The quest for more efficient and stable materials to support sophisticated electronic devices is reaching new heights, thanks to groundbreaking research focused on covalent organic frameworks (COFs). Recently, researchers have developed dual-linker COF films featuring record-setting properties such as ultralow dielectric constants and exceptional thermal stability, making them ideal candidates for high-fidelity signal transmission and high-temperature electromechanical sensing.
Integrated circuits (ICs) are at the heart of modern technology, powering everything from smartphones to advanced artificial intelligence systems. With the complexity of ICs rapidly increasing and components miniaturizing to nanoscale dimensions, there is growing concern over signal integrity—especially at high frequencies. Traditional low-dielectric materials have struggled to meet the new demands of technology. Recognizing this challenge, researchers turned to COFs, crystalline polymers with porous structures, which are known for their adjustable properties.
According to the findings published on January 22, 2024, the team synthesized COF films using interfacial polymerization techniques. By altering the ratios of the linkers—1,3,5-Tris(4-aminophenyl) benzene and tetrafluoroterephthalaldehyde—the researchers achieved highly functional materials. The resulting F30-TAPB-TPA-COF demonstrated remarkable performance with a dielectric constant of just 1.25 at 1 kHz and dielectric loss as low as 0.0015, significantly surpassing conventional polymer materials like polyimide.
The incorporation of fluorine was pivotal. "The introduction of fluorine enables us to effectively modulate the dielectric properties by adjusting the electron cloud density of COF films," the authors noted. This adjustment not only produced superior dielectric characteristics but also resulted in impressive thermal conductivity of 0.48 Wm−1K−1—essential attributes for efficiently dissipative thermal management.
High-frequency electrical signal transmission is another area where these COFs shine. When testing signal fidelity and transmission performance at frequencies up to 3 GHz, the F30-TAPB-TPA-COF exhibited minimal degradation and crosstalk. Specifically, it showed over six times less power decay compared to polyimide films, making it exceptional for applications requiring high fidelity.
But what does this mean for the future of electronics? The material’s capacity to maintain approximately 90% of its output voltage even at elevated temperatures (up to 120 °C) highlights its potential application for high-temperature electromechanical sensors. This capability sets it apart from traditional materials like fluorinated ethylene propylene (FEP), which only sustain around 80% of their voltage output under similar conditions.
The flexibility and elasticity of the F30-TAPB-TPA-COF also offer advantages for innovative designs. The COF film can withstand up to 10,000 bending cycles without any significant change, making it suitable for flexible electronics—an increasingly relevant area as wearables and bendable devices continue to grow.
Overall, the authors conclude, "this work paves the way for scalable application of ultralow dielectric constant covalent organic framework thin films in signal transmission and electromechanical sensing." With the unique properties these COFs present, it becomes clear they represent the forefront of research and development within the field of electronics—offering the potential to revolutionize how devices transmit data and sense the environment.