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Published on: September 19, 2020
Soluble Perfluorocyclobutyl Aryl Ether-Based Polyimide for High-Performance Dielectric Material
Mingchen Jia1, Yongjun Li1, Chunqing He2
1Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032, People's Republic of China.
A new perfluorocyclobutyl (PFCB) biphenyl ether-based polyimide, PFCBBPPI, demonstrates exceptional low dielectric constant (k) value durability and water resistance. This advanced dielectric material maintains stable performance even under humid conditions, outperforming traditional polyimides.
Area of Science:
- Polymer Science
- Materials Science
- Dielectric Materials
Background:
- Dielectric materials require durable low dielectric constant (k) values, especially under humid conditions, to prevent performance degradation due to moisture absorption.
- Existing polyimides often suffer from increased k values when exposed to moisture, limiting their application in demanding environments.
Purpose of the Study:
- To synthesize and characterize a novel perfluorocyclobutyl (PFCB) biphenyl ether-based polyimide (PFCBBPPI) with enhanced low-k value durability and thermal stability.
- To evaluate the moisture resistance and dielectric performance of the synthesized PFCBBPPI under various humidity conditions.
Main Methods:
- Synthesis of PFCBBPPI polymer.
- Thermal analysis including glass transition temperature (Tg) and 5% weight loss temperature determination.
- Water uptake measurements and dielectric constant (k) analysis under different humidity levels.
- Contact angle tests and positron annihilation lifetime spectroscopy (PALS) to assess hydrophobicity and free volume.
Main Results:
- PFCBBPPI exhibited a high glass transition temperature (Tg) of 310.3 °C and a 5% weight loss temperature of 510.5 °C, indicating excellent thermal stability.
- The polymer demonstrated extremely low water uptake (0.065 ± 0.018%), the best recorded for polyimides, ensuring superior water resistance.
- PFCBBPPI films showed less than 2% increase in k value after 6 hours of moisture exposure and maintained k below 2.50 even after 2 weeks at 75% relative humidity, significantly outperforming Kapton.
- Hydrophobic nature and small free volume fraction were confirmed as reasons for the remarkable moisture resistance.
Conclusions:
- PFCBBPPI possesses outstanding moisture resistance and high durability of its low-k value, attributed to its hydrophobic characteristics and low free volume.
- The superior performance of PFCBBPPI makes it a highly suitable candidate for dielectric applications in both dry and humid environments.
- This novel polyimide offers a significant advancement for electronic components requiring stable dielectric properties under challenging conditions.
