Increasing the surface quality of corundum ceramics

The development of hybrid integrated circuits places ever-higher requirements on ceramic dielectric substrates, specifically on the degree of their surface roughness. It was established [I] that the surface roughness of corundum ceramics usually increases exponentially with an increase of sintering temperature, especially during the period of intensive growth of corundum crystals. The main sources of pit formation on the surface are defects that occur during machining of the ceramics, primarily during rough grinding. The number and size of pits depend on the dimensions of the crystals in the ceramic.