High-Modulus Negative Photosensitive Polyimide for i-line

The novel negative-type photosensitive polyimide precursor to protect ELK for Flip-chip package was developed. High modulus was achieved by the rigid structure of main polymer, and film transparency was achieved to modify the side chain unit by tuning the ratio of particular non-acryloyl groups and acryloyl groups. This polyimide composition showed high modulus value (nearly 6.0GPa) and could pattern by i-line. This polyimide composition also showed high chemical resistance property. Thus, this polyimide composition will be suitable for Flip-chip package to protect ELK as surface protective and interlayer dielectric film.