Application for WLP at Positive Working Photosensitive Polybenzoxazole

摘要

A positive working photosensitive polybenzoxazole (PBO) for use as a semiconductor surface coating material has been developed. This material has been widely used as a buffer coating to protect electrical circuitry on 1C chips in the semiconductor market. We have now developed a new positive working photosensitive PBO for Wafer Level Packaging (WLP). These cured PBO films have very low water absorption and low dielectric constant in addition to high adhesion to a wide range of substrates including SiO{sub}2, etc. Additionally, the patterned profile of the developed and cured film has the desired taper shape, which makes these materials suitable as the interlayer dielectric film for WLP.