Over the last few years, low-temperature curing polyimide (PI) has turned out to be a significant target for the advanced electronic package. Although the curing accelerators have been confirmed to be capable of significantly decreasing the curing temperature, their effects on properties have not been comprehensively examined. In this study, polyamide acid is synthesized by pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA), and the process of low-temperature imidization is investigated by introducing six accelerators, i.e., quinoline (QL), isoquinoline (IQL), 2-methyl quinoline (2-QL), 4-methyl quinoline (4-QL), 8-methyl quinoline (8-QL), as well as 5,6,7,8-tetrahydroquinoline (THQL). As revealed from the results, the polyimide films formed using 4-QL and QL have exhibited prominent mechanical, thermal, and electrical properties. For the PI-4-QL, the tensile strength is 151.87 MPa, elongation-at-break reaches 161.36%, and the weight loss of 5% is observed at 533 °C; for the PI-QL, the tensile strength is 134.82 MPa, elongation-at-break reaches 145.16%, and the weight loss of 5% reaches 545 °C. As indicated from the results, the boiling point, acidity and molecular structure of the low-temperature curing accelerators show significant effects. Lower acidity and steric hindrance between the accelerator and amide bond facilitate the low-temperature imidization of polyamide acid. Furthermore, the as-prepared low-temperature cured PIs of 4-QL and QL would exhibit wide applications in advanced packaging industry.

中文翻译：

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固化促进剂对低温酰亚胺化聚酰亚胺的综合性能研究

在过去的几年中，低温固化聚酰亚胺（PI）已成为高级电子封装的重要目标。尽管已经证实固化促进剂能够显着降低固化温度，但是尚未全面检查其对性能的影响。在这项研究中，聚酰胺酸是通过均苯四甲酸二酐（PMDA）和4,4'-二氨基二苯醚（ODA）合成，并且低温酰亚胺化的过程中，通过引入6个加速器，调查即，喹啉（QL），异喹啉（IQL），2-甲基喹啉（2-QL），4-甲基喹啉（4-QL），8甲基喹啉（8-QL）以及5,6,7， 8-四氢喹啉（THQL）。从结果可以看出，使用4-QL和QL形成的聚酰亚胺膜表现出突出的机械，热和电性能。对于PI-4-QL，抗张强度为151.87 MPa，断裂伸长率达到161.36％，在533°C下观察到5％的失重。对于PI-QL，抗张强度为134.82 MPa，断裂伸长率达到145.16％，失重5％达到545°C。从结果可以看出，低温固化促进剂的沸点，酸度和分子结构显示出显着的效果。促进剂和酰胺键之间较低的酸度和位阻有利于聚酰胺酸的低温酰亚胺化。此外，所制备的4-QL和QL低温固化PI将在先进包装行业中显示出广泛的应用。