Acoustic Phenomena in Damaged Ceramic Capacitors

Nondestructive Acoustic Testing of Ceramic Capacitors Using One-Class Support Vector Machine With Automated Hyperparameter Selection

“…In this study, the authors continue their prior work reported in [22] and [23] by showing that MLCC acoustic emission measurement can be used as a practical quality assurance testing method without the need for a laborious and errorprone labeling process. This is successfully demonstrated by identifying damaged MLCCs using the one-class support vector machine, a machine learning model trained only on pristine capacitor samples.…”

“…A more recent method introduced by the authors is based on electrically exciting the component to vibration, simultaneously measuring the vibrations using a point contact sensor [22]. However, while the acoustic emissions carry information about the structural condition of a capacitor, the signs of damage can be hard to detect.…”

“…The raw data used in this study originate from measurements performed by the authors in [22] and [23]. The measurements were conducted by subjecting soldered MLCCs to an excitation signal, simultaneously measuring the acoustic response of the capacitor using a piezoelectric point contact sensor placed on top of the component (see Fig.…”

“…A selected set of the MLCCs were also inspected for cracks with X-ray imaging because their acoustic signatures appeared slightly anomalous. The cross-sectioning and X-ray imaging were performed in the same study as the acoustic measurements; more comprehensive descriptions of the methods are available in [22] and [23].…”

Lock-in Thermography Failure Detection on Multilayer Ceramic Capacitors After Flex Cracking and Temperature–Humidity–Bias Stress

“…These short circuits are very detrimental and can destroy the MLCC and even the surrounding circuit [4], [5]. The flex cracks induced by bending cannot be detected by electrical measurements or identified from the surface through optical inspection [6], [7], and the resulting failure after humidity and applied voltage bias can be difficult to detect on a populated board [8], [9]. Therefore, it is desired to have a testing method to identify the leakage due to flex crack defects in a non-destructive way.…”