A1 Journal article (refereed), original research

Acoustic phenomena in damaged ceramic capacitors


Open Access publication

Publication Details
Authors: Levikari Saku, Kärkkäinen Tommi, Andersson Caroline, Tamminen Juha, Silventoinen Pertti
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Publication year: 2018
Language: English
Related Journal or Series Information: IEEE Transactions on Industrial Electronics
Volume number: 65
Issue number: 1
Start page: 570
End page: 577
Number of pages: 8
ISSN: 0278-0046
eISSN: 1557-9948
JUFO-Level of this publication: 3
Open Access: Open Access publication

Abstract

Multilayer Ceramic Capacitors are prone to mechanical defects and damage
because of the fragility of the ceramic dielectric. Because these
faults are often not recognized by visual or electrical inspection, a
nondestructive, fast way of detecting these defects would be very
useful. Ceramic capacitors are known to generate acoustic emissions,
caused by mechanical vibration of the capacitor body. Physical defects
alter the mechanical properties of the capacitor, which, in turn, affect
the acoustic signature of the capacitor. In this paper, acoustic
information is acquired directly from both pristine and damaged
capacitors. An experiment was conducted where capacitors were driven
with a voltage chirp over a wide range of frequencies, and subsequent
acoustic emissions were measured with a piezoelectric point contact
sensor. Test boards were bent to cause flex cracks to the soldered
capacitors, which were measured acoustically before and after bending. A
comparison of these measurements showed that PCB bending causes
characteristic changes to the capacitor acoustic response, which can be
correlated with the resulted damage.


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Last updated on 2018-19-10 at 07:55