Are holes in the underfill always a sign of damage?

mbcontrol

Member
A general question:
Are holes in the underfill (see pictures) always a sign of damage?
Or do such holes also arise during the manufacturing process of circuit boards?

2021_0918_230808_hole_in_underfill_004.png2021_0918_230808_hole_in_underfill_005.png2021_0918_230808_hole_in_underfill_006.png
 

it-solve

Member
Looks like air bubbles from the manufacturing process no? I have seen damage like this once, but I could see burns around the hole
 
Top