Authored By:
K. Weide-Zaage, J. Schlobohm, H. Fremont, A. Farajzadeh, J. Kludt
Information Technology Laboratory, Leibniz University Hannover
Hannover, Germany
Laboratoire IMS, Universite Bordeaux I
Talence Cedex, France
Summary
Investigations of electro- and thermomigration as well as the mechanical stress concerning the reliability of the through silicon vias, BGA-PoP-Packages as well as ubumps which are the most critical areas for the emergence of failure, remains a major concern in reliability studies.
Generally measurements are time consuming and expensive and the time-to-market cycle is in the focus of interest too. Due to this, simulations offer a possibility for a fast analysis of weak links and problematical areas in the investigated structures and avoid re-design.
Conclusions
With the help of simulations the weakest links as well as locations with high thermal-electrical and mechanical loads can be determined in 3-D applications. In this paper different examples like electro- and thermomigration effects as a failure mechanism in Package on Package PoP-BGA, CuSn pillars, u-bumps, flip chip with power metal and TSV were resented. Furthermore the influence of the stress distribution on the possible local fracture appearances was shown in a (PoP).
The simulations help to avoid time consuming long term tests and give a hint for the possible failure location. Due to this work intensive micro sections for failure analyses can be placed more easily. This paper proves that finite element simulation bring a big effort concerning reliability investigations in 3-D integration. In future the process induced stress should also be included in the simulations of bumps.
Initially Published in the SMTA Proceedings
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