ABSTRACT In package, it¡¦s easy to have defects in the solder joint, for the request of environment protection, lead-free solder research is one of the most important topics now. In soldering, the adhesion, diffusion barrier, and wettability of the interface between UBM and a lead-free solder, and the caused IMC structure that are important elements to influence long-term reliability tests. The thesis is aimed to investigate the combination of pure tin/Al-NiV-Cu UBM/STD Au substrate under reliability tests. The samples are bare dies in which the combination is pure tin/ Al-NiV-Cu UBM and packages of is pure tin/Al-NiV-Cu UBM/STD Au substrate. The goals are to realize the mechanical properties under multiple reflows and long term HTST tests with different temperatures and the operational life. We also uses SEM to observe the growth of IMC and the failure modes that help us to realize the connection between failure modes and IMC. The results of experiment can be concluded as follows. In a bare die, 260¢Jmultiple reflows test causes delamination between IMC and die, but doesn¡¦t affect the mechanical properties of it, and HTST test lowers the bump shear strength of it. In package, multiple reflows test and HTST test lower the mechanical properties significantly, the result also means that the adhesion between bump and die will drop significantly as tests go on. In HTOL test with the conditions of 150¢J and 320mA, the average stable service time of the package is 892 hours, and the average ultimate service time of the package is 1,053 hours, most probable failure site is in R1 joint.

The fatigue-induced solder joint failure of surface mounted electronic devices has become one of the most critical reliability issues in electronic packaging industry. Prediction of the shape of solder joints has drawn special attention to the related development and engineering applications. Numerous solder joint models, based on energy minimization principle and analytical methods, have been proposed and developed. The methods are extensively utilized to the shape design of solder joint. However, it is important to find a suitable method to real applications. Herein, a series of experiments with different geometric parameters of SAC405 solder joints were carried out and the results were compared with the prediction by Surface Evolver Program. The changes of geometric shape with respect to different parameters of solder joint were also discussed. The influence of the geometric parameters, such as volume of solder joint, package weight, solder surface tension, and gravity force to the shape of solder joint were investigated. Two experiments with SAC405 solder balls were carried out. One is to observe the different reflowed geometry shape of solder balls with various volumes, and another is to observe the different reflowed geometry shape of solder balls with various loadings on them. The results show that the models made by Surface Evolver program are very similar to the real shapes observed by experiments, and the differences are between -3% ~ 6.5%. Thus, the results show that the predicted shapes are satisfactorily suitable. Finally, the predicted models by Surface Evolver program were also put into the ANSYS program, and preceded the fatigue life prediction due to thermal cycling tests. The comparison of the effect on fatigue life with respect to different geometry shapes is illustrated. The results show the shape of solder ball due to high loadings is better than that in thermal cycling tests.

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Thesis (Ph. D.)--University of Queensland, 2001. / Includes bibliographical references.

No description available.

No description available.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Also available in print.

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2007. / Ume, Charles, Committee Chair ; Book, Wayne, Committee Member ; Michaels, Jennifer, Committee Member ; Sitaraman, Suresh, Committee Member ; Tsui, Kwok-Leung, Committee Member ; Goyal, Deepak, Committee Member.

Thesis (Ph.D.)--University of California, Berkeley, 2002. / Chair: John W. Morris, Jr. Includes bibliographical references.

Thesis (M.S.)--State University of New York at Binghamton, Department of Mechanical Engineering, 2007. / Includes bibliographical references (leaves 121-122).