文档介绍：科目:PCB设计与布板技术实训项目:班别:姓名:学号:系别:专业:指导老师:绘制电路图二、元器件参数对应封装选择及说明本次设计元器件的参数及封装如下:DescriptionDesignatorFootprintLibRefQuantityPolarizedCapacitor(Axial)C1CAPPR2-~D56CAPPR2-~Q8SFM-T3/~R26AXIAL--InParallel-OutShiftRegisterU1DIP-14SN74LS164N1General-PurposeSingleBipolarTimerU2DIP-8NE555N1上表列出的是电路图所需要元器件的所有封装,其中C1和C3都选择了CAPPR2-,其他的电容封装都选择了RAD-,DS1到DS56都选择了CAPPR2-,这可以看出不同的元器件可以用相同的封装,对于各种元器件的封装,我们要选择恰当,才能更好的布局,元器件的封装的选择不仅影响布局而且还影响布线,从而影响整个PCB板的设计,所以在选择封装时要慎重考虑好影响整个PCB板的主要因素,为制作良好的PCB板做铺垫。三、ERC与网络表ERC电路规则检查没有错误,所以整个电路图是没有错;网络表是检查电路图有没有封装和漏接线的工具,生成网络表如下图所示:[U2DIP-8NE555N][U1DIP-14SN74LS164N][RP1RP1RPot][R12AXIAL-][R11AXIAL-][R10AXIAL-][R9AXIAL-][R8AXIAL-][R7AXIAL-][R6AXIAL-][R5AXIAL-][R4AXIAL-][R3AXIAL-][R2AXIAL-][R1AXIAL-][Q8SFM-T3/][Q7SFM-T3/][Q5SFM-T3/][Q4SFM-T3/][Q3SFM-T3/][Q2SFM-T3/][Q1SFM-T3/][DS56CAPPR2-][DS55CAPPR2-][DS54CAPPR2-][DS53CAPPR2-][DS52CAPPR2-][DS51CAPPR2-][DS50CAPPR2-][DS49CAPPR2-][DS48CAPPR2-][DS47CAPPR2-][DS46CAPPR2-][DS45CAPPR2-][DS44CAPPR2-][DS43CAPPR2-][DS42CAPPR2-][DS41CAPPR2-][DS40CAPPR2-][DS39CAPPR2-][DS38CAPPR2-][DS37CAPPR2-][DS36CAPPR2-][DS35CAPPR2-][DS34CAPPR2-][DS33CAPPR2-][DS32CAPPR2-][DS31CAPPR2-][DS30CAPPR2-][DS29CAPPR2-][DS28CAPPR2-][DS27CAPPR2-][DS26CAPPR2-][DS25CAPPR2-][DS24CAPPR2-][DS23CAPPR2-][DS22CAPPR2-][DS21CAPPR2-][DS20CAPPR2-][DS19CAPPR2-][DS18CAPPR2-][DS17CAPPR2-][DS16CAPPR2-][DS15CAP