Delamination is the splitting apart of layers inside a board: glass from resin, prepreg from core, or copper from laminate. It shows as blisters or bulges after reflow or rework, often when absorbed moisture turns to steam, when the board passes its decomposition temperature, or when lamination was poor. Acceptance criteria tolerate only small, isolated blisters that leave conductor spacing intact, because spreading delamination breaks traces and plated holes and opens paths for leakage.
Board blistered next to the BGA after the third rework cycle, that's delamination, scrap it.
Also heard as
- delam
- layer separation
Related terms
Measling
White spots or crosses inside a laminate where glass fibers have parted from the resin at weave crossings.
Bake
To heat bare boards or moisture-sensitive parts in an oven to drive out absorbed water before soldering.
Tg
Glass transition temperature: the point where a board's resin turns from rigid to rubbery and expands much faster.
Popcorning
Cracking of a plastic IC package in reflow when absorbed moisture flashes to steam, sometimes with an audible pop.
Same word, different worlds
Separation of a coating from its substrate or of one coating layer from another.
Concrete & CementA surface layer that has split away from the concrete below it, found by the hollow sound it makes when tapped.
NonwovensSeparation of the layers of a laminate or multilayer nonwoven, such as an SMS or a film composite.