[sdiy] Hand soldering TQFP packages

[Seb Francis]

Thanks for the links John.  I don't think I'll be going as far as 
solder-screening - I'm only making very small quantity boards (usually 1 
offs).  In the past I've just use a soldering iron to manually solder 
and have had good success with 0.8mm pitch parts, but I felt like I was 
getting near my limit!

I've thought about tinning the PCB pads then using a hot air paint 
stripper gun to reflow the solder (this works well for de-soldering, but 
I haven't tried it for soldering).  And the hot-plate/skillet method on 
sparkfun also looks like a really good way.

Regarding the need to tin (or apply solder paste to) the pads first: I 
guess this depends on the PCB manufacturing process - I've used some SMT 
to DIP adapters in the past where it was only necessary to apply a flux 
pen, then place the component on and heat each leg (there was already 
enough solder on the PCB to make a good join).  But the lead-free PCBs 
I've been getting recently are very different to this - they have a 
matte almost white colour finish that definitely needs tinning (or 
solder paste) first.

Seb


John Luciani wrote:
> On 6/11/06, Seb Francis <seb at burnit.co.uk> wrote:
>
>> Anyone tried hand-soldering these 0.5mm pitch SMT packages?
>
> I have successfully soldered a few of MSP430F169 (64 pin QFP, 0.5mm 
> pitch)
> packages. You will get solder bridges between the pins which you can
> easily clean
> up with solder-wick. With a very fine tip, a lot of practice and a 
> steady hand
> you could probably do this size without bridging.
>
> If you are going to do a lot of these devices you may want to get a
> solder-screen
> and either a toaster oven or a skillet. There are couple of 
> application notes
> at www.sparkfun.com and the www.seattlerobotics.org
>
> (* jcl *)
>