Does anyone here uses the Footprint -> Attributes “Normal” / “Normal+Insert” / “Virtual” ?
For what proposes?
Thanks!
Of course yes. Normal+Insert for all SMT parts. Normal for THT components, and Virtual for edge connectors, test points, etc.
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Graphic symbols as well
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Attributes are used mainly when you generate Fabrication output file for Pick and Place machine
File, Fabrication outputs, Footprint position (.pos) File
Virtual, as we talked, is for connector, test points and mechanical parts 
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My take on this:
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‘normal’ is for parts that should turn up in your BOM, but not turn up in the position file for SMT (usually through hole devices, but can be other stuff as well)
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‘virtual’ is for things that you need footprints for (symbols, test points, fiducials, etc…) which must not turn up in a BOM,
but will turn up in a position file afaik(edit: that is wrong) -
‘normal+insert’ is for SMT devices that need to be part of the BOM and in the position file
Have a read here:
https://rheingoldheavy.com/category/education/kicad/
(the two tutorials on BOM and the one on Design for Manufacturing)
PS: don’t know if you’ve seen it, but I put up some code that reads out all these things from your local footprints into a csv… still didn’t get it to import changed stuff back into the repos, but I’ll get there - just wrestling with an AVR at the moment
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virtual will not turn up (correctly) in position file
virtual is for pcb made connector, test points etc, which are not smd objects to be picked up to be placed by the machine
Hm, who would have thought that… thx @maui .
Fiducials need ‘normal+insert’ to work for the pos file, and will then appear in the BOM… meh.
Never heard about it. 
Our PCBA house never ask for it.
Never did any PCBA, but I know that they can user the vision system (of the P&P) to choose any mark to work as a Fiducial…(eg a tht hole, a smd PAD…etc) So in fact the fiducial (or any other reference mark) is an alignment pattern that will be at same position for all the boards.
Fiducial is a symbol, it will not be placed. But maybe some PCBA can use that information for double check the positions…
Yeah, the thing with fiducials is that they are round and the solder mask/copper is further away from the copper dot in the center compared to your normal pads (for example: 1mm copper dot - 0.5mm or bigger solder mask distance).
Machine vision will have an easy play with them, as there should be no soldermask/silkscreen covering parts of them.
Drill holes have alignment errors… might not matter for 1208, but 0402 or 0.35 pitch needs more accuracy.
The only thing that is created with the pads and doesn’t show alignment errors and has no problems with soldermask/silkscreen are fiducials.
PS: you need 2, better 3 per board to cover the two axis. The further apart, the better.
The P&P machine which is used in our company for small series uses three type of fiducials.
- First - on the panel frame - to check the panel alignment. The diagonal fiducial is checked by vision system. Top left is checked first and the operator is informed about the matching score. If less than 97%, the operator is asked to repositioning or correct. Then the bottom right is checked and the machine evaluate the distance deltas and skew. If the second fiducial can not be found then the P&P program failed - in many cases the main reason is rotated panel.
- Second - on the particular PCB’s on the panel - is used as the origin. Every component is relative to this point. There is an option to use this fiducial as “bad mark”. The P&P program will skip this origin, and this PCB is omitted. In another case, they are not checked by vision system.
- Third - two diagonal, optional, around the component - is used for the precise positioning in high pin count or with small “pitch” devices. These fiducials are defined at machine components library level. It’s funny to see how machine take the IC from the tube or tray and watch fiducials with the vision system, then finally place it on the board after a while.
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