsofthioureaguanidinehydrochlorideonelectrolesscopperplating[J].J.Electrochem.Soc.,1985,132(5):1047~1049.
[12] BindraP,RoldanJ.Mechanismofelectrolessmetalplating(Ⅱ.Formaldehydeoxidation)[J].J.Electrochem.Soc.,1985,132:2581_2589.
[13] BurkeLD,AhernMJG.,RyanTG.AninvestigationoftheanodicbehaviorofcopperanditsanodicallyproducedoxidesinaqueoussolutionsofhighpH[J].J.Electrochem.Soc.,1990,137:553~561.
[14] HeJB,LinJX.AstudyofanodicprocessofcopperinNaOHsolution[J].ChemicalJournalofChineseUniversities,1996,2:290~293.
[15] KondoK,IshidaN,IshikawaJ,etal.Kineticsofelectrolesscopperplatinginthepresenceofexcesstriethanolamine[J].Bull.Chem.Soc.Jpn.,1992,65:1313~1316.