A new process to fabricate the electromagnetic stepping micromotor using LIGA process and surface sacrificial layer technology

(整期优先)网络出版时间:2001-02-12
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Inthispaper,anewprocesstofabricateanelectromagneticsteppingmicromotorusingsurfacescarificiallayertechnology(SSLT)isillustrated,andtheSEMphotoofthesteppingmicromotorisshowed.Thetorqueofthesteppingmicromotorwithmaxsimumtorqueof60μNmisdirectlycalculatedbyusingelectromagneticslawsandthelawofconservationofenergy.ThestatorandtheshaftandtherotorofthemicromotorwiththematerialofnickelarefirstallfabricatedbynormalLIGAprocessatthesametime.ThesacrificiallayerstructurewiththematerialofAZresistismadeonthesurfaceoftherotorbyusingSSLT.ThestatorandtheshaftarefixedtogetherwithcoppersubstrateinsteadoftheoldTisubstratebyelectroplating.AfterremovingtheTisubstrate,PMMAresistandthesacrificiallayerstructure,therotorisseparatedfromthestatorandnewcoppersubstrate,andcanrotateonthenewsubstratedrivenbymagneticforce.Thefourcoilswith300turnseacharewoundonironbarsbyhandusingmicroscopeandsteppingmotor.Thebarsareassembledbyhandintothestatorholesfromrearofnewcoppersubstratetofromamagneticcircuitwiththestatorandtherotor.Apowersupplywithfourconsecutivepulsesprovidesthecurrentforthecoilswoundontheironbarsadnproducesthemagneticforcetodrivetherotortorunwiththespeedof60rpm.