Toward Terahertz: Prospective Planning for 6G Communication Materials, Role and Challenges of High-Frequency, High-Speed Hydrocarbon Resins

While the commercial deployment of 5G continues in full swing worldwide, cutting-edge exploration in communication technology has already set its sights on the next generation of mobile communication—6G. 6G networks will transcend mere speed enhancements, aiming to establish a ubiquitous network that “integrates terrestrial and space domains while intelligently connecting all things.” Realizing this vision hinges on expanding into higher frequency bands—millimeter waves and even terahertz (THz) frequencies. This quantum leap in frequency imposes unprecedented disruptive demands on the entire communications supply chain, particularly the foundational 6G communication materials.

The most significant challenge arising from this frequency leap—from 5G's Sub-6GHz and millimeter waves to the potential 100GHz+ terahertz bands for 6G—is the dramatic increase in “free-space path loss.” Signal attenuation during propagation through air becomes extremely severe, necessitating the minimization of losses throughout the entire link, from the signal source to the transmitting antenna. At this point, the dielectric loss inherent in the circuit substrate material itself becomes the critical factor determining whether communication can be achieved. Traditional substrate materials exhibit astronomical losses in the terahertz band, rendering them completely unusable.

Within this forward-looking framework, high-frequency, high-speed carbon-hydrogen resins—already demonstrating exceptional performance in the millimeter-wave band—are regarded as one of the most promising candidate materials for the 6G era. Their core competitiveness stems from a molecular structure engineered for “lossless transmission.” Through deep hydrogenation processes, their molecular chains achieve high saturation and purity, fundamentally eliminating polar vibrational modes that cause energy absorption and dissipation under high-frequency electromagnetic fields. This enables their dielectric loss factor (Df) to remain exceptionally low even at extremely high frequencies, making it possible for terahertz signals to survive within circuits.

Beyond ultra-low loss, 6G communications demand higher levels of integration and multifunctionality from materials. For instance, massive MIMO antenna arrays will evolve toward ultra-large scales, requiring greater integration between antennas and RF chips. This necessitates that 6G communication materials not only exhibit outstanding electrical properties but also possess robust thermal management capabilities and mechanical reliability. The high thermal decomposition temperature (>400°C) and tunable coefficient of thermal expansion (CTE) of high-performance hydrocarbon resins enable better compatibility with semiconductor chips. This aids in addressing heat dissipation challenges posed by high-density integration and ensures long-term reliability within complex structures.

Of course, advancing toward the terahertz range presents new challenges and development directions for hydrocarbon resins themselves. For instance, further loss suppression in ultra-high frequency bands requires composites with novel low-loss fillers; surface modification techniques enhance bonding strength with finer circuit patterns; and new forms better suited for 3D packaging and heterogeneous integration must be explored.

In summary, while the final technical standards for 6G remain undetermined, the demand for ultra-low-loss, highly stable 6G communication materials is clear. Advanced polymer materials, exemplified by high-frequency, high-speed carbon-hydrogen resins, are securing a favorable position in this future-oriented technological race. Leveraging their robust performance foundation and significant optimization potential, they will play a pivotal role in defining next-generation communication technologies.