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CALCE conducted its annual Fall technical review and road mapping meeting on 23-24 October, 2019 at University of Maryland. On the first day, findings from research projects of the 2019 research year were presented. The following day was used for discussions of research roadmaps. Many of the projects were presented by graduate students and the attendees voted on the quality, clarity, and depth of the presentations. Qian Jiang, a PhD student of Prof. Dasgupta received the best presenter award for presenting her research on “Investigation of Copper RDL Fatigue Failure in WLCSP Assemblies under Thermal Cycling”.
In her presentation, she talked about Redistribution layer (RDL) architectures, used in wafer-level chip scale packages (WLCSP) and in interposers for heterogeneous integration, present the possibility of multiple degradation modes under thermal cycling and power cycling. In her presentation she covered the following degradation modes.
1) Fatigue cracks in the copper redistribution layer;
2) Fatigue cracks in PBO dielectric layer;
3) Failure at various interfaces between the PBO and copper layers; and
4) Cracks in the die active and passivation layer.
The study was conducted collaboratively by CALCE and the sponsor, with the research tasks conducted partly at CALCE and partly during an internship that the CALCE student completed at the sponsor’s site.
Publications of Qian can be found here.
For further information about her research, please contact Prof. Dasgupta, dasgupta@umd.edu
November 14, 2019
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