Passive device embedded substrate for application of RF module

Purpose The purpose of this study is to form fabrication and electrical characteristics of passive device embedded substrate that is embedded chip bead inductor and chip capacitor inside substrate for the application of radio frequency (RF) modules. Design/methodology/approach Passive device embedded substrate was fabricated using embedding process that consists of lamination process, laser drilling at the electrode Cu pads of passive components, electro-less Cu plating formation process such as photolithography, electrolytic Cu plating and etching. Impedance and capacitance characteristics of the fabricated passive device embedded substrate were evaluated. Findings By checking what embedded components are placed in the appropriate place using failure analysis via connection performance between copper plane and embedded components was verified. For measuring electrical characteristics of the fabricated passive device embedded substrate, the evaluation was done using test methods like continuity test for checking interconnections which are not connected to any embedded components and in-circuit test for checking interconnections which are connected to any embedded component. From in-circuit testing for embedding passive components with series and parallel circuits, the authors verified how to test passive device embedded substrate by using capacitance and impedance measurement with the comparison of measured results between good samples and bad samples. Originality/value Ultra miniaturized and low-profile mobile products are driving the need for embedded passive component integration technologies using a novel manufacturing-compatible organic substrate and interconnect technologies. Fabrication and test methods for passive device embedded substrate described in this paper are expected to lead to be developed to make quality measurable for the application of RF modules.