Hell, It ain't that exciting but it sure got my attention. I asked Steve,
again, to post three pics on his outstanding site. The first shows the
overall view, top down of course, of solder columns at 10x. The second has a
bug in it at 60x. Probably one of those little brown "lady bug" like
creatures infesting us all (damn they're bad, aren't they?). The third is a
more slanted view showing the "columns" that seem partially formed solder
joints that didn't take.

The strange thing, to me, is the CSP/DSP parts fell off the board on
arrival. However, a large ceramic BGA on the same board exhibited perfect
solder ball squat and joint formation.

My question is how do these columns form into almost perfect structures
without reflowing around and into the balls? Eutectic means, I'm told, going
from a solid state to a liquid state without going through a plastic state.

Again, how did this occur without reflowing and effecting a solder joint?

MoonMan

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