Modeling Thermal Stress Behavior in Microelectronic Components

1990 ◽  
Vol 112 (1) ◽  
pp. 35-40 ◽  
Author(s):  
G. C. Scott ◽  
G. Astfalk
Keyword(s):  
Mechanical Properties ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Elevated Temperatures ◽  
Underlying Mechanism ◽  
Mechanical Failure ◽  
Computational Techniques ◽  
Thermal And Mechanical Properties ◽  
Stress Cracking ◽  
Microelectronic Components

Thermal stress cracking is a significant mechanical failure mode in microelectronic components. This failure results from elevated stresses in components exposed to elevated temperatures due to the mismatch of thermal and mechanical properties of the constituent materials. The underlying mechanism responsible for these elevated stresses is not well understood. Therefore, we developed general mathematical and computational techniques for modeling the evolution of these stresses. As a test vehicle, we applied these techniques to thermal stress evolution in multilayer ceramic capacitors (MLCC). Thermal stress cracking has been implicated in significant, industry-wide problems associated with the cracking of these components. The model is used to solve for the transient development of thermal and mechanical gradients across the two spatial dimensions of the MLCC mid-plane. Material types with different thermal and mechanical properties and the interfaces between the material types are specifically included in the model. The stress field solutions are used to indicate when and where mechanical failure is expected to occur. The solutions of the model equations have been obtained using special partial differential equation solvers implemented on a CONVEX C120/220 supercomputer. The model is used to investigate the effects of MLCC termination geometry and material properties on the evolution of thermal stresses.

Estimation of Effective Thermal and Mechanical Properties of Particulate Thermal Interface Materials (TIMs) by a Random Network Model

2017 ◽  
Author(s):  
Pavan Kumar Vaitheeswaran ◽  
Ganesh Subbarayan
Keyword(s):  
Mechanical Properties ◽  
Network Model ◽  
Thermal Stresses ◽  
Volume Fraction ◽  
Random Network ◽  
Thermal Interface Materials ◽  
Thermal And Mechanical Properties ◽  
Thermal Interface ◽  
Classical Models ◽  
Interface Materials

Particulate thermal interface materials (TIMs) are commonly used to transport heat from chip to heat sink. While high thermal conductance is achieved by large volume loadings of highly conducting particles in a compliant matrix, small volume loadings of stiff particles will ensure reduced thermal stresses in the brittle silicon device. Developing numerical models to estimate effective thermal and mechanical properties of TIM systems would help optimize TIM performance with respect to these conflicting requirements. Classical models, often based on single particle solutions or regular arrangement of particles, are insufficient as real-life TIM systems contain a distriubtion of particles at high volume fractions, where classical models are invalid. In our earlier work, a computationally efficient random network model was developed to estimate the effective thermal conductivity of TIM systems [1,2]. This model is extended in this paper to estimate the effective elastic modulus of TIMs. Realistic microstructures are simulated and analyzed using the proposed method. Factors affecting the modulus (volume fraction and particle size distribution) are also studied.

Thermal and mechanical properties of Al/Al2O3 composites at elevated temperatures

2012 ◽  
Vol 531 ◽  
pp. 18-27 ◽  
Author(s):  
Pradeep Gudlur ◽  
Adam Forness ◽  
Jonathan Lentz ◽  
Miladin Radovic ◽  
Anastasia Muliana
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Thermal And Mechanical Properties

Thermal stress analysis of in-plane two-directional functionally graded plates subjected to in-plane edge heat fluxes

2016 ◽  
Vol 232 (8) ◽  
pp. 693-716
Author(s):  
MK Apalak ◽  
MD Demirbas
Keyword(s):  
Mechanical Properties ◽  
Thermal Stress ◽  
Functionally Graded ◽  
Heat Fluxes ◽  
Material Composition ◽  
Stress Distributions ◽  
Thermal And Mechanical Properties ◽  
Functionally Graded Plates ◽  
Spatial Derivatives ◽  
Derivatives Of

This study investigates the thermal stress and deformation states of bi-directional functionally graded clamped plates subjected to constant in-plane heat fluxes along two ceramic edges. The material properties of the functionally graded plates were assumed to vary with a power law along two in-plane directions not through the plate thickness direction. The spatial derivatives of thermal and mechanical properties of the material composition were considered, and the effects of the bi-directional composition variations and spatial derivative terms on the displacement, strain and stress distributions were also investigated. The heat conduction and Navier equations describing the two-dimensional thermo-elastic problem were discretized using finite-difference method, and the set of linear equations were solved using the pseudo singular value method. The compositional gradient exponents and the spatial derivatives of thermal and mechanical properties of the material composition were observed to play an important role especially on the heat transfer durations, the displacement and strain distributions, but had a minor effect on the temperature and stress distributions.

Thermal Stresses in Materials with Temperature-Dependent Properties

1991 ◽  
Vol 44 (9) ◽  
pp. 383-397 ◽  
Author(s):  
Naotake Noda
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Metal Forming ◽  
Thermal Stresses ◽  
Main Theme ◽  
Thermal And Mechanical Properties ◽  
Temperature Dependent ◽  
Accurate Analysis ◽  
Thermoelastic Problems ◽  
Temperature Dependent Properties

The present review on thermal stresses in materials with temperature-dependent properties focuses on papers published after 1980. The thermal and mechanical properties in materials subjected to thermal loads due to high temperature, high gradient temperature, and cyclical changes of temperature are dependent on temperature. The main theme of the thermoelastic problems in materials and structures with temperature-dependent material properties is to establish analytical procedures to solve the governing differential equations. In the thermo-inelastic problems, however, we must perform more accurate analysis of the practical problems (weld, heat treatment, metal forming, etc) taking account of the temperature-dependent material properties by use of numerical procedures (finite element methods, mainly).

scholarly journals Influence of additives of tungsten oxide nanoparticles on the thermophysical and mechanical properties of polymer composite materials

2021 ◽  
Vol 1 (79) ◽  
pp. 55-61
Author(s):  
A. A. Agisheva ◽  
◽  
L. K. Tastanova ◽  
A. Z. Bekeshev ◽  
M. N. Umurzakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tungsten Oxide ◽  
Elevated Temperatures ◽  
Industrial Applications ◽  
Thermal And Mechanical Properties ◽  
Functional Additives ◽  
Tungsten Oxide Nanoparticles ◽  
Quality Of Products ◽  
The Stability

Tungsten containing particles as functional additives have high potential for the reinforcement of different materials, such as polymer-based resins. The thermal and mechanical properties of polymer composites with additions of tungsten oxide were investigated. Incorporation of 1% WO3 nanoparticles increases the Young‘s modulus. An increase in the stability of the materials at elevated temperatures and an improvement in the mechanical properties of the resins are observed. Tungsten containing nanoparticles increase the quality of products for industrial applications.

scholarly journals Thermal and mechanical properties of steel-fibre-reinforced concrete at elevated temperatures

1996 ◽  
Vol 23 (2) ◽  
pp. 511-517 ◽  
Author(s):  
T. T. Lie ◽  
V. K. R. Kodur
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Reinforced Concrete ◽  
Fire Resistance ◽  
Elevated Temperatures ◽  
Steel Fibre ◽  
Fibre Reinforced Concrete ◽  
Thermal And Mechanical Properties ◽  
Steel Fibre Reinforced Concrete ◽  
Deformation Properties

For use in fire resistance calculations, the relevant thermal and mechanical properties of steel-fibre-reinforced concrete at elevated temperatures were determined. These properties included the thermal conductivity, specific heat, thermal expansion, and mass loss, as well as the strength and deformation properties of steel-fibre-reinforced siliceous and carbonate aggregate concretes. The thermal properties are presented in equations that express the values of these properties as a function of temperature in the temperature range between 0 °C and 1000 °C. The mechanical properties are given in the form of stress–strain relationships for the concretes at elevated temperatures. The results indicate that the steel fibres have little influence on the thermal properties of the concretes. The influence on the mechanical properties, however, is relatively greater than the influence on the thermal properties and is expected to be beneficial to the fire resistance of structural elements constructed of fibre-reinforced concrete. Key words: steel fibre, reinforced concrete, thermal properties, mechanical properties, fire resistance.

INFLUENCE OF TEMPERATURE-DEPENDENT RESIN BEHAVIOR ON NUMERICAL PREDICTION OF EFFECTIVE CTES OF 3D WOVEN COMPOSITES

2021 ◽  
Author(s):  
KOSTIANTYN VASYLEVSKYI ◽  
BORYS DRACH ◽  
IGOR TSUKROV
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Epoxy Resin ◽  
Elevated Temperatures ◽  
Impact Resistance ◽  
Woven Composites ◽  
Nonlinear Dependence ◽  
Thermal And Mechanical Properties ◽  
Effective Coefficients ◽  
3D Woven Composites

3D woven composites are well known for their high strength, dimensional stability, delamination, and impact resistance. They are often used in aerospace, energy, and automotive industries where material parts can experience harsh service conditions including substantial variations in temperature. This may lead to significant thermal deformations and thermally-induced stresses in the material. Additionally, 3D woven composites are often produced using resin transfer molding (RTM) technique which involves curing the epoxy resin at elevated temperatures leading to accumulation of the processing-induced residual stress. Thus, understanding of effective thermal behavior of 3D woven composites is essential for their successful design and service. In this paper, the effective thermal properties of 3D woven carbon-epoxy composite materials are estimated using mesoscale finite element models previously developed for evaluation of the manufacturing-induced residual stresses. We determine effective coefficients of thermal expansion (CTEs) of the composites in terms of the known thermal and mechanical properties of epoxy resin and carbon fibers. We investigate how temperature sensitivity of the thermal and mechanical properties of the epoxy influences the overall thermal properties of the composite. The simulations are performed for different composite reinforcement morphologies including ply-to-ply and orthogonal. It is shown that even linear dependence of epoxy’s stiffness and CTE on temperature results in a nonlinear dependence on temperature of the overall composite’s CTE.

Sign in / Sign up

Export Citation Format

Share Document