资源描述：
《Copper Powders for Capacitors》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、CopperPowdersforCapacitorsDr.RudolfHuenertECKAGranulateMicroMetGmbHHovestrasse46a20539HamburgGermanyTel.+494088885109Fax+494088885150Emailr.huenert@ecka-granules.comIntroductionThechoiceofmetalstobeusedinelectronicscomponentsmanufacturingislimitedbytheirnaturalabundance,th
2、eirphysicalandchemicalpropertiesandofcausebytheircost.Whileinformeryears,metallizationsystemsusingpreciousmetals,especiallythePalladiumbasedsystemssufferedatremendouscostincreasestartinginabout1997,whichconsequentlycausedthedevelopmentandintroductionofmorecompetitiveNickel
3、basedelectrodesystems.Today,themajorityofMLCCisproducedusingNi-BMETechnologyincombinationwithCopper-Termination.FirsttypesofMLCCusingCopperinternalelectrodesarealsoalreadyavailableinthemarket,providingatechnicalsolutionespeciallyforveryhighfrequencyapplications(>5GHz),forw
4、hichNickelbasedsystemscannotbeusedduetotheferromagneticnatureofNickel.Withtheconstanttrendoftechnologicaldevelopment,tousehigherandhigherfrequencies,itisexpectedthatCopperwillincreaseitsimportancenotonlyasthestandardmaterialforTerminations,butalsoasastandardBME-materialasw
5、ell.11CopperPowderProductionAlthoughitissometimesdiscussedtosupplymetalpowdersproducedbysomegrindingormillingtechnique,capacitorgradeCopperpowderscanonlybeproducedbyphysicaland/orchemicalmethodsdirectlygeneratingthedesiredparticlesizeandmorphology.Thetechnicalpossibilities
6、ofsuchpowderproductionaredescribedhereafter.AtomisationTheprocessofatomisationisabasicmetallurgicalprocess,meltingtheCopperusingacrucibleandproducingthemetalpowderbypouringthemoltenmetalthroughaceramicnozzlesystem,whileapplyinghighpressuregasorwater:Theprocessistechnically
7、wellestablished,butitislimitedintheyieldoffinesizedpowders.Typically,theyieldofcapacitorgradeparticlesizeis<<10%,whichlimitsbothavailabilityandcostaspects:12Contaminationcausedbyabrasionintheatomisation-nozzleisanotherfactor,whichshouldcarefullybetakenintoaccount,whenconsi
8、deringwhethertouseatomisedpowdersinhigh-performanceelectroniccomponents.Electrolyticpreci
