Wishlist: Add knowledge of hole tolerance / drill oversize in pads and vias
Description
When drilling a board, there is often some slight movement when the drill impacts the board, causing the drill hole to be slightly off centre on the pad. In addition, the drill hole itself might be larger than specified due to this movement and tolerances in drill bits. Usually this is not a problem as the pad is almost always larger than the drill hole.
However, in some cases it is desirable to remove the inner layer pads to reduce capacitance and/or increase track routing density (see #2014 (closed)). [Note: this will become a possibility in KiCad once pad stacks are implemented (see #2402)]
When removing inner layer pads, the uncertainty in the exact drill hole position becomes important as it could result in shorted tracks.
This could be resolved by having knowledge of a drill oversize parameter or even better, absolute hole tolerance ( + and - tolerances ). This setting could be applied at board level or at individual pad/via level.
This value would be used by DRC engine to calculate whether there is enough clearance between a track and a hole.
NOTE: This feature request is possibly related to #2371 (closed)
Steps to reproduce
N/A
KiCad Version
Application: KiCad
Version: (5.1.6)-1, release build
Libraries:
wxWidgets 3.0.4
libcurl/7.66.0 OpenSSL/1.1.1d (Schannel) zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.1.1) nghttp2/1.39.2
Platform: Windows 8 (build 9200), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8)
Boost: 1.71.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.66.0
Compiler: GCC 9.2.0 with C++ ABI 1013
Build settings:
USE_WX_GRAPHICS_CONTEXT=OFF
USE_WX_OVERLAY=OFF
KICAD_SCRIPTING=ON
KICAD_SCRIPTING_MODULES=ON
KICAD_SCRIPTING_PYTHON3=OFF
KICAD_SCRIPTING_WXPYTHON=ON
KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
KICAD_SCRIPTING_ACTION_MENU=ON
BUILD_GITHUB_PLUGIN=ON
KICAD_USE_OCE=ON
KICAD_USE_OCC=OFF
KICAD_SPICE=ON