Numerical Investigation of Thermo-Mechanical Behaviour of Ball Grid Array Solder Joint at High Temperature Excursion

2011 ◽  
Vol 367 ◽  
pp. 287-292 ◽  
Author(s):  
E.H. Amalu ◽  
N.N. Ekere ◽  
R.S. Bhatti ◽  
S. Mallik ◽  
G. Takyi ◽  
...  
Keyword(s):  
High Temperature ◽  
Solder Joint ◽  
Numerical Investigation ◽  
High Temperatures ◽  
Structural Integrity ◽  
Mechanical Response ◽  
Coefficient Of Thermal Expansion ◽  
Electronic Systems ◽  
Bonded Materials ◽  
Transient Thermal

The solder joints of surface mount components (SMCs) experience thermal degradation culminating in creep and plastic shear strain deformation when subjected to cyclic temperature load over time. Degradation at the joints is due to thermal stress induced by the incompatible, differential and nonlinear expansion mismatch of the different bonded materials in the assembly. The stress magnitude influences the strain behaviour. Plastic strain response of solder joint is critical at the materials interface at the lower part of the joint due to the occurrence of wider variation in the coefficient of thermal expansion of the bonded materials and this may lead to static structural failure. The life expectancy of electronic components reduces exponentially as the operating temperature increases thus making reliability a key concern for electronic systems operating at high temperatures and in harsh environments. This paper reports on the numerical investigation of thermo-mechanical response of a critical BGA joint especially the character of plastic deformation of SnPb solder used in forming the joint as well as the joint’s high temperature reliability. The analysis uses a 3-D models to predict the effect of the transient thermal load on the static structural integrity of a single BGA joint. In this study, the base diameter of solder ball (interface between the PCB, copper pad and the solder) experienced higher damage than the top diameter interconnects. The paper provides a simplified methodology to study the reliability of BGA solder joint at high temperatures excursion.

Assessing the Impact of Shallow Gas Hydrate Dissociation on Structural Integrity in Deepwater Wells

2021 ◽  
Author(s):  
P. V. Suryanarayana ◽  
Miodrag Bogdanovic ◽  
Kuhanesapathy Thavaras Pathy ◽  
M. Razali Paimin
Keyword(s):  
Gas Hydrate ◽  
Structural Integrity ◽  
Mechanical Response ◽  
Preliminary Assessment ◽  
Shallow Gas ◽  
Hydrate Dissociation ◽  
Integrity Assessment ◽  
Well Integrity ◽  
Transient Thermal ◽  
The Impact

Abstract Shallow gas hydrate zones are present in some deepwater fields. During production, the shallow hydrates may dissociate due to heat-up of the near wellbore formation, which can extend radially to several meters from the wellbore. This can compromise structural integrity of the well (particularly structural strings), cause subsidence, and impact subsea equipment installations. This problem is well known, and has been addressed in the literature. An enthalpy-based transient thermal simulation is required to determine the dissociation front. Further, post-dissociation formation mechanics and well integrity assessment are complex, requiring numerical approaches such as Finite Element Analyses. In this paper, we present an approach that allows a preliminary assessment of the severity of the impact of dissociation on well integrity, so that a more complex assessment may be undertaken only for severe situations. The main objectives of the preliminary assessment are: to model hydrate dissociation front and the radial extent of dissociation as a function of depth; evaluate response of formation to this dissociation; analyze mechanical response of the well to the modified mechanical properties within dissociated zone; and confirm well integrity. The paper describes the approach, and introduces two thermal metrics to assess the likely severity of the integrity impact of hydrate dissociation. Using these metrics, the need for a more detailed analysis can be determined. Further, load analysis and integrity checks of the structural strings and the wellhead that can be performed as part of the preliminary assessment are discussed. An illustrative example is used to demonstrate the approach.

scholarly journals Numerical Investigation of the Transient Behavior of a Hot Gas Duct under Rapid Depressurization

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
JingBao Liu ◽  
ShengYao Jiang ◽  
Tao Ma ◽  
RiQiang Duan
Keyword(s):  
High Temperature ◽  
Numerical Investigation ◽  
Structural Integrity ◽  
Transient Behavior ◽  
Pressure Differential ◽  
Key Factors ◽  
Pressure Transient ◽  
Hot Gas ◽  
Large Pressure ◽  
Decisive Parameter

A hot gas duct is an indispensable component for the nuclear-process heat applications of the Very-High-Temperature Reactor (VHTR), which has to fulfill three requirements: to withstand high temperature, high pressure, and large pressure transient. In this paper, numerical investigation of pressure transient is performed for a hot gas duct under rapid depressurization. System depressurization imposes an imploding pressure differential on the internal structural elements of a hot gas duct, the structural integrity of which is susceptible to being damaged. Pressure differential and its imposed duration, which are two key factors to evaluate the damage severity of a hot gas duct under depressurization, are examined in regard to depressurization rate and insulation packing tightness. It is revealed that depressurization rate is a decisive parameter for controlling the pressure differential and its duration, whereas insulating-packing tightness has little effect on them.

High Temperature Dynamic Mechanical Properties Characterization of Polymer Coatings via Nanoindentation

2021 ◽  
pp. 1-17
Author(s):  
Yusuke Matsuda ◽  
Aref Samadi-Dooki ◽  
Yinjie Cen ◽  
Gisela Vazquez ◽  
Luke Bu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperatures ◽  
Mechanical Response ◽  
Polymer Coatings ◽  
Dynamic Mechanical Properties ◽  
Industrial Applications ◽  
Dynamic Mechanical ◽  
Mechanical Properties Characterization

Abstract Polymer coatings are widely used in industrial applications. The mechanical properties of these polymer coatings are known to vary with temperature and deformation rate. The characterization of the dynamic mechanical properties of these coatings at high temperatures via traditional uniaxial testing is challenging due often to their brittleness and small size. In this paper, the mechanical properties of polymer coatings are reported with emphasis on their dynamic mechanical properties at temperatures up to 280 °C characterized by a dynamic nanoindentation technique with a sharp indenter tip. Nanoindentation was used to characterize the mechanical response with emphasis on dynamic mechanical properties of polymer coatings enclosed in a high-temperature stage. To verify the method, the viscoelastic properties of a reference PET were also characterized by uniaxial cyclic tensile testing which exhibited an excellent agreement with the proposed technique. The proposed nanoindentation method can be applied to other polymer coatings and thin films that are used in applications at high temperatures.

Temperature-Dependent Coefficient of Thermal Expansion of Silicon Nitride Films Used in Microelectromechanical Systems

1999 ◽  
Vol 605 ◽  
Author(s):  
Melissa Bargmann ◽  
Amy Kumpel ◽  
Haruna Tada ◽  
Patricia Nieva ◽  
Paul Zavracky ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Silicon Nitride ◽  
Cantilever Beam ◽  
High Temperatures ◽  
Microelectromechanical Systems ◽  
Coefficient Of Thermal Expansion ◽  
Temperature Dependent ◽  
Temperature Property ◽  
Silicon Nitride Films

AbstractMicroelectromechanical systems (MEMS) have potential application in high temperature environments such as in thermal processing of microelectronics. The MEMS designs require an accurate knowledge of the temperature dependent thermomechanical properties of the materials. Techniques used at room temperature often cannot be used for high-temperature property measurements. MEMS test structures have been developed in conjunction with a novel imaging apparatus designed to measure either the modulus of elasticity or thermal expansion coefficient of thin films at high temperatures. The MEMS test structure is the common bi-layered cantilever beam which undergoes thermally induced deflection at high temperatures. An individual cantilever beam on the order of 100 νm long can be viewed up to approximately 800°C. With image analysis, the curvature of the beam can be determined; and then the difference in coefficient of thermal expansion between the two layers can be determined using numerical modeling. The results of studying silicon nitride films on silicon oxide are presented for a range of temperatures.

A Study on Fretting Fatigue Behavior of Degraded 1Cr-0.5Mo Steel

2004 ◽  
Vol 261-263 ◽  
pp. 1221-1226 ◽  
Author(s):  
Jae Do Kwon ◽  
Sang Jin Cho ◽  
Yong Tak Bae
Keyword(s):  
High Temperature ◽  
Fatigue Strength ◽  
High Temperatures ◽  
Structural Integrity ◽  
Fatigue Behavior ◽  
Fretting Fatigue ◽  
Basic Data ◽  
Maximum Value ◽  
Degraded Material ◽  
Strength Difference

The aged degradation of material is observed when heat-resisting steel is exposed for long periods of time at high temperatures. In the present study, the degraded 1Cr-0.5Mo steel that is used for long periods of time at high temperature(about 515°C) and artificially reheat-treated materials are prepared. These materials were used to study the effect of aged degradation on fretting fatigue behavior. Through this experiment, it is found that the fretting fatigue strength of reheat-treated 1Cr-0.5Mo steel is approximately 46 percent lower than that of the plain fatigue strength of the same material. Furthermore, the fretting fatigue strength of degraded 1Cr-0.5Mo steel was less than 53 percent of the same material™s plain fatigue strength. The maximum value of fatigue strength difference is observed as 57 percent between the fretting fatigue of degraded material and plain fatigue of reheat-treated material. These results can be used as basic data in a structural integrity evaluation of heat-resisting steel considering aged degradation effects.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

CARLSON ALLOY C601

Alloy Digest ◽  
1994 ◽  
Vol 43 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
High Temperatures ◽  
Stress Corrosion Cracking ◽  
Heat Treating ◽  
Resistance To Stress ◽  
Extended Exposure ◽  
Sulfur Containing

Abstract Carlson Alloy C601 is characterized by high tensile, yield and creep-rupture strengths for high temperature service. The alloy is not embrittled by extended exposure to high temperatures and has excellent resistance to stress-corrosion cracking, to carburizing, nitriding and sulfur containing environments. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on forming, heat treating, machining, and joining. Filing Code: Ni-458. Producer or source: G.O. Carlson Inc.

NILO ALLOY 36

Alloy Digest ◽  
1987 ◽  
Vol 36 (8) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Constant Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Iron Nickel

Abstract NILO alloy 36 is a binary iron-nickel alloy having a very low and essentially constant coefficient of thermal expansion at atmospheric temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-79. Producer or source: Inco Alloys International Inc..

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