Plastic forming of Al2O3 ceramic substrates

The purpose of this work was to evaluate the production of ceramic substrates, particularly of Al2O3, by viscous plastic processing (VPP). This technique was developed as an alternative route for the production of thin substrates (<2 mm thick), offering significant advantages over other processes, above all in terms of cost and productivity. The methodology consists of mixing ceramic powders and relatively low amounts of organic additives to prepare a plastic mass, which is homogenized in a mixer or by extrusion processing and conformed by rolling. The aim of this study was the selection of organic additives for different alumina particle sizes in order to establish a correlation between the combination of binder, lubricant and plasticizer and the characteristics of superficial finishing of the conformed ceramic body, homogeneity of thickness and microstructural defects. The results show that powders with an average particle size of 0.44 μm are suitable to produce highly dense substrates.