I would like to discuss your use of KiCad’s PCBNew layers.
Obviously I want to skip the use of Technology layers as theis use is rather obvious and unambiguous. I’d like to focus on the use of “Auxiliary” layers:
Is there any intended/recommended use for them?
CrtYd: I assume it’s the definition of mechanical “circumfence” of our modules (components/footprints) which may extend away from their pads, and should be used to indicate potential mechanical collission between neighboring components. And so should be used to fully define a footprint. Correct?
ECO to my understanding is the layer used to indicate proposed changes to the design (https://en.wikipedia.org/wiki/Engineering_change_order).
Any ideas/examples on how to use them for this purpose?
Drawings - I use these for any additional drawings that illustrate some mechanical relations between the PCB and the “real world”. E.g. outline of the enclosure used to house my PCB. Is it also the layer that the board related dimensions shall live in?
Comments. I populate my textual items here (designators, values and e.g. changelog), but this makes my project a bit cumbersome for further handling (especially preparing the assembly documentation). Will elaborate on in furhter on.
F/B.Fab - I do my Test jig drawings here. I kind of use a simplified system consisting of two milled plastic boards, one positions my pcb and the other one use to keep my test probes. This way I use both “F/B.Fab” layers to design my Test Jig boards. But maybe I’m doing something wrong here.
Now let’s get back to my assembly drawings. Apart fromt he physical location of compoenents, and their identification (designator, value) what is important: Pin1 location, and Polarity marking.
Where do you locate these? It’s a common practice to have them printed on a silkscreen layer, but there are reasons I don’t use a silkscreen on a board side with SMD components installed. So where to have them indicated, to be able to easily generate proper assembly documentation? Which layer they should be located on? Or maybe this is the kind of information that should live on the “F/B.Fab” layers?
Other thing is, where to put the designators/values? In the default library, the references are put on the Silkscreen. I don’t remember exatly where the values are. I’d prefer if the texual descriptions (des/val) were drawn on separate layers, with the option to include them on the silkscreen. What’s your opinion on the current way of handling these?
And what’s the way other (favored) packages deal with the above mentioned aspects? I don’t have any experience with packages other than KiCad which is my tool of choice since 2012.