KiCAD should speak of "hole size" instead of "drill size"
Hello,
PCB fabrication houses usually consider that the layout of vias indicates the "finished hole size". To be consistent with this convention, KiCAD should speak of "hole size" instead of "drill size".
Why does it matter? In the case of a PTH, the "finished hole size" is actually smaller than the "drill size" because of the plating that is added. There is a typical reduction of the diameter by 0.10 mm, so for a PTH described in KiCAD as "Via Drill 0.1 mm", the real drill size will be 0.2 mm (diameter of the drill-bit that is used). We understand that the description used in KiCAD does not correspond to the reality, and that KiCAD should use the word "hole" instead of "drill" in this occasion at least.
Reference:
- https://www.eurocircuits.com/finished-hole-size: "The finished hole size or end diameter of the hole is the diameter that the PCB designer specifies in his PCB layout."
- https://www.eurocircuits.com/phd-production-hole-diameter: This page explains that for PTH, "Drill Size" = "Finished Hole Size" + 0.10 mm
Suggested change in KiCAD:
- In the "Board Setup" (design rules and net classes), "Via Drill" should be renamed to "Via Hole".
- Maybe change only this, because the word "drill" is used at so many places in the KiCAD data files that making a deep change would be too complicated.
Olivier (Debian Linux, KiCAD 5.1.8)
External discussion about this: https://forum.kicad.info/t/definition-of-via-size-and-via-drill/26481/16
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