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NMT Community Archive >
Materials and Metallurgical Engineering >
Majumdar, Bhaskar S. >
Please use this identifier to cite or link to this item:
http://hdl.handle.net/10136/22
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| Title: | Smart Lead-Free Solders Via Shape-Memory Alloy Reinforcement |
| Authors: | Dutta, I.
Majumdar, B.S.
Chen, T.
Chung, C.
Ye, B. |
| Keywords: | microelectroni solder joints
thermo-mechanical cycling
joint failure
smart solder
memory alloy |
| Issue Date: | Nov-2006 |
| Publisher: | Materials Research Society |
| Citation: | MRS Fall Meeting, Boston, MA, November 27-December 1, 2006 |
| Abstract: | Microelectronic solder joints are exposed to aggressive thermo-mechanical cycling (TMC) during service,
resulting in strain localization near solder / bond-pad interfaces, which eventually leads to low-cycle
fatigue (LCF) failure of the joint. In order to mitigate these strain concentrations and thereby improve
LCF life, a 'smart solder' reinforced with a martensitic NiTi based shape memory alloy (SMA) is being
developed. This paper presents an overview of processing, characterization and modeling of these
composite solders, and articulates the role of NiTi particles on strain evolution in composite solders.
Based on finite element modeling and experiments on model single fiber composites, it is shown that
NiTi pariculate reinforcements can reduce inelastic strain levels in the solder via shape recovery
associated with the B19'®B2 transformation. In situ TMC studies in the SEM, in conjunction with strain
analysis via digital image correlation, show evidence of reverse deformation in the solder commensurate
with the NiTi phase transformation, demonstrating the conceptual viability of the smart solder approach.
Details of processing and joint formation, and the resultant microstructures of smart solder are discussed.
Finally, results of TMC experiments on monolithic solder and NiTi/solder composite joints are reported,
highlighting the beneficial effect of shape-memory transformation in reducing inelastic strain range, and
hence enhancing the LCF life, of solders. |
| URI: | http://hdl.handle.net/10136/22 |
| Appears in Collections: | Majumdar, Bhaskar S.
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Files in This Item:
| File |
Description |
Size | Format |
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| MRS 2006-v2 (2).pdf | | 593Kb | Adobe PDF | View/Open |
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