With the explosive growth of industries such as artificial intelligence, 5G/6G communications, high-end consumer electronics, and new energy vehicles, flexible printed circuit boards (FPCs), acting as the "neural network" of electronic devices, are undergoing a profound transformation driven by materials science, precision manufacturing, and intelligent testing. The industry is no longer content with merely being "flexible," but is evolving towards higher density, higher frequency, higher reliability, and more intelligent production methods. The following is a summary and interpretation of the latest technological developments in the FPC industry.

I. Materials Innovation: Continuous Breakthroughs in Performance Boundaries

The performance foundation of FPCs lies in materials. Current materials research and development revolves around three main themes: high frequency and high speed, environmental sustainability, and structural innovation.

· High-Frequency Materials Compete for Next-Generation Communication

· Core Requirements: To meet the stringent requirements of ultra-low signal loss (LOSS) for 5G millimeter-wave and even future 6G communications, traditional polyimide (PI) is no longer adequate due to its high dielectric constant (Dk) and loss factor (Df).

* **Mainstream Solutions:** Liquid crystal polymers (LCPs) and modified polyimide (MPI) have become the mainstream choices for high-frequency FPCs. LCPs perform better in the millimeter-wave band, while MPIs offer a cost advantage in the Sub-6GHz band.

* **Latest Developments:** Furukawa Electric Industries of Japan has recently developed a low-dielectric material based on polyphenylene sulfide (PPS). Its dielectric constant and loss are reduced by approximately 40% compared to traditional rigid materials, and its density is reduced by approximately 70%. It can also be applied to FPCs requiring heat processing. This provides a new lightweight, low-loss solution for high-power devices such as base station antennas.

* **Environmental Protection and Structural Materials Go Hand in Hand:**

* **Environmental Trends:** With global regulations restricting perfluoroalkyl substances (PFAS), developing fluorine-free or low-fluorine high-frequency materials has become a clear direction. Domestic companies such as Kingfa Science & Technology have also launched low-carbon LCP materials that have passed international sustainability certification, responding to the green needs of the industry chain.

* **Structural Innovation:** While pursuing ultra-thinness, material composite technology is also developing. For example, PI/PET composite substrates, through co-extrusion processes, have improved temperature resistance to 150°C while maintaining low costs, and are rapidly penetrating the wearable device market.