Characterization of low loss materials for high frequency PCB application

As communication and broadband application technologies rapidly evolve, traditional FR-4 materials may no longer perform well in the high frequency range. The demand for low dielectric constant (Dk) and dissipation factor (Df) base materials for PCB applications has increased continuously. As the frequency increases, the concern for signal transmitting delay increases and the effect from the signal loss becomes more significant. In this paper, the performance of laminate and PCB based on the newly developed low DK/Df material is presented. A number of test results and applications are also discussed. The material shows high Tg (glass transition temperature), high Td (decomposition temperature), low CTE (coefficient of thermal expansion), and low moisture absorption. Good through hole quality was found after solder float test showing that properties of the material is well balanced. The material is also compatible with lead-free assembly as the samples remained intact after reflow for 6 cycles.