Drop Test Simulation for the Component-Level Reliability of Module Packages

2010 ◽  
Vol 2010 (1) ◽  
pp. 000220-000226
Author(s):  
Yu Gu ◽  
Daniel Jin
Keyword(s):  
Parametric Modeling ◽  
Drop Test ◽  
Parametric Models ◽  
Component Level ◽  
Test Board ◽  
Module Size ◽  
Drop Tests ◽  
Explicit Dynamic ◽  
Board Level ◽  
The Impact

The component-level drop reliability of micro-electronic packages has been a concern. Proper modeling approaches can significantly reduce the time and costs and provide valued data support not only on the failure analysis but also on product development. Based on finite element methods, the presented study performed explicit dynamic drop modeling to simulate the actual drop tests using ANSYS and LS-DYNA. A generic over-molded LGA (land grid array) module was selected and 3D parametric models were utilized to carry out the study. As in the actual drop test, the standard JEDEC test board and JEDEC drop condition were applied. The over-molded modules together with the test board under 1500G gravity was simulated to identify the failure locations. The results were fairly correlated to the actual FA observation. Potential key factors such as solder pad size, pitch size, module size, and thickness were studied through the parametric modeling. The impact of board side defect, such as solder void, was also studied because it is common to have this kind of defect in assembly. Besides component-level drop reliability, we also studied the board-level drop reliability by investigating the LGA solder stress.

Failure Analysis of Halogen-Free Printed Circuit Board Assembly Under Board-Level Drop Test

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Hung-Jen Chang ◽  
Chau-Jie Zhan ◽  
Tao-Chih Chang ◽  
Jung-Hua Chou
Keyword(s):  
Printed Circuit Board ◽  
Drop Test ◽  
Circuit Board ◽  
Printed Circuit Board Assembly ◽  
Printed Circuit ◽  
Plastic Ball ◽  
Circuit Board Assembly ◽  
Halogen Free ◽  
Board Level ◽  
The Impact

In this study, a lead-free dummy plastic ball grid array component with daisy-chains and Sn4.0Ag0.5Cu Pb-free solder balls was assembled on an halogen-free high density interconnection printed circuit board (PCB) by using Sn1.0Ag0.5Cu solder paste on the Cu pad surfaces of either organic solderable preservative (OSP) or electroless nickel immersion gold (ENIG). The assembly was tested for the effect of the formation extent of Ag3Sn intermetallic compound. Afterward a board-level pulse-controlled drop test was conducted on the as-reflowed assemblies according to the JESD22-B110 and JESD22-B111 standards, the impact performance of various surface finished halogen-free printed circuit board assembly was evaluated. The test results showed that most of the fractures occurred around the pad on the test board first. Then cracks propagated across the outer build-up layer. Finally, the inner copper trace was fractured due to the propagated cracks, resulting in the failure of the PCB side. Interfacial stresses numerically obtained by the transient stress responses supported the test observation as the simulated initial crack position was the same as that observed.

Hybrid Simulation Method for PWB Level Drop Tests

2005 ◽  
Author(s):  
Jiansen Zhu ◽  
Esa Hussa ◽  
Juscelino Okura ◽  
Santosh Shetty
Keyword(s):  
Large Deformation ◽  
Simulation Method ◽  
Standard Test ◽  
Test Method ◽  
Drop Test ◽  
Nonlinear Material ◽  
Time Curve ◽  
Impulse Duration ◽  
Drop Tests ◽  
The Impact

PWB level drop tests are widely used as a standard test method to evaluate the reliability of PWB and packages under drop conditions (JEDEC Standard JESD22-B104-A). The drop height and test setup need be adjusted in order to achieve the requirements of a peak shock of 1500g and an impulse duration of 0.5 ms. Generally, the ground need be covered with a thin layer of rubber pad to absorb some of the impact energy. However, this rubber pad will bring challenges for modelling due to large deformation, nonlinear hyperelasticity, and contact. And sometimes, it may also cause the convergence problem. Therefore, a hybrid drop simulation method was developed. This hybrid method can not only circumvent the difficulties mentioned, but also increase the efficiency and reduce the CPU time of PWB drop simulation. When simulating a PWB board level drop test, generally, not only the PWB and the components assembled on it need be modelled, but also the drop vehicle, rubber pad, and ground should be included in the model. For the hybrid drop simulation, however, only part of drop vehicle need be modeled and there is no need to model the ground and the contact between the ground and the drop vehicle. Then an acceleration time curve measured from drop test is applied to the hybrid model so that the responses of the model will mimic the real drop situation. In this way, not only the simulation time is reduced due to smaller model sizes, but also can some difficulties related to large deformation, contact, and nonlinear material properties be avoided. Finally, a comparison of a bare PWB and a populated PWB drop cases was used to validate this hybrid drop simulation method. A reasonable correlation was achieved.

Benchmarking of Explicit Dynamic Finite Element Analysis for Storage and Transportation Casks Under Impact Loading Conditions

2017 ◽  
Author(s):  
Shinji Yoshida ◽  
Toshiki Okamoto ◽  
Shunsuke Takagi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Foot Drop ◽  
Element Analysis ◽  
Dynamic Finite Element ◽  
Dynamic Finite Element Analysis ◽  
Drop Tests ◽  
Analytical Accuracy ◽  
Explicit Dynamic ◽  
The Impact

Impact analyses for storage and transportation cask drop tests were performed using the explicit dynamic finite element analysis code to demonstrate analytical accuracy and benchmark the analytical code. The test series for this benchmarking were provided by Sandia National Laboratories (SNL) as the Structural Evaluation Unit Benchmark Problem Statement. 30 foot and 120 foot drop test cases in which the test unit was dropped from 30 feet and 120 feet onto an essentially rigid target were selected as the benchmarking problems. A comparison of deformation and acceleration between the actual cask drop tests and those predicted by explicit dynamic finite element analysis performed using LS-DYNA was performed in this paper. The simulation results showed reasonably good agreement with respect to deformation and acceleration between the calculated and the measured result by adjusting the material properties of the impact limiter to match the amount of crush.

Logical and Parametric Modeling of the Prerequisities and the Establishment of a Measure of the Certainty of the Implementation of the Incident in Sistem

2017 ◽  
Vol 6 (2) ◽  
pp. 3-11
Author(s):  
Есипов ◽  
Yuriy Esipov ◽  
Джиляджи ◽  
M. Dzhilyadzhi ◽  
Черемисин ◽  
...  
Keyword(s):  
Security Analysis ◽  
Quantitative Measure ◽  
Parametric Modeling ◽  
Parametric Models ◽  
Calculation Algorithm ◽  
Fuzzy Measures ◽  
Important Region ◽  
Safety Parameters ◽  
Impact Attenuation ◽  
The Impact

Based on the factor of parametric modeling specifically given system “object — factors — protection worker” the problem of determining a quantitative measure of the possible implementation options (outcomes) of the occurrence of the incident was testedby: 1) construction of parametric and logical assumptions; 2) identifying their coherence in relation to the selected occurrence, and 3) calculating possible (fuzzy) measures of the occurrence of the incident taking into account the completeness and reliability of the initial data about the system. The numerical estimation of safety parameters in practically important region of analysis is given: the impact of “less” or “much less” susceptibility. The demonstration of the possible use of parametric models “impact — attenuation — sensitivity” in the range of occurrence of apical outcomes from injury (disease) to a critical, or death is given. It is shown that the proposed method of security analysis and the calculation algorithm is standardized and can be applied to assess both integral and differential risk of complex systems.

Analysis on the Effect of Input Impact Profiles in Drop Test

2007 ◽  
Author(s):  
Jiang Zhou ◽  
Ratna P. Niraula ◽  
Kendrick Aung
Keyword(s):  
Dynamic Response ◽  
Impact Load ◽  
Block Diagram ◽  
Input Pulse ◽  
Drop Test ◽  
System Level ◽  
System Response ◽  
Time Duration ◽  
Board Level ◽  
The Impact

The objective of this paper is to develop an analytical or mathematical predicative model for the evaluation of dynamic response of a structural element in a microelectronic or an optoelectronic product to an impact load occurring as a result of drop or shock test. Closed-form theoretical solution was obtained to simulate the board level drop test. The block diagram based SIMULINK analysis was introduced to determine the response with various impact configurations for the system level drop test as well. This study will help reliability engineers to design the impact input profiles and obtain the desired responses, and to calibrate and validate finite element analysis results quickly for both board level and system level drop test. It was found that time durations of the input profiles play an important role in the dynamic response. The system response can be designed by carefully choosing the impact time duration. Certain input pulse time results in the response with very low ringing after first or second peaks.

Correlation studies for component level ball impact shear test and board level drop test

2008 ◽  
Vol 48 (7) ◽  
pp. 1069-1078 ◽  
Author(s):  
E.H. Wong ◽  
R. Rajoo ◽  
S.K.W. Seah ◽  
C.S. Selvanayagam ◽  
W.D. van Driel ◽  
...  
Keyword(s):  
Shear Test ◽  
Drop Test ◽  
Component Level ◽  
Ball Impact ◽  
Correlation Studies ◽  
Board Level

Mechanical and Thermal Assessment by BAM of a New Package Design for the Transport of SNF From a German Research Reactor

2020 ◽  
Author(s):  
Steffen Komann ◽  
Viktor Ballheimer ◽  
Thomas Quercetti ◽  
Robert Scheidemann ◽  
Frank Wille
Keyword(s):  
Research Reactor ◽  
Drop Test ◽  
Radioactive Material ◽  
Test Facility ◽  
Test Sequence ◽  
Thermal Safety ◽  
Package Design ◽  
Drop Tests ◽  
Approval Procedure ◽  
The Impact

Abstract For disposal of the research reactor of the Technical University Munich FRM II a new transport and storage cask design was under approval assessment by the German authorities on the basis of International Atomic Energy Agency (IAEA) requirements. The cask body is made of ductile cast iron and closed by two bolted lid systems with metal seals. The material of the lids is stainless steel. On each end of the cask the wood-filled impact limiters are installed to reduce impact loads to the cask under drop test conditions. In the cavity of the cask a basket for five spent fuel elements is arranged. This design has been assessed by the Bundesanstalt für Materialforschung und -prüfung (BAM) in view to the mechanical and thermal safety analyses, the activity release approaches, and subjects of quality assurance and surveillance for manufacturing and operation of the package. For the mechanical safety analyses of the package a combination of experimental testing and analytical/numerical calculations were applied. In total, four drop tests were carried out at the BAM large drop test facility. Two tests were carried out as a full IAEA drop test sequence consisting of a 9m drop test onto an unyielding target and a 1m puncture bar drop test. The other two drop tests were performed as single 9m drop tests and completed by additional analyses for considering the effects of an IAEA drop test sequence. The main objectives of the drop tests were the investigation of the integrity of the package and its safety against release of radioactive material as well as the test of the fastening system of the impact limiters. Furthermore, the acceleration and strain signals measured during the tests were used for the verification of finite-element (FE) models applied in the safety analysis of the package design. The FE models include the cask body, the lid system, the inventory and the impact limiters with the fastening system. In this context special attention was paid to the modeling of the encapsulated wood-filled impact limiters. Additional calculations by using the verified numerical model were done to investigate e.g. the brittle fracture of the cask body made of ductile cask iron within the package design approval procedure. The thermal safety assessment was based on analytical energy balance calculations and FE analyses. As an additional point of evaluation in frame of approval procedure, the effect of possible impact limiter burning under accident conditions of transport was considered by the applicant and assessed by BAM. This paper describes the package design assessment from the point of view of the competent authority BAM including the applied assessment strategy, the conducted drop tests and the additional calculations by using numerical and analytical methods.

scholarly journals Design of custom cranial prostheses combining manufacturing and drop test finite element simulations

2020 ◽  
Vol 111 (5-6) ◽  
pp. 1627-1641
Author(s):  
G. Palumbo ◽  
A. Piccininni ◽  
G. Ambrogio ◽  
E. Sgambitterra
Keyword(s):  
Finite Element ◽  
Manufacturing Process ◽  
Numerical Models ◽  
Thickness Distribution ◽  
Drop Test ◽  
Constant Thickness ◽  
Fe Model ◽  
Flat Disk ◽  
Drop Tests ◽  
The Impact

Abstract In this work, impact puncture tests (drop tests) have been used to both tune numerical models and correlate the performance of customised titanium cranial prostheses to the manufacturing process. In fact, experimental drop tests were carried out either on flat disk-shaped samples or on prototypes of titanium cranial prostheses (Ti-Gr5 and Ti-Gr23 were used) fabricated via two innovative sheet metal forming processes (the super plastic forming (SPF) and the single point incremental forming (SPIF)). Results from drop tests on flat disk-shaped samples were used to define the material behaviour of the two investigated alloys in the finite element (FE) model, whereas drop tests on cranial prostheses for validation purposes. Two different approaches were applied and compared for the FE simulation of the drop test: (i) assuming a constant thickness (equal to the one of the undeformed blank) or (ii) importing the thickness distribution determined by the sheet forming processes. The FE model of the drop test was used to numerically evaluate the effect of the manufacturing process parameters on the impact performance of the prostheses: SPF simulations were run changing the strain rate and the tool configuration, whereas SPIF simulations were run changing the initial thickness of the sheet and the forming strategy. The comparison between numerical and experimental data revealed that the performance in terms of impact response of the prostheses strongly depends on its thickness distribution, being strain hardening phenomena absent due to the working conditions adopted for the SPF process or to the annealing treatment conducted after the SPIF process. The manufacturing parameters/routes, able to affect the thickness distribution, can be thus effectively related to the mechanical performance of the prosthesis determined through impact puncture tests.

scholarly journals Biomechanical performance of leather and modern football helmets

2013 ◽  
Vol 119 (3) ◽  
pp. 805-809 ◽  
Author(s):  
Steven Rowson ◽  
Ray W. Daniel ◽  
Stefan M. Duma
Keyword(s):  
Technical Note ◽  
Drop Test ◽  
Biomechanical Analysis ◽  
Head Acceleration ◽  
Impact Performance ◽  
Performance Differences ◽  
Football Helmets ◽  
Drop Tests ◽  
The Impact

With the increased national concern about concussions in football, recent research has focused on evaluating the impact performance of modern football helmets. Specifically, this technical note offers a biomechanical analysis of classic leather helmets compared with modern helmets. Furthermore, modern helmets were examined to illustrate the performance differences between the better- and worse-performing ones. A total of 1224 drop tests were performed from a range of drop heights and impact locations on 11 different helmet types (10 modern and 1 leather helmet model). The resulting head acceleration was used to assess the risk of concussion for each drop test. The results of this analysis demonstrate that modern helmets are significantly and substantially superior to leather helmets in all impact scenarios, and that notable differences exist among modern helmets.

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