Low cost characterization of the electrical properties of thin film and mold compound for embedded wafer level packaging (EMWLP)

Abstract

In recent years, embedded wafer level package (EMWLP) technology has become a promising platform for SiP integration [1] due to its relatively low cost and good electrical performance [1–2]. As the platform is being considered for higher frequency applications (eg. 77-GHz radar), it becomes pertinent to characterize for the dielectric properties of the materials involved. Another concern is that the dielectric properties of inhomogeneous materials (eg. mold compound) may vary from batch to batch. Thus, it is desirable to have structures which are compact to enable in-situ dielectric characterization. In this work, we propose meander T-resonator structure for in-situ dielectric characterization. We also attempt to extract for the relative permittivity of the mold compound in a coplanar waveguide (CPW) configuration, based on analytical expressions. Lastly, we compare the results extracted from both the T-resonator and transmission line (TL) structure.