Baked not fried chips.

[fanie]

Sorry, I forgot to mention.

We don't add solder paste for soldering those fine pitched jobbies, the solder being little balls (check with a microscope) cause shorts between the pins and you'll have to rework under a microscope. The PCB's we get come with the pads soldered (tinned) and is then cleaned with a hot air knife, so a tiny amount of solder is still left on each pad. To solder these use only flux on the footprint, be aware if you handle the chips by hand and the pins gets bent it's back to the microscope yet again.

[Bruce]

NOTE: The Zephyrtronics' hot-air soldering system I mentioned above has been sold.

[Ron Marcus]

Just an update... I've been using the new 16F690 in the (Yikes!) QFN (QLP)package. The convection oven works great, but I tried a technique someone may have posted here. I fluxed the board and IC pads, aligned it with a tweezer, and used a soldering iron with a relatively large ball of molten solder on it. Of course, the fine solder traces shorted with solder here and there as I moved the iron around the chip. When I was sure all pads and traces were coated with solder, I placed some very fine solder wick against the chip where the pads meet the PCB traces. I heated it with the solder iron, and low and behold, it pulled off all of the extra solder! I had the IC perfectly soldered in under a minute! If you haven't tried this technique, I highly reccomend it. I am actually looking forward to the next fine pitch surface mount build I have coming up.

Cheers,
Ron