Reliability Modeling and Assessment of Embedded Capacitors in Organic Substrates

Abstract

Understanding and quantifying the RLC characteristics of the embedded passives under thermomechanical deformation during fabrication and accelerated thermal conditions is necessary for their successful implementation. Embedded passives are composite layers with dissimilar material properties compared to the neighboring layers in the integral substrate. The ongoing project explores the fabrication, multifield physics-based reliability modeling and accelerated testing of embedded passive test vehicles. As a first step, in this paper, the effect of thermomechanical deformation on the electrical characteristics of embedded capacitors is studied at frequencies from 100 KHz to 2 GHz using two test vehicles. Test vehicles with embedded passives were fabricated and were subjected to accelerated thermal cycles between 55 C to 125 C, between 40 C to 125 C and high humidity and temperature conditions of 85 C/85% RH. Significant changes in the electrical parameters of the embedded capacitors are observed. The fabrication process mechanics with multiphysics global-local modeling methodology is demonstrated to study the effect of thermal cycling on the electrical characteristics of embedded capacitors. The results obtained from the multiphysics global-local modeling methodology are validated against the measured electrical characteristics of the fabricated functional test boards. The effect of changes in electrical parameters of embedded passives on system performance of low-pass filters is presented.