3D large deformation and nonlinear stress analyses of tin whisker initiation and growth on lead-free components

2004 ◽  
Author(s):  
J.H. Lau ◽  
S.H. Pan ◽  
Chen Xa
Keyword(s):  
Large Deformation ◽  
Lead Free ◽  
Tin Whisker ◽  
Nonlinear Stress ◽  
Stress Analyses

3D Nonlinear Stress Analysis of Tin Whisker Initiation on Lead-Free Components

2003 ◽  
Vol 125 (4) ◽  
pp. 621-624 ◽  
Author(s):  
John H. Lau ◽  
Stephen H. Pan
Keyword(s):  
Stress Analysis ◽  
Compressive Stress ◽  
Chemical Reaction ◽  
Plastic Material ◽  
Copper Substrate ◽  
Three Dimensional ◽  
Lead Free ◽  
Tin Whisker ◽  
Weak Spot ◽  
Nonlinear Stress

In this study, a three-dimensional (3D) nonlinear stress analysis of the tin whisker initiation on a pure matte Sn-plated copper substrate is investigated. The structure is subjected to a compressive stress acting at the Sn layer which is generated by the spontaneous chemical reaction of the Sn layer and the Sn5Cu6 layer. The Sn layer is assumed to be an elasto-plastic material. The results presented herein is useful in understanding why the compressive stress in the Sn layer can initiate a tin whisker near the weak spot of a SnOx layer.

Lead-Free Solder/Gold Metallization Interdiffusion in Electronic Interconnects – Challenges and their Control

2008 ◽  
Author(s):  
Nausha Asrar
Keyword(s):  
Solder Joint ◽  
Coefficient Of Thermal Expansion ◽  
Void Formation ◽  
Lead Free ◽  
Gold Content ◽  
Lead Free Solder ◽  
Whisker Formation ◽  
Tin Whisker ◽  
Free Solder ◽  
Gold Metallization

Abstract While considerable amount of researches and investigations have been made on lead-free solder joint reliability, limited number of literatures are available on the effect of gold content on lead-free solder joint performance. The challenges of lead-free solder/gold metallization interdiffusion during high temperature application/test are: gold embrittlement, intermetallics growth, void formation, and tin-whisker formation. Tin whiskers causing system failures in earth and space-based applications have been reported. This paper illustrates a few case histories of such challenges. The results confirmed that the synergistic effects of void formation, intermetallic compounds formation due to the thick gold plating, and coefficient of thermal expansion mismatch between organic and ceramic substrates resulted in brittle fracture of the solder joint. The tin whisker formation was attributed to the compressive stress in the tin solder material, which was caused by diffusion of the end-cap metallization, formation of intermetallics, and thermal cycling of the soldered components.

Standards for Tin Whisker Test Methods on Lead-Free Components

2009 ◽  
Vol 32 (1) ◽  
pp. 216-219 ◽  
Author(s):  
Tadahiro Shibutani ◽  
Michael Osterman ◽  
Michael Pecht
Keyword(s):  
Test Methods ◽  
Lead Free ◽  
Tin Whisker

Influence of laminate type on tin whisker growth in tin-rich lead-free solder alloys

2012 ◽  
Vol 177 (15) ◽  
pp. 1286-1291 ◽  
Author(s):  
Agata Skwarek ◽  
Mariusz Pluska ◽  
Andrzej Czerwinski ◽  
Krzysztof Witek
Keyword(s):  
Whisker Growth ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Tin Whisker ◽  
Free Solder

The influence of porosity on whisker growth in electroplated tin films

2006 ◽  
Vol 21 (12) ◽  
pp. 2971-2974 ◽  
Author(s):  
J.P. Winterstein ◽  
M.G. Norton
Keyword(s):  
Whisker Growth ◽  
Control Method ◽  
Stress Relief ◽  
Lead Free ◽  
Tin Whisker ◽  
Tin Films ◽  
The Past ◽  
Compressive Stresses ◽  
Time Period ◽  
Lead Free Solders

Tin whisker growth has been observed since the 1950s and has become of more interest in the past 15 to 20 years due to the desire to use lead-free solders, pure tin being a good lead-free candidate. In the same time period, failure of satellites and other devices using pure tin solders has been blamed on tin whisker growth. The accepted driving force for whisker growth is compressive stresses in films. This article reports a microstructure-control method of limiting whisker growth through the introduction of pores that permit an alternate means of stress relief.

Analysis of tin whisker growth on lead-free alloys with Ni presence under thermal shock stress

2011 ◽  
Vol 176 (4) ◽  
pp. 352-357 ◽  
Author(s):  
Agata Skwarek ◽  
Mariusz Pluska ◽  
Jacek Ratajczak ◽  
Andrzej Czerwinski ◽  
Krzysztof Witek ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Whisker Growth ◽  
Lead Free ◽  
Tin Whisker ◽  
Shock Stress

Large Deformation Mechanics of the Enucleated Eyeball

1984 ◽  
Vol 106 (3) ◽  
pp. 229-234 ◽  
Author(s):  
L. A. Taber
Keyword(s):  
Large Deformation ◽  
Strain Energy Function ◽  
Membrane Action ◽  
Filled Rubber ◽  
Highly Nonlinear ◽  
Nonlinear Stress ◽  
Deformation Mechanics ◽  
Type Of Failure ◽  
Energy Formulation ◽  
Good Agreement

Large deformation of enucleated pig eyeballs under rigid cylindrical indenters was studied analytically and experimentally. The analytic model for the eyeball consists of a fluid-filled spherical membrane composed of an incompressible, elastic material with an exponential strain energy function. The Rayleigh-Ritz technique provided an approximate solution via a potential energy formulation. Comparison with results from tests on eyeballs and a water-filled rubber (Mooney-Rivlin) shell shows good agreement at large deflection, where membrane action dominates. Due to the highly nonlinear stress-strain relations for the sclera, the load remains relatively small until the indenter displacement approaches 40–60 percent of the eyeball radius, and then the load increases rapidly. Depending on the indenter size, either a perforation or a rupture type of failure occurs.

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