Experimental and Modeling Studies of Looping Process for Wire Bonding

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Fuliang Wang ◽  
Yun Chen
Keyword(s):  
Finite Element ◽  
Friction Force ◽  
Material Properties ◽  
High Speed ◽  
Gold Wire ◽  
Tension Force ◽  
Fe Model ◽  
High Speed Camera ◽  
Dynamic Finite Element ◽  
Key Technologies

Looping is one of the key technologies for modern thermosonic wire bonders, and it has been affected by many interacting factors. In this study, the wire looping process was observed with a high-speed camera, and the evolution of wire profiles during looping and the capillary trace were obtained through experiments. A dynamic finite element (FE) model was developed to learn the details of the looping process, where real capillary geometry dimensions, capillary trace, diameter of bonded ball and the gold wire material were used, and the friction force and air tension force were considered. The simulated profiles were compared with those of the experiment. Using the verified FE model, the effects of material properties, capillary parameters, and capillary traces on the looping process were studied, and the relationships between the final profiles and parameters were discussed.

Predicting the High Speed Cutting Process of Titanium Alloy by Finite Element Method

2011 ◽  
Author(s):  
Xiangqin Zhang ◽  
Xueping Zhang ◽  
A. K. Srivastava
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Cutting Process ◽  
Fe Model ◽  
Dry Cutting ◽  
Friction Coefficients ◽  
Machining Conditions

To predict the cutting forces and cutting temperatures accurately in high speed dry cutting Ti-6Al-4V alloy, a Finite Element (FE) model is established based on ABAQUS. The tool-chip-work friction coefficients are calculated analytically using the measured cutting forces and chip morphology parameter obtained by conducting the orthogonal (2-D) machining tests. It reveals that the friction coefficients between tool-work are 3∼7 times larger than that between tool-chip, and the friction coefficients of tool-chip-work vary with feed rates. The analysis provides a better reference for the tool-work-chip friction coefficients than that given by literature empirically regardless of machining conditions. The FE model is capable of effectively simulating the high speed dry cutting process of Ti-6Al-4V alloy based on the modified Johnson-Cook model and tool-work-chip friction coefficients obtained analytically. The FE model is further validated in terms of predicted forces and the chip morphology. The predicted cutting force, thrust force and resultant force by the FE model agree well with the experimentally measured forces. The errors in terms of the predicted average value of chip pitch and the distance between chip valley and chip peak are smaller. The FE model further predicts the cutting temperature and residual stresses during high speed dry cutting of Ti-6Al-4V alloy. The maximum tool temperatures exist along the round tool edge, and the residual stress profiles along the machined surface are hook-shaped regardless of machining conditions.

Age Dependent and Anisotropic Material Properties of Immature Porcine Sclera

2013 ◽  
Author(s):  
Jami M. Saffioti ◽  
Brittany Coats
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Anisotropic Material ◽  
Computational Models ◽  
Fe Model ◽  
Ocular Tissues ◽  
Load Bearing ◽  
Anisotropic Properties ◽  
Age Dependent ◽  
Testing Protocols

Current finite element (FE) models of the pediatric eye are based on adult material properties [2,3]. To date, there are no data characterizing the age dependent material properties of ocular tissues. The sclera is a major load bearing tissue and an essential component to most computational models of the eye. In preparation for the development of a pediatric FE model, age-dependent and anisotropic properties of sclera were evaluated in newborn (3–5 days) and toddler (4 weeks) pigs. Data from this study will guide future testing protocols for human pediatric specimens.

Modeling and Experimental Study of a Wire Clamp for Wire Bonding

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Fuliang Wang ◽  
Dengke Fan
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Energy Conservation ◽  
Design Process ◽  
Gold Wire ◽  
Wire Bonding ◽  
Fe Model ◽  
Amplification Ratio ◽  
Model Studies ◽  
Thermosonic Wire Bonding

A wire clamp is used to grip a gold wire with in 1–2 ms during thermosonic wire bonding. Modern wire bonders require faster and larger opening wire clamps. In order to simplify the design process and find the key parameters affecting the opening of wire clamps, a model analysis based on energy conservation was developed. The relation between geometric parameters and the amplification ratio was obtained. A finite element (FE) model was also developed in order to calculate the amplification ratio and natural frequency. Experiments were carried out in order to confirm the results of these models. Model studies show that the arm length was the major factor affecting the opening of the wire clamp.

Damage Length Predictor for High-Speed Craft

1999 ◽  
Vol 36 (04) ◽  
pp. 203-210
Author(s):  
Steven P. McGee ◽  
Armin Troesch ◽  
Nickolas Vlahopoulos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
High Speed ◽  
Historical Data ◽  
Element Analysis ◽  
Damage Prediction ◽  
Structural Layout ◽  
Vessel Speed ◽  
Indenter Geometry

In 1994 the International Maritime Organization adopted the Code of Safety for High-Speed Craft (HSC Code). After two years of use, several shortfalls were found, one being the damage length predictor, which is based on traditional steel, mono-hulled vessels. Other damage predictors were developed based on historical data, but they do not account for variables such as aluminum or fiberglass construction, transverse members, indenter geometry variation, or for the case where the vessel comes to rest on the grounding object. This paper proposes a damage prediction model based on material properties, structural layout, grounding object geometry, and vessel speed. The model incorporates four grounding mechanisms: plate cutting, plate tearing, crushing of plate behind transverse members, and transverse member failure. The method is used to determine the resistance energy, compared to the kinetic energy, of the vessel, to determine an effective damage length. Finite-element analysis was used to model the failure of both aluminum and steel transverse members with significant differences in the results. It was found that the transverse members provided the majority of the resistance energy in one grounding mechanism and negligible resistance energy in another.

Finite element simulation of folding carton erection failure

2007 ◽  
Vol 221 (7) ◽  
pp. 753-767 ◽  
Author(s):  
D M Sirkett ◽  
B J Hicks ◽  
C Berry ◽  
G Mullineux ◽  
A J Medland
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
High Speed ◽  
Element Model ◽  
Machine Material ◽  
Linear Elastic ◽  
Element Simulation ◽  
Packaging Industry ◽  
First Time ◽  
The Eu

In response to recent European Union (EU) regulations on packaging waste, the packaging industry requires greater fundamental understanding of the machine-material interactions that take place during packaging operations. Such an understanding is necessary to handle thinner lighter-weight materials, specify the material properties required for successful processing and design right-first-time machinery. The folding carton industry, in particular, has been affected by the new legislation and needs to realize the potential of computational tools for simulating the behaviour of packaging materials and generating the necessary understanding. This paper describes the creation and validation of a detailed finite element model of a carton during a common packaging operation. The model is applied here to address the problem of carton buckling. The carton was modelled using a linear elastic material definition with non-linear crease behaviour. Air inrush suction, which is believed to cause buckling, was quantified experimentally and incorporated using contact damping interactions. The results of the simulation are validated against high-speed video of carton production. The model successfully predicts the pattern of deformation of the carton during buckling and its increasing magnitude with production rate. The model can be applied to study the effects of variation in material properties, pack properties and machine settings. Such studies will improve responsiveness to change and will ultimately allow end-users to use thinner, lighter-weight materials in accordance with the EU regulations.

Experimental Study of Kick up Phenomenon in Thermosonic Wire-Bonding

2012 ◽  
Vol 160 ◽  
pp. 77-81
Author(s):  
Jing Jing Tian ◽  
Lei Han
Keyword(s):  
Image Processing ◽  
Experimental Study ◽  
High Speed ◽  
Gold Wire ◽  
Wire Bonding ◽  
Processing Method ◽  
Experimental Results ◽  
High Speed Camera ◽  
Depth Study ◽  
Thermosonic Wire Bonding

Kick-up phenomenon during looping is an important factor in thermosonic wire bonding. In this study, the loping process during wire bonding was recorded by using high-speed camera, and wire profiles evolution was obtained from images sequence by image processing method. With a polynomial fitting, the wire loop profiling was described by the curvature changing, and kick-up phenomenon on gold wire was found between the instant of 290th frame(0.0537s) to 380th frame (0.0703s), the change of curvature is divided into three phases, a looping phase, a mutation phase and a kick-up phase. While in the kick-up phase, the kick up phenomenon is the most obvious. These experimental results were useful for in-depth study of kick-up phenomenon by simulation.

FEM-Based Simulation of Temperature in Speed Stroke Grinding with 3D Transient Moving Heat Sources

2011 ◽  
Vol 223 ◽  
pp. 733-742 ◽  
Author(s):  
Barbara Linke ◽  
Michael Duscha ◽  
Anh Tuan Vu ◽  
Fritz Klocke
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Material Removal ◽  
Structural Changes ◽  
Numerical Technique ◽  
Temperature Fields ◽  
Fe Model ◽  
Measured Temperature ◽  
Temperature Dependent ◽  
Removal Rates

The grinding process is one of the most important finishing processes to obtain high surface quality. Nowadays, grinding is also considered as a high performance process with high material removal rates. Nevertheless, to avoid thermally-induced structural changes poses a major challenge for this manufacturing technology. Until now, the Finite Element Method (FEM) has been widely applied as a proper numerical technique to predict workpiece properties in machining processes. However, actual models in grinding are limited to conventional grinding processes with simple workpiece profiles and low table speeds. In this paper, finite element simulations are expanded to 3-dimensional (3D) models with temperature-dependent material properties and heat source profiles derived from experimental results, i.e. tangential forces. Both temperature simulation and measurement were conducted for deep grinding, pendulum grinding and speed stroke grinding in the table speed range of vw= 12 m/min to 180 m/min and specific material removal rates of Q’w= 40 mm³/mms. Overall, the simulation results show a good agreement with the measured temperature and surface integrity after grinding. This research indicates that a 3D FE model with temperature dependent material properties can predict realistic temperature fields in speed stroke grinding. Therefore, the experiment and measurement costs and time can be reduced by FEM simulation.

Sensitivity of lightweight deflectometer deflections to layer stiffness via finite element analysis

2015 ◽  
Vol 52 (7) ◽  
pp. 961-970 ◽  
Author(s):  
Christopher T. Senseney ◽  
Jacob Grasmick ◽  
Michael A. Mooney
Keyword(s):  
Finite Element ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Experimental Studies ◽  
Fe Model ◽  
Element Analysis ◽  
Soil System ◽  
Dynamic Finite Element ◽  
Back Calculation ◽  
Measurement Depth

A dynamic finite element (FE) model of lightweight deflectometer (LWD) loading on a two-layer soil system, validated with an analytical solution and experimental data, is presented. Peak dynamic FE vertical deflections can be substantially different (almost always smaller) than FE static deflections. The numerically simulated measurement depth of the LWD center sensor is found to be 2–2.5 times the plate diameter, deeper than other experimental studies. Using the FE model, we conduct a sensitivity analysis of peak vertical deflections to the top layer Young’s modulus and underlying Young’s modulus of two-layer systems. Peak deflections from the center sensor are found to be more sensitive to the top layer Young’s modulus while peak deflections at radial offsets are found to be more sensitive to the underlying layer Young’s modulus. Sensitivities of layer moduli to FE deflections offer guidance in selecting weighting factors for the inverse solver in an LWD back-calculation procedure.

Automated Segmentation of Swine Skulls for Finite Element Model Creation Using High Resolution μ-CT Images

2019 ◽  
Vol 16 (03) ◽  
pp. 1842012 ◽  
Author(s):  
Zimo Zhu ◽  
Donna C. Jones ◽  
G. R. Liu ◽  
Sajjad Soleimani ◽  
Xu Huang ◽  
...  
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Complex Structure ◽  
Model Development ◽  
Element Model ◽  
Fe Model ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Detailed Model ◽  
Bone Mineral Density Loss

Finite element (FE) analysis has been widely used to investigate bone responses to mechanical loading. Research in long bones has been straight forward because modeling of these bones requires only two material properties. Such an FE model may provide an adequate approximation of the anatomy for many cases. However, a more detailed model of skull bones is needed to accurately capture its complex structure of multiple bone pieces and the various mineral densities distributed throughout these bone pieces. Unfortunately, FE model development incorporating both complex geometries and anatomically accurate material properties is both computationally and labor intensive. In this study, a method is proposed to automatically segment micro-computed tomography ([Formula: see text]-CT) scan images of bone pieces to build an FE model of a full swine hemi-skull. Using the Digital Imaging and Communications in Medicine (DICOM) files from scanned bones, the complete geometry of each bone piece is recreated through seven customized processing algorithms. After assembling the bone pieces to form the skull, experimentally derived Young’s modulus values are correlated to grayscale values to produce a detailed FE model for accurate simulation. This detailed skull model can be used to predict strain/stress patterns in response to various loading regimes to facilitate research questions in fracture healing and growth, as well as bone tissue engineering and bone mineral density loss (e.g., osteoporosis).

scholarly journals Effect of Torsional Element towards High-Speed Rotating Shaft’s Critical Speed at Different Boundary Conditions

2019 ◽  
Vol 8 (4) ◽  
pp. 6787-6792
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
High Speed ◽  
Critical Speed ◽  
Element Model ◽  
Accurate Estimation ◽  
Fe Model ◽  
Rotating Shaft ◽  
Different Boundary Conditions ◽  
The Difference

Efficiency improvement that can be provided by the high-speed rotating equipment becomes a concern for designers nowadays. Since the high-speed rotating machinery was capable of rotating at very near to critical speed, the accurate estimation of critical speed needs to be considered. This paper investigated the effect of torsional element towards critical speed of high-speed rotating shaft system for pinned-pinned (P-P), clamped-free (C-F) and clamped-free (C-F) boundaries condition. The Nelson’s finite element model that considers the torsional effect was developed for formulating the finite element (FE) model. This FE model was used to derive Mathieu-Hill’s equation and then solved by applying the Bolotin’s theory. From the solution, the Campbell’s diagram of the high-speed shaft was plotted. It was found that torsional motion has significant effect on the critical speed for different boundary conditions. The difference between critical speed of 4DOF and 5DOF models can be as high as 6.91 %.

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