Applications of newly developed positive photosensitive block co-polyimides to CSPs

Meeting the challenging market-defined needs of CSPs (chip sized packages) industry requires a new substrate technology that provides higher I/O densities, higher performance, thinner and lighter packaging structures than previously available solutions. In this paper, the first applications to CSP interposer (CSP-IP) processes by newly developed positive photosensitive block co-polyimides (PPI), which P I R&D Co., Ltd. of Japan has commercialized recently, are discussed.