21 Dec
2007
21 Dec
'07
5:26 p.m.
Al Kossow wrote:
Two approaches that I've seen for conventional
soldering iron
mounting involve what I'll call "flood and suck" that involves
covering all of the leads on one side of the QFP on the PCB with
solder and then using a solder "sucker" (such as a Soldapullt) to
remove the excess.
The other approach uses solder wick (solder removal braid), laying
the braid over the QFP leads and PCB and heating and applying solder
*through* the braid to the leads.
--
I've used "flood and wick" successfully applying liquid flux before
the "flood".
I suspect soldering through braid accomplishes the same thing.
I've had success with QFP packages here with the
flood/wick/"spot"method.
Coat both parts with solder liberally while separate, and use wick to
take off all excess.
Then, place part on pads and use a fine tip weller tip to heat each pin
separately, pressing it down just a bit.
You can also suck off the excess in the first step, I had wick handy.
After a few tries, you learn how much solder to leave on. I like my
approach (trial and error), as it keeps the amount of time heating the
IC to a minimum.
Jim
--
Jim Brain, Brain Innovations (X)
brain at jbrain.com
Dabbling in WWW, Embedded Systems, Old CBM computers, and Good Times!
Home: http://www.jbrain.com