6 ms·

I could not find it on ddg/google right now, but I remember seeing some absolutely beautiful plant/vine-like trace routes done by the soviet auto-routing tools

I could not find it on ddg/google right now, but I remember seeing some absolutely beautiful plant/vine-like trace routes done by the soviet auto-routing tools of past ages. I feel a bit sad that the 45degree aesthetic is the only one that survived today.

deleted 5y ago
[deleted]
Dork1234 5y ago
I also thought 45 degrees is used to reduce ESD, provide the best use of die space, and reduce stress on the metal with high current. Maybe all of that is a myth? Any other angle doesn't have the same benefits.
- picture 5y ago
  Any-angle routing may actually be better for use of space and reducing stress. I sometimes get more traces packed around a bend with any-angle. And most polymide PCBs are any-angle or at least super rounded with teardrops, having sharp transitions of any type would act as weak points.[1] ESD really doesn't make sense, maybe you meant EMI or EMC? There's nothing particularly special about 45 degrees other than the ease of modeling [1]: Some macbook trackpad, note the polymide/flex substrate and rounded tracks. This isn't fully any-angle like what TopoR does though https://commons.wikimedia.org/wiki/File:Apple_MacBook_Pro,_model_A1278_-_trackpad_-_connector-8395.jpg https://commons.wikimedia.org/wiki/File:Apple_MacBook_Pro,_m...
marcodiego 5y ago
https://en.wikipedia.org/wiki/TopoR https://en.wikipedia.org/wiki/TopoR
- deleted 5y ago
  [deleted]
- the-dude 5y ago
  Parent is downvoted for only providing a link, but : TopoR is a free-angle PCB autorouter ( it has other tricks too ). It is of Russian origin and commercial software!
adrian_b 5y ago
It is not a question of aesthetic. In old integrated circuit manufacturing processes, with large minimum dimensions, it was possible to draw arbitrary curves without problems. Some of the software tools were limited to straight lines or even to straight lines only at certain angles, just because the limitation simplified the algorithms, but if one really wanted, it was possible to draw anything on the masks. On modern manufacturing processes, with extremely small minimum sizes, it has become more and more difficult to predict which will be the differences in geometry between what you draw on the mask and what will be made on the surface of the semiconductor wafer, after photolithography and etching of the layer that must be patterned. In order to make the photolithography and etching processes more predictable, the design rules have become more and more restrictive, e.g. by allowing only vertical, horizontal and 45 degree straight lines, or only vertical and horizontal lines, or even on some layers only traces parallel to a certain direction. Moreover there are a lot of extra constraints, e.g. the need to place dummy patterns around those that are useful, because the same pattern in a different neighborhood will be distorted in a different way, which could be hard to predict.

deleted 5y ago

[deleted]

Dork1234 5y ago

I also thought 45 degrees is used to reduce ESD, provide the best use of die space, and reduce stress on the metal with high current. Maybe all of that is a myth? Any other angle doesn't have the same benefits.

picture 5y ago
Any-angle routing may actually be better for use of space and reducing stress. I sometimes get more traces packed around a bend with any-angle. And most polymide PCBs are any-angle or at least super rounded with teardrops, having sharp transitions of any type would act as weak points.[1] ESD really doesn't make sense, maybe you meant EMI or EMC? There's nothing particularly special about 45 degrees other than the ease of modeling [1]: Some macbook trackpad, note the polymide/flex substrate and rounded tracks. This isn't fully any-angle like what TopoR does though https://commons.wikimedia.org/wiki/File:Apple_MacBook_Pro,_model_A1278_-_trackpad_-_connector-8395.jpg https://commons.wikimedia.org/wiki/File:Apple_MacBook_Pro,_m...

marcodiego 5y ago

https://en.wikipedia.org/wiki/TopoR https://en.wikipedia.org/wiki/TopoR

deleted 5y ago
[deleted]
the-dude 5y ago
Parent is downvoted for only providing a link, but : TopoR is a free-angle PCB autorouter ( it has other tricks too ). It is of Russian origin and commercial software!

adrian_b 5y ago

It is not a question of aesthetic. In old integrated circuit manufacturing processes, with large minimum dimensions, it was possible to draw arbitrary curves without problems. Some of the software tools were limited to straight lines or even to straight lines only at certain angles, just because the limitation simplified the algorithms, but if one really wanted, it was possible to draw anything on the masks. On modern manufacturing processes, with extremely small minimum sizes, it has become more and more difficult to predict which will be the differences in geometry between what you draw on the mask and what will be made on the surface of the semiconductor wafer, after photolithography and etching of the layer that must be patterned. In order to make the photolithography and etching processes more predictable, the design rules have become more and more restrictive, e.g. by allowing only vertical, horizontal and 45 degree straight lines, or only vertical and horizontal lines, or even on some layers only traces parallel to a certain direction. Moreover there are a lot of extra constraints, e.g. the need to place dummy patterns around those that are useful, because the same pattern in a different neighborhood will be distorted in a different way, which could be hard to predict.