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?
I would be reallllly careful using a heat gun - that can very easily destroy the big BGA chip on that board.
If I had to guess, the pads aren’t properly cleaned and also your iron’s tip may not be cleaned and tinned properly. Ribbon cable pads aren’t very small, so solder should melt onto them and stick quite quickly - you don’t have to heat a board long for that to happen.
Also, the metal shield you’re referring to is exactly that - an EMI shield, usually. A big piece of metal that is grounded and meant to help prevent interference. They’re typically made of steel, so solder usually does not stick directly to them! You’d have trouble soldering wires right onto an EMI shield unless it happened to be copper, which again, it likely is not.
I just brought the shield up as a point of reference to describe what I’m referring to. However, in the videos and posts I’ve seen for the chip I have, they all seem to have some portion of solder touching the shield.