Stats

More Content

Full round shape and route keepout problem

soll

There is an issue that I encounter quite often when using full round shapes. As you can see in the images below, the shape (green) is drawing some kind of fillets in the edges of the route keepout shape (pink).
This does not happen every time. On the second picture, you can see that the shape is not generating copper inside of the route keepout.
Both images are 0603 capacitors (our footprint has a route keepout between the pads). Both GND shapes have the exact same parameters (I copied the shape with no error to create the shape with an error). Orientation of the component doesn't change anything. I tried updating the shape, updating all shapes (from DRC window), updating DRCs, I did a DBdoctor check, I tried changing constraints...

I am using Allegro 17.2

Bad Keepout

Good Keepout


Why are shapes randomly filleting inside route keepout ? How can I prevent that ?

Thank you.

  • SandeepVarrier
    +1

    Did you try using acute angle trim control in shape parameters > Void Control> Acute angle trim control >Full round.

    can you also try using the variable “shape_full_round_expand_rko” under Setup > User Preferences > Shape > General.

  • soll
    0 in reply to SandeepVarrier

    hello, yes the shapes are Full Round. The problem isn't there when using the other "acute angle trim control" options. But our customers don't want sharp angles on the edges of the shapes so I use the full round option.

    I tried the User pref setting you provided and it works ! Thank you, didn't thought about checking the User preferences for that kind of thing.

Cadence Guidelines

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.