Liquid crystal polymers (LCP) for high performance SOP applications

Electronic devices will increasingly rely on new materials with improved properties such as lower coefficient of thermal expansion preferably close to silicon, higher modulus, lower permittivity & loss, lower moisture absorption, better thermal conductivity, good dimensional stability, and more importantly reduced warpage particularly after the build-up process. The thermal properties of LCP's have led to increasing interest for the packaging community. This work deals with the evaluation of LCP's for future electronic packaging applications. LCP samples obtained from industry were analyzed using TA instruments. The samples with the properties best matched to the needs of future electronic packaging applications will be chosen based on the thermal analysis data presented for (i) fabrication of a base substrate using solely reinforced LCP, (ii) evaluating LCP for use as a carrier film, (iii) performing laser ablation techniques for via formation in the build up layers, and (iv) plating of the vias and the films for through hole Z-direction connections and X, Y, signal lines. In the present work, application of LCP as a dielectric layer for the system-on-package process has been evaluated. It is expected that the reinforced LCP films can also be utilized as a substrate material thereby providing the unique opportunity for superior compatibility between the substrate and the dielectric layer.