Electroless Nickel/Gold Under-Bump-Metallization Cost Comparisons

Abstract

The Under-Bump-Metallurgy (UBM) is an integral part of all wafer bumping processes. This thin film layer is typically deposited by physical vapor deposition (PVD-sputtering), electroplating, or electroless plating. The electroless plating process is widely considered the lowest cost technology within the electronics packaging industry. Its implementation has been driven by the need to further reduce the costs of manufacturing. In this study, the electroless processes and their costs are analyzed using a new cost model. This cost model is based on a cost-resource structure; where the cost of materials, labor, equipment, facilities, utilities and miscellaneous costs are combined with the product mix and production schedule to calculate costs for each process step.