A novel photosensitive polyimide: a polyimide containing the hydroxytriphenylamine structure with diazonaphthoquinone

A novel photosensitive polyimide based on a polyimide containing the hydroxytriphenylamine structure (HTA-PI) and 2,3,4-tris[1-oxo-2-diazonaphthoquinone-4-sulfonyloxy] benzophenone (D4SB) as a photoreactive compound has been developed. The HTA-PI was prepared by the ring-opening polyaddition of 4,4'-hexafluoroisopropylidenebis(phthalic anhydride) (6FDA) and 4,4'-diamino-4 "-hydroxytriphenylamine (DHTA), followed by thermal cyclization in refluxing N-methyl-2-pyrrolidone (NMP). The resulting polyimide film showed excellent transparency to 436 nm light. Photosensitive polyimide containing 30 wt% of D4SB showed a sensitivity of 800 mJ cm(-2) and a contrast of 0.8 when it was exposed to 436 nm light followed by development with 5% tetramethylammonium hydroxide (TMAH) aqueous solution at 45 degrees C.