A Quality-Improved Folded Inductor Embedded in MCM-L Organic Packaging Substrate Using an Unfilled Via Process

This paper presents a folded inductor implemented with a multichip module, which involves a laminate organic packaging technology with an unfilled via process. The folded inductor had an increased inductor layer surface area because of the unfilled vias along the inductor layer. Thus, the quality (
Q
) factor of the inductor improved as the series resistance, resulting from the skin effect, decreased. The
Q
-factor for a folded inductor showed a maximum improvement of 32% by including contact resistances, in comparison with the
Q
-factors of a normal planar inductor.