scholarly journals Analysis on Structural Stress of 64 × 64 InSb IRFPAs with Temperature Dependent Elastic Underfill

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Liwen Zhang ◽  
Wei Tian ◽  
Qingduan Meng ◽  
Mengfang Sun ◽  
Na Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Maximum Stress ◽  
Elastic Model ◽  
Structural Stress ◽  
Temperature Dependent ◽  
Stress Maximum ◽  
Maximal Stress ◽  
Indium Bump ◽  
Simulation Results ◽  
Short Time

To improve the reliability of InSb IRFPAs, underfill has usually been filled between InSb chip and Si ROIC. Around the glass transition temperature, underfill shows viscoelasticity, yet, far below it, which shows apparently temperature dependent mechanical properties. Basing on the temperature dependent elastic model of underfill, firstly a small format array of8×8elements InSb IRFPAs is investigated by changing indium bump diameters and heights; simulated results show that the maximum stress in InSb chip has nothing to do with underfill height and is dependent on indium bump diameter; the varying tendency is just like the horizontally extended letter U. When indium bump diameter is set to 24 μm with height 21 μm, the maximal stress in InSb chip reaches minimum. To learn the stress in64×64elements in short time, with the above optimal structure, InSb IRFPAs array scale is doubled once again from8×8to64×64elements. Simulation results show that the stress maximum in InSb chip is strongly determined by arrays format and increases with array scale; yet, the stress maximum in Si ROIC almost keeps constant and is independent on array sizes; besides, the largest stress locates in InSb chip, and the stress distribution in InSb chip is uniform.

Dependence of Structural Stress on Indium Bump Sizes in 8×8 InSb Focal Plane Array

2011 ◽  
Vol 189-193 ◽  
pp. 2289-2293
Author(s):  
Li Gong Sun ◽  
Chao Meng ◽  
Qing Duan Meng
Keyword(s):  
Integrated Circuit ◽  
Maximum Stress ◽  
Finite Element Method Simulation ◽  
Array Detector ◽  
Structural Stress ◽  
Readout Integrated Circuit ◽  
Maximal Stress ◽  
Indium Bump ◽  
Simulation Results ◽  
Maximum Stresses

Based on viscoplastic Anand’s model, the structural stress of 8×8 InSb array detector with underfill dependent on indium bump sizes is systemically researched by finite element method. Simulation results show that as the diameters of indium bump decrease from 36μm to 20μm in step of 2μm, the maximum stress existing in InSb chip first reduces sharply, then increases flatly, and reaches minimum with indium bump diameter 32μm. The maximum stress in Si readout integrated circuit (ROIC) fluctuates at 320MPa with amplitude less than 50MPa, almost half stress in InSb chip. Yet the maximum stress in the indium bump array is almost unchangeable and keeps at 16.3MPa. When the height of indium bump increases from 9μm to 21μm in step of 6μm, the maximal stress in InSb chip first reduces sharply from 800MPa to 500MPa, then almost retains constant. With indium bump diameter 32μm and height 21μm, the maximum stresses in whole 8×8 InSb array detector reaches minimum 458MPa, besides, the stress distribution at the contacts areas is uniform and concentrated, the stress value is smallest and this structure is promising to avoid device invalidation.

Finite Element Analysis on Structural Stress of 16×16 InSb IRFPA with Viscoelastic Underfill

2011 ◽  
Vol 314-316 ◽  
pp. 530-534 ◽  
Author(s):  
Li Wen Zhang ◽  
Jin Chan Wang ◽  
Qian Yu ◽  
Qing Duan Meng
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
Viscoelastic Model ◽  
Finite Element Method Simulation ◽  
Von Mises Stress ◽  
Structural Stress ◽  
Element Analysis ◽  
Indium Bump ◽  
Final Yield ◽  
Von Mises

The thermal stress and strain, from the thermal mismatch of neighboring materials, are the major causes of fracture in InSb IRFPA. Basing on viscoelastic model describing underfill, the structural stress of 16×16 InSb IRFPA under thermal shock is studied with finite element method. Simulation results show that as the diameters of indium bump increase from 20μm to 36μm in step of 2μm, the maximum stress existing in InSb chip first increases slightly, and fluctuates near 28µm, then decreases gradually. Furthermore, the varied tendency seems to have nothing to do with indium bump standoff height, and with thicker indium bump height, the maximal Von Mises stress in InSb chip is smaller. All these mean that the thicker underfill is in favor of reducing the stress in InSb chip and improving the final yield.

MODELING AND INJURY REPAIR ANALYSIS OF ARTICULAR CARTILAGE BASED ON FIBER CONTENT

2019 ◽  
Vol 19 (08) ◽  
pp. 1940050
Author(s):  
MONAN WANG ◽  
YUANXIN JI ◽  
YUZHENG MA ◽  
JUNTONG JING
Keyword(s):  
Mechanical Properties ◽  
Liquid Phase ◽  
Volume Fraction ◽  
Solid Phase ◽  
Von Mises Stress ◽  
Elastic Model ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Simulation Results ◽  
Von Mises

It has great guiding significance for the prevention of osteoarthritis and the mechanical state of cartilage after tissue engineering repair to study the relationship between the mechanical properties of cartilage and its structure. This paper considered both the consideration of the solid phase, liquid phase, fiber-reinforced phase in the cartilage and the influence of the contents of major fibers and minor fibers near the cartilage surface. Based on these, a tangential zone of cartilage was established, and a certain improvement and optimization of the fiber-reinforced porous elastic model was performed. The Abaqus software and the Fortran language were used to complete simulation. Simulation results were compared with experiment’s results to verify the validity of the model. Finally, the model was used to perform finite element analysis of different degrees of repairable depth under sliding conditions. Several results were obtained. When the indenter is farther from the interface at the repair site, the mechanical changes in the cartilage are relatively stable. The contact stress of the tangential layer repair and the full-layer repair is small. The volume fraction of the liquid phase in the tangential layer and the full layer repair is lower than that in the other layer regions. The liquid flow rate and the Von Mises stress at the junction of the tangential layer repair are very high. Simulation results were used to explore differences in cartilage mechanical properties of different repairable depths, so as to select the best repairable depth for cartilage.

Finite Element Analysis on Structural Stress of 8×8 InSb Infrared Focal Plane Array

2010 ◽  
Vol 34-35 ◽  
pp. 207-211 ◽  
Author(s):  
Qing Duan Meng ◽  
Xiao Ling Zhang ◽  
Xiao Lei Zhang ◽  
Wei Guo Sun
Keyword(s):  
Finite Element ◽  
Focal Plane ◽  
Maximum Stress ◽  
Focal Plane Array ◽  
Von Mises Stress ◽  
Design Parameters ◽  
Structural Stress ◽  
Infrared Focal Plane Array ◽  
Indium Bump ◽  
Von Mises

Based on viscoplastic Anand’s model, the structural stress of 8×8 InSb infrared focal plane array (IRFPA) detector is systemically analyzed by finite element method, and the impacts of design parameters including indium bump diameters, heights and InSb chip thicknesses on both von Mises stress and its distribution are discussed in this manuscript. Simulation results show that as the diameters of indium bump decreases from 36 μm to 24 μm in step of 2 μm, the maximum stress existing in InSb chip reduces first, increases then linearly with reduced indium bump diameters, and reaches minimum with indium bump diameter 30 μm, the stress distribution at the contacts areas is uniform and concentrated. Furthermore, the varied tendency has nothing to do with indium bump standoff height. With indium bump diameter 30 μm, as the thickness of InSb chip reduces from 21 μm to 9 μm in step of 3 μm, the varying tendency of the maximum stress value in InSb chip is just like the letter U, as the indium bump thickness decreases also from 21 μm to 6 μm in step of 3 μm, the maximum stress in 8×8 InSb IRPFA decreases from 260 MPa to 102 MPa, which is the smallest von Mises stress value obtained with the indium diameter 30 μm, thickness 9 μm and InSb thickness 12 μm.

Finite Element Analysis on Structural Stress of 8×8 Infrared Focal Plane Array Integrating with Microlens Arrays

2012 ◽  
Vol 442 ◽  
pp. 162-166
Author(s):  
Li Wen Zhang ◽  
Ming Shao ◽  
Qiang Yu ◽  
Peng Fei Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Focal Plane ◽  
Maximum Stress ◽  
Focal Plane Array ◽  
Structural Stress ◽  
Element Analysis ◽  
Microlens Arrays ◽  
Infrared Focal Plane Array ◽  
Indium Bump

Based on finite element analysis, the structural stress of 8×8 InSb Infrared Focal Plane Array integrating with microlens arrays dependent on indium bump sizes is systemically researched. Simulation results show that as the diameters of indium bump increase from 16μm to 38μm in step of 2μm, the maximum stress existing in InSb chip first reduces, then increases, and reaches minimum with indium bump diameter 32μm. Yet the maximum stress in the indium bump array is almost unchangeable and keeps at 16.5MPa. The maximum stress in Si readout integrated circuit almost half stress in InSb chip. Besides, the stress appearing on those regions situating just on microlens array is much smaller than its surrounding regions, and the stress distribution is uniform at contacting areas between InSb chip and indium bump.

JESSOP JS17Cr-4Ni

Alloy Digest ◽  
1982 ◽  
Vol 31 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Food Processing ◽  
Precipitation Hardening ◽  
High Strength ◽  
Heat Treating ◽  
Steel Company ◽  
Lower Strength ◽  
Nickel Copper ◽  
Short Time

Abstract JESSOP JS17Cr-4Ni is a martensitic, precipitation-hardening chromium-nickel-copper stainless steel. It provides an excellent combination of high strength and hardness, short-time low-temperature precipitation hardening and good mechanical properties at temperatures up to 600 F (316 C). Its corrosion resistance is quite good but inferior to lower strength grades produced for corrosion-resistance applications. JS17Cr-4Ni is used widely for critical applications in the aerospace, chemical, food processing and other industries. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-412. Producer or source: Jessop Steel Company.

scholarly journals Temperature-Dependent Creep Behavior and Quasi-Static Mechanical Properties of Heat-Treated Wood

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 968
Author(s):  
Dong Xing ◽  
Xinzhou Wang ◽  
Siqun Wang
Keyword(s):  
Mechanical Properties ◽  
Creep Behavior ◽  
Cell Walls ◽  
Treated Wood ◽  
Crosslinking Reaction ◽  
Depth Sensing ◽  
Temperature Dependent ◽  
Heat Treated ◽  
Static Mechanical ◽  
Static Mechanical Properties

In this paper, Berkovich depth-sensing indentation has been used to study the effects of the temperature-dependent quasi-static mechanical properties and creep deformation of heat-treated wood at temperatures from 20 °C to 180 °C. The characteristics of the load–depth curve, creep strain rate, creep compliance, and creep stress exponent of heat-treated wood are evaluated. The results showed that high temperature heat treatment improved the hardness of wood cell walls and reduced the creep rate of wood cell walls. This is mainly due to the improvement of the crystallinity of the cellulose, and the recondensation and crosslinking reaction of the lignocellulose structure. The Burgers model is well fitted to study the creep behavior of heat-treated wood cell walls under different temperatures.

scholarly journals Geometrical Effects on Ultrasonic Al Bump Direct Bonding for Microsystem Integration: Simulation and Experiments

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 750
Author(s):  
Jun-Hao Lee ◽  
Pin-Kuan Li ◽  
Hai-Wen Hung ◽  
Wallace Chuang ◽  
Eckart Schellkes ◽  
...  
Keyword(s):  
Shear Strength ◽  
Joint Strength ◽  
Maximum Stress ◽  
Geometrical Parameters ◽  
Experimental Demonstration ◽  
Joint Shear Strength ◽  
Element Analysis ◽  
Ultrasonic Bonding ◽  
Simulation Results ◽  
Geometrical Effects

This study employed finite element analysis to simulate ultrasonic metal bump direct bonding. The stress distribution on bonding interfaces in metal bump arrays made of Al, Cu, and Ni/Pd/Au was simulated by adjusting geometrical parameters of the bumps, including the shape, size, and height; the bonding was performed with ultrasonic vibration with a frequency of 35 kHz under a force of 200 N, temperature of 200 °C, and duration of 5 s. The simulation results revealed that the maximum stress of square bumps was greater than that of round bumps. The maximum stress of little square bumps was at least 15% greater than those of little round bumps and big round bumps. An experimental demonstration was performed in which bumps were created on Si chips through Al sputtering and lithography processes. Subtractive lithography etching was the only effective process for the bonding of bumps, and Ar plasma treatment magnified the joint strength. The actual joint shear strength was positively proportional to the simulated maximum stress. Specifically, the shear strength reached 44.6 MPa in the case of ultrasonic bonding for the little Al square bumps.

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