Disturbed Solder Joint
What is a disturbed solder joint? This is an interesting and difficult question to answer. To simplify, the formation of a disturbed solder joint happens during the solidification process of the alloy. When alloys are in their molten state their surface appearance can be easily affected by outside mechanical influences.
Major cause for the formation of a disturbed solder joint is usually due to some outside vibration of the assembly during the cooling process. Another is easily caused by operators. Reaching into a system and removing an assembly prior to the solder joints ability to solidify, or the PCB transferring from one conveyor to another while the alloy remains in the liquid state. It is the movement of the assembly while the alloy is in the liquid state that creates a disturbed solder joint.
If you solder a disturbed joint by mistake, it doesn’t matter because the joint can be repaired by reheating and allowing it to cool undisturbed. in addition, you can prevent it by prepare properly which includes immobilizing the joint and stabilizing the work in a vise.