This is different than the RF stuff where corners may be or are important only in the high end of the spectrum, and possibly not everywhere where they have been used. Mechanically every corner matters because a physical object, when it is bent, always breaks in the weakest spot first, and all inner corners are weak spots.
It’s even so that a thinner trace (or other object) is stronger than an othewise wider one that has a weak spot, even when the weak spot is itself wider than the thinner trace. That’s a law of physics, and it’s practical, not just theoretical.
Of course if a flex board is bent once and there’s no vibration later it doesn’t matter much.
PCB panelization is of interest to people who make their own PCBs from scratch.
For most of us it would conflict with the CAM tools used by the PCB fab, to get minimum waste of their blanks
Needs for a certain panelization for assembly reasons can always be solved by direct communication with the PCB fab
Planar transformer. I did the transformers in Eagle CAD because I know how.
In another design I needed one turn per layer. Red = one turn.
My last hand full of designs I used the foot print editor to make rounded traces. Not good.
Now 5 people that would use rounded traces.
The post title “…discussion” implies “discussion, not ‘Announcements and News”
Having Patents on medical connectors - one for use with Flex Circuit, peaks my interest, I thus add the below screenshots of p13, p14 from ‘Flex Circuits Design Guide’ from Minco.com.
The full document is worth a review for those designing Flex Circuits… Of particular interest to references in the above posts on Corners. Also, good insightful tips on capturing/holding down Pads (if you make/tweak footprints…)
While here, I’ll finish-up re Curved Tracks with following image…
(fyi - re method 1, draw trace/track on different layer because cannot attach to what it
thinks is a filled zone. Note: I did not fuss with making precise geometry/dim’s)
I don’t know how many people want to penalize their boards (except when the board does something wrong), but out of interest: which popular EDA packages have panelizing support? Is it really a “basic” feature?
The tool we use at work has that capability https://www.orcad.com/products/orcad-panel-editor/overview. We panelize the boards to match the particular parameters of our manufacturing process (including pick and place, soldering, de-panelling, in circuit test etc).
Yes, JW Avalanche Generator. Well spotted. I’ve PM’d you but I would be happy to put this on GitHub if anyone else was interested. I have yet to produce one and I don’t really have good enough equipment to full test this design.
The final product is the single PCB, not the panel. The panel is internal in manufacturing, and must be made according to the requirements of the manufacturing process. Different manufacturers or batch sizes require different panels. It is then best to let the manufacturer to take care of the panelization.
And indeed, as elekgeek states, this is how it is usually done: the EMS asks the bare board fabricator to supply a panel to his spec; for the fabricator’s CAM software it is a piece of cake. If CAD supplies a panel chances are it is wrong, and the fabricator must depanelize and repanelize. (Worse, the data is typically ‘flattened’, the definition of the single PCB and their location is lost, and it has become a single big PCB. This is a nightmare in fabrication, for instance in electrical test: what is the meaning of a net number in a panel? There are few things a fabricator hates more in incoming data than a flattened panel.)
For the majority of use cases there is no need for CAD to panelize, quite in the contrary.
Then there is the use case of internal manufacturing, brought up by bobc. There a panel is needed. No discussion. In the example the CAD system is used, or abused, for CAM functions. The question is whether this is desirable to load the CAD system with that. There is quite inexpensive software dedicated to panelization, I believe. Compared to the cost of an assembly line its cost is surely peanuts.
CAD software has other priorities than panelization.
I would also include myself as one who would love to see KiCAD include curved traces. I recently made a thin curved PCB that was about 1cm wide, at a radius of 7cm, traversing ~170 degrees of a circle. The fact that KiCAD could happily make neat and clean curved shapes on the edge.cuts layer, but couldn’t do it on the copper layer was rather disappointing.
I’m re-creating some old car foil cluster circuit traces, so I really need rounded traces for several reasons.
As a work around, “could I” make my traces using the polygon tools as another layer, then change them to copper layer either through property selection or editing the file manually?
You could draw them as polygons on the copper layer, but that sounds pretty painful. If I were doing this, I’d just use free-angle routing and very small segments to approximate the curves. (well, I’d actually use a nightly build, but…)
