Pours - Best practices


#1

We are looking for some advice and best practices for using pours within Upverter. Partial answers/suggestions touching on one or several of below topic areas also welcome.

Our project
We are designing a 50x50mm hex-shaped board with around 75 components. To conform with UL we have two separate isolated grounds separated by a “no-copper”
isolation barrier, and for input wires/connectors before TVS diodes need to observe a larger creepage distance than rest of circuit. We are leaning towards a 2-layer board
design, partly because of our perception that Upverter can’t handle all the pours in a 4-layer design. One of the corners cut off to form the hex shape also serves as a small daughter board. Our minimum number of pours is thus 2+2+2=6 pours. (For a 4-layer
board we would have 4+4+4=12.)
Our design environment is FireFox 61.0 on MacOS.

Side note: For those not afraid of reading a large spec, IPC2221A provides good background mtrl and recommends parameter values for clearance and creepage distances. Much easier to understand than the UL specs in terms of PCB manufacturing and assembly choices you will need to make.

What are best practices in the following areas:
A) Environment and daily usage

  • Are certain browsers better at handling pours (eg by using webworkers) or is all the computation done on the server side and we should shift our work to periods
    when they are unloaded?
  • Does each pour take up significant browser side memory, and if so would closing unrelated browser tabs help?
  • Our current practice is to keep all pours “unpoured” whenever we stop working for the day, since we observe long delays loading/reloading designs that have the pours “poured”. We also tend to only have one pour at a time “poured”. Can we get same performance benefit from just “hiding” or filtering out the pours? (Not even sure “hiding” as suggested in an old blog post is still supported). A pour with 4-5 components generates in a few seconds, while a single pour with 40+ components takes several minutes to render (and locks the Upverter UI while doing so)

B) Pour layout and config parameters

  • Is it possible to have multiple smaller overlapping pours (eg with different clearance distance parameter settings). Right now we define lots of pour polygon points in the area of the design “before” the TVS diodes to ensure we get adequate creepage distance.
  • Assuming split overlapping pours, would fewer components per pour speed up their generation and rendering?
  • How should the “pour order” parameter be used? Is it for controlling which of several overlapping pour areas have precedence?
  • Our experience is that hatched pours increase probability of getting islands, so we settled on solid pours.

#2

Thank you for all the details here!

We have a new server side pour in Alpha that should help with the memory and speed or regenerating pour issue. I will try to get you into the beta group when we start the roll out in the coming weeks (might be as early as next week :slight_smile:

I always keep my pours unpoured when I design as well, I am hoping the new pour code will make it so you are re-pour whenever you would like … it is much faster.

you can have multiple overlapping pours, you should change the “pour” order in the pour dialog to make sure that the pours get filled in the correct order. pour order determines what copper is generated first, then the next pour will respect the copper and clearance of the already filled pour(s). This way you can have a pour that is fully surrounded by another pour with clearance respected.

I also use solid pours unless I am doing flex boards.


#3

Hi, do you think I could be in the beta group as well? I literally spend hours doing correction on my pour due to the slow process of repouring.


#4

Ya, I will send you a direct message when we roll out the first beta group.