After having spent 4 hours to hot air solder, multimeter probe, apply flux around the sort circuiting pads, re-hot air, re-probe and finally apply wick & iron to get rid of those shorts I am now concerned with possibly having overwicked them. I can't tell for sure if there is pin to pad connectivity and wouldn't know how to test for it. Also, I wouldn't want to go on soldering the rest of the board only to find out at the end that my no lead packaged chip is not working.
Is there any way I could test this connectivity for a LGA package? It does not expose its pins on the side, it only has bottom pins. I don't know if the multimeter probes are touching the solder joint or just the bare solderless pads underneath.
I tried the resistance to GND measuring method from this answer. My joints are a wreck... Aside from that, I can understand cases 1 and 4 below, but how about 2 and 3?
- DMM reading of 1.4 M - probably for the healthy solder joint
- DMM reading of 1.0 M - how so?
- DMM reading all over the place, or slowly decrementing, or slowly incrementing
- DMM reading out of range - probably no contact between the pin and pad