Feature request: polygons with nets
Description
Currently, polygons are only supported on non-copper layers. Polygons CAN be moved to copper layers by editing their properties, but there is no way to assign a net to them. DRC detects them as no net and creates errors when they are overlaid on tracks or pads with net assignments. Polygons are useful, particularly when placing sot-23 size voltage regulators that benefit from large copper pads for heat sinking.
There currently is a way to produce such heatsink pads using filled zones, however it is very laborious if a ground plane zone is being used, as the designer is required to trace the ground plane zone boundary around the heatsink zones, leaving sufficient clearance to avoid the "copper area inside copper area" error, as well as sufficient clearance between the ground plane zone points to avoid the "self-intersecting zone" error. An alternative is to use lots and lots of overlapping tracks to form a copper pour. As with the zone outline method, this method is laborious, and requires careful control of the autoroute feature.
Steps to reproduce
KiCad Version
Version: 5.1.10-88a1d61d58~88~ubuntu20.04.1, release build
Libraries:
wxWidgets 3.0.4
libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3
Platform: Linux 5.8.0-50-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
Boost: 1.71.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.68.0
Compiler: GCC 9.3.0 with C++ ABI 1013
Build settings:
USE_WX_GRAPHICS_CONTEXT=OFF
USE_WX_OVERLAY=ON
KICAD_SCRIPTING=ON
KICAD_SCRIPTING_MODULES=ON
KICAD_SCRIPTING_PYTHON3=ON
KICAD_SCRIPTING_WXPYTHON=ON
KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
KICAD_SCRIPTING_ACTION_MENU=ON
BUILD_GITHUB_PLUGIN=ON
KICAD_USE_OCE=ON
KICAD_USE_OCC=OFF
KICAD_SPICE=ON