By using pulse electrodeposition, a copper nanopillar array (CuNPA) was filled into porous anodized aluminum oxide (AAO) films to achieve a highly thermal conductive interconnector with anisotropic property. After 120 min pulse deposition, CuNPA uniformly filled the pores of AAO with a pore-filling percentage of 99.4%, as the ion concentration in AAO pores can re-equilibrate to electrolyte concentration during the current-off period. The CuNPA-filled AAO film showed a high thermal conductivity of 153.12 W/(m·K) in the vertical direction and a low thermal conductivity of 3.43 W/(m·K) in the horizontal direction. Hence, the anisotropic ratio of the thermal conductivity reached 44.64. Moreover, the fabrication process was facile and cost-effective, showing a potential application prospect in the field of high-density packages and power electronic devices.

No abstract

Though copper nano-pillars (CNPs) filled in anodic aluminum oxide (AAO) film has been developed for many years, the high pore-filling percentage in AAO is still a bottleneck. We have demonstrated a new electrodeposition method to fill CNPs in AAO without the seed layer which is required in the traditional electrodeposition process. CNPs with uniform heights were obtained and the pore-filling percentage reached up to 97.5%. Low current density is beneficial for the high pore-filling percentage due to the uniform growing rate in different nanoscale pores. The high temperature increased the diffusion velocity of ions and enhanced the pore filling percentage but also corroded the AAO film simultaneously. Results showed that CNPs grains with <220> orientation were fabricated. Electrodeposition with low electric current could contribute to the forming of CNPs with (220) preferred orientation due to the promotion of dehydration reduction processes. The thermal conductivities of Cu-AAO interposers reaches 92.34 W/(m·K) and 3.19 W/(m·K) in vertical and horizontal directions, respectively.

Municipal Solid waste incineration bottom ash(MSWI BA) is a silicon-calcium-aluminum oxide obtained by high-temperature calcining of municipal waste. Its appearance is similar to natural sand, and its chemical composition is similar to cement clinker. It can be used as concrete fine aggregate replace natural sand in a small amount. This paper tested the physical and chemical properties of MSWI BA, and obtained the compressive strength and microscopic pore structure parameters through experiments of 5 water-binder ratios, 3 sand replacement ratios, and 2 curing ages of municipal solid waste incineration MSWI BA concrete, and analyzed the relationship between pore structure and mechanical properties. The results show that the compressive strength of MSWI BA replacement sand concrete decreases with the increase of air content, bubble chord length and bubble spacing coefficient, and increases with the increase of bubble specific area. The fractal dimension of bubble distribution of MSWI BA replacement sand concrete is between 1.833∼2.259, and that of ordinary concrete is between 2.138∼2.495. The compressive strength increases with the increase of the fractal dimension of bubble distribution.

No abstract