Popcorn effect

[Jane11]

What is popcorn effect ?

Components can absorb humidity from air
and if we apply big heat on these
parts humidity inside don't have enough time to evaporate and starts to make big pressure
that causes mechanical damage of affected parts. When soldering BGA chips it is a well known problem.
What method do you use to avoid the popcorn effect?
Thanks for the feedback

 

[ClydeCrashKop]

Digikey packs surface mount components in a sealed bag with desiccant. The label says not to open it until you are ready to use it.

 

[crutschow]

Where I worked, they baked the multi-layer PCBs in an oven for a day or so to drive out all the moisture otherwise the plated feedthroughs would sometimes delaminate from the heat of soldering. Don't remember what temperature they used but obviously it was safely below the boards maximum operating temperature.

 

[4pyros]

yep preheat
Even wave solder machines use preheat.

 

[Cicero]

Yeah, where I work we bake certain components, like some caps, IC's, pcb's etc. Again, I'm not 100% sure on the temperatures, but there are general standards for this kind of thing.