Electromigration induced thermomigration in microbumps by thermal cross-talk across neighboring chips in 2.5D IC

Menglu Li, King-Ning Tu, Dong Wook Kim, Sam Gu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations

Abstract

This paper investigates the thermal cross-talk between the powered microbumps under one chip and the un-powered microbumps under the neighboring chip. Both chips were on a Si interposer for 2.5D IC. The Joule heating from the powered chip was found to be transferred laterally along the interposer to the unpowered chip and produced a temperature gradient in the microbumps in the unpowered chip. Void formation is observed in both the powered and the unpowered microbumps. The latter is due to thermomigration (TM), and the former is due to electromigration (EM). The amount of voids is bigger by TM than by EM. The void nucleation and growing is studied by examining the un-powered microbumps at different stages during electromigration tests. The nucleation of voids at the cold end in TM is observed, which indicates that Sn atoms diffuse from cold end to hot end. The current-enhanced surface electromigration of Sn along the side walls of Cu pillars to form intermetallic compound is observed in the powered microbumps that were subjected to a 5.3 × 104 A/cm2 current density at 150 °C for a period of time. The depletion of Sn will cause serious void formation in these powered microbumps.

Original languageEnglish
Title of host publication2016 International Reliability Physics Symposium, IRPS 2016
PublisherInstitute of Electrical and Electronics Engineers Inc.
PagesPA31-PA34
ISBN (Electronic)9781467391368
DOIs
StatePublished - 22 Sep 2016
Event2016 International Reliability Physics Symposium, IRPS 2016 - Pasadena, United States
Duration: 17 Apr 201621 Apr 2016

Publication series

NameIEEE International Reliability Physics Symposium Proceedings
Volume2016-September
ISSN (Print)1541-7026

Conference

Conference2016 International Reliability Physics Symposium, IRPS 2016
CountryUnited States
CityPasadena
Period17/04/1621/04/16

Keywords

  • Electromigration
  • Microbumps
  • Side diffusion
  • Thermal crosstalk
  • Thermomigration

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