How does the Shape's Clearance work for PTH and Non-PTH?Originally posted in cdnusers.org by leonlee
For example, I have two though hole, one is plated, the other is non-plated:
Plating: Drill: Top Pad: Top Anti Pad:
Pad1: Plated 1 circle1.5 1.9
Pad2: Non-Plated 1 circle 1 (unuseful) 3.0
Now, there is a Net Shape arround them, the shape has a Net Spacing Type property with 0.15mm(6mil) for Shape to Pin.
If the Clearance setting sets Thru pin: DRC and Oversize value:0. The radius of Void around Pad1 is equal to 0.9mm(0.5+0.25+0.15), that means the spacing between Shape and drill edge is 0.4mm. The spacing to pad edge is 0.15mm. For Pad2. the radius of Void is 0.65mm and spacing to drill is 0.15mm.
If use the setting:Thru pin: Thermal/anti and Oversize value:0. The Void radius arround Pad1 is 0.95mm. The spacing to drill is 0.45mm, And spacing to pad edge is 0.2mm. For Pad2 void radius is 1.5mm. The spacing is and 1mm.
Now, my problem is:
When I use DRC clearance, the spacing for Non-Plated pad is not correct. and use Thermal/anti, the spacing for Plated pad is larger than my constraint.
I am not sure that my descreption is clear enough. I think it is a problem to deal with the clearance between Shape and PTH/NPTH.
BTW, I use SPB15.5.1.