Adhesion of moulding compounds on various surfaces. A study on moisture influence and degradation after high temperature storage

It is well known that high temperature storage can degrade moulding compounds for chip encapsulation to such an extent that the adhesions to surfaces like copper (lead frames) or polyimide (chip coating) decreases drastically causing delamination. During normal operation of electronic components, heat is generated locally (bond wire, or chip surface) degrading the moulding compound and reducing the adhesion which in extreme cases can destroy the metallisation or bond wires.