Dynamic Analysis of HSDB System and Evaluation of Boundary Non-linearity through Experiments

2016 ◽  
Vol 66 (3) ◽  
pp. 210
Author(s):  
K. Chandrakar ◽  
P.L. Venkateshwara Rao ◽  
P. Rajendran ◽  
C. Satyanarayana
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
High Speed ◽  
Printed Circuit Board ◽  
Structural Integrity ◽  
Mechanical Design ◽  
Circuit Board ◽  
Element Analysis ◽  
Maximum Acceleration ◽  
Vibration Tests

<p class="FAIMTextBody">This paper deals with mechanical design and development of high speed digital board (HSDB) system which consists of printed circuit board (PCB) with all electronic components packaged inside the cavity for military application. The military environment poses a variety of extreme dynamic loading conditions, namely, quasi static, vibration, shock and acoustic loads that can seriously degrade or even cause failure of electronics. The vibrational requirement for the HSDB system is that the natural frequency should be more than 200 Hz and sustain power spectrum density of 14.8 Grms in the overall spectrum. Structural integrity of HSDB is studied in detail using finite element analysis (FEA) tool against the dynamic loads and configured the system. Experimental vibration tests are conducted on HSDB with the help of vibration shaker and validated the FE results. The natural frequency and maximum acceleration response computed from vibration tests for the configured design were found. The finite element results show a good correlation with the experiment results for the same boundary conditions. In case of fitment scenario of HSDB system, it is observed that the influence of boundary non-linearity during experiments. This influence of boundary non-linearity is evaluated to obtain the closeout of random vibration simulation results.</p>

Dynamic – Thermal Analyses of a Structurally Reconfigured Electronics Package Onboard Mini Satellite

2014 ◽  
Vol 592-594 ◽  
pp. 2117-2121 ◽  
Author(s):  
P. Veeramuthuvel ◽  
S. Jayaraman ◽  
Shankar Krishnapillai ◽  
M. Annadurai ◽  
A.K. Sharma
Keyword(s):  
Finite Element ◽  
Printed Circuit Board ◽  
Thermal Environment ◽  
Thermal Analyses ◽  
Simulation Models ◽  
Element Model ◽  
Circuit Board ◽  
Element Analysis ◽  
Transfer Path ◽  
Vibration Responses

The electronics package in a spacecraft is subjected to a variety of dynamic loads during launch phase and suitable thermal environment for the mission life. The dynamic and thermal analyses performed for a structurally reconfigured electronics package. Two different simulation models are developed to carry out the analyses. This paper discusses in two parts, in part-1, the vibration responses are determined at various critical locations, including on the Printed Circuit Board (PCB) for the vibration loads specified by launch vehicle using Finite Element Analysis (FEA). The mechanical properties of PCB are determined from the test specimens, which are then incorporated in the finite element model. In part-2, the steady-state temperature distributions on the components and on the PCB are determined, to check the effectiveness of heat transfer path from the components to the base of the package and to verify the predicted values are within the acceptable temperature limits specified. The predicted temperature values are then compared with on-orbit observations.

scholarly journals Study on the Impact of Lead Sidewall Solder Coverage and Corner Lead Size on Joint Reliability

2021 ◽  
pp. 62-69
Author(s):  
Jefferson Talledo
Keyword(s):  
Solder Joint ◽  
Integrated Circuit ◽  
High Speed ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Element Analysis ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
Solder Fatigue ◽  
The Impact

Solder joint reliability is very important to ensure that an integrated circuit (IC) semiconductor package is functional within its intended life span as the solder joint establishes electrical connection between the IC and the printed circuit board (PCB). Solder fatigue failure or crack under thermal cycling is one of the common problems with board-mounted packages. There are several factors or package characteristics that have impact on solder fatigue life like package size and material properties of the package components. This paper presents a thermo-mechanical modeling of a leadframe-based semiconductor package to study the impact of lead sidewall solder coverage and corner lead size on the solder joint reliability. Finite element analysis (FEA) technique was used to calculate the solder life considering 50% and 100% package lead sidewall solder coverage as well as smaller and larger critical corner leads of the package. The results of the analysis showed that higher lead sidewall solder coverage and larger lead could significantly increase solder life. Therefore, ensuring lead sidewall solder wettability to have higher solder coverage is beneficial. The study also reveals that packages with side wettable flanks are not only enabling high speed automated optical inspection required for the automotive industry, but they are also providing improved solder joint reliability.

scholarly journals Model Updating and Structural Optimization of Circular Saw Blades with Internal Slots

2014 ◽  
Vol 6 ◽  
pp. 546496
Author(s):  
Wei-Hsin Gau ◽  
Kun-Nan Chen ◽  
Yunn-Lin Hwang
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Structural Integrity ◽  
Model Updating ◽  
Element Model ◽  
Frequency Separation ◽  
Element Analysis ◽  
Sizing Optimization ◽  
Rotating Speed ◽  
Circular Saw

Circular diamond saws rotating in high speed are widely used to cut hard materials, and narrow slots on saw blades are sometimes used to reduce the blades' vibration and noise. Sizing optimization of the internal, annular slots on saw blades is investigated in this paper. First, an accurate finite element model representing an actual saw blade is obtained by model updating. Then, sizing optimization on two types of annular slots is performed to maximize the frequency separation between the finite element analysis results and the saw blade's operational speed and to reduce the possibility of structural resonance. Optimization results demonstrate great improvements in frequency separation from the rotating speed of 500 Hz for the optimized models, and stress analyses on the optimized blade models confirm the structural integrity of the designs.

Finite Element Analysis of Static and Dynamic Characteristics of High-Speed Horizontal Machining Center Bed

2014 ◽  
Vol 889-890 ◽  
pp. 58-61 ◽  
Author(s):  
Peng Wang ◽  
Yan Rui Zuo ◽  
Li Na Ren ◽  
Dong Dong Song
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Lightweight Design ◽  
Element Analysis ◽  
Static And Dynamic Characteristics ◽  
Machining Center ◽  
Analysis Theory ◽  
Work Area

Based on the theory of finite element and modal analysis theory, analysis of static and dynamic characteristics of the lathe bed has been done. The static displacement contours and mode natural frequency and displacement contours have been given to realize the structure optimization of lathe bed of high-speed horizontal machining center. It is shown that the bed has good static stiffness and natural frequency and the deformation of lathe bed mainly occurred in the tray conversion mechanism and the cutter location. The deformation of processing work area is small and has certain light weight space, which lay the foundation for the lightweight design of the bed.

Research on Delamination of Plastic Packaging Device during Reflow Soldering

2015 ◽  
Vol 645-646 ◽  
pp. 226-231
Author(s):  
Pei Sheng Liu ◽  
Ying Lu ◽  
Jin Xin Huang ◽  
Long Long Yang
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Printed Circuit Board ◽  
Fem Simulation ◽  
Circuit Board ◽  
Element Analysis ◽  
Reflow Soldering ◽  
Plastic Packaging ◽  
Finite Element Software ◽  
Low Profile

Due to the application of lead-free solders, the quality and reliability of plastic packaging device are influenced by the increase of reflow temperature. In this paper, a low-profile quad flat package (LQFP) is chosen to illustrate the interface deformation during reflow soldering. The stress analysis theory and the finite element analysis (FEM) simulation are introduced in this paper. By means of finite element software, the distribution of hygrostress, thermal stress and the deformation of device on the printed circuit board (PCB) are analyzed and calculated under different temperature. The relationship between delamination length and deformation is given. The simulation results show that the warping phenomenon is found at the apex angle of the device; delamination is easily produced in the interfaces between different materials by thermal stress, and possibly leads to the device failure.

Improvement of Thermo-Mechanical Reliability of Wafer-Level Chip Scale Packaging

2018 ◽  
Vol 140 (1) ◽  
Author(s):  
Lei Shi ◽  
Lin Chen ◽  
David Wei Zhang ◽  
Evan Liu ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Finite Element ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Coefficient Of Thermal Expansion ◽  
Equivalent Stress ◽  
Circuit Board ◽  
Electrical Performance ◽  
Design Parameters ◽  
Wafer Level ◽  
Element Analysis

Due to low cost and good electrical performance, wafer-level chip scale packaging (WLCSP) has gained more attention in both industry and academia. However, because the coefficient of thermal expansion (CTE) mismatches between silicon and organic printed circuit board (PCB), WLCSP technology still faces reliability challenges, such as the solder joint fragile life issue. In this paper, a new WLCSP design (WLCSP-PN) is proposed, based on the structure of WLCSP with Cu posts (WLCSP-P), to release the stress on the solder joints. In the new design, there is a space between the Cu post and the polymer which permits NiSn coating on the post sidewall. The overcoating enhances the solder–post interface where cracks were initiated and enlarges the intermetallic compounds (IMC) joint area to enhance the adhesion strength. Design of experiment (DOE) with the Taguchi method is adopted to obtain the sensitivity information of design parameters of the new design by the three-dimensional (3D) finite element model (FEM), leading to the optimized configuration. The finite element analysis results demonstrate that compared to WLCSP-P, the proposed WLCSP-PN reduces the package displacement, equivalent stress, and plastic strain energy density and thus improves the fatigue life of solder joints.

Finite Element Analysis on Natural Properties of a Micro Drill with Ultrasonic Vibration

2015 ◽  
Vol 764-765 ◽  
pp. 285-288
Author(s):  
Bo Wun Huang ◽  
Wu Tsan Chen ◽  
Jung Ge Tseng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ultrasonic Vibration ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Machining Accuracy ◽  
Drilling Process ◽  
Element Analysis ◽  
Natural Properties ◽  
Micro Drill

Finite element analysis on natural properties of a micro drill with ultrasonic vibration is considered to study. Because getting smaller aperture in the printed circuit board (PCB), it tends to be more severe due to vibration. The vibration has adverse effects to machining accuracy and surface roughness which will increase tool abrasion and further accelerate the destruction from material fatigue. There are many ways to produce perforations, such as laser micro-machining and micro-drilling. The industry still adopts micro drill piercing process due to the cost and technical considerations. In order to enhance the cutlery life and the quality of the drilling process, the cutting characteristic of bur is important. Hence, the vibration during drilling must be suppressed. This study is to investigate the natural properties of a micro drill under ultrasonic vibration (50 kHz) excited with a piezoelectric-driven actuator and numerically by using finite element analysis.

Optimized Design of the Structure of High-Speed Railway Bearing Test Rig

2012 ◽  
Vol 479-481 ◽  
pp. 1442-1445
Author(s):  
Xian Zhao Jia ◽  
Yong Jian Yu ◽  
Hong Bin Liu
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
High Speed ◽  
Dynamic Performance ◽  
Element Model ◽  
Optimized Design ◽  
Test Rig ◽  
Element Analysis ◽  
High Speed Railway ◽  
Main Spindle

This paper establishes the finite element model of main spindle in the test rig for high-speed railway bearing. Utilizing the finite element analysis software ANSYS, the modal analysis for spindle is carried on. Preliminary determination is that spindle resonance occurs. Structural optimization is carried out by increasing first natural frequency and reducing weight of main spindle in order to avoid resonance. The results showed that the position of support bearings is determined. The first natural frequency is increased by reducing spindle weight. The dynamic performance of the spindle is improved, avoiding the resonance region effectively.

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