Soldering Practice TQFP100

I was cleaning up my lab earlier today and found some old soldering practice boards and thought I’d share.  This was from about six months ago when I needed to solder an atmega 2560 chip for a robot controller.  I didn’t have time for mistakes so I sent it out to be made by Macrofab because I’d had a bad experience with the same chip in the past. There were some delays from Macrofab and I don’t like having to outsource things so while I was waiting I ordered six test boards from OSHpark and some chips and got to practicing.  In this case the test chips were some random audio chip which at about $1/chip was the cheapest chip in a TQFP100 package (0.4mm pitch), which is the same as the ATmega2560.  I messed up a couple of pins on the first two boards but the third time was the charm and all of them after that were perfect.  The whole thing was much easier than expected and led me to try and figure out what went so poorly before.  Turns out the previous attempts had been with a flux pen that was several years past expiration; such a silly mistake to ruin a board.  Anyway, there you go with my little trip down memory lane.