Evaluation of the Strength of Interface for Multi-Layered Materials in Photonic Devices

2015 ◽  
Author(s):  
Hideo Koguchi ◽  
Naoki Kimura
Keyword(s):  
Numerical Analysis ◽  
Thermal Stresses ◽  
Electronic Device ◽  
Silicon Film ◽  
Unit Load ◽  
Slow Cooling ◽  
Element Analysis ◽  
Environment Temperature ◽  
Sapphire Plate ◽  
Critical Intensity

Recent electronic device packaging, for instance, CSP has a bonded structure of IC chip and polymers, and delamination occurs frequently at the interface between IC and a resin. Furthermore, thermal stresses which are caused by a temperature variation in the bonding process of CSP and heat cycles for environment temperature will influence on the strength of interface. In the present paper, the delamination test for specimens with different thicknesses of an interlayer is carried out to investigate the strength of multi-layered joints, and the critical value for the intensity of singularity at delamination of interface is determined through a numerical analysis using a boundary element analysis. In experiment, a silicon wafer is joined with a silicon-on-sapphire (SOS) plate by a resin. The SOS is composed of silicon film and sapphire plate. The joining strength in silicon, resin and SOS joints with a rectangular bonding area is investigated. The bonded specimens are prepared under different cooling rate. Load is applied to the specimen so as to delaminate at the interfaces of silicon film and sapphire. Delamination occurs at the interface between silicon film and sapphire plate in the specimen. Nominal stress for delamination is about 2.23–3.59 MPa. From a comparison of the strength of joint for rapid and slow cooling conditions, it is found that the residual stress reduces the strength of joint. In the numerical analysis, the intensity of singularity at the corner of interface for a unit load is determined. The intensity of singularity at the corner of the interface is related to the intensities of singularity in the radial direction and on the angle from the side free surface. The critical intensity of singularity for delamination of the interface is obtained by multiplying the force at delamination. Then, the critical intensity of singularity is determined as 168 MPa•mm0.18 regardless of the thickness of silicon film.

Evaluation of Strength in Joints of Silicon and Sapphire Coating Silicon

2013 ◽  
Author(s):  
Hideo Koguchi ◽  
Naoki Kimura
Keyword(s):  
Thermal Stresses ◽  
Electronic Device ◽  
Silicon Film ◽  
Sio2 Film ◽  
Nominal Stress ◽  
Slow Cooling ◽  
Environment Temperature ◽  
Bonding Area ◽  
Sapphire Plate ◽  
Silicon Resin

Recent electronic device packaging, for instance, Chip size package (CSP) has a bonded structure of IC chip and polymers, and delamination occurs frequently at the interface between IC and a resin. Furthermore, thermal stresses which are caused by a temperature variation in the bonding process of CSP and heat cycles for environment temperature will influence on the strength of interface. In the present paper, the delamination test for specimens with different bonding areas and geometries is carried out to investigate the strength of multi-layered joints. In particular, a silicon wafer is joined with a silicon-on-sapphire (SOS) plate by a resin. The SOS is composed of silicon film, SiO2 film and sapphire plate. The thicknesses of silicon film, SiO2 film and sapphire plate are 0.45μm, 0.2μm, 600μm, respectively. The joining strength in silicon, resin and SOS joints with triangular and rectangular bonding area is investigated. The triangular and rectangular shape bonding areas are 3mm2 and 12mm2, respectively. The bonded specimens are prepared under different cooling rate. Load is applied to the specimen so as to delaminate at the interfaces of SiO2 film and sapphire. From the delamination test, it is found that residual thermal stress and the geometry of bonding area affect the strength of interface. In the case of the triangular area specimen, delamination occurs at the interface between SiO2 film and sapphire plate in the silicon-resin-SOS specimen. The nominal stress for delamination is about 1.99MPa. In the case of rectangular bonding area specimen, delamination occurs at the interface between SiO2 film and sapphire plate in the silicon-resin-SOS specimen. Nominal stress for delamination is about 2.23MPa. From a comparison of the strength of joint for rapid and slow cooling conditions, it is found that the residual stress reduces the strength of joint.

Finite Element Analysis of Thermal Stresses in Circumferential Cast Clasps of Removable Partial Dentures

2007 ◽  
Vol 23 ◽  
pp. 229-232
Author(s):  
Liliana Sandu ◽  
Nicolae Faur ◽  
Cristina Bortun ◽  
Sorin Porojan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stresses ◽  
Element Analysis ◽  
3 Dimensional ◽  
Thermal Changes ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Back Action ◽  
Aggressive Effect

Several studies evaluated the removable partial dentures by the finite element analysis, but none of them evaluated thermal stresses. The purpose of the study was to explore the influence of thermal oral changes induced by hot/cold liquids and food on the circumferential cast clasps of removable partial dentures. A 3-dimensional finite element method was used to explore the temperature distribution, thermal stress and the influence of thermal changes on stresses and displacements of circumferential clasps during functions. Thermal variations induce stresses in dental clasps, high temperatures having a more aggressive effect than lower one. Cold liquids and food induce high stresses in the retentive clasp arms while hot ones in the occlusal rests of the clasps and for the back action clasp also in the minor connector. The study suggests the importance of consFigureidering thermal variations for stress analyses of the cast clasps.

Three Turnaround Heat Treating Studies

2003 ◽  
Author(s):  
Jaan Taagepera ◽  
Marty Clift ◽  
D. Mike DeHart ◽  
Keneth Marden
Keyword(s):  
Heat Treatment ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Heat Treating ◽  
Element Analysis ◽  
Stress Profiles ◽  
Insight Into

Three vessel modifications requiring heat treatment were analyzed prior to and during a planned turnaround at a refinery. One was a thick nozzle that required weld build up. This nozzle had been in hydrogen service and required bake-out to reduce the potential for cracking during the weld build up. Finite element analysis was used to study the thermal stresses involved in the bake-out. Another heat treatment studied was a PWHT of a nozzle replacement. The heat treatment band and temperature were varied with location in order to minimize cost and reduction in remaining strength of the vessel. Again, FEA was used to provide insight into the thermal stress profiles during heat treatment. The fmal heat treatment study was for inserting a new nozzle in a 1-1/4Cr-1/2Mo reactor. While this material would ordinarily require PWHT, the alteration was proposed to be installed without PWHT. Though accepted by the Jurisdiction, this nozzle installation was ultimately cancelled.

Elastic Thermal Stresses in Bimetallic Pipe Welds

1980 ◽  
Vol 102 (4) ◽  
pp. 430-432 ◽  
Author(s):  
R. D. Blevins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Intensity ◽  
Maximum Stress ◽  
Thermal Stresses ◽  
Simple Expression ◽  
Element Analysis ◽  
Maximum Stress Intensity ◽  
Bimetallic Pipe ◽  
Uniform Change

The elastic thermal stresses in a welded transition between two pipes of the same size but different alloys are explored. A stress-free temperature is postulated and the stress due to a uniform change in temperature is characterized by the maximum stress intensity in the weld. A simple expression for predicting this maximum stress intensity is developed based on the results of finite element analysis.

Numerical Analysis of Non-Radial Blading in a Low Speed and Low Pressure Turbine for Electric Turbocompounding Applications

2021 ◽  
Author(s):  
Eva Alvarez-Regueiro ◽  
Esperanza Barrera-Medrano ◽  
Ricardo Martinez-Botas ◽  
Srithar Rajoo
Keyword(s):  
Numerical Analysis ◽  
Numerical Simulations ◽  
Thermal Stresses ◽  
Waste Heat ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Turbine Rotor ◽  
Operating Conditions ◽  
Blade Angle ◽  
Low Speed

Abstract This paper presents a CFD-based numerical analysis on the potential benefits of non-radial blading turbine for low speed-low pressure applications. Electric turbocompounding is a waste heat recovery technology consisting of a turbine coupled to a generator that transforms the energy left over in the engine exhaust gases, which is typically found at low pressure, into electricity. Turbines designed to operate at low specific speed are ideal for these applications since the peak efficiency occurs at lower pressure ratios than conventional high speed turbines. The baseline design consisted of a vaneless radial fibre turbine, operating at 1.2 pressure ratio and 28,000rpm. Experimental low temperature tests were carried out with the baseline radial blading turbine at nominal, lower and higher pressure ratio operating conditions to validate numerical simulations. The baseline turbine incidence angle effect was studied and positive inlet blade angle impact was assessed in the current paper. Four different turbine rotor designs of 20, 30, 40 and 50° of positive inlet blade angle are presented, with the aim to reduce the losses associated to positive incidence, specially at midspan. The volute domain was included in all CFD calculations to take into account the volute-rotor interactions. The results obtained from numerical simulations of the modified designs were compared with those from the baseline turbine rotor at design and off-design conditions. Total-to-static efficiency improved in all the non-radial blading designs at all operating points considered, by maximum of 1.5% at design conditions and 5% at off-design conditions, particularly at low pressure ratio. As non-radial fibre blading may be susceptible to high centrifugal and thermal stresses, a structural analysis was performed to assess the feasibility of each design. Most of non-radial blading designs showed acceptable levels of stress and deformation.

Thermal stresses in multilevel interconnections: Aluminum lines at different levels

1997 ◽  
Vol 12 (9) ◽  
pp. 2219-2222 ◽  
Author(s):  
Y-L. Shen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stresses ◽  
Element Analysis ◽  
Future Studies ◽  
Level Lines ◽  
The Finite Element Analysis ◽  
Staggered Arrangement ◽  
Upper Level ◽  
Different Levels

Numerical results on the evolution of thermal stresses in multilevel interconnects are presented. Two levels of aluminum lines with an aspect ratio of unity, aligned vertically or arranged in a staggered manner, are considered by recourse to the finite element analysis. The stresses are found to be significantly higher in the lower-level lines than in the upper-level lines, for both the aligned and staggered arrangements. The stress magnitudes are generally smaller in lines of staggered arrangement, compared to the case of aligned lines. Implications of the present findings are discussed, with directions of future studies highlighted.

scholarly journals Finite Element Analysis of Artificially Frozen C-Phi soil

2019 ◽  
Vol 8 (4) ◽  
pp. 12722-12728
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Frozen Soil ◽  
Experimental Results ◽  
Soil Freezing ◽  
Strength Parameter ◽  
Frozen Ground ◽  
Element Analysis ◽  
Test Setup ◽  
Geological Conditions

Artificial Ground Freezing techniques eliminate the need for structural supports during the course of an excavation, as frozen ground is solid and waterproof. At present, it is adopted as an effective way to deal with various construction ground control challenges such as the mitigation of seepage infiltration into tunnels and shaft excavations; or ground strengthening for excavation. In-depth knowledge of the frozen soil characteristics through experiments and the development of suitable constitutive models that suit the geological conditions of our country are necessary to predict the strength and behavior of the frozen soils. Numerical analysis of frozen soil can be used for mass works like tunneling which cannot be experimentally verified. This paper presents a validation of experimental results obtained from laboratory setup and soil freezing system for C-Phi soil. The main aim is to compare numerical and experimental results and hence obtaining the shear strength parameter of the soil, similar to the conventional triaxial test setup. To perform numerical analysis Finite element tool ANSYS 19 is used. Soil model is made in ANSYS 19 and required loads are inputted to performed the analysis similar to the experimental method. The result obtained from experimental test setup and numerical analysis was verified and compared and it was found that values of numerical results lies closer to experimental results

scholarly journals Minimizing Residual Stress in Brazed Joints by Optimizing the Brazing Thermal Profile

2020 ◽  
Author(s):  
Ben Mann ◽  
Kurtis Ford ◽  
Mike Neilsen ◽  
Dan Kammler
Keyword(s):  
Elastic Material ◽  
Curie Point ◽  
Thermal Strain ◽  
Optimization Techniques ◽  
Filler Materials ◽  
Thermal Profile ◽  
Slow Cooling ◽  
Element Analysis ◽  
Material Models ◽  
Cooling Rates

Abstract Ceramic to metal brazing is a common bonding process used in many advanced systems such as automotive engines, aircraft engines, and electronics. In this study, we use optimization techniques and finite element analysis utilizing viscoplastic and thermo-elastic material models to find an optimum thermal profile for a Kovar® washer bonded to an alumina button that is typical of a tension pull test. Several active braze filler materials are included in this work. Cooling rates, annealing times, aging, and thermal profile shapes are related to specific material behaviors. Viscoplastic material models are used to represent the creep and plasticity behavior in the Kovar® and braze materials while a thermo-elastic material model is used on the alumina. The Kovar® is particularly interesting because it has a Curie point at 435°C that creates a nonlinearity in its thermal strain and stiffness profiles. This complex behavior incentivizes the optimizer to maximize the stress above the Curie point with a fast cooling rate and then favors slow cooling rates below the Curie point to anneal the material. It is assumed that if failure occurs in these joints, it will occur in the ceramic material. Consequently, the maximum principle stress of the ceramic is minimized in the objective function. Specific details of the stress state are considered and discussed.

scholarly journals A Review on Numerical Analysis of RC Flat Slabs Exposed to Fire

2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Analysis ◽  
Bending Moment ◽  
Mechanical And Thermal Properties ◽  
Vertical Deflection ◽  
Element Analysis ◽  
Flat Slabs ◽  
Numerical Studies ◽  
The Finite Element Analysis

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.

Finite Element Analysis of Casing Material Behavior in Steam Injection Well Operations

2015 ◽  
Vol 799-800 ◽  
pp. 196-200
Author(s):  
Abhilash M. Bharadwaj ◽  
Sonny Irawan ◽  
Saravanan Karuppanan ◽  
Mohamad Zaki bin Abdullah ◽  
Ismail bin Mohd Saaid
Keyword(s):  
Finite Element ◽  
Oil Recovery ◽  
Thermal Stresses ◽  
Oil And Gas ◽  
Extreme Temperature ◽  
Injection Pressure ◽  
Oil And Gas Industry ◽  
Steam Injection ◽  
Material Behavior ◽  
Element Analysis

Casing design is one of the most important parts of the well planning in the oil and gas industry. Various factors affecting the casing material needs to be considered by the drilling engineers. Wells partaking in thermal oil recovery processes undergo extreme temperature variation and this induces high thermal stresses in the casings. Therefore, forecasting the material behavior and checking for failure mechanisms becomes highly important. This paper uses Finite Element Methods to analyze the behavior two of the frequently used materials for casing - J55 and L80 steels. Modeling the casing and application of boundary conditions are performed through Ansys Workbench. Effect of steam injection pressure and temperature on the materials is presented in this work, indicating the possibilities of failure during heating cycle. The change in diameter of the casing body due to axial restriction is also presented. This paper aims to draw special attention towards the casing design in high temperature conditions of the well.

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