Deformation behavior of tin and some tin alloys

Yang, Fuqian; Li, J. C. M.

doi:10.1007/s10854-006-9016-4

Cited by 59 publications

(29 citation statements)

References 102 publications

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“…A misorientation angle of approximately 60°is a common twinning angle for Sn, 21 and the EBSD results show that the four analyzed 60°boundaries had an average misorientation of 61.8°, which is indicative of (301)[À103] twins rotated around the [010] axis. 22 The commercially pure Sn sample that was most heavily twinned was analyzed in further detail to enable us to determine if any additional information could be gained from the x-ray diffraction patterns that might be an indication of twinning.…”

Section: Tin On Graphite Substratesmentioning

confidence: 97%

Microstructure and In Situ Observations of Undercooling for Nucleation of β-Sn Relevant to Lead-Free Solder Alloys

Elmer

Specht

Kumar

2010

Journal of Elec Materi

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Difficult nucleation of b-Sn during solidification of tin and tin-based lead-free solder alloys can result in high degrees of undercooling of the liquid prior to solidification. The undercooling can produce solder joints with large grains, anisotropic behavior, and undesirable mechanical properties. This paper describes our examination of the amount of undercooling of tin on both graphite (non-wetting) and copper (wetting) surfaces using in situ x-ray diffraction. The microstructure was further characterized by optical microscopy, scanning electron microscopy, and electron backscattering diffraction imaging microscopy. Undercoolings as high as 61°C were observed for Sn solidified on graphite, while lower undercoolings, up to 30°C, were observed for Sn solidified on copper. The microstructure of the high purity Sn sample solidified on graphite showed very few grains in the cross-section, while the commercially pure Sn sample solidified with only one grain and was twinned. Tin solidified on copper contained significant amounts of copper in the tin, intermetallic phase formation at the interface, and a eutectic microstructure.

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Section: Tin On Graphite Substratesmentioning

confidence: 97%

Microstructure and In Situ Observations of Undercooling for Nucleation of β-Sn Relevant to Lead-Free Solder Alloys

Elmer

Specht

Kumar

2010

Journal of Elec Materi

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“…In spite of the large amount of literature published on these alloys, their use in small structures such as controlled collapse chip connection (C4) solder joints in flip-chip packages results in a largely unexplained variability in their mechanical and diffusive properties. 1 The small number of grains in lead-free solder joints 2 and the dependence of the microstructure on the thermal or process history, 3 physical size, 4 and chemical composition 5 are typically invoked to explain this variability, in light of the fact that tin is highly anisotropic in its elastic response 6 and creep properties. 7 The creep properties of solder joints are especially important during the reflow used to join the semiconductor device to substrates, where large stresses can develop in the joints due to the difference in thermal expansion between device and substrate, leading to mechanical damage in the device.…”

Section: Introductionmentioning

confidence: 99%

Large-Scale Correlations in the Orientation of Grains in Lead-Free Solder Joints

Sylvestre¹,

Blander²

2008

Journal of Elec Materi

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A large number of lead-free Sn-Ag-Cu controlled collapse chip connection (C4) solder joints ($100 lm in diameter) in flip-chip microelectronic packages were studied by electron backscatter diffraction (EBSD) in order to describe the statistical distribution of grain size and coincident site lattice boundaries associated with 60 deg twins in the Sn phase, as a function of silver content. It is shown that lower silver content results in smaller grains, and a lower propensity for grains to exhibit twinning symmetries. Indirect measurements of the creep properties of these joints were also obtained as a function of silver content, showing that, in the strain rate and temperature conditions that are the most relevant to the microelectronic industry, solder joints with low silver content are more susceptible to creep deformation.

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“…Kink formation is related to plastic deformation, such as sliding and twinning [15,21]. Because the sliding and twinning of tin depend on the tin crystal orientation, certain kink angles should be more common than others [24][25][26]. Figure 5.26 shows an example of a whisker with a kink angle of 45 ∘ .…”

Section: Measuring the Kink Angle And Length Of Tin Whiskersmentioning

confidence: 99%