DEVELOPMENT OF HIGHLY RELIABLE LOW TEMPERATURE CURABLE PHOTOSENSITIVE POLYIMIDE

Positive tone photosensitive polyimide having low temperature curability and extremely good Cu migration was developed. In order to develop, we investigated the effect of polyimide structure and photosensitive method. We observed the polyimide structure affected the Cu migration resistance mainly. Polyimide having soft segment shows better Cu migration resistance. Soft segment unit in polyimide back-bone may add better flowability to cover Cu without any damage to show better Cu migration resistance. In addition, void formation was observed between Cu and polyimide layer. The void was formed due to Cu oxide diffusion at high temperature storage. To suppress the void generation, we found some anti-oxidation method is effective. In order to obtain fine pattern formation as well as high Cu migration, we developed positive tone photosensitive polyimide coating and B-stage sheet using soft segment in the polyimide with thermal cross linker.