Allegro PCB Design Tutorial

Working with Vias

It is alwars a good idea to have at least two different kind of vias - smaller vias for signal routing and bigger size via power power and ground signal routing. The bigger vias increase the current carrying capaity but they occupy more space and are potebtially not good for signal integrity purpose. Vias inside the BGA area have to be very small in order to fit in the small space.

Once you have defined two or more different types of vias, you need to assign them to different nets. This is done using the Constraint Editor. The steps involved are

- Go to Constraint Manager ,select Physical, Physical Constraint Setup.
- Select the power nets and double click the cell under via. Assign the bigger size via for the power nets. Repeat it for all the power nets.
- If any signal via need bigger or special via assign it accordingly.

Once you do that, the right vias are automatcally assigned as you route and drop vias. You should assign constraints before you start routing. It makes your life much easier.

Her is the youtube that explains the whole thing.

We have created youtube for it.