Surface tension keeps them stuck on as the solder melts. I have not
tried doing that with bigger components so I do not know what the
limit is.
One thing you do have to worry about with surface tension is
tombstoneing. That is when a small part like an 0402 or 0201 pops up
vertically while reflow soldering. It can happen when you do not get
the amount of solder paste even on both pads,the part was not evenly
placed over the solder paste or there is uneven heating of the board.
That is when it comes in handy to have a good quality soldering iron
and a magnifier to lay the part back down.
--- In Homebrew_PCBs@yahoogroups.com, "eeks123" <eeks123@...> wrote:
>
>
> > Tacky enough that I have populated boards on both sides at the same
> > time then stuck in the oven. The parts that went on the bottom side
> > were smaller items like 0402 chip capacitors, but they did not go
> > anywhere.
> >
> > Of course if you do that you will need to add feet to the board so it
> > is not resting on the bottom.
> >
>
>
> amazing! when solderpaste gets liquid components should drop.. that's
> a question i was making myself, is it possible to populate components
> on both sides when reflow-soldering? i thought you had to hand-solder
> components on the second side, if not, bad things would happen..
>