프리프레그 가공을 통한 인쇄회로 기판의 유효 유전상수 하향 조정

Abstract

As electronic devices become more compact, the thickness of the layer in printed circuit boards(PCBs) decreases, and the characteristic impedance of transmission lines with a minimum allowable trace width often becomes less than 50 Ω. Reducing the minimum trace width or switching to a dielectric with lower dielectric constant is prohibitive owing to increased manufacturing costs. We propose a new way of reducing the effective dielectric constant by drilling holes in prepreg. We perform measurements and simulations to verify the effectiveness of the proposed approach. Results demonstrate that using drilled prepreg enables the lowering of the effective dielectric constant by up to 7 %.