Development of Multi-layered Build-Up Insulation Dry-Film Material for Ultra-Low Transmission Loss Wirings for High-Speed Semi-Conductor Packaging

摘要

An advanced build-up insulation dry-film material to realize ultra-low transmission loss in next-generation substrates is developed. In order to lower the transmission loss in substrate, the biggest challenge is to realize lower both of dielectric loss and scattering loss. In this paper, we propose a build-up film with multi-layered structure - an insulation layer with a thin primer layer - to have ultra-low transmission loss characteristics with its low dielectric loss tangent (Df) and its low scattering loss by its smooth interfaces with good adhesion against copper. We formulated the low-Df insulation material (Df=0.0035 at 10GHz). We fabricated strip-line waveguides using the new build-up insulation material on the substrates. We thus demonstrated this material successfully obtains low transmission loss of below 0.04dB/mm at 10GHz and that of below 0.17dB/mm at 50GHz.