Characteristics of z-axis interconnects using magnetically aligned anisotropic conductive adhesives (ACAs) are analyzed for their applicability for small pad sizes. In order to evaluate the performance of ACAs, a statistical estimation of the failure rate of interconnects was carried out using top-view images of assembled samples. Through a column mapping process, the failure rate is calculated as a function of pad size. The calculated and measured results indicate that the location of the formed columns is the predominant effect determining interconnect failure. The developed failure estimation approach is effective in demonstrating the effects of scaling to smaller particles in ACAs.