一直都没有理解Thermal relief Pad 和Anti Pad的关系,现在弄明白了。具体如下: 假设现在要做的板子是四层板子,具体分层如下: Begin layer: top Internal1: VCC Internal2: GND End layer: bottom 假设有通孔类焊盘,所连接的网络为VCC,如下图所示, 顶层为regular pad 底层也为regular pad 通孔internal1层即为thermal relief pad (此处是一般是通过flash焊盘将drill和internal1连接) 通孔internal2层即为Anti pad (此处一般是通过Anti Pad将internal2和drill进行隔离) 尺寸: Drill_Size >= Physical_Pin_Size+10mil(我们一般取0.25~0.3mm) Regular Pad >= Drill_Size+16mil(Drill_Size < 50mil) (0.4mm 1.27) Regular Pad >= Drill_Size+30mil(Drill_Size >= 50mil) (0.76mm 1.27) Regular Pad >= Drill_Size+40mil(Drill为矩形或椭圆形时) (1mm ) Regular Pad ,Thermal Relief,Anti PAD焊盘之间的尺寸关系或公式 1、Anti Pad直径=Thermal Relief直径=Regular Pad+20mil (我们一般取0.2mm) 2、Soldermask直径=Regular Pad+4mil (我们一般取0.1mm) 3、Flash内径=Drill_Size+16mil(我们一般取0.5mm) 4、Flash外径=Drill_Size+30mil(我们一般取0.8mm) 5、Flash焊盘开口Wed大小: 当Drill_Size <= 10mil时:wed = 12mil; 当Drill_Size = 11~40mil时:wed = 15mil; 当Drill_Size = 41~70mil时:wed = 20mil; 当Drill_Size = 71~170mil时:wed = 30mil; |