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DOI: 10.5445/IR/1000078333

Electromigration Mechanism of Failure in Flip-Chip Solder Joints Based on Discrete Void Formation

Chang, Y.-W.; Cheng, Y.; Helfen, L. F.; Xu, F.; Tian, T.; Scheel, M.; Di Michiel, M.; Chen, C.; Tu, K.-N.; Baumbach, T.

Abstract:
In this investigation, SnAgCu and SN100C solders were electromigration (EM) tested, and the 3D laminography imaging technique was employed for in-situ observation of the microstructure evolution during testing. We found that discrete voids nucleate, grow and coalesce along the intermetallic compound/solder interface during EM testing. A systematic analysis yields quantitative information on the number, volume, and growth rate of voids, and the EM parameter of DZ*. We observe that fast intrinsic diffusion in SnAgCu solder causes void growth and coalescence, while in the SN100C solder this coalescence was not significant. To deduce the current density distribution, finite-element models were constructed on the basis of the laminography images. The discrete voids do not change the global current density distribution, but they induce the local current crowding around the voids: this local current crowding enhances the lateral void growth and coalescence. The correlation between the current density and the probability of void formation indicates that a threshold current density exists for the activation of void formation. There is a sign ... mehr


Zugehörige Institution(en) am KIT Laboratorium für Applikationen der Synchrotronstrahlung (LAS)
Institut für Photonenforschung und Synchrotronstrahlung (IPS)
Publikationstyp Zeitschriftenaufsatz
Jahr 2017
Sprache Englisch
Identifikator ISSN: 2045-2322
URN: urn:nbn:de:swb:90-783339
KITopen ID: 1000078333
HGF-Programm 56.03.20; LK 01
Erschienen in Scientific reports
Band 7
Seiten Art.Nr. 17950
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
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