Ground in 2 layer boards

[danT]

On 2 layer boards, I have seen many engineers define ground planes on the entire top and bottom layers. Then they proceed to place and route the components. They put a lot of vias to connect top and bottom ground planes. Is that a good practice? They used Eagle.

[qdrives]

Yes, and do not leave islands.

[robertferanec]

Normally I try to keep bottom as solid as possible and only use very short tracks there. If you like, have a look at our 28pins open source project layout:

https://www.28pins.com/

Also, this is not direct answer to you question, but I hope it will help.

Generally, unless the board is super simple or it is manufactured in big quantities, I would never use 2 layer again - a lot of problems. Today, 4 layer PCBs are cheap (e.g 8 USD for 100x100mm is very cheap):