超声波扫描显微镜sonscan上课讲义.ppt

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1、超声波扫描显微镜sonscan1、超声波基础知识BasicsofAcousticsULF<20HzAudible20Hz–20KHzSOUNDUltrasound20KHz>超声的应用：清洗,焊接,治疗,成像和传感超声波清洗和焊接：20KHz~40KHz超声波成像：>5MHzBasicsofUltrasound(超声波基础)Ultrasoundisanelasticdisturbancethatpropagatesthroughmaterials(mainlysolidsandliquids)atfrequenciesabove20KHz.(超声波的频率在20KHz以上，人不

2、能听到)Anultrasonicwavecannotpropagatethroughavacuumatanyfrequencyorthroughairatfrequenciesabove10MHz.(任何频率超声波都不能穿透真空。当超声波频率大于10MHz时，也不能穿透空气)ThepressuresgeneratedatthefocalspotareinthemicroJoulerangeandarenotharmfultoevenmoderatelydelicatesamples.Thepulseintheacousticmicroscopehasverylowenergy

3、incomparison.(C-SAM使用的超声波的频率和能量不会对人体和样品有害。)BasicsofUltrasound(超声波基础)UltrasoundatInterfaces(界面处的超声波)Whenanultrasoundpulseimpingesonaninterface,partoftheenergyisreflectedandparttransmitted.(在界面处的超声波，有些会被反射，有些会穿过该界面。)Therelativestrengthofthetransmitted(T)andreflected(R)ultrasoundataninterfacei

4、sgovernedbytheacousticimpedanceofthematerialsoneachsideoftheinterface.(在界面处超声波反射和穿过的相对强度是由界面两边物质的声阻抗决定的。)AcousticImpedance(Z)-theproductofthedensityofthematerialandthevelocityofultrasound(Z=V).(声阻抗是物质的密度和超声波在该物质中的传播速度的乘积。)1Material2Transmittedwave(穿透波)Reflectedwave(反射波)ReflectionCoefficien

5、t(R)(反射系数R)TransmissionCoefficient(T)(穿透系数T)UltrasoundatInterfaces(界面处的超声波)Z1Z2AcousticImpedanceofMaterials(声阻抗值)AcousticImpedance(Z)-istheproductofamaterialsdensitytimesitsultrasonicvelocityZ=VInpracticalterms-AcousticImpedanceisamaterialscharacteristicpropertythatdeterminestheamountofref

6、lectedandtransmittedenergythatoccurswhenanultrasonicwaveencountersaboundaryorinterfacebetweentwomaterials.5MHz15MHz30MHz50MHz75MHz100MHz150MHz230MHz300MHz300micron95micron60micron40micron28micron4micron9micron15micron20micronLowFrequencyGreaterPenetrationHighFrequencyHigherResolutionSampleB

7、ackSurfaceSampleSurfaceFrequency,ResolutionandPenetration(频率、分辨率和穿透力)1SiMetallization10MHz100MHz1GHzFlipChipsWaferBondingBGAsThickFilmAdhesionThinFilmsPlasticICsCSPPorosity&cracksinMetalsCeramicsMedicalUltrasoundHermeticSealIntegrityPenetration(穿透能力)---