nRF51822 2 Layer Layout

[Mike McCormack]

I have been looking at the nRF51822 for a project, and have looked at several designs available on the web for reference (I prefer to plagiarize working stuff rather than invent new errors myself.) When comparing the Nordic layout recommendations and the layout of the BBC Micro:Bit I am wondering just how much leeway there is in working with the part. Looking at the Micro:Bit

I see they have shrunk the center pad considerably, routed signals under the part, used very long power feeds and violated a couple other "rules." The press releases indicate Nordic worked very closely on the design, so I was hoping to get some insight on the real design rules and / or feedback on the design practices used.

Cheers

Mike

[Mike McCormack]

This is obviously a combined plot, but the copper layer is definitely one of the elements as traces and vias are shown. There is clearly routing and vias where the part's bottom pad should be.

[Dave_couling]

Sorry didn't mean to click answer.

Yes the copper layer is there since there are traces. Still can't tell the size of the Solder Mask opening nor the paste mask. It is likely fine as long as there is a solid contact to the Ground pad. The only real difference between the a smaller one like the one in the photo and the recommended size is thermal relief if i'm not mistaken. Once the connecting pad-size gets large enough.