Latest Technology of Stress Buffer Material for Semiconductor Application

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.