Moisture Diffusion and Hygroscopic Swelling of Adhesives in Electronics Packaging

Author(s):  
Ruiyang Liu ◽  
Huayan Wang ◽  
Jing Wang ◽  
Hohyung Lee ◽  
S. B. Park ◽  
...  
2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Dapeng Liu ◽  
Seungbae Park

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.


2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Samson Yoon ◽  
Changsoo Jang ◽  
Bongtae Han

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.


Author(s):  
Jiang Zhou ◽  
Tong Yan Tee ◽  
Xueren Zhang

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.


2019 ◽  
Vol 75 ◽  
pp. 159-166 ◽  
Author(s):  
Rawdha Kessentini ◽  
Olga Klinkova ◽  
Imad Tawfiq ◽  
Mohamed Haddar

2009 ◽  
Vol 12 (2) ◽  
pp. 144-153 ◽  
Author(s):  
Tomonori Mizutani ◽  
Toru Ikeda ◽  
Kiyoshi Miyake ◽  
Noriyuki Miyazaki

Author(s):  
Katja Reiter ◽  
Hans Bundgaard

Abstract Based on the requirements regarding target, reproducibility, and specimen surface quality, an automatic system for controlled material removal and target preparation has been developed. The tool is for metallographic failure analysis of electric and microelectronic components, and provides an accuracy of 5 micrometer. This article presents details of sample preparation and device evaluation methods. The images presented show typical objects of examination in the analysis of microstructures and materials in the electronics packaging industry with brief comments. For automatically controlled material removal and preparation, the tool offers alignment and measuring of the sample prior to the preparation. The desired preparation layers were achieved precisely and reproducibly with several specimens of the same kind. The automatic preparation system allowed the preparation of critical samples within a short time, with high precision and with excellent reproducibility.


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