Not a problem, i have done two boards now with thin QFN (32 and 24 pin i
think both 0.5mm spacing).
The thermal pad is a bit of a pain though, since one IC needed quite a bit
of heatsinking. Can't plate vias so i ended up making a large hole and
filling it with solder. Not ideal but works. Maxim suggests to make a
large via/hole if you don't need heatsinking, then you can take it off
with a soldering iron by heating through there.
I solder them by smearing some SMD paste on the board and using hot air
after careful placement. Works great, bridges can be cleared with solder
braid, excess solder is pressed out from under the case and beads up at
the sides. Make the pads longer so that they extend a bit straight outside.
You can even reflow them by putting a soldering iron with a large tip and
a good sized ball of solder against the top. It will heat through the case
and melt the solder underneath. Probably useful if there's a bad
connection.
But, what good is this all when you can't find the part because it got
lost in the bubbles of the antistatic foam? They already have to put some
components in SMD reel strips to keep them. Stupid people! why can't they
use DIL?
ST
On Wed, 25 Jan 2006 16:24:15 +0100, Anthony <toftat@...> wrote:
> After great success with through hole boards, I have a new project
>
> starting, one of the components I want to use is the nRF905 from nordic
>
> semiconductor, the '905 is only available in a QFN package which
>
> doesn't seem to be the most hobbiest friendly of formats. As far as I
>
> can tell there are no legs on it...
>
>
> Is it possible to hand solder one of these, filling in the gap? do they
>
> make sockets for them (I have found prototype sockets on line but $400-
>
> $500 each they are a bit out of budget)
>
>
> Any ideas folks?
>
>
> Anthony
>