Nah, doesn't fit.
If i heat with hot air from above the powdery stuff must be hotter than
the board.
ST
On Mon, 21 Nov 2005 21:46:59 +0100, Alan King <alan@...> wrote:
>
>
> Think of having your board right at the melt point, and taking a solid
>
> lead pencil and writing on the traces. Pencil stays solid, but where
>
> you're touching the traces is melting. Traces are above the melt temp,
>
> but you're only getting melt when you make it touch. For sure it is
>
> melting some, just not a lot. Remember it takes a lot more energy for
>
> the phase change, so right near the melt temp you'll melt the surface
>
> but not have near enough extra heat to melt the rest of the solder
>
> balls. Might also be doing something with the flux at a higher temp, as
>
> someone else noted recently it stays on much longer just at the melt
> temp..
>
>
> Think of how you draw on your iron tip with solder, as the iron is
>
> just heating up, leaves a nice shiny path. And won't melt the rest of
>
> the solder very fast yet, because it doesn't have enough extra heat.
>
>
> Things well above the melt temp uaually oxidize much faster than
>
> things right at it, part of the reason a temp controlled soldering iron
>
> is a good thing too..
>
>
> Alan
>