Transient analysis on hygroscopic swelling characterization using sequentially coupled moisture diffusion and hygroscopic stress modeling method

Jiang Zhou

doi:10.1016/j.microrel.2008.03.027

Transient analysis on hygroscopic swelling characterization using sequentially coupled moisture diffusion and hygroscopic stress modeling method

Microelectronics Reliability ◽

10.1016/j.microrel.2008.03.027 ◽

2008 ◽

Vol 48 (6) ◽

pp. 805-810 ◽

Cited By ~ 10

Author(s):

Jiang Zhou

Keyword(s):

Transient Analysis ◽

Moisture Diffusion ◽

Modeling Method ◽

Stress Modeling ◽

Hygroscopic Swelling

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Transient Analysis on Hygroscopic Swelling Characterization Using Sequentially Coupled Moisture Diffusion and Hygroscopic Stress Modeling Approach

Electronic and Photonic Packaging, Electrical Systems Design and Photonics, and Nanotechnology ◽

10.1115/imece2005-81847 ◽

2005 ◽

Cited By ~ 5

Author(s):

Jiang Zhou ◽

Tong Yan Tee ◽

Xueren Zhang

Keyword(s):

Previous Analysis ◽

Moisture Diffusion ◽

Moisture Distribution ◽

Stress Modeling ◽

Modeling Approach ◽

Hygroscopic Swelling ◽

Measured Deformation ◽

The Impact ◽

Uniform Moisture ◽

Comprehensive Study

One of the challenges for the hygroscopic swelling characterization is to investigate the impact of non-uniform moisture distribution across the specimen using currently available metrologies. Our recent studies have shown that the current averaged approach might overestimate the coefficient of hygroscopic swelling as much as 250%. In our previous analysis, however, the hygroscopic stress induced deformation has not been taken into consideration. As a matter of fact, due to non-uniform moisture distribution during the test, the total measured deformation includes two parts—one is from the hygroscopic swelling itself, and the other is from the hygroscopic stress induced deformation. This paper provides a comprehensive study on the impacts of non-uniform moisture distribution and the effect of hygroscopic stress by using a sequentially coupled moisture diffusion and hygroscopic stress modeling approach. The results show that the hygroscopic stress induced displacement is relatively small, although the elastic strain caused by the hygroscopic stress accounts for about one third of the total strain. The results in our previous study are proved to be acceptably accurate, even through the hygroscopic stress induced deformation is neglected in the previous analysis.

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A Note on the Normalized Approach to Simulating Moisture Diffusion in a Multimaterial System Under Transient Thermal Conditions Using ansys 14 and 14.5

Journal of Electronic Packaging ◽

10.1115/1.4026661 ◽

2014 ◽

Vol 136 (3) ◽

Cited By ~ 20

Author(s):

Dapeng Liu ◽

Seungbae Park

Keyword(s):

Material Property ◽

Thermal Conditions ◽

Moisture Diffusion ◽

Electronic Components ◽

Current Version ◽

Temperature Dependent ◽

Moisture Concentration ◽

Hygroscopic Swelling ◽

Packaging Industry ◽

Transient Thermal

Moisture can have significant effects on the performance and reliability of electronic components. Accurately simulating moisture diffusion is important for designers and manufacturers to obtain a realistic reliability evaluation. Beginning with version 14, ansys is capable of simulating diffusion and related behaviors, such as hygroscopic swelling, with newly developed elements. However, a normalized approach is still required to deal with the discontinuity of concentrations at the material boundaries, and normalization of the moisture concentration in transient thermal conditions is tricky. Case studies have shown that normalizing the moisture concentration with respect to a time- or temperature-dependent material property will lead to erroneous results. This paper re-addresses the issues of performing diffusion simulations under transient thermal conditions and more general anisothermal conditions (temporally and spatially), and suggests an easy-to-use approach to cope with the limitations of the current version for users in the electronic packaging industry.

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Nonlinear Stress Modeling Scheme to Analyze Semiconductor Packages Subjected to Combined Thermal and Hygroscopic Loading

Journal of Electronic Packaging ◽

10.1115/1.2912181 ◽

2008 ◽

Vol 130 (2) ◽

Cited By ~ 18

Author(s):

Samson Yoon ◽

Changsoo Jang ◽

Bongtae Han

Keyword(s):

Finite Element ◽

Stress Analysis ◽

Moisture Diffusion ◽

Combined Loading ◽

Numerical Accuracy ◽

Element Analysis ◽

Viscoelastic Composite ◽

Nonlinear Stress ◽

Hygroscopic Swelling ◽

Semiconductor Packages

A nonlinear finite element modeling (FEM) scheme to analyze the combined effect of thermal and hygroscopic deformation is presented. The scheme employs the conventional moisture diffusion, heat transfer, and stress analysis routines available in the commercial FEM package, but offers a unique way of linking the routines to conduct a nonlinear stress analysis of semiconductor packages subjected to moisture as well as temperature excursions. Strategies to implement the proposed scheme using commercial finite element analysis softwares are discussed. The numerical accuracy of the scheme is confirmed with the analytical solution of elastic/viscoelastic composite cylinder subjected to the combined loading of thermal expansion and hygroscopic swelling.

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