As electronic products evolve toward higher frequencies, greater speeds, and miniaturization, the selection of raw materials must take the following trends into account:
Widespread Adoption of High-Frequency Substrates: The demand for materials with low dielectric loss has surged in sectors such as 5G communications and automotive radar; consequently, the market share for PTFE-based substrates (Df ≤ 0.001) and ceramic-filled substrates (Df ≤ 0.002) continues to expand.
Upgrading of Flexible Substrates: Wearable devices and foldable smartphones are driving the evolution of PI films toward ultra-thin profiles (≤ 12.5 μm) and high modulus values (≥ 4 GPa). Concurrently, LCP (Liquid Crystal Polymer) films are beginning to displace PI in certain applications due to their exceptionally low water absorption rate (≤ 0.04%).
Heightened Environmental Standards: EU regulations such as RoHS and REACH restrict the use of hazardous substances-including lead and halogens-making lead-free solders (specifically the Sn-Ag-Cu system) and eco-friendly solder masks (free of benzene-based solvents) the industry norm.
Material selection requires a comprehensive assessment of performance requirements, budgetary constraints, and manufacturing capabilities. For instance, mainboards for consumer electronics typically utilize a combination of FR-4 substrates, electrolytic copper foil, and liquid photosensitive ink. Automotive electronics, conversely, require high-Tg (glass transition temperature ≥ 170°C) substrates and rolled copper foil to withstand thermal cycling tests ranging from -40°C to 150°C. Flexible printed circuit boards (FPCs), meanwhile, prioritize the use of PI film and ultra-thin copper foil to facilitate dynamic bending functionality.
