Experimental and numerical investigation of microvia reliability

Dramatic advances in the electronics industry have lead to higher I/O, finer pitch and smaller footprint off chip interconnects to meet the cost, performance and size requirements. Microvia substrate technologies will play a crucial role in the printed wiring board (PWB) industry to accommodate these high I/O chips. A comprehensive experimental and theoretical program is underway at the Georgia Institute of Technology to develop the microvia, substrate technologies. The experimental aspect of this program involves fabrication in a class 1000 clean room facility to understand the effect of process parameters on yield and reliability of the microvia and high density wiring (HDW) structures. The theoretical program aims to understand the mechanics of deformation and thus predict and enhance the reliability of the microvia structures. The focus of this paper is (a) to characterize the effect of microvia geometry parameters on the evolution of stain and (b) to determine the effect of dielectric material property on the thermomechanical reliability of the microvias (c) to understand the effect of processing parameters on yield.