Improvement of chemical resistance of positive-tone photosensitive polyimide coatings in the electroless plating process

We found that positive-tone photosensitive polyimide (posi-PSPI) shows not to be compatible for electroless Ni/Au plating process which are used for Au micro bumping. In order to meet compatibility for the process, we improved chemical resistance of positive-tone photosensitive polyimide especially for electroless plating process. Changing of polyimide polymer structure is most effective to obtain chemical resistant for the electroless plating process. The obtained PSPI are useful for saving bumping process and reliable in forming pattern.