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23rd International Conference on Electronic Packaging Technology (ICEPT)

作者： Yang, Li Cai, Zhikuang Xu, Binbin Huang, Shoukun Liu, Lu Nanjing Univ Posts & Telecommun Coll Int Circuit Sci & Engn Natl & Local Joint Engn Lab RF Integrat & Micro A Nanjing Peoples R China Nanjing Univ Posts & Telecommun Nantong Inst Nanjing Peoples R China

ISBN: (数字)9781665499057

ISBN: (纸本)9781665499057

During the plastic packaging process, voids and weld lines are common problems. As the volume of Power Modules is becoming smaller and thinner, more and more attention has been paid to solve the void defects. Power Modules have complex structures and dense components, which may cause void risks. In this article, an improved 3D mold flow technology for High-Density Power Modules package is conducted to predict the location of the voids generation and the number of weld lines throughout the plastic encapsulation process, which is mainly about to find the best optimization to reduce the risk of voids through the two parts. The first part is including three aspects which are gate locations, viscosity property of materials, and segment injection. According to the simulation verification, the results show that the best gate location and a reasonable range of viscosity properties for the material can effectively decrease the voids risk. In addition, segment injection has more advantages than uniform injection in terms of reducing voids risks When the melt flows through the top of the highest component of Power Module package. The second part is the verification of DoEs (Design of Experiments) that show the influence of the solder ball size and ball to substrate area ratio on the number of weld lines by comparing different kinds of experiments. The results show that the smaller the balls size, and the pitch is not sufficiently large, the greater the number of weld lines. Therefore, through the comparison of the above experimental data, it is very necessary to find an optimal scheme to reduce production defects during the molding process of the products, and greatly improve the reliability of the product.

关键词： mold flow Voids Weld lines DoEs

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Experimental Study of the mold flow Induced by a Swirling flow Nozzle and Electromagnetic Stirring for Continuous Casting of Round Blooms

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METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE 2019年第2期50卷 716-731页

作者： Schurmann, Dennis Willers, Bernd Hackl, Gernot Tang, Yong Eckert, Sven Helmholtz Zentrum Dresden Rossendorf eV HZDR Bautzner Landstr 400 D-01328 Dresden Germany RHI Magnesita A-8700 Leoben Austria

This study focuses on an experimental investigation of the fluid flow in round bloom continuous casting using a 1:3 model of the industrial casting process. A swirling flow nozzle, represented by the specific design of the RHI Magnesita GYRONOZZLE, is used to produce a swirling motion in the cylindrical mold. The test section is integrated into the Mini-LIMMCAST facility at HZDR, which is operated at room temperature using the ternary alloy GaInSn. Systematic measurements of horizontal and vertical velocity profiles are performed by means of the Ultrasound Doppler Velocimetry. The second part of the study focuses on the interaction between the flow driven by the GYRONOZZLE and concurrent electromagnetic stirring in the mold (M-EMS) by applying rotating magnetic fields (RMFs) at different magnetic flux densities. The effect of the GYRONOZZLE on the flow pattern inside the mold is examined with and without superimposed RMFs and compared to those of a standard single-port nozzle. The measurements reveal that the GYRONOZZLE induces a swirling flow in the whole mold. It is further shown that the influence of a simultaneously applied RMF is mainly restricted to the lower part of the mold since the transport of angular momentum to the top is suppressed by the jets pouring out from the GYRONOZZLE.

关键词： fluid flow flow PATTERNS Electromagnetic stirring detection zone mold flow nozzles Continuous casting VELOCITY PROFILING swirling flow

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基于mold flow的覆盖板注射成型过程分析

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大连交通大学学报 2022年第3期43卷 79-82页

作者：韩坤男王大勇王洋李仁杰大连交通大学材料科学与工程学院辽宁大连116028 东北特殊钢集团股份有限公司辽宁大连116000 大连多利电器用品有限公司辽宁大连116600

以汽车覆盖板的注射成型为例,运用mold flow软件对塑件熔体填充过程、保压、熔接痕以及气穴等进行了模拟分析.设计了两种不同的冷却系统,在保证模具结构合理且完整的同时,分析其对制件的成型质量影响.对两种不同冷却系统的模拟分析数据... 详细信息

以汽车覆盖板的注射成型为例,运用mold flow软件对塑件熔体填充过程、保压、熔接痕以及气穴等进行了模拟分析.设计了两种不同的冷却系统,在保证模具结构合理且完整的同时,分析其对制件的成型质量影响.对两种不同冷却系统的模拟分析数据进行比较,得出更加合理的工艺参数和模具结构,提升了塑件成型的品质,创造了更好的经济效益.

关键词：覆盖板 mold flow 模流分析翘曲变形

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Bubbly mold flow in Continuous Casting: Comparison of Numerical flow Simulations with Water Model Measurements

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STEEL RESEARCH INTERNATIONAL 2020年第12期91卷 2000415-2000415页

作者： Javurek, Mirko Wincor, Raimund Johannes Kepler Univ Linz Inst Fluid Mech & Heat Transfer Altenbergerstr 69 A-4040 Linz Austria Voestalpine Stahl GmbH Business Unit Slabs BTT Tech Proc Voestalpine Str 3 A-4020 Linz Austria

The impact on the mold flow of inert gas bubbles originating from a gas injection at the top of the submerged entry nozzle is investigated. Results from a physical model using water and air are compared with corresponding numerical flow simulation results. In numerical models, the bubble velocities are determined by calculating the force equilibrium between buoyancy, drag force, and other forces acting on the bubbles. For the observed bubble size in the physical model, the so-determined rising velocity of the bubbles is significantly too high in comparison to the water model experiment. Various effects can influence the rising velocity of bubbles. One of them is that the presence of turbulence obviously reduces the rising velocity. The influence of turbulence models and of a turbulence-induced bubble drag modification is analyzed in numerical flow simulations and compared to water model results.

关键词： argon injection computational fluid dynamics mold flow numerical flow simulation water model

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基于mold flow的覆盖版注射成型过程分析

基于Mold flow的覆盖版注射成型过程分析

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作者：韩坤男大连交通大学

学位级别：硕士

近些年,在制造业中越来越多的产品开始使用塑料材料,塑料材料的质量和成本相较金属材料更低,在特定环境下拥有比金属材料更高的性能。汽车行业在工业发展中占据着不可或缺的地位,塑料材料比金属材料更轻便,有着更好的塑性,塑料材料的应... 详细信息

近些年,在制造业中越来越多的产品开始使用塑料材料,塑料材料的质量和成本相较金属材料更低,在特定环境下拥有比金属材料更高的性能。汽车行业在工业发展中占据着不可或缺的地位,塑料材料比金属材料更轻便,有着更好的塑性,塑料材料的应用也相应大大增加。塑料材料在成型过程中容易出现一定程度的缺陷,比如填充不满或熔接痕、气穴等问题,以往汽车零件注塑企业设计师们通常根据经验来设计模具,再通过试模的数据进行调整,直到得到符合设计要求的工艺参数,这种方法费时费力,且容易“走弯路”,造成不必要的浪费。现在大多数汽车以及其他制造企业开始使用计算机辅助工程(CAE)进行对注塑过程的仿真模拟。大大缩短模具设计和开发的周期,并且降低了企业成本。通过运用计算机辅助工程(CAE)软件mold flow对塑件进行注塑过程的仿真模拟分析,根据所得数据,对塑件在实际生产过程中产生的一系列缺陷,如:填充不满、翘曲变形、熔接痕等问题进行处理。通过优化模拟数据,改变模拟时的工艺参数等方法,对模具设计进行优化,得到更好的设计方案,提升模具设计和优化的效率,大幅提升企业实际生产力。本文以某汽车覆盖板塑件为例,运用计算机辅助工程(CAE)软件mold flow对其成型过程进行数值模拟,并针对塑件在注塑成型出现的气穴、熔接线和翘曲变形等问题,优化和设计出新的浇注系统和冷却系统方案,并且将所设计出的不同方案分别进行模拟分析。通过分析两种浇注系统的填充时间、熔接痕等结果确定了单浇口浇注系统更优;分析三种冷却系统方案,得出在结合模具结构特点的情况下冷却效果更好的回型冷却系统。最终,结合冷却系统和浇注系统的优化方案得到最优方案。最后运用mold flow软件所得到的最终优化方案的模具设计及工艺参数,在实际生产中进行验证。将所得到的实验结果与模拟结果相比较,验证了模拟分析结果的真实性和可靠性,其可用于实际生产中,对模具设计进行优化。

关键词：注塑成型汽车覆盖板计算机辅助工程 mold flow 翘曲变形

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mold flow evaluation during production of iF steel grade with an advanced multiple measurement mold audit tool “XMAT”

Mold flow evaluation during production of iF steel grade wit...

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AISTech 2018 Iron and Steel Technology Conference and Exposition

作者： Aranda, Vinicius Lourenco, Fabio Demuner, Leonardo Miranda, Moisés Ramos, Tiago Minovsky, Johannes Hilgenhöner, Enno Berns, Shayne Ternium Brazil Av. João XXIII Rio de Janeiro23560-352 Brazil Vesuvius Brazil Av. Brasil 49550 Rio de Janeiro23065-480 Brazil Vesuvius Germany Gelsenkirchener Strasse 10 Borken46325 Germany Vesuvius USA 250 Park West Drive PittsburghPA15227 United States

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URANS Simulation of Continuous Casting mold flow: Assessment of Revised Turbulence Models

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STEEL RESEARCH INTERNATIONAL 2015年第4期86卷 400-410页

作者： Kratzsch, Christoph Timmel, Klaus Eckert, Sven Schwarze, Ruediger Tech Univ Bergakad Freiberg Inst Mech & Fluiddynam D-09599 Freiberg Germany Helmholtz Zentrum Dresden Rossendorf Inst Fluiddynam D-01328 Dresden Germany

A time resolving numerical model of single phase mold flows is formulated in the frame of Reynolds-averaged Navier-Stokes (RANS) simulations. Three revised eddy viscosity turbulence models besides the often used Standard k-epsilon model for steady and unsteady RANS simulations are evaluated with the computational fluid dynamics (CFD) software tool OpenFOAM. The performance of the numerical model and the different turbulence models is tested with help of the mini-LIMMCAST facility. Numerical data are compared with experimental results focusing especially on the jet flow region. The different turbulence models lead to slight deviations from the experimental data in the case of steady state calculation. For the time-averaged unsteady RANS equations (URANS) results, a crucial influence by the discretization order is observed. In the case of unsteady results a mix between first and higher order accuracy schemes is necessary for representative results. The use of the Standard k-epsilon model and the RLZ k-epsilon model can lead to unstable behavior in the case of URANS simulations. The study concludes, that in the case of qualitative, temporally resolved informations, and temporally averaged results, an unsteady RANS simulation can keep up with a large eddy simulations (LES).

关键词： mini-LIMMCAST mold flow OpenFOAM RANS unsteady URANS

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Investigation on the effect of the packaging-induced stress on the reliability of a MEMS sensor package 24

Investigation on the effect of the packaging-induced stress ...

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24th International Conference on Electronic Packaging Technology (ICEPT)

作者： Chen, Danyang Ni, Yan Wang, Han Zhu, Cheng Qin, Junjie Yang, Daoguo Guilin Univ Elect Technol Sch Mech & Elect Engn Guilin Peoples R China

ISBN: (纸本)9798350338812;9798350338829

Currently, with the increasing trend towards miniaturization and thinning of semiconductor devices, ensuring product reliability has become a crucial aspect in electronic packaging. This paper specifically focuses on MEMS temperature and humidity sensors and utilizes moldex3D software for three-dimensional mold flow simulation analysis. The purpose of the analysis is to predict the distribution of potential air traps and identify the locations of weld lines. The influence of gate location and gate quantity on process defects and reliability issues is investigated using a single-factor method. The results clearly indicate that the design of the gate system has a significant impact on the reliability of sensor packaging. The simulation results for different gate locations demonstrate that placing the gate in the middle achieves a more balanced flow of epoxy resin. However, insufficient filling pressure in this configuration may result in an increase in the occurrence of air traps and weld lines. When multiple gates are used in the simulation, it is observed that the number of air traps does not decrease with an increase in the quantity of gates. Nonetheless, multiple gates promote a more balanced resin flow, although some convergence occurs, leading to the generation of numerous air traps at the convergence points. Additionally, excessive injection pressure can cause overflow and wire shifting at the window opening of the temperature and humidity sensor. In conclusion, the design of the gate system should carefully consider the structural characteristics of the product and the transfer molding process. It is evident that the gate system design plays a crucial role in the formation of air traps and weld lines. Therefore, a rational gate system design is vital to ensure both the yield and reliability of sensor products.

关键词： MEMS mold flow Temperature and humidity sensor Weld lines Air traps

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Effect of slide-gate opening on mold flow structure

Effect of slide-gate opening on mold flow structure

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AISTech 2014 Iron and Steel Technology Conference

作者： Giirsoy, K.A. Yavuz, M.M. Mechanical Engineering Department Middle East Technical University Ankara 06800 Turkey

ISBN: (纸本)9781935117421

Continuous casting system is known to be operating most efficiently under the steady state conditions'. Transport rate of molten steel from tundish to the caster mold is among the parameters desired to be constant. flow through the tundish to the mold can be controlled by different flow rate control systems including stopper rods and slide-gate mechanisms2. These two tundish flow rate control mechanisms are commonly preferred in industry, where each one has its own advantages and shortcomings. Ladle changes in continuous casting machines result in liquid steel level changes in tundishes. During this transient event of production, in order to keep the production rate constant, slide-gate opening is increased to reduce the pressure drop across the gat which helps to keep the mass flow rate same at the reduced liquid level in tundish. Computational fluid dynamic (CFD)) modeling is performed to investigate the effect of slide-gate opening on mold flow structure. First of all, a detailed validation of the CFD models is conducted using available experimental data along with the comparison of different turbulence models. Then, different slide-gate openings are simulated to understand their effects on mold flow. Finally, a stopper rod simulation is also performed to ultimately compare the performances of different flow rate control mechanisms considering the mold flow structure. The results indicate that the meniscus velocities change significantly for different slide-gate openings at the same throughput condition. This change reaches to 35% if the flow rate controller is switched to stopper rod. Therefore, considering the mold flow structure during ladle change, it may not be a very good idea to keep the cast speed constant. Instead, the cast speed may be modified in order to obtain a relatively steady mold flow structure.

关键词： mold flow Continuous Casting CFD Turbulence Modeling Slide-Gate Stopper Rod stopper rod Tundishes mold flow Continuous casting Moulds dies turbulence models computational fluid dynamics charge flow devices flow structure liquid steel flow control GATE OPENING continuous caster

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Iterative approach in the design of the optimal configuration for the injection system of a test plate from composite material 8th

Iterative approach in the design of the optimal configuratio...

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8th International Conference on Advanced Materials and Structures (AMS)

作者： Foltut, Daniel Buzdugan, Monica Ramona Pascal, Dragos Toader Stan, Daniel Politehn Univ Timisoara Dept Mat & Mfg Engn Bulev Mihai Viteazu 1 Timisoara 300222 Romania VITESCO Technol Engn Romania Calea Buziasului 11A Timisoara 300699 Romania

Any new material needs to be characterized by mechanical, electrical, thermal and chemical properties. Filled polymers, which belong to composite materials category, are difficult to characterize from mechanical point of view because of the variations in properties with the fiber orientation. This introduces the need of mechanical testing for different fiber orientations, a money and time-consuming task. The goal of this work is to design a polymeric material plate, reinforced with fiber glass, from which tensile test samples can be cut at different fiber orientations, in order to determine the mechanical properties of the studied material. This study aimed to give a solution with a compact and effective design of gating and plate dimensions and give strong input information for the injection process parameters needed to obtain the desired fiber orientation in the matrix material of the plate. The polymer for which the mold was designed is a polyphthalamide reinforced with 40% fiber glass. To obtain the scope of this work, in dimensioning the injection system and gates, recommendations from literature were used and finite element analysis was applied to determine the fiber orientation and injection pressure for each iteration of the design. The iterative simulations were performed using moldflow Advisor (c) software and the CAD models were made using SolidWorks (c) student edition. The current study describes the configuration of the path runner and nest for the injection with pellicular gate of a test plate from polyphthalamide reinforced with 40% fiber glass, for an optimum fiber orientation with the probability of alignment on the X axis of 80% on the surface layer of the plate and 85% probability in 25% of the thickness, measured from surface layers. (c) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 8th International Conference on Advanced Materials and Structures - AMS 2020.

关键词： Iterative simulation mold flow Injection molding Fiber reinforced polymers Mechanical testing

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