On Sun, 29 Feb 2004 15:06:12 -0800, John Miles
wrote:

In article ,
says...
"Carl R. Stevenson" wrote in message
...

The packaging is not "impossible" - it just takes some different
techniques
to do the
soldering - read the QEX article on a DDS/PLL synthesiser in the latest
issue of QEX

I'm pretty comfortable with SOP's and can get along with a TSSOP's, although
I can't say I like it. In that article, he used TQFP's which, although I
haven't yet had the need, I suspect I can deal with. I use the same
technique for TSSOP's that he describes in the article.

Actually, the 16-pin PLL chips are TSSOPs, while the AD9852/AD9854
packages I used are considered "LQFP" packages. These are a little
thicker than TQFP but are otherwise pretty similar. The DDSes have the
same spacing between pins as the TSSOPs (0.5 mm) but more of 'em (80).


But when I tried to order samples of 9854's the other day, the only choice
was BGA's. I have no clue how to deal with them. Yeah, solder paste and an
oven MAYBE, but without machine placement seems like a crap shoot.

That's not good news. BGAs really *are* the end of the world for
homebrewing as far as I'm aware. I have not heard of any techniques for
soldering them by hand.


I've done a fair number by hand @ work. They self center nicely, and
don't really require any solder other than the balls. Just some fresh
liquid flux and a heat gun, and a little practice. They do self center
nicely. You can also reflow in a toaster oven if you really want to.
(Not the one in the kitchen, please!).



Dave