PCB线宽与电流关系

PCB线宽与电流关系一、计算方法如下：先计算Track的截面积，大部分PCB的铜箔厚度为35um（不确定的话可以问PCB厂家）它乘上线宽就是截面积，注意换算成平方毫米。有一个电流密度经验值，为15~25安培/平方毫米。把它称上截面积就得到通流容量。I=KT0.44A0.75（K为修正系数，一般覆铜线在内层时取0.024，在外层时取0.048T为最大温升，单位为摄氏度（铜的熔点是10601）A为覆铜截面积，单位为平方MIL（不是毫米mm，注意是squaremil.）I为容许的最大电流，单位为安培（amp）一般10mil=0.010inch=0.254可为1A,250MIL=6.35mm,为8.3A二、数据：PCB载流能力的计算一直缺乏权威的技术方法、公式，经验丰富CAD工程师依靠个人经验能作出较准确的判断。但是对于CAD新手，不可谓遇上一道难题。PCB的载流能力取决与以下因素：线宽、线厚（铜箔厚度）、容许温升。大家都知道，PCB走线越宽，载流能力越大。在此，请告诉我：假设在同等条件下，10MIL的走线能承受1A，那么50MIL的走线能承受多大电流，是5A吗？答案自然是否定的。请看以下来自

国际权威机构提供的数据：线宽的单位是：Inch（inch英寸=25.4millimetres毫米）1oz.铜=35微米厚，2oz.=70微米厚，1OZ=0.035mm1mil.=10-3inch.TraceCarryingCapacityTempRise10C20CCopper1/2oz.1oz.2oz.1/2oz.(f1oz.L/XX2oz.L2oz.1oz.2“if"AAx/)j*^^^***^TraceWidthMaximumCurrentAmpsinchmm.0100.2541.0L40.61.21.6.7LS2.2.0150.3S1120.8L32.4L01.63.0,0200.508.7j二2.11.01.73.0L22.43.6.0250.635,91.72.51.22.23.31.52.84.0.0300.7621.93.0L42.SIT1.73.25.0.0501.271・52.64.02.03.66.02.64.473.075L9052.03.55.72.84.57.83.56.010.0.1002.542.64.26.93.56.09.94.37.512.5.2005.084.27.01L56.010.011.07.513.020.5.2506355.08.312.37.212.320.09.。15.024.5美国线材规格UnRegistered美国线材规格外径截面秋电阻值正常电流最大电流外径截面秘电阻值正常电流AWG0000公制mm英制nchKK9(mm2)&km)42324826AWG22英制inch褊W03247丝m)1.2801.46000C104040%85.010.21335.538262348.51.0221.165O0|。，：70.364867430262662103.524002010.20478940.8080.9218.250.324953.490.332111240.725001790162；-79.60.6410.731■i7350.289342.410.421674190.926I0.40400159012811430.5060.577.540.53132.7151.3270.4030.46035.8326.670.66105.2120.0280.320.0126008042270.3180.36245.190.204321.150.8483.595.2290.2870.01130.06472890.2550.29154.620.161916.771.0666.275.5300.2540.01：.i05LI；3610.2000.22864110.16213.352.559.9310.2260.0CS9I.■•-JI3210.1580.18173.670144310.651.6841.647.5320.2030.008{(.6830.1280.14683.260.12858.372.1133.037.7330.0Q2X'>9440.1010.1152.91U.11446.632.6726.229.8340.160/W/'-LJl9560.0790.091102.590.10195.2S3.^20.823.735|0.142.二日据占r.015912000.0630.072112.30.09074.174.2416.518.836Io13012?15300.0500.057122.050.08083.3325.3113.114.93713770.0410.046131.820.07226276.6910.411.824000.0320.036141.630.064120758.458.294Z0.003521000.0250.0281G1.450.05711C4G10C6.5740003140000.0190.022161.290.0508131813.55.2今."右0.0160.018171150.045310261634.1.4*-/,63000.0130.014181.020.04030.810721.43.2-55440.0100.011190.9120.03590566726926102000.0080.009200.6130.0320.519933.92.CL91800.0060.00721■'•】一「二G4116427/46163000.0050.006Dm=*七”x"密%Di”438.489Di=1000外径英制inch栈II!(rnm2)mli史祉ill”!i--|2)Ll!：'.■lj/'kn；Irn-n<r.'li:■■i-'ri•，J-.1.'inch107.25C.6^00253D.5700225460.3643□.324900179U01590.1281001420.1D21001260.20430011301矿90QKO0162D00QB9C.C^IOI0ODBC0.11+43.6315000c30.D201010^91.加—,—=410005037QC.D72D2.6270.004(^!.ii00^41e4!>WiU」0.05T1QQM0.050S二ii■■id1026「今|/CW50.040308107-D002^0.9120.035905667■盘00020CC^2DI1C<0D01j.2016.1S0210.02S504116i-I00016(J.31316,300三，实验：实验中还得考虑导线长度所产生的