Types and Research Progress of Negative Photosensitive Polyimide

Negative photosensitive polyimide has become an indispensable material in the field of microelectronics due to its excellent thermal, mechanical, and dielectric properties. Based on the structure and synthesis process of negative photosensitive polyimide (PSPI), it can be classified into ester-based PSPI, ionic PSPI, chemical amplification PSPI, and self-increasing sensitivity PSPI. This paper provides a comprehensive comparison of the characteristics and advantages and disadvantages of different types of negative photosensitive polyimides, as well as their corresponding research progress. With the highly integrated microelectronics technology and the development of fan-out wafer-level packaging technology, higher requirements have been put forward for negative photosensitive polyimide materials, such as lower dielectric constant, lower coefficient of thermal expansion, and lower curing temperature. Therefore, this paper further introduces the different modification methods and microscopic mechanisms of negative photosensitive polyimide materials, and compares and analyzes the advantages and disadvantages of various modification methods, so as to provide a theoretical basis for the design and development of high-performance negative photosensitive polyimide materials.