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.
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.