Noclean is hard to clean and may be conductive. I had problems in rf circuits even with my mega8 running at 8MHz. Just today I reworked 21 QFN's with water soluble flux and just swishing them in a tub of 140 degree water and drying the board they worked at 1 GHz. There was no problem washing the flux from under the part, it seems.
Brian
--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan <stefan_trethan@...> wrote:
>
> No-clean for me.
>
> I just don't see how I could get the water soluble out from under QFN
> packages and similar tight spots.
>
> ST
>