[Eliyaooo]

Hello to All,
I'm looking for a method for improving adhesion between cured epoxy thin film(c-staged) to other b-staged epoxy thin film (Not fully crosslinked),any suggestions? Adhesion bonding performed under heat pressing conditions.
Maybe any good reference?

Thanks.

[Polytriazole]

Can you mechanically roughen the surface of the C-toughened epoxy first?  Increased surface area should increase bonding.  You could also chemically (extreme pH or oxidation) roughen the surface as they often do for poly(tetrafluoroethylene) films and sheets.

You can also try swelling both layers (b and c type) with a mutual solvent to try and get them to interpenetrate before finalizing the curing process.  Or, with the second epoxy layer, swell the fully cured layer with one epoxy component before adding a layer of the other. 

I think the key here is either maximizing the interface between the two epoxy layers, or allowing them to chemically interpenetrate.