Hello Friends
I'm sorry if this a silly question.
When drawing a trace between two smt components, I need to change layer from top to bottom and then back. When I do this in PCB layout, I get via holes automatically placed at the transition point.
My question is simply this. Are these via holes required or should I delete them from the layout? I am designing with surface mount devices.
Thank you
John McKenney
Brand new interactions and interfaces. 
Easy to use and quick to get started. 
Think about it: without vias or the leg of a through hole component, how do you make a net routed as a track on the top layer connect to the same net routed on the bottom layer?
So yes, you need vias.
:)