Enhancing adhesion performance of sputtering Ti/Cu film on pretreated composite prepreg for stacking structure of IC substrates

Successive pretreatments containing mechanical grinding, desmearing and O2/CF4 plasma were employed to modify the surface of polymer-based composite prepreg to improve the adhesion with sputtering Ti/Cu film. Surface morphology and roughness were characterized to find out the difference of microstructure change for pretreated prepreg. In addition, the variation of chemical bonding and surface wettability for pretreated prepreg were investigated for the possible explanation on the adhesion enhancement between Ti/Cu film and prepreg. The results indicated that the pretreatment of prepreg could lead to better adhesion performance of 6.54 N/cm between Ti/Cu film and prepreg, compared to the case for untreated prepreg with that of 1.77 N/cm.