Advanced Vertical Interconnect Technology with High Density Interconnect and Conductive Paste

Advanced vertical interconnect technology that combines traditional HDI (high density interconnect) structures feature micro-vias and conductive paste-vias was developed to fabricate multilayer printed circuit board, such as ultra-multilayer printed circuit board like probe card or IC testing board, having excellent electrical performance, mechanical reliability and mass productivity at reasonable cost. This advanced multilayer printed circuit board constituted of high elastic modulus thermosetting dielectric composition with interstitial via holes (IVH) and/or Cu micro-vias (HDI), besides sintered conductive paste-vias buried in low elastic modulus thermosetting dielectric composition. The latter composition will properly act as mechanical buffering layer of vertical interconnection between upper and lower multilayer boards. This paper discuss about manufacturing process factor, that is pre-curing temperature, affecting the optimum electrical performance at the interface of HDI Cu lands and conductive paste with interposing low elastic modulus dielectric material in the first place. In the second place, analysis of observations for the micro structure and sintering condition at the interface of conductive paste and HDI Cu land by using SEM and energy dispersive X-ray spectrometry (EDX). In addition, mechanical reliabilities, estimated by using structural analysis method and signal transmission properties by way of this buried conductive paste using frequency and time-domain simulation analyses were discussed.. From these results, this advanced vertical interconnect technology with sintered conductive paste and low elastic dielectric has sufficient mechanical reliability and electrical property for passing high-speed signal up to 15 Gbps.