Reliability Study of Package Stacking Under Thermomechanical Conditions

2005 ◽  
Author(s):  
Jiansen Zhu ◽  
Kazuo Ishibahsi ◽  
Tommi Reinikainen
Keyword(s):  
Thermal Cycling ◽  
Modeling And Simulation ◽  
Simulation Method ◽  
The Other ◽  
Thermal Cycling Test ◽  
Reliability Study ◽  
Fea Modeling ◽  
Die Stacking ◽  
Simulation Results ◽  
Intellectual Properties

With the increased requirements for smaller size and more functions, hand held devices will use more and more small components to reduce the PWB areas. One of the solutions is stacked package. There are two kinds of stacked packages: one is die stacking and the other is package stacking. The package stacking is a more flexible solution for device manufacturers because the packages to be stacked could come from different vendors. All the packages can be tested separately before stacking so that there is no need for device manufacturers to acquire good dies or intellectual properties for die testing. In this study, the focus will be on the package stacking. The package stacking can be ASIC and memory stacking or memory and memory stacking. Three different stacked packages are selected for this study. Here the focus is on FEA modeling and simulation method for package stacking. Finally, the simulation results are compared with the results of thermal cycling test. A reasonable correlation is achieved based on current simulation method.

Dynamic Modeling and Simulation of Stratospheric Airships

2012 ◽  
Vol 457-458 ◽  
pp. 237-244
Author(s):  
Guo Chang Hu ◽  
Mei Ping Wu
Keyword(s):  
Modeling And Simulation ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Theoretical Basis ◽  
Simulation Method ◽  
Autonomous Control ◽  
Overall Design ◽  
Stratospheric Airship ◽  
Simulation Results ◽  
Motion Characteristics

Aiming at the requirements of autonomous control for stratospheric airships, based on description of the modeling plant and forces analysis in detail, the dynamic model is established by Newton Method. The motion characteristics of airships under control action are analyzed using simulation method. Simulation results indicate the correctness of dynamic model, and can make itself a theoretical basis for the overall design of the stratospheric airship.

A Modeling and Simulation Method for SVPWM

2014 ◽  
Vol 548-549 ◽  
pp. 815-818
Author(s):  
Jia Quan Lin ◽  
Xu Yu Cheng ◽  
Xin Mu
Keyword(s):  
Modeling And Simulation ◽  
Vector Function ◽  
Simulation Method ◽  
Working Time ◽  
Time Model ◽  
Basic Vector ◽  
Wave Symmetry ◽  
Simulation Results ◽  
Set Up ◽  
Working Time Model

The SVPWM technique plays an important role in the DC-AC transform. The modeling and simulation for SVPWM were proposed in this paper. The sector calculating model and basic vector working time model were set up. The effective vector function of time was set up. The triangle wave symmetry modulation was established too. The simulation results show that the model proposed in this paper is effective and has application value.

An Intuitionistic Fuzzy Based Novel Approach to CPU Scheduler

2020 ◽  
Vol 16 (4) ◽  
pp. 316-328
Author(s):  
Supriya Raheja
Keyword(s):  
Fuzzy Inference ◽  
The Other ◽  
Simulation Environment ◽  
Inference System ◽  
Intuitionistic Fuzzy ◽  
Novel Approach ◽  
Continuous Feedback ◽  
Simulation Results ◽  
Effectiveness And Efficiency ◽  
Unique Capability

Background: The extension of CPU schedulers with fuzzy has been ascertained better because of its unique capability of handling imprecise information. Though, other generalized forms of fuzzy can be used which can further extend the performance of the scheduler. Objectives: This paper introduces a novel approach to design an intuitionistic fuzzy inference system for CPU scheduler. Methods: The proposed inference system is implemented with a priority scheduler. The proposed scheduler has the ability to dynamically handle the impreciseness of both priority and estimated execution time. It also makes the system adaptive based on the continuous feedback. The proposed scheduler is also capable enough to schedule the tasks according to dynamically generated priority. To demonstrate the performance of proposed scheduler, a simulation environment has been implemented and the performance of proposed scheduler is compared with the other three baseline schedulers (conventional priority scheduler, fuzzy based priority scheduler and vague based priority scheduler). Results: Proposed scheduler is also compared with the shortest job first CPU scheduler as it is known to be an optimized solution for the schedulers. Conclusion: Simulation results prove the effectiveness and efficiency of intuitionistic fuzzy based priority scheduler. Moreover, it provides optimised results as its results are comparable to the results of shortest job first.

scholarly journals Effect of Intermetallic Compound Bridging on the Cracking Resistance of Sn2.3Ag Microbumps with Different UBM Structures under Thermal Cycling

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1065
Author(s):  
Chun-Chieh Mo ◽  
Dinh-Phuc Tran ◽  
Jing-Ye Juang ◽  
Chih Chen
Keyword(s):  
Electron Microscope ◽  
Intermetallic Compound ◽  
Thermal Cycling ◽  
Thermal Cycle ◽  
Crack Formation ◽  
Thermal Cycling Test ◽  
Under Bump Metallization ◽  
Reflow Time ◽  
Cracking Resistance ◽  
Scanning Electron

In this study, the effect of intermetallic compound (IMC) bridging on the cracking resistance of microbumps with two different under bump metallization (UBM) systems, Cu/solder/Cu and Cu/solder/Ni, under a thermal cycling test (TCT) is investigated. The height of the Sn2.3Ag solders was ~10 µm, which resembles that of the most commonly used microbumps. We adjusted the reflow time to control the IMC bridging level. The samples with different bridging levels were tested under a TCT (−55–125 °C). After 1000 and 2000 TCT cycles (30 min/cycle), the samples were then polished and characterized using a scanning electron microscope (SEM). Before IMC bridging, various cracks in both systems were observed at the IMC/solder interfaces after the 1000-cycle tests. The cracks propagated as cyclic shapes from the sides to the center and became more severe as the thermal cycle was increased. With IMC bridging, we could not observe any further failure in all the samples even when the thermal cycle was up to 2000. We discovered that IMC bridging effectively suppressed crack formation in microbumps under TCTs.

Study of HVDC System and Subsynchronous Oscillation

2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu
Keyword(s):  
Power Plant ◽  
Time Domain ◽  
Simulation Method ◽  
Time Domain Simulation ◽  
Stable Convergence ◽  
Turbine Generator ◽  
Plant Model ◽  
Subsynchronous Oscillation ◽  
Hvdc System ◽  
Simulation Results

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably

scholarly journals Cheating at Craps

2021 ◽  
Vol 48 (4) ◽  
pp. 53-61
Author(s):  
Andrea Marin ◽  
Carey Williamson
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Modeling And Simulation ◽  
Analytical Model ◽  
Quantitative Evaluation ◽  
Mathematical Analysis ◽  
Simulation Modeling ◽  
Analytical Modeling ◽  
The World ◽  
Simulation Results

Craps is a simple dice game that is popular in casinos around the world. While the rules for Craps, and its mathematical analysis, are reasonably straightforward, this paper instead focuses on the best ways to cheat at Craps, by using loaded (biased) dice. We use both analytical modeling and simulation modeling to study this intriguing dice game. Our modeling results show that biasing a die away from the value 1 or towards the value 5 lead to the best (and least detectable) cheating strategies, and that modest bias on two loaded dice can increase the winning probability above 50%. Our Monte Carlo simulation results provide validation for our analytical model, and also facilitate the quantitative evaluation of other scenarios, such as heterogeneous or correlated dice.

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