I’m trying to solder on the flex cable for a PicoFly. I’ve added some solder to the bottom two points that are touching the metal surrounding the CPU. However, I seem to only be making a bigger and bigger ball of solder when trying to melt it. I’ve upped the temperature on my iron but that doesn’t seem to be doing anything. What am I doing wrong?
Flux is important. If you aren’t using flux core solder, that could be part of the problem. Flux cleans the surface and it’s easier for the solder to stick. (Flux also comes separately and it a wide variety of formulations.)
If flux isn’t the issue, then it absolutely is heat. I tried to Google for a picture of the “metal surrounding the CPU”, but I couldn’t find one. From your description, it sounds like that metal is still sinking too much heat away which also wouldn’t allow solder to flow.
Soldering to larger metal pieces is always a challenge. You likely need a lot more heat applied for the shortest time possible. Another option is to heat up the entire board with a hot air gun first, but I suspect that is not an option for you.
Big soldering tips can be used to flow as much heat into the part as fast as possible before the heat gets a chance to spread out.
(A picture of your problem would be a nice-to-have. I am not familiar with your exact components, but I solder things quite a bit.)
The metal shield maybe? There’s probably a word for it but I mean the bit the white arrow is pointing. The board in this picture isn’t the same board, but I’m not able to grab a picture of the board in question at the moment. I am using flux, I just hadn’t mentioned it.