一直都沒有理解Thermal relief Pad 和Anti Pad的關系,現在弄明白了。具體如下: 假設現在要做的板子是四層板子,具體分層如下: Begin layer: top Internal1: VCC Internal2: GND End layer: bottom 假設有通孔類焊盤,所連接的網絡為VCC,如下圖所示, 頂層為regular pad 底層也為regular pad 通孔internal1層即為thermal relief pad (此處是一般是通過flash焊盤將drill和internal1連接) 通孔internal2層即為Anti pad (此處一般是通過Anti Pad將internal2和drill進行隔離) 尺寸: Drill_Size >= Physical_Pin_Size+10mil(我們一般取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為矩形或橢圓形時) (1mm ) Regular Pad ,Thermal Relief,Anti PAD焊盤之間的尺寸關系或公式 1、Anti Pad直徑=Thermal Relief直徑=Regular Pad+20mil (我們一般取0.2mm) 2、Soldermask直徑=Regular Pad+4mil (我們一般取0.1mm) 3、Flash內徑=Drill_Size+16mil(我們一般取0.5mm) 4、Flash外徑=Drill_Size+30mil(我們一般取0.8mm) 5、Flash焊盤開口Wed大小: 當Drill_Size <= 10mil時:wed = 12mil; 當Drill_Size = 11~40mil時:wed = 15mil; 當Drill_Size = 41~70mil時:wed = 20mil; 當Drill_Size = 71~170mil時:wed = 30mil; 當Drill_Size >= 170mil時:wed = 40mil;
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allegro焊盤尺寸與Anti-Pad焊盤的理解.doc
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