EFFECTS OF ELECTROLYTES ON NANOPOROUS ANODIC ALUMINUM OXIDE FORMATION ON AN AL SUBSTRATE FOR ELECTRONIC PACKAGING

Abstract

Recently, nanoporous anodic aluminum oxide (AAO) structure is receiving great interest from various researchers owing to its potential impact on thermal management in electronic packages. Dimensions such as the pore diameter, pore height, and interpore distance of nanoporous AAO are factors influencing effective heat dissipation. For proper AAO dimensioning, this work fabricated the nanoporous structure on Al5052 using three different types of electrolytes. In a two-step anodization process, a nanoporous template was fabricated using phosphoric (0.3 M), sulfuric (0.3 M), and oxalic (0.3 M) acids. Porosity and morphology were investigated via field emission scanning electron microscopy. The morphology of AAO showed that oxalic acid forms a uniform honeycomb-like structure over other electrolytes. Furthermore, this electrolyte resulted in 22% porosity, 36–50-nm pore diameter, and ~2.6-μm pore height, thereby helping in effectively dissipating the heat of components in an electronic packaging.