Re: [SeattleRobotics] Soldering down TQFP packages
On Fri, May 26, 2006 at 12:34:41PM -0700, Larry Barello wrote:
> I think I might have just discovered a clever way to solder down large pin
> count TQFP packages.
> I was replacing a 64 pin TQFP mega128 processor. I cut the leads with my
> trusty dull exacto knife, daubed on some no-clean flux, removed all the lead
> ends (and made the pads all shiny). Then some more flux and tack the chip
> down on one end by soldering one pin.
> In soldering down the opposite corner, I made a big goober of solder on a
> couple pins so I pulled out some stranded wire to make a solder wick. And
> when I wicked off the blob I noticed that about three or four pins looked
> perfectly soldered down.
> Then I loaded up the wick with solder, pressed it up against the pins/pad,
> heated until the solder melted and then dragged the wick across all the
> pins. WOW. Beautiful, shiny, just enough solder to fill in all area
> between pad and pin, no hint of bridging, joints. It looks just like it did
> the day it came out of the oven (except for a bit of no-clean flux on the
Is this kind've what you're describing? This is how I do the
ATmega128 TQFP. Takes only a minute or two and I never have bridges:
Click on the image image of the ATmega128 which will play a movie of
the technique. It's really very easy!
Also, further down the page you'll find an easy way to SMT solder even
the tiniest flecks of SMD caps and resistors.
I _much_ prefer to solder SMT by hand than through hole. Once you do
a few boards, it's much quicker and more reliable. No leads to trim
or fight with trying to get them to fit into the holes.
ATmega128 based MAVRIC controllers