Nonlinear resonant acoustic detection of cracks in multilayer ceramic capacitors

Time-domain analysis of resonant acoustic nonlinearity arising from cracks in multilayer ceramic capacitors

“…The study reported here is an extension of a previous study [8] that focused on the dependence of resonant frequencies on the amplitude of resonant tone-burst excitation of type-1210 MLCCs with and without visible cracks that were generated by thermal quenching from elevated temperatures. In that previous work, resonant frequencies were found to shift approximately linearly with excitation amplitude, and the magnitudes of these shifts were found to be strongly correlated with the presence of visible cracks.…”

“…A number of alternate approaches for detecting cracks in MLCCs have been previously explored [2,3,4,5,6,7,8], and the relative advantages, disadvantages, and limitations of some of these approaches have been discussed by Erdahl and Ume [3] (through 2004) and Teverovsky [2] (through 2008) . Over the past several years, our research in this area has employed resonant ultrasound spectroscopy (RUS) and electromechanical resonance [6,7,8].…”

“…Over the past several years, our research in this area has employed resonant ultrasound spectroscopy (RUS) and electromechanical resonance [6,7,8]. In two previous studies [7,8], we explored the sensitivity of nonlinear acoustic measurements to the presence of cracks.…”

“…Over the past several years, our research in this area has employed resonant ultrasound spectroscopy (RUS) and electromechanical resonance [6,7,8]. In two previous studies [7,8], we explored the sensitivity of nonlinear acoustic measurements to the presence of cracks. An advantage of this approach over linear acoustic spectroscopy is that nonlinear measurements are based on relative shifts in resonant frequency or harmonic amplitude as a function of excitation amplitude [9] and, therefore, are insensitive to variations in frequencies that arise from dimensional variations of the MLCCs.…”

“…The current report is focused on extracting values of nonlinear amplitude dependence of MLCC frequencies from an analysis of the time dependence of the phase during ringdown. This analysis employs waveforms that were acquired in parallel with the frequency measurements presented in our earlier report [8]. The primary motivation for pursuing this alternative approach is that it is expected to eventually enable more rapid characterization of acoustic nonlinearity, because it does not require acquisition of data at multiple excitation levels.…”