Recent Progress of Photosensitive Polyimides

Photosensitive polyimides (PSPIs) have been attracting great attention as insulating materials in microelectronic industry, and can be directly patterned to simplify processing steps. This article reviews recent works on development of PSPIs. After brief introduction, a typical PSPI formulation was described in comparison with a conventional method, followed by major strategies for the patterning. A number of recent reports on PSPIs were then divided into two major terms; positive-working and negative-working, and highlighted with focus on their chemistries up to pattern formation. In addition to the photosensitivity of PSPIs picked up in this review, other important subjects such as low-temperature imidization and low dielectric constants were also discussed.