Flexure strength of multilayer ceramic capacitors

The flexure strength (MOR) of multilayer ceramic (MLC) capacitors has been investigated by three point loading tests, using a specially designed, miniaturised test rig. The starting materials were blanks and MLC capacitors of Z5U and X7R formulations containing different numbers of electrodes and ink laydown concentrations. It was found for blanks that MOR decreased as the specimen thickness increased, while for X7R capacitors the MOR increased with the number of electrodes. Electron microscopy showed major differences in the mode of fracture of Z5U and X7R MLC capacitors. In as fired components the MOR varied with the ink laydown concentration, but in equivalent components which had been terminated and annealed, the flexure strength was uniformly high and independent of ink concentration. BCT/349