QFN56 Footprint

[ime95mos]

What's the easiest way of creating a QFN 56 Footprint with a big center pad beneath that needs to connect to 25 vias to ground(?)

[lacy]

Here's an idea. Not sure if it will work for you. Create your footprint with your pad. Make sure it is it is grounded in the netlist when placed and then create a power plane on the ground. This should automattically hook all grounds to it without having to run 25 lines.

I hope this is what you were needing. If not let me know and maybe I can come up with something else.

[ime95mos]

Would you recommend using the wizard?

[lacy]

You could try the component wizard. This would allow you to modify an exixsting footprint style to your current footprint. You will probably still end up having to add pads to it to get the number you need especially the pad/pads underneath the IC.

The other creation method is a little more complex, but doable. If you need to know more info about both techniques I would recommend carefully reading Ultiboard's manual and the tutorials on NI's website.

I hope some of this was of some use.