Effect of lapping and polishing on the strength of alumina ceramics

Sintered alumina ceramic substrates are in increasing demand for use in micro-electronics. Usually, two processes of manufacturing are industrially employed. Substrates made by tape casting are commercially available 'as fired' products without lapping or polishing; whereas the substrates made by pressing invariably require polishing to attain the requisite surface finish. A study was made by using Instron strength measuring instrument to determine the decrease in strength on polishing compared to the 'as fired' products. It was observed that the decrease in strength was only marginal, and surface flaws generated by lapping and polishing are likely to be made up when resistive ink or paste is printed on the surface and fired thereafter. © 1980 Taylor & Francis Group, LLC