The boards arrived on Saturday. I finally had time to sit down Monday night and begin populating one. Full disclosure, this was my first time doing and fine pitch or SMT work. I began by doing a full electrical test on one of the boards, which it passed. I then decided to start with the TM4C since it was going to be the most difficult.

I cleaned the pads with IPA 99 then carefully aligned and taped down the IC with Kapton tape. I put down some liquid flux along one edge, put a blob of solder on my iron and dragged the tip across the pins. That worked well, with the exception of a few bridges that were easily remedied with solder wick. I repeated this three more times all of which had good success except for the last row. Evidently while dragging the iron across the pins I must have pressed too hard because I had bent one of the pins over into its neighbor, to which it was soldered.

I tried flowing solder over it again while bending it back into place with tweezers with no success, except to bend it too far and into its other neighbor. I was left with desoldering the whole IC and straightening the pin, to which I opted to start on another board instead. This time everything went on just fine. So I now have one fully populated board.

With fingers crossed I plugged in the USB connector. The LED did not light up. I checked for the 5V USB rail. It was there. I checked for the 3.3V regulator output. It was not there. What could possibly be wrong. Did I ruin the component while soldering it down? I decided to take another look at my schematic , end eventually took a look at its datasheet. And there it was, staring me in the face. The part & footprint that I had place in the schematic was the wrong one. I had simply renamed it to be the part I was actually using, which of course had a different pin assignment.

So now I'm off to fix this issue with some deadbug style soldering. I've fixed the schematic locally, but still need to commit and push it to the git repo.

Lessons Learned

1. Practice soldering similar components before attempting it on your actual board.
2. Double check your datasheets and schematics before sending your boards to the fab shop.