Thermo-Mechanical Reliability and Electrical Performance of Indium Interconnects and Under Bump Metallization

This thesis presents reliability analysis of indium interconnects and Under Bump Metallization (UBM) in flip chip devices. Flip chip assemblies with the use of bump interconnections are frequently used, especially in high density, three-dimensional electronic devices. Currently there are many methods for interconnect bumping, all of which require UBM. The UBM is required for interconnection, diffusion resistance and quality electrical contact between substrate and device. Bonded silicon test vehicles were comprised of Indium bumps and three UBM compositions: Ti/Ni/Au (200\xc5/1000\xc5/500\xc5), Ti/Ni (200\xc5/1000\xc5), Ni (1000\xc5). UBM and indium were deposited by evaporation and exposed to unbiased accelerated temperature cycling(-55°C to 125°C, 15°C/min ramp rate). Finite Element Analysis (FEA) simulations were used to gain understanding of non-linear strain behavior of indium interconnects during temperature cycling. Experimental testing coupled with FEA simulations facilitated cycle-to-failure calculations. FEA results show plastic strain concentrations within indium bump below failure limits. It has been demonstrated that fabrication of Ti/Ni/Au, Ti/Ni, and Ni UBM stacks performed reliably within infant mortality failure region.

Name thesis:degree_name

Mechanical Engineering

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Mechanical Engineering

Year

2015

Author dc:creator

• Leger, Jon-Claude

Contributors dc:contributor

• Shen, Yu-Lin
• Tehrani, Mehran
• Bauer, Todd
• Homeijer, Sara
• Young, Nathan

• Reliability
• Microelectronics
• Indium
• Under Bump Metallization

Language dc:language

English

Identifier

https://digitalrepository.unm.edu/me_etds/85

OAI identifier oai:identifier

oai:digitalrepository.unm.edu:me_etds-1084