Mean-time-to-failure study of flip chip solder joints on Cu/Ni(V)/Al thin-film under-bump-metallization

The μPILR interconnect is a copper pillar manufactured as a part of a substrate pad. In this paper, we discuss the electromigration (EM) performance of Pb-free μPILR interconnects in a multi-pair daisy chain within 150μm pitch flip-chip packages. Electromigration performance of μPILR interconnects has shown a significant improvement and noticeably delayed electromigration induced failures. Voids initially begin to appear at Cu6Sn5 and solder interface on the die side, with eventual open failure due to excessive void formation along with a severe depletion of Cu Under Bump Metallization (UBM). No failure was observed on the substrate side of the interconnect regardless of the current direction. The enhanced performance of the μPILR interconnect along with other reliability benefits makes it an excellent alternative to conventional solder joints including thin film stack UBMs, thicker copper UBM as well as copper pillar on die.

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Electromigration analysis of solder joints under ac load: A mean time to failure model

Journal of Applied Physics ◽

10.1063/1.3693532 ◽

2012 ◽

Vol 111 (6) ◽

pp. 063703 ◽

Cited By ~ 23

Author(s):

Wei Yao ◽

Cemal Basaran

Keyword(s):

Solder Joints ◽

Time To Failure ◽

Failure Model ◽

Mean Time To Failure ◽

Mean Time

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On classes of life distributions based on the mean time to failure function

Journal of Applied Probability ◽

10.1017/jpr.2020.91 ◽

2021 ◽

Vol 58 (2) ◽

pp. 289-313

Author(s):

Ruhul Ali Khan ◽

Dhrubasish Bhattacharyya ◽

Murari Mitra

Keyword(s):

Damage Model ◽

Replacement Policy ◽

Time To Failure ◽

Mean Time To Failure ◽

Moment Convergence ◽

Life Distributions ◽

Cumulative Damage Model ◽

The Mean ◽

Age Replacement ◽

Mean Time

AbstractThe performance and effectiveness of an age replacement policy can be assessed by its mean time to failure (MTTF) function. We develop shock model theory in different scenarios for classes of life distributions based on the MTTF function where the probabilities $\bar{P}_k$ of surviving the first k shocks are assumed to have discrete DMTTF, IMTTF and IDMTTF properties. The cumulative damage model of A-Hameed and Proschan [1] is studied in this context and analogous results are established. Weak convergence and moment convergence issues within the IDMTTF class of life distributions are explored. The preservation of the IDMTTF property under some basic reliability operations is also investigated. Finally we show that the intersection of IDMRL and IDMTTF classes contains the BFR family and establish results outlining the positions of various non-monotonic ageing classes in the hierarchy.

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Contribution to Rolling Bearing Reliability Modeling

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.2497 ◽

2011 ◽

Vol 110-116 ◽

pp. 2497-2503 ◽

Cited By ~ 1

Author(s):

Zdenek Vintr ◽

Michal Vintr

Keyword(s):

Operating Time ◽

Rolling Bearing ◽

Time To Failure ◽

Rolling Bearings ◽

Mean Time To Failure ◽

Reliability Modeling ◽

Time Between Failures ◽

Large Groups ◽

Mean Time

Rolling bearings are usually considered to be non-repaired items the reliability of which is characterized by mean time to failure, or so called basic rating life. Reliability describes these parameters well in case the bearings are used in operation up to the very time the failure occurs, or during the time corresponding with basic rating life. In case of railway applications the bearings are often used in large groups and are preventively replaced after much shorter operating time as compared with their basic rating life. In the article there is a model which enables us to describe the bearings reliability in this specific case and to specify a number of failures which might be expected from a group of bearings during operating time, or to determine mean operating time between failures of bearings.

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