I am trying to make a filled zone however it seems to cut corners.
What setting is to fill it as a block without rounding the edges? I would like the zone to be a plain rectangle
Try this:
1 Like
What is the scale of this rounding?
R is 0.1mm or 10mm?
I think small rounding can come from different reason than big rounding.
I have no corner smoothing, 0
The radius seems small maybe 0.1-0.2mm
Now I am at work where I have KiCad so was able to check it.
Such small rounding comes from âMinimum widthâ parameter. KiCad (8.0.4) allows me to set it minimum to 0.025. I donât show the result as I have KiCad at another PC, but corner looks more corner probably in a cost of time used for zone filling.
By the way. Remember that real processes are not so accurate as you can see at screen.
1 Like
Yes, that improves it but there is always a little bit of rounding. I guess this is the best that can be done. THank you
The question is why sharp corner you call being the best.
In past KiCad didnât had rounded rectangle pads. Since it has I use only rounded pads to have it being best.
I donât agree with that.
The best that can be done is not worry about it. Stopping to twiddle with irrelevant details can be very difficult. It has something to do with the weird ways in which human brains operate.
1 Like
Well actually small details like this can have a huge impact especially over the frequency range I am working on so having to re-simulate all my ADS is more effort. Key to good designs is attention to detail. But everyone has it working methods and Iâm not here to give you life advice so neither should you.
The point was more about understanding the tool not necessarily the end result. If something doesnât work as expected its normal to figure out why not? And yes, in this case it a small thing but in others can be critical
I guess I am trying to achieve something right so best can be done is phrase that means closest to target. Doesnât refer to the actual quantitative qualities of the action. Thanks for your help.
When placing Graphic polygon I was able to set Line Width to 0mm so to get as sharp corner as possible.
Whenever zone has to go in narrow places (including corners) you should imagine minimum width track being used there. Track ends are rounded.
Yeah, I could also get it done with graphic polygon, but I didnât realize there is the same rule applied to tracks and zones. My main issue was whether that came from some setting I had wrong or is just how the tool works. I guess itâs the second. Thanks for your help.
Yeah, I donât want to go in that direction.
It does make me wonder in which frequency range you are working.
I once read about a prototype for a radar installation that worked, but the production variant did not work anymore. The cause was the prototypes were milled, and the etched production PCBâs had less straight edges and this resulted in signal reflections and âsmearingâ of the signal spectrum.
Setting the Minimum Width to the smallest allowed (0.025mm) gets me a corne radius of near to half of that, which makes sense, the minimum width would then be itâs diameter.
Iâll assume it would have a real difference for your circuit. Even then it may be better to work with a defined radius, instead of with sharp corners. With sharp corners you rely more on the production process of your PCB manufacturer and the resolution of the machines they use. With rounded corners the result on the final PCB will be closer to the the design files you send them. This is also a part of the reason that IPC started recommending to use pads with rounded corners. The aperture for the solder paste stencil are then more reproducible, and donât rely on the laser diameter of whomever makes the stencils.
If you really want sharp corners. Maybe designing your thing as a footprint is an option. A quick check verifies that SMT pads can have sharp corners. Arbitrary graphics (polygons, lines, arcs etc) can also be added to pads.
Setting aside the âwhyâ it does it, take a look at the thickness of a Human Hair and consider if spending time on something this trivial is worth the time spent posting. Just because we can calculate to umpteenth resolution does not mean much if the machine/whatever making it canât do thatâŚ
ADDED: Forgot⌠the Corner Radius is based on the Lineâs Width. Screenshot below shows three different Line-Width results of filled shape.
Whoâs going to make the PCB? Check their requirements - this is from JLCPCB
MY pcb will be milled not etched so you canât take jlc precision as good. JLC is low cost, affordable solution. Again, the point is that the tool does something unexpected, so it is generally good to know the source of the mismatch between expectation and reality. In this case was a small difference but in others it can be the difference between a missed connection or it being connected.
Yes, my PCB will be milled as ristimes in the circuit have frequencies up to 60Ghz.
Thank for your help. I was aware of the work around.
Also, yes IPC recommends rounded pads but having done a lot of production support they lower yields and come with more issues so itâs not all improvements
Sharp corners should be avoided.
Minimal rounding of corners will not hurt, check with your ADS.
Etching copper will have some (microscopic) rounding, solder paste stencil apertures are harder to clean with laser cut sharp corners.
Old style software could not produce bezier curves etc and made the âlookâ square and clunky, as a compromise, not as a design objective.
Square patterns in RF boards relate to some simplified math, Klopfer lines avoid that. Do an EM sim and see how your sharp corners behave. For high voltage sharp corners add voltage stresses.
In nature sharp corners are rare, and for PCB current flow the corners may not see much activity.
Sharp corners is a low tech artifact.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.