Role of Out-of-Plane Coefficient of Thermal Expansion in Electronic Packaging Modeling

1999 ◽  
Vol 122 (2) ◽  
pp. 121-127 ◽  
Author(s):  
Manjula N. Variyam ◽  
Weidong Xie ◽  
Suresh K. Sitaraman
Keyword(s):  
Thermal Expansion ◽  
Electronic Packaging ◽  
Thermal Loading ◽  
Coefficient Of Thermal Expansion ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Dissimilar Materials ◽  
3D Models ◽  
Material Behavior ◽  
Element Analysis

Components in electronic packaging structures are of different dimensions and are made of dissimilar materials that typically have time, temperature, and direction-dependent thermo-mechanical properties. Due to the complexity in geometry, material behavior, and thermal loading patterns, finite-element analysis (FEA) is often used to study the thermo-mechanical behavior of electronic packaging structures. For computational reasons, researchers often use two-dimensional (2D) models instead of three-dimensional (3D) models. Although 2D models are computationally efficient, they could provide misleading results, particularly under thermal loading. The focus of this paper is to compare the results from various 2D, 3D, and generalized plane-deformation strip models and recommend a suitable modeling procedure. Particular emphasis is placed to understand how the third-direction coefficient of thermal expansion (CTE) influences the warpage and the stress results predicted by 2D models under thermal loading. It is seen that the generalized plane-deformation strip models are the best compromise between the 2D and 3D models. Suitable analytical formulations have also been developed to corroborate the findings from the study. [S1043-7398(00)01402-X]

Analysis of a Virtual Prototype First-Stage Rotor Blade Using Integrated Computer-Based Design Tools

2006 ◽  
Author(s):  
Michel Arnal ◽  
Christian Precht ◽  
Thomas Sprunk ◽  
Tobias Danninger ◽  
John Stokes
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Thermal Loading ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Life Assessment ◽  
Element Analysis ◽  
Pressure Losses ◽  
Cooling Channels ◽  
Internally Cooled

The present paper outlines a practical methodology for improved virtual prototyping, using as an example, the recently re-engineered, internally-cooled 1st stage blade of a 40 MW industrial gas turbine. Using the full 3-D CAD model of the blade, a CFD simulation that includes the hot gas flow around the blade, conjugate heat transfer from the fluid to the solid at the blade surface, heat conduction through the solid, and the coolant flow in the plenum is performed. The pressure losses through and heat transfer to the cooling channels inside the airfoil are captured with a 1-D code and the 1-D results are linked to the three-dimensional CFD analysis. The resultant three-dimensional temperature distribution through the blade provides the required thermal loading for the subsequent structural finite element analysis. The results of this analysis include the thermo-mechanical stress distribution, which is the basis for blade life assessment.

scholarly journals 3D Printing Experimental Validation of the Finite Element Analysis of the Maxillofacial Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Jingheng Shu ◽  
Haotian Luo ◽  
Yuanli Zhang ◽  
Zhan Liu
Keyword(s):  
Finite Element ◽  
3D Printing ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Image Data ◽  
3D Models ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Asymptomatic Subjects ◽  
Bottom To Top

Contacts used in finite element (FE) models were considered as the best simulation for interactions in the temporomandibular joint (TMJ). However, the precision of simulations should be validated through experiments. Three-dimensional (3D) printing models with the high geometric and loading similarities of the individuals were used in the validation. This study aimed to validate the FE models of the TMJ using 3D printing models. Five asymptomatic subjects were recruited in this study. 3D models of mandible, disc, and maxilla were reconstructed according to cone-beam CT (CBCT) image data. PLA was chosen for 3D printing models from bottom to top. Five pressure forces corresponding to the central occlusion were applied to the 3D printing models. Ten strain rosettes were distributed on the mandible to record the horizontal and vertical strains. Contact was used in the FE models with the same geometries, material properties, loadings, and boundary conditions as 3D printing models to simulate the interaction of the disc-condyle, disc-temporal bone, and upper-lower dentition. The differences of the simulated and experimental results for each sample were less than 5% (maximum 4.92%) under all five loadings. In conclusion, it was accurate to use contact to simulate the interactions in TMJs and upper-lower dentition.

Three-Dimensional Stress Singularity Analysis Around the Solder Joints in Electronic Packaging Using Eigen Analysis

2003 ◽  
Author(s):  
Monchai Prukvilailert ◽  
Hideo Koguchi
Keyword(s):  
Mechanical Properties ◽  
Electronic Packaging ◽  
Flip Chip ◽  
Solder Bump ◽  
Three Dimensional ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
Singularity Analysis ◽  
Contact Angles ◽  
Eigen Analysis

Electronic packaging has several kinds of joint structures of metal, ceramic and polymer. It is well known that the stress singularity occurs at the vertex of joint where the dissimilar materials are bonded together. In this paper, the model in the first analysis is an electronic package using surface mount technology (SMT), the order of stress singularity is investigated, when the mechanical properties of solder, adhesive and resin vary for several values of contact angles between the solder with the chip and with a Cu land. Furthermore, the model in the second analysis is a Flip-Chip-on-Board packaging (FCOB), in which the order of stress singularity at the solder bump is investigated varying the mechanical properties of solder, underfill and the contact angle between the solder bump with a Cu track. After that, the displacement and stress fields for several values of the order of stress singularity are calculated by solving an eigen equation.

Clamp Load Decay in Preloaded Dissimilar Lightweight-Material Joints due to Cyclic Temperature

2014 ◽  
Author(s):  
Sayed A. Nassar ◽  
Amir Kazemi ◽  
Mohamad Dyab
Keyword(s):  
Finite Element ◽  
Temperature Profile ◽  
Thermal Loading ◽  
Dissimilar Materials ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Temperature Load ◽  
Cyclic Temperature ◽  
Material Creep ◽  
Aluminum And Magnesium Alloys

Experimental and Finite Element methods are used for investigating the effect of cyclic thermal loading on the clamp load decay in preloaded single-lap bolted joints that are made of dissimilar-materials. Joint material combinations include steel and lightweight materials such as aluminum and magnesium alloys, with various different thicknesses. The range of cyclic temperature profile varies between −20°C and +150°C. A computer-controlled environmental chamber is used for generating the desired cyclic temperature profile and duration. Real time clamp load data is collected using high-temperature load cells. Percent clamp load decay is investigated for various combinations of joint materials, initial preload level, and test specimen thicknesses. Thermal and material creep finite element analysis is performed using temperature-dependent mechanical properties. FEA result has provided insight into interesting experimental observations regarding model predictions and the experimental data is discussed.

scholarly journals Thermal analysis of metal-ceramic bonding using finite element method

2014 ◽  
Vol 3 (2) ◽  
pp. 216 ◽  
Author(s):  
S. Gopinath ◽  
R Sabarish ◽  
R. Sasidharan
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Bonding Strength ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Processing Temperature ◽  
Element Analysis ◽  
Metal Ceramic ◽  
The Difference

This paper reports a finite element study of effect of bonding strength between metal and ceramic. The bonding strength is evaluated with different processing temperature and holding time. The difference between the coefficients of linear thermal expansion (CTEs) of the metal and ceramic induces thermal stress at the interface. The mismatch thermal stress at the interface region plays an important role in improving bonding strength. Hence, it is essential to evaluate the interface bonding in metal-ceramics joints. The Al/SiC bonding was modeled and analyzed using finite element analysis in ANSYS (v.10). Keywords: Bonding Strength, Coefficient of Thermal Expansion, Thermal Stress, Interface, Al/Sic, FEA.

Mean-field homogenization of thermoelastic material properties of a long fiber-reinforced thermoset and experimental investigation

2020 ◽  
Vol 54 (25) ◽  
pp. 3777-3799
Author(s):  
Loredana Kehrer ◽  
Jeffrey T Wood ◽  
Thomas Böhlke
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Mean Field ◽  
Material Behavior ◽  
Fiber Reinforced Polymers ◽  
Material System ◽  
Fiber Reinforced ◽  
Thermoset Resin ◽  
Thermoelastic Material ◽  
Fiber Orientation Distribution

Fiber-reinforced polymers contribute significantly to weight-reducing components for various industrial applications. A discontinuous glass fiber-reinforced thermoset resin is considered which is produced by the sheet molding compound (SMC) process. Related to the production process, the samples considered in this work exhibit an anisotropic fiber orientation distribution which highly affects the thermomechanical properties. The thermoviscoelastic material behavior of three selected samples is characterized by means of dynamic mechanical analysis. These tests show the temperature-dependent elastic modulus and the glass transition of the composite. Measurements of the thermal expansion of the SMC composite provide data on the coefficient of thermal expansion (CTE). These experimental investigations provide data for the thermoelastic material modeling. Aiming at the prediction of the effective thermal and mechanical properties, a Hashin–Shtrikman-based homogenization method is presented. Based on an eigenstrain formulation, the effective Young’s modulus and CTE are computed in two steps. Moreover, the mean-field method is given in dependence of a variable reference stiffness allowing to tailor the approach to the material system. The influence of this variable reference stiffness on the effective quantities as well as the predicted behavior is analyzed with respect to the experiments. The presented numerical results are in good agreement with the experimental data.

Three-dimensional braided composites with zero, negative and isotropic thermal expansion behavior

2020 ◽  
Vol 54 (13) ◽  
pp. 1761-1781
Author(s):  
SA Pottigar ◽  
B Santhosh ◽  
RG Nair ◽  
P Punith ◽  
PJ Guruprasad ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensional ◽  
Braided Composites ◽  
Fiber Volume ◽  
Braided Composite ◽  
Expansion Behavior ◽  
Unit Cells ◽  
Composite Configuration

Three-dimensional braided composites with zero, negative and isotropic coefficient of thermal expansion are presented based on an analytical homogenization technique. The configuration of the braided composites is worked out considering the exact jamming condition leading to higher fiber volume fraction. A total of four configurations of three-dimensional-braided composite representative unit cells were analyzed. Among these, two arrangements are 4-axes and the other two are 5-axes. Special emphasis is given on the detailed description of the representative unit cells. Analysis reveals that a three-dimensional-braided composite configuration with thermoelastic isotropic properties having same coefficient of thermal expansion along x-, y-, and z-axes is achievable. As a special case, the homogenization model is used to predict, for the first time, a configuration of braided architecture and material leading to zero coefficient of thermal expansion along x-, y- and z-directions.

Effects of Imperfections on Bifurcation of Multi-Layer Microstructures of MEMS under Thermal Loading

2007 ◽  
Vol 339 ◽  
pp. 276-280
Author(s):  
Y.T. Yu ◽  
Wei Zheng Yuan ◽  
D.Y. Qiao
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Finite Element Simulation ◽  
Thermal Loading ◽  
Coefficient Of Thermal Expansion ◽  
Element Simulation ◽  
Simulation Results ◽  
Structural Bifurcation

Bifurcation of multi-layer microstructures subjected to thermal loading can be harmful for reliability and stability of MEMS structures. In this paper, three imperfections of geometry, coefficient of thermal expansion and thermal loading were introduced to investigate their effects on structural bifurcation by finite element simulation. Results show that bifurcation is strongly influenced by the imperfections. With larger deviation of imperfections, it results in a decreasing temperature to trigger the bifurcation and a gradual beginning of it.

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