6 Jan
2008
6 Jan
'08
2:31 a.m.
On 1/6/08, Chuck Guzis <cclist at sydex.com> wrote:
I tried my hand at soldering a 68 pin TQFP using the
"push the blob
down" method described on a YouTube video. It worked pretty well,
but for one side of the QFP, where there were several solder bridges.
The bridges were easy to clean up using a bit of solder wick. About
the only thing I'd do differently is to tack down two corners rather
than one--it's easy with just one corner tacked to displace the
package slightly with just the pressure of the soldering tip.
I didn't try the "flood and suck" method.
I used the largest chisel tip on my old Weller TC201 iron, a PTC6--a
blunt tip suited to soldering #14 wire, but it holds a lot a solder.
Thanks all for the suggestions,
Chuck
I had a job a few years back that involved a LOT of soldering SMT
parts onto circuit boards. I had to put in a whole lot of 64-pin
(think it was 64...) chips over the course of a summer, and I quickly
found out my favorite/easiest method.
It's best if you can work under a microscope; we had binocular
microscopes that were perfect under low magnifications. After placing
the board under the 'scope, I'd apply copius flux, then tack down two
corners. Then I'd swap all the pins with flux again. Next, I'd take my
rather fine-tipped soldering iron, get a blob of solder on the tip,
and quickly swipe it down the pins along one side. Inspection would
reveal that almost all the pins now had very nice fills and very few
were bridged. Any bridges were very easy to fix, usually requiring
just a quick swipe of the soldering iron.
Basically, the biggest aids to doing this are having a decent
microscope and a fine-tipped soldering iron. With those, you can
easily solder in dozens of these guys.
John
--
Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn