Low temperature curing polyimides with covalent-boned 5-aminobenzimidazole

Abstract Polyimides (PIs) with remarkable mechanical, thermal, dielectric properties have been extensively employed in electronic package of integrated circuit industry. However, PI is imidized at high temperature (>350 oC) traditionally, which limits its application in thin-film transistor and fan-out wafer level package (FOWLP). In this work, active curing catalyst of 5-aminobenzimidazole is introduced in covalent bond to get a low temperature curable polyimide with superior comprehensive properties. The results prove that PI-3 can be imidized completely at 200 oC in 2 hours and the imidization index could be as high as 1.03. Besides, the PI films exhibit excellent thermal stability of which the temperature for 5% weight loss is as high as 526 oC and glass transition temperature is 428 oC which is obtained by dynamic mechanical analyzer. Moreover, the tensile test shows the tensile strength of PI-3 is 91 MPa and elongation at break is about 15%. All these results prove the superior performance of the low temperature curing PIs, showing great potentials in the advanced package in the FOWLP and the others.