pH-induced phase evolution and enhanced physical properties of co-precipitated WO3-CuO powders and reduced bodies for microelectronics packaging

Abstract WO3-CuO powder and its reduced bodies for microelectronics packaging were successfully prepared by co-precipitation combined with reductive sintering in H2 atmosphere. The phase evolutions, morphologies, and agglomeration states of the co-precipitated precursors and dried and reduced powders under different pH values were studied in detail. Furthermore, the physical properties of the sintered bodies were investigated. The experimental result demonstrated that the morphology of the co-precipitated powders could be remarkably influenced by the pH values of the reaction solution. The prepared WO3-CuO powder under pH = 4 exhibited a uniform size distribution and better dispersibility, and the corresponding sintered bodies showed a dense and defect-free microstructure. Thermal conductivity as high as 221.0 W m−1 K−1 and an expansion coefficient lower than 6.6 × 10−6 K−1 were simultaneously obtained in the sintered bodies. The W-Cu reduced bodies in this study possess great potential for application in electronics packaging.