Investigation of the Lead-On-Chip Package’s Reliability

1998 ◽  
Vol 120 (2) ◽  
pp. 171-174 ◽  
Author(s):  
P.-H. Tsao ◽  
L. C. Chang ◽  
T. C. Chen ◽  
C. Haung ◽  
C. Z. Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Flexural Modulus ◽  
Test Chip ◽  
Element Analysis ◽  
Thermally Induced ◽  
Molding Compounds ◽  
Different Types ◽  
Induced Stresses ◽  
On Chip

An assembly test chip (ATC), consisting of varieties of test structures, had been utilized to monitor the package integrity of SOJ lead-on-chip (LOC) packages after various reliability tests. Two different types of epoxy molding compounds, namely biphenyl and EOCN epoxies, were chosen to investigate their effects on package’s reliability. After the reliability tests, silicon chip crack was observed in three test samples due to the existence of a large chip backside chipping (˜120 μm). Qualitative study about this failure mechanism was carried out by a finite element analysis and it was found that, due to the higher flexural modulus and CTE of the biphenyl epoxy, the thermally induced stresses developed in the chip encapsulated by this epoxy during reliability tests were more likely to cause the crack propagation in the silicon chip than those induced by using EOCN type epoxy.

Parametric Modeling of Underground Powerhouse for Finite Element Analysis

2013 ◽  
Vol 405-408 ◽  
pp. 3222-3228
Author(s):  
Rong Gang Yin ◽  
Zhi Guo Li ◽  
Hong Xiang She ◽  
Jian Hai Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Model ◽  
Parametric Modeling ◽  
Element Analysis ◽  
Underground Powerhouse ◽  
Interactive Interface ◽  
Different Types ◽  
Basic Ideas ◽  
Display Window

In order to improve the modeling efficiency for finite element analysis pre-processing, a parametric modeling method of underground powerhouse for finite element analysis is proposed. By inputting the basic geometric parameters, different types of underground powerhouse models are built by using this method. The basic ideas, basic principle and the process of this parametric modeling are presented. And the parametric modeling procedure is coded by using VC++, interactive interface and display window are designed by using MFC and OpenGL. Finite element model of Houziyan underground powerhouse which is built by using the procedure proves that this method greatly improves the efficiency and precision of modeling.

An Improved Joint Model and Equations for Flexibility of Tubular Joints

1990 ◽  
Vol 112 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Y. Ueda ◽  
S. M. H. Rashed ◽  
K. Nakacho
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bending Moment ◽  
Joint Model ◽  
Initial Stiffness ◽  
Element Analysis ◽  
Joint Flexibility ◽  
Elastic Plastic ◽  
Tubular Joints ◽  
Different Types

In tubular frames with simple joints, joints may show considerable flexibility in the elastic as well as the elastic-plastic ranges. Such flexibility may have large effects on the behavior of the structure as a whole. In a previous paper, an effective simple model of tubular joints is developed. The model takes account of joint flexibility in the elastic as well as the elastic-plastic ranges based on elastic-fully plastic load-displacement relatioships. In this paper an improved joint model is presented to provide better accuracy while maintaining simplicity. The accuracy of the model is confirmed through comparisons with results of finite element analysis. Equations to evaluate the initial stiffness of tubular T and Y-joints when braces are subjected to axial compression or in-plane bending moment are also presented. Such equations for different types of joints in different loading conditions are needed in order to avoid expensive calculations to evaluate the initial stiffness of joints.

scholarly journals Finite Element Analysis Research on Buckling Behaviour of Unrestrained Stiffened Cold Formed Steel Box Sections

2020 ◽  
Vol 9 (2) ◽  
pp. 1033-1043
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Ultimate Strength ◽  
Element Analysis ◽  
Face To Face ◽  
Different Types ◽  
Cold Formed Steel ◽  
Element Method

This research mainly concentrates on ultimate strength and buckling behaviour of cold formed steel (CFS) laterally un-braced longitudinally stiffened box sections under flexure. A total of five various stiffener combinations for box sections has been studied by modifying the shape of a simple end stiffened section by the provision of intermediate stiffeners along web, flange or both along web and flange. The influence of different types of stiffeners with respect to various aspect radio’s (H/T, B/T, C/T and H/B) have been studied using Finite Element Method (FEM), and recommendations have been proposed on provisions of different stiffener’s combinations. This study mainly details with ultimate strength and buckling behaviour of CFS laterally unbraced stiffened box sections made by C sections connected face to face.

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