Latest Technology of Stress Buffer Material for Semiconductor Application

Abstract

Because polyimide (PI) / polybenzoxazole (PBO) materials make semiconductor reliability drastically improved, they have been applied to stress buffer layer for over 30 years. Their purpose used to prevent IC chip from mechanical attack by molding compound filler. In recent years, PI / PBO are required to perform stress relief. In addition to this, they have come to be used as dielectric layer for Cu redistribution layer application as semiconductor package type changes. Therefore, various properties and balanced performances are necessary for PI / PBO materials. This paper reviews latest PI / PBO technologies in semiconductor application.

Effect of Cross-linker on Photosensitive Polyimide to Achieve Full Imidization and Lower Stress for Good Reliability

“…Due to the excellent thermal, mechanical and electrical properties as well as good chemical resistance, polyimide (PI) and poly(benzoxazole) (PBO) have been widely used as stress buffer coatings and redistribution layers (RDL) for packages that have copper re-routing distribution layers to improve the reliability of semiconductor devices [1,2].…”

Low Stress, High Modulus, Photosensitive Polyimide

“…Due to their excellent thermal, mechanical and electrical properties as well as good chemical resistance, polyimide (PI) and poly(benzoxazole) (PBO) have been widely used as stress buffer coatings and cover coating films for wafer level chip size packages that have copper re-routing distribution layers to improve the reliability of semiconductor devices [1,2]. In addition, to simplify opening connection via or bonding windows, photosensitive PI (PSPI) and PBO (PSPBO) have become popular due to the elimination of photo-resist processes [3][4][5].…”