Local Stress Analysis by XRD Single Crystal Method and Kossel Diffraction Applied to a Flip Chip Structure

2017 ◽  
Author(s):  
A.-L. Lebaudya ◽  
R. Pescia ◽  
W. Kpobieb ◽  
M. Fendler
Keyword(s):  
Single Crystal ◽  
Stress Analysis ◽  
Flip Chip ◽  
Local Stress

Finite Element Analysis of Stress Singularities in Attached Flip Chip Packages

2000 ◽  
Vol 122 (4) ◽  
pp. 301-305 ◽  
Author(s):  
A. Q. Xu ◽  
H. F. Nied
Keyword(s):  
Contact Angle ◽  
Finite Element ◽  
Glass Fiber ◽  
Flip Chip ◽  
Three Dimensional ◽  
Stress Singularity ◽  
Local Stress ◽  
Stress Singularities ◽  
Element Analysis ◽  
Three Dimensional Finite Element

Cracking and delamination at the interfaces of different materials in plastic IC packages is a well-known failure mechanism. The investigation of local stress behavior, including characterization of stress singularities, is an important problem in predicting and preventing crack initiation and propagation. In this study, a three-dimensional finite element procedure is used to compute the strength of stress singularities at various three-dimensional corners in a typical Flip-Chip assembled Chip-on-Board (FCOB) package. It is found that the stress singularities at the three-dimensional corners are always more severe than those at the corresponding two-dimensional edges, which suggests that they are more likely to be the potential delamination sites. Furthermore, it is demonstrated that the stress singularity at the upper silicon die/epoxy fillet edge can be completely eliminated by an appropriate choice in geometry. A weak stress singularity at the FR4 board/epoxy edge is shown to exist, with a stronger singularity located at the internal die/epoxy corner. The influence of the epoxy contact angle and the FR4 glass fiber orientation on stress state is also investigated. A general result is that the strength of the stress singularity increases with increased epoxy contact angle. In addition, it is shown that the stress singularity effect can be minimized by choosing an appropriate orientation between the glass fiber in the FR4 board and the silicon die. Based on these results, several guidelines for minimizing edge stresses in IC packages are presented. [S1043-7398(00)00904-X]

Evaluation of homogenization for global/local stress analysis of textile composites

1995 ◽  
Vol 31 (2) ◽  
pp. 137-149 ◽  
Author(s):  
John Whitcomb ◽  
Kanthikannan Srirengan ◽  
Clinton Chapman
Keyword(s):  
Stress Analysis ◽  
Local Stress ◽  
Textile Composites

Stress analysis of the multi-layer stagger-split die for synthesizing gem quality large single crystal diamond

2018 ◽  
Vol 83 ◽  
pp. 54-59
Author(s):  
Liang Zhao ◽  
Mingzhe Li ◽  
Rui Li ◽  
Erhu Qu ◽  
Liyan Wang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Stress Analysis ◽  
Large Single Crystal ◽  
Single Crystal Diamond

High Resolution 3D Reconstruction of an Atherosclorotic Plaque by a Combination of Histology and 3D Ultrasound

2009 ◽  
Author(s):  
Ahsan Choudhury ◽  
Michael Luppi ◽  
Warren Hopkins ◽  
Hao Gao ◽  
Saroj Das ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Stress Analysis ◽  
Plaque Rupture ◽  
Local Stress ◽  
3D Ultrasound ◽  
Plaque Morphology ◽  
Local Stress Concentration ◽  
Arterial Plaque ◽  
Cerebral Ischemic ◽  
Ischemic Attack

The sudden rupture of a vulnerable arterial plaque is a major cause of cerebral ischemic attack. Triggering of sudden rupture is a result of unfavourable plaque morphology, and is also a result of local stress concentration acting on the plaque. Computational stress analysis on a realistic plaque model is an important tool to assess the vulnerability of plaque rupture. However, the accuracy of the stress analysis is heavily dependent on the accuracy of the 3D reconstruction of the plaque geometry. The derivation of accurate vessel geometries from medical imaging has proved to be difficult due to limited image spatial resolution (at about 0.3mm in-plane) and the lack of contrast between the plaque components.

Influence of Attachment Rigidity on Stress Analysis

2011 ◽  
Vol 138-139 ◽  
pp. 74-78
Author(s):  
Yue Qiang Qian ◽  
Fu Jun Liu ◽  
Zhang Wei Ling ◽  
Shuai Kong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cylindrical Shell ◽  
Stress Analysis ◽  
Shell Thickness ◽  
Equivalent Stress ◽  
Local Stress ◽  
Pressure Vessels ◽  
Equivalent Stresses ◽  
Typical Method

In pressure vessels design, WRC107 provides a typical method of local stress analysis to supports and attachments. But influence of the rigidity of attachments on calculation is not considered. For fatigue analysis of round hollow attachment on cylindrical shell, equivalent stresses calculated by WRC107 were compared with those by finite element method. Three attachment thickness configurations, that half, equal, double of the shell thickness were tested. Results show that, in key point Au defined by WRC107 equivalent stress decreases while attachment rigidity increases, and in key point Cu, equivalent stress increases while attachment rigidity increases. When the thickness of attachment equals to that of shell, equivalent stress of WRC107 in Cu comes closest to FEM.

Advanced x-ray stress analysis method for a single crystal using different diffraction plane families

2008 ◽  
Vol 92 (23) ◽  
pp. 231903 ◽  
Author(s):  
Muneyuki Imafuku ◽  
Hiroshi Suzuki ◽  
Kazuyuki Sueyoshi ◽  
Koichi Akita ◽  
Shin-ichi Ohya
Keyword(s):  
Single Crystal ◽  
Stress Analysis ◽  
Analysis Method ◽  
Diffraction Plane ◽  
X Ray
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