简介:3Dprintingisdisruptingthedesignandmanufactureofelectronicproducts.3Dprintingelectronicsoffersgreatpotentialtobuildcomplexobjectwithmultiplefunctionalities.Particularly,ithasshowntheuniqueabilitytomakeembeddedelectronics,3Dstructuralelectronics,conformalelectronics,stretchableelectronics,etc.3Dprintingelectronicshasbeenconsideredasthenextfrontierinadditivemanufacturingandprintedelectronics.Overthepastfiveyears,alargenumberofstudiesandeffortsregarding3Dprintingelectronicshavebeencarriedoutbybothacademiaandindustries.Inthispaper,acomprehensivereviewofrecentadvancesandsignificantachievementsin3Dprintingelectronicsisprovided.Furthermore,theprospects,challengesandtrendsof3Dprintingelectronicsarediscussed.Finally,somepromisingsolutionsforproducingelectronicswith3Dprintingarepresented.
简介:Ahigh-speedandhigh-resolutionopticalA/Dquantizerisproposed.Itsarchitectureisdiscussed.Bitcircuitsarebuiltbyusingthephasemodulatorsinparallel.Basedonthedifferentcharacterofthehalf-wavevoltageforeveryphasemodulatorandthepolarizedbiasdesignofincidentlight,theRFinputsignaliscodedandtransmittedintheformofopticaldigitalsignal.Accordingtotheprincipleofthearchitecture,thehigh-resolutionquantizerswith8-bitand12-bit,etal.arebuilt,whichoperateat100GS/s.Theirquantizationnoiseisinvariablealmostwithbitcircuitsincreasing.Thesimulationresultof4-bitA/Dquantizerisalsogiven.
简介:Thispaperproposesanewtechniquethatisusedtoembeddepthmapsintocorresponding2-dimensional(2D)images.Sincea2Dimageanditsdepthmapareintegratedintoonetypeofimageformat,theycanbetreatedasiftheywereone2Dimage.Thereby,itcanreducetheamountofdatain3Dimagesbyhalfandsimplifytheprocessesforsendingthemthroughnetworksbecausethesynchronizationbetweenimagesfortheleftandrighteyesbecomesunnecessary.Weembeddepthmapsinthequantizeddiscretecosinetransform(DCT)dataof2Dimages.Thekeytothistechniqueiswhetherthedepthmapscouldbeembeddedinto2Dimageswithoutperceivablydeterioratingtheirquality.Wetrytoreducetheirdeteriorationbycompressingthedepthmapdatabyusingthedifferencesfromthenextpixeltotheleft.Weassumethatthereisonlyonenon-zeropixelatmostononehorizontallineintheDCTblockbecausethedepthmapvalueschangeabruptly.Weconductanexperimenttoevaluatethequalityofthe2Dimagesembeddedwithdepthmapsandfindthatsatisfactoryqualitycouldbeachieved.
简介:Byusingd-formfunction,anewconstructionoffrequencyhoppingsequencewithoptimalHammingcorrelationispresentedinthisarticle,whichgeneralizestheresultspresentedbyDing(2007).Furthermore,anewclassofnon-powerfunctionstyled-formfunctionisproposedandanupperboundoftheHammingautocorrelationofthecorrespondingsequenceisalsoderived.
简介:随着产业界要求产品越来越小,越来越轻,运行速度越来越快,对020l元件的使用逐年增加。十个020l元件所占的面积最多只占一个0402元件的三分之一。因此,可以把部件组装得更紧密,从而减小PCB板的尺寸。采用020l元件遇到的主要问题是:随着元件尺寸的减小,工艺窗口也减小了。与1206元件相比,0201的元件已表明其直立的可能性比前者要大9倍,而与0402元件相比,则其可能性要比0402元件大2点5倍。因此,在表面组装020l元件时,要更多注意设计和工艺。总的来说,现已知静态因素(如PCB板和模板设计)比工艺中的动态因素(如印刷参数,贴装参数,回流参数)更能影响缺陷数量。部分动态参数确实能对组装过程产生很大的影响(如在回流焊中空气与氮气环境),但是总的来说,静态因素对可能产生的缺陷数影响要比动态因素大得多。在此研究过程中,优化组装参数和设计参数对组装参数的影响都以PPM缺陷数表示。本篇论文中集中了研究中的数据和对元件组装时进行的多次评估中搜集的数据。首先在每一加工步骤中工艺参数,然后再对整个过程进行研究。检测的部分工艺参数包括印刷工艺中的印刷压力,印刷速度,模板擦拭频率,及回流焊气体,回流曲线和回流曲线上升速度等。从这些研究中可以得到适应高速的020l组装工艺的可靠的工艺窗口。该窗口已证明能使DPM小于200。