Nonlinear Thermal and Mechanical Analysis in the Vibration of a Printed Wiring Board

2000 ◽  
Author(s):  
Xiaoling He ◽  
Robert Fulton
Keyword(s):  
Dynamic Analysis ◽  
Modal Analysis ◽  
Temperature Variation ◽  
Equations Of Motion ◽  
Mechanical Analysis ◽  
Response Analysis ◽  
Printed Wiring Board ◽  
Simply Supported ◽  
Laminate Theory ◽  
Wiring Board

Abstract Nonlinear laminate theory is applied and extended for the printed wiring board dynamic analysis. Equations of motion for the isotropic laminates are derived for vibration response analysis of the simply supported printed wiring board under mechanical and thermal loads. Temperature variation in spatial domain is taken into consideration. The effect of the temperature variation on the response character is analyzed and demonstrated by means of numerical results. Modal analysis is made to predict the vibration behavior in terms of deflection and stresses. Lamina stresses are used for failure prediction.

Nonlinear Dynamics Analysis of a Laminated Printed Wiring Board

2002 ◽  
Vol 124 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Xiaoling He ◽  
Robert E. Fulton
Keyword(s):  
Dynamic Response ◽  
Large Deflection ◽  
Equations Of Motion ◽  
Response Analysis ◽  
Printed Wiring Board ◽  
High Acceleration ◽  
Dynamic Stress Field ◽  
Laminate Theory ◽  
Wiring Board ◽  
Nonlinear Elastic

Nonlinear laminate theory is applied for the printed wiring board (PWB) dynamic response analysis. Equations of motion for the nonlinear elastic deformation of the isotropic laminates are derived for the dynamic response of a simply supported PWB. Numerical results are generated for the nonlinear response characterization of the PWB deformation. Comparisons are made between the response of linear and nonlinear systems. Results show that PWB is in large deflection under high acceleration or certain pressure load. Nonlinear theory gives more accurate results for the large deflection than the linear theory does. Besides, lamina stresses are analyzed and illustrated from finite difference computation. The analytical derivation in modal approach and the stress analysis provide the basis for PWB reliability studies, especially the defect and failure induced by the dynamic stress field.

Comparison of First-Order Shear and Plane Strain Assumptions in Warpage Prediction of Simply Supported Printed Wiring Boards

2000 ◽  
Vol 123 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Yarom Polsky ◽  
I. Charles Ume
Keyword(s):  
Plane Strain ◽  
Plate Theory ◽  
Shear Deformation Theory ◽  
Transverse Load ◽  
Transverse Shear Strain ◽  
Printed Wiring Board ◽  
Simply Supported ◽  
First Order ◽  
Support Conditions ◽  
Wiring Board

The influence of transverse shear strain in the lamination theory modeling of Printed Wiring Board (PWB) deflection due to support conditions was examined. The in-plane mechanical properties of the core materials of a commercial PWB were measured as a function of temperature. Classical laminated plate theory and first-order shear deformation theory solutions for the out-of-plane deflection of a bare board configuration with two opposite edges simply supported and the remaining edges free were obtained. The weight of the board was approximated as a distributed transverse load. The effect of material property decrease with temperature and FR-4 layer thickness were examined to compare first-order shear and plane strain assumptions for the predicted warpage.

Dynamic Analysis to Confirm Lead Failure of a 352-Pin CQFP Under Shock

2009 ◽  
Author(s):  
Michael Feng ◽  
Peter Kwok ◽  
Dariusz Pryputniewicz ◽  
Ryan Marinis ◽  
Ryszard Pryputniewicz
Keyword(s):  
Dynamic Analysis ◽  
Thermal Cycling ◽  
Random Vibration ◽  
Plastic Material ◽  
Response Spectrum ◽  
Mechanical Shock ◽  
Shock Pulse ◽  
Printed Wiring Board ◽  
Test Environment ◽  
Wiring Board

During qualification testing of an electronics module, several leads in one corner of a 352 pin ceramic quad flat pack (CQFP) component failed. The module was exposed to several different environments including sine vibration, thermal cycling, random vibration, and shock. The last test environment applied was seven consecutive shocks normal to the printed wiring board. Given the severity of the shock response spectrum, it was believed that the shocks normal to the board were the culprit. Therefore, a finite element model (FEM) was created of the module to diagnose the cause of the failure. The FEM modeled all 352 CQFP leads using quadratic beam elements. Besides the CQFP, the FEM also included the aluminum frame, the printed wiring board, and several adjacent components. It was validated by comparing the board’s mode frequencies and shapes computed in ANSYS to those imaged by optoelectronic holography on the test hardware. ANSYS was also used to rule out sine vibration, random vibration, and thermal cycling as causes of the failure. To evaluate the stress levels in the leads during the shock pulse, the actual acceleration experienced by the hardware during a shock pulse was recorded and used in an explicit dynamic analysis in LS-DYNA. In addition, a bilinear elastic-plastic material model was used for the kovar leads. The analysis showed that the suspect leads reached their ultimate tensile strength by the fourth consecutive shock. These results confirmed that the leads failed due to the consecutive shock pulses. The FEM was subsequently used to evaluate a redesign of the module to mitigate the risk to mechanical shock.

Nonlinear Dynamics Analysis of a Printed Wiring Board With Simple and Clamped Boundary Conditions

2001 ◽  
Author(s):  
Xiaoling He
Keyword(s):  
Nonlinear Dynamics ◽  
Boundary Conditions ◽  
Equations Of Motion ◽  
Nonlinear Resonance ◽  
Failure Criteria ◽  
Dynamics Analysis ◽  
Printed Wiring Board ◽  
Resonance Behavior ◽  
Condition Effect ◽  
Wiring Board

Abstract Dynamic response of a printed wiring board (PWB) is analyzed in nonlinear dynamics approach. Equations of motion for the simply supported PWB and the clamped PWB are obtained by the Galerkin’s method. A 2-layer plastic PWB made of isotropic laminates is studied for its boundary condition effect on the vibratory behavior in deflection and stresses. Failure due to plane stress interaction is estimated based on the composite failure criteria. It is found that nonlinear resonance occurs almost periodically in both frequency and temporal domain. Load frequency and magnitude affect the deflection response under different boundary conditions. Resonance behavior is critical in PWB failure prediction based on the stress analysis. The analytical results can be extended to the nonlinear dynamics analysis of the thin laminated plate.

Characterization and Modeling of Printed Wiring Board Warpage and its Effect on LGA Separable Interconnects

2004 ◽  
Vol 127 (2) ◽  
pp. 178-184 ◽  
Author(s):  
J. Cepeda-Rizo ◽  
Hsien-Yang Yeh ◽  
N. Teneketges
Keyword(s):  
Printed Wiring Board ◽  
Out Of Plane ◽  
Mechanical Fastening ◽  
Laminate Theory ◽  
Wiring Board ◽  
Plane Displacement

The paper presents a study on printed wiring board (PWB) warpage caused by the mechanical fastening of separable interconnects, known as land grid array (LGA) package assemblies. Out-of-plane displacement of the PWB were measured and characterized, as well as force-per-pin values of the LGA, and correlations were made between the two. Classical laminate theory was utilized to describe the warpage behavior of the assembly and a model was presented to solve the out-of-plane displacements. An overall assessment of the assembly was made and compared to the mechanical specification of the LGA.

Vertical Response of Multi-Story Structures at the Instance of Maximum Horizontal Response

2002 ◽  
Author(s):  
Tomoyo Taniguchi
Keyword(s):  
Modal Analysis ◽  
Seismic Design ◽  
Equations Of Motion ◽  
Normal Modes ◽  
Degree Of Freedom ◽  
Response Analysis ◽  
Governing Equations ◽  
Single Degree Of Freedom ◽  
Shear Modes ◽  
Direct Numerical Integration

A vertical response of a multiple degree of freedom system vibrating in axial modes at the instance of its maximum horizontal response vibrating in shear modes is analyzed by superposition of normal modes. The coincident vertical response acceleration at the instance of the maximum horizontal response acceleration between two independent single degree of freedom systems indicated probabilistic properties. It is of interest to extend concepts of the response coincidence in the response analysis of multi-story structures. Nevertheless, the distribution of the coincident vertical response along the building height may be the most important in connection with the seismic design. Its probable distribution and an approximate upper bound are investigated to determine an analysis constant. The analysis constant enables the computation of the coincident vertical response of multi-story structures at the instance of the maximum horizontal response by the modal analysis. The results of the proposed method and the direct numerical integration of governing equations of motion are compared, and conclusions are drawn about the use of the modal analysis to the coincident vertical response of multi-story structures.

Reliability Analysis on the Chaos Induced by the Effect of the Transient Temperature Variation of a Printed Wiring Board

2001 ◽  
Author(s):  
Xiaoling He ◽  
Robert Fulton
Keyword(s):  
Temperature Variation ◽  
Thermal Loading ◽  
Chaotic Behavior ◽  
Mechanical Load ◽  
Harmonic Excitation ◽  
Transient Temperature ◽  
Printed Wiring Board ◽  
Load Effect ◽  
Temporal Oscillation ◽  
Wiring Board

Abstract The transient response of a printed wiring board (PWB) under mechanical and thermal loading is analyzed. The thermal load is caused by the time-dependent temperature variation of the PWB. Analytical solution is obtained for the equation of motion in nonlinear dynamics analysis. Numerical results showed that the response is in chaotic behavior under harmonic excitation due to the transient thermal effect. PWB response is characterized with respect to the thermal and mechanical load effect in both phase diagram and temporal oscillation.

Finite Element Analysis Framework for Dynamic Vehicle-Bridge Interaction System Based on ABAQUS

2020 ◽  
Vol 20 (03) ◽  
pp. 2050034 ◽  
Author(s):  
Xuzhao Lu ◽  
Chul-Woo Kim ◽  
Kai-Chun Chang
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Nonlinear Material ◽  
Response Analysis ◽  
Dynamic Crack ◽  
Analysis Framework ◽  
Cracked Beam ◽  
Simply Supported ◽  
Finite Element Software ◽  
Interaction System

This paper presents a unified framework for dynamic analysis of vehicle-bridge interaction (VBI) systems using a commercial finite element software suite (ABAQUS[Formula: see text]). This framework can provide bridge designers and engineering practitioners with a general platform to analyze the coupled system with high modeling efficiency and accuracy in modeling and outputting. Moreover, it has readily available nonlinear material/element models and nonlinear dynamic analysis functions for complex structures. This analysis framework was first validated with a classical VBI problem involving a sprung mass moving on a simply supported beam, whose closed-form solution is readily available. Validation for the application on complex structure was then presented with a typical 16-car Japanese high-speed train (Shinkansen) and a three-block bridge. The cars comprised car bodies, bogies and wheelsets, which were all modeled as rigid bodies and which were connected with springs and dashpots. The bridge was modeled with typical three-dimensional solid elements. Interaction between wheelsets and tracks was realized using the penalty method. Rail irregularity was also considered in the analysis. The consistency between calculated dynamic responses and field experiment data of certain pre-specified observation points validated the proposed method. Furthermore, ease in analyzing VBI problems involving nonlinear material properties and with high spatial resolutions was demonstrated with a classical cracked beam problem: a point mass moving on a simply supported cracked beam. Both linear and nonlinear crack models were employed. The former model assigned crack surfaces with a mechanical contact property and showed its accuracy in comparison to the reference model. The latter assigned a nonlinear material model in crack-prone zones and illustrated the potential applicability to dynamic crack propagation simulation in VBI problems. The present framework was further applied to seismic response analysis of a train-bridge interaction system involving material nonlinearity and separation between track and wheel under a strong earthquake.

Thermal and Mechanical Analysis of a Multichip Module

1992 ◽  
Vol 264 ◽  
Author(s):  
M. S. Hu
Keyword(s):  
High Speed ◽  
Mechanical Analysis ◽  
High Density ◽  
Electrical Performance ◽  
Multichip Module ◽  
Multichip Modules ◽  
Printed Wiring Board ◽  
Proper Design ◽  
Wiring Board ◽  
High Density Packaging

AbstractHigh speed, high density packaging requirements have made multichip modules (MCM) one of the most active areas of research in the electronic industry.High density printed wiring board (PWB) have low production cost and good electrical performance. However, the most questioned issue in application is the reliability. As a result, a thermal and mechanical analysis on a MCM has been conducted to understand its feasibility. The results indicate that with proper design, the components can operate under satisfactory conditions on PWB laminates.

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