You can't do traces on the component side for a through hole board, no way to solder the pins, at least on some components. There is no fixture needed as I start with the bottom up and drill from the bottom as well. I am using single sided boards already, the copper is on the bottom. I'll check out the DRC tool thing, haven't looked into it at all. If I have to use a surface mount part, I put the component on the bottom so I can still use a single sided board.
Matt |