1、JournalofMechanicalScienceandTechnologyJournal of Mechanical Science and Technology 21(2007)1452-1455Micro press forming and assemblingofmicro partsin a progressive dieMing Yang:,Ken-ichi Manabe/and Kuniyoshi Ito3IGraduate School0/system design,TokyoMetropolitan Univ.,Japan,2GraduateSchoolofScience
2、and Engineering,TokyoMetropolitan Univ.,Japan,3SekiCorporation,Tokyo,Japan(Manuscript Received May 31,2007;Revised August 30,2007;Accepted September 30,2007)AbstractAmicro press formingand in-processassembly technology were developedand applied to fabricationof metal partsand units.Technologiesbased
3、 on high-energybeams,such as ion and short pulse laser were developed for fabricationof featuresof dies in micro scale and finishingsurface in nano scale.Inaddition,DLC coatingon surfaceofthe die wasdeveloped in order to improve wear-resistance and reduce friction.A micro gear with diameterof0.2 mm
4、wasproducedusing sheet metals.Furthermore,a unit part with threecomponentswasfabricatedina preciseprogressive dieusing the micro press system.The resultsshow that the micro metal forming couldbe a new technology for fabricationof microdevices,suchas MEMS,bio-chipsinlow cost and with largequantities.
5、Keywords:Micro press forming;Automatic assembly;Progressive die;Micro metallic device1.IntroductionMEMS(Micro Mechanical Electro system)andBiochips attract attention in this decade.These kindsofmicro devices are mainly madeofsilicon or glass,and fabricated by using micro machining technique,which us
6、ually costsveryhigh.Fabrication tech-nology for providing the MEMS stably in lower costis an important issue.Since the micro machiningtechnique is based on photolithography that pro-cesses features in 2 dimensions or 2.5 dimensions,MEMScanonly have restricted structures with fra-gile materials.On th
7、e contrary,metals have the pro-pertiesofductility,conductivity so thatMEMSfabricated based on metal forming could have morefreedom in structure with high strength and ductilematerials.On the other hand,metal forming in sub-Corresponding author.Tel.:+81425858440,Fax.:+81425858440E-mail address.yangtg
8、tmu.ac.jpmillimeter or micrometer scales also becomes a veryimportant issue for the audio-video or informationtechnological devices due to miniaturizationofthestructure parts 1,2.The authors have been working on a novel micrometal forming technology in which micro parts orunits are fabricated by mic
9、ro press formingandautomatic assembly processes in a progressive die 3.Several kinds of sheet metals are supplied into the dieby feeders and formed simultaneously in several stepsand then,assembled together to a unit in the pro-gressive die.We also introduced high-energy beamsfor the fabrication of
10、micro die with featureofseveralmicrometers and using DLC(Diamond Liked Car-bon)coating technique to form film on the surfaceofthe die for improving the wear-resistance 4.Inthis study,we attempt to develop several kindsofdie for punching and deep drawing,and utilize topress forming in a progressive d
11、ie to produce someM.Yang et al./JournalofMechanical Science and Technology21(2007)1452-14551453micro metallic parts and units.2.Micropress forming for fabrication of memsPress forming is oneofmost significant metalforming process for fabricationofcomplicated partsin a press machine.Mostofparts used
12、in Audio-Video(AY)and Information Technological(IT)de-vices are fabricated by the press forming.The featureofthese parts became smaller and smaller these years.Furthermore,MEMS and Biochips consist of multi-parts constructing a system or a unit with complicatedstructure.Fabrication of parts/units wi
13、th featureofsub-millimeters using press forming could be impor-tant in next few years.The issues for forming partswith sub-millimeters features are:-Developmentofnew method for fabrication andevaluationofdie with featureofsub-millimeters,-Surface treatment of die for protection from wearand breakage
14、,-Development and evaluation of metallic ma-terials with fme grains,-Handling and assemblyofmicro parts.Inthis study.we proposed a micro fabricationsystem by using press forming to form micro parts inmulti-steps and then,to assemble parts into a unit in aprogressive die.Fig.I shows conceptionofthe m
15、icrofabrication system.Several kinds of materials su-pplied into the progressive die by feeders,respectively,and formed simultaneously in the progressive die inseveral steps and then,assembled together in thesame die.As the result,a unit part could beformedasan output of the press forming.In order t
16、o establishthe micro fabricationsystem,accuracyofeachelementofdies in dimensions andofalignment ischallengeable.The issues are shown as follows:Fig.I.Schematic configurationofpress forming and in-pro-cess assembly in a progressive die.-Establishing new methods for fabrication andevaluationofdie features smaller than 20 um,-Keeping errors in dimension and allocationoftheelements smaller than 1urn,-Treatmentofdie surface for protection fromwearing and degradation and for processes withoutlubricant
