Test Method Development to Quantify the In Situ Elastic and Plastic Behavior of 62%Sn–36%Pb–2%Ag Solder Ball Arrays in Commercial Area Array Packages at −40 °C , 23 °C, and 125 °C

2005 ◽  
Vol 127 (4) ◽  
pp. 483-495 ◽  
Author(s):  
Ahmad Abu Obaid ◽  
Jay G. Sloan ◽  
Mark A. Lamontia ◽  
Antonio Paesano ◽  
Subhotosh Khan ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Solder Ball ◽  
Method Development ◽  
Failure Modes ◽  
Test Methods ◽  
Shear Loading ◽  
Test Method ◽  
Plastic Behavior ◽  
Area Array

The objective of this study is to describe and evaluate test methods developed to experimentally characterize the in situ mechanical behavior of solder ball arrays connecting printed wiring boards to area array packages under tensile, compressive, and shear loading at −40, 23, and 125 °C. The solder ball arrays tested were composed of 62%Sn–36%Pb–2%Ag solder alloy. Finite element modeling was performed. The results indicated that the test fixture should be geometrically equivalent to the projected shape of the ball grid array to achieve uniform loading. Tension, compression, and shear tests were conducted. For tensile loading the interfaces and the solder balls are loaded in series resulting in a large apparent strain (13%). Various interfacial failure modes are observed. Under compression and shear loading the effect of the interfaces are negligible and therefore a significant deformation and a remarkable yielding behavior of solder ball arrays can be observed. Furthermore, the specimens tested under shear loading showed different failure modes such as cohesive or adhesive failure modes depending on the test temperature. From the overall results, it has been determined that shear loading is the most representative test to measure the actual mechanical behavior of solder in ball grid arrays.

Experimental In Situ Characterization and Creep Modeling of Tin-Based Solder Joints on Commercial Area Array Packages at −40 °C , 23 °C , and 125 °C

2004 ◽  
Vol 127 (4) ◽  
pp. 430-439 ◽  
Author(s):  
Ahmad Abu Obaid ◽  
Jay G. Sloan ◽  
Mark A. Lamontia ◽  
Antonio Paesano ◽  
Subhotosh Khan ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Constitutive Model ◽  
Solder Ball ◽  
Solder Joints ◽  
Shear Loading ◽  
Area Array ◽  
Commercial Area ◽  
Wide Range ◽  
Solder Balls

The objective of this work was to experimentally determine the in situ creep behavior and constitutive model equations for a commercial area array package and printed wiring board assembly at −40, 23, and 125 °C through shear loading. The chip is connected to the printed circuit board by means of solder joints made of 62%Sn–36%Pb–2%Ag alloy. It was shown that the creep rate of solder ball arrays could be investigated using a stress relaxation method. Under the shear relaxation mode, the creep strain increases with temperature and can be described by a power law model with coefficients determined by finite element modeling (FEM). An analytical model was developed to describe the stress relaxation of an array with an arbitrary number of solder balls by defining an equivalent solder ball shear area as a fitting parameter. The resulting constitutive model is in excellent agreement with both FEM and experimental results at all test temperatures. A parametric study is conducted to investigate the creep response as a function of temperature for arrays consisting of a wide range of solder balls.

scholarly journals Test Method Development and Determination of Three-Dimensional Strength and Failure Modes of Polyvinyl Chloride Structural Foams

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Akira Miyase ◽  
Su Su Wang
Keyword(s):  
Polyvinyl Chloride ◽  
Failure Modes ◽  
Test Methods ◽  
Shear Loading ◽  
Test Method ◽  
Damage And Failure ◽  
Out Of Plane ◽  
Loading Modes ◽  
Structural Foams

A comprehensive study has been conducted to develop proper test methods for accurate determination of failure strengths along different material directions of closed-cell polymer-based structural foams under different loading modes. The test methods developed are used to evaluate strengths and failure modes of commonly used H80 polyvinyl chloride (PVC) foam. The foam's out-of-plane anisotropic and in-plane isotropic cell microstructures are considered in the test methodology development. The effect of test specimen geometry on compressive deformation and failure properties is addressed, especially the aspect ratio of the specimen gauge section. Foam nonlinear constitutive relationships, strength and failure modes along both in-plane and out-of-plane (rise) directions are obtained in different loading modes. Experimental results reveal strong transversely isotropic characteristics of foam microstructure and strength properties. Compressive damage initiation and progression prior to failure are investigated in an incremental loading–unloading experiment. To evaluate foam in-plane and out-of-plane shear strengths, a scaled shear test method is also developed. Shear loading and unloading experiments are carried out to identify the causes of observed large shear damage and failure modes. The complex damage and failure modes in H80 PVC foam under different loading modes are examined, both macroscopically and microscopically.

Review of material test standardization status for the material qualification of laminated thermosetting composite structures

2020 ◽  
pp. 073168442095810
Author(s):  
Sang Yoon Park ◽  
Won Jong Choi
Keyword(s):  
Composite Materials ◽  
Material Properties ◽  
Composite Structures ◽  
Failure Modes ◽  
Laminated Composite ◽  
Test Methods ◽  
Test Method ◽  
Experimental Comparison ◽  
Laminated Composite Materials ◽  
Design Values

This paper presents a review of recent literature related to the static mechanical testing of thermoset-based carbon fiber reinforced composites and introduces a material qualification methodology to generate statistically-based allowable design values for aerospace application. Although most test methods have been found to be effective in determining the specific material properties by incorporating them into the material qualification and quality control provisions, a full validation to clarify the behavior of thermoset-based laminated composite materials is currently lacking, particularly with regard to the characterization of compressive, in-plane, interlaminar shear, and damage tolerance properties. The present study obtains information on the different types of test method that can be employed within the same material properties, and makes an in-depth experimental comparison based on the past literatures. A discussion on the scope of theoretical analysis involves a description of how the proposed test method can be adequate for obtaining more accurate material properties. This discussion is directly applicable to the assessment of material nonlinearity and the geometrical effect of specimens. Finally, the resulting failure modes and the effect of each material property are studied to aid the understanding of the load distribution and behavior of laminated composite materials.

Plasticity in the Thickness Direction of Paperboard Under Combined Shear and Normal Loading

2001 ◽  
Vol 123 (2) ◽  
pp. 184-190 ◽  
Author(s):  
N. Stenberg ◽  
C. Fellers ◽  
S. O¨stlund
Keyword(s):  
Mechanical Behavior ◽  
Test Piece ◽  
Yield Function ◽  
Shear Loading ◽  
Plastic Behavior ◽  
Thickness Direction ◽  
Initial State ◽  
Normal Loading ◽  
Elastic Plastic ◽  
Out Of Plane

Creasing and offset printing are both examples of paperboard converting operations where the stress state is multiaxial, and where elastic-plastic deformation occurs in the thickness direction. Optimization of paperboard for such operations requires both advanced modeling and a better understanding of the mechanical behavior of the material. Today, our understanding and modeling of the out-of-plane properties are not as well established as our knowledge of the in-plane behavior. In order to bridge this gap, a modification of the Arcan device, which is well known in other fields, was developed for the experimental characterization of the out-of-plane mechanical behavior of paperboard. A fixture attached to the Arcan device was used to control the deformation in the test piece during loading. The test piece was glued to the device with a high viscosity adhesive and left stress-free during curing to achieve an initial state free of stresses. The apparatus proved to work well and to produce reliable results. Measurements of the mechanical behavior in combined normal and shear loading generated data points for the determination of the yield surface in the stress space. The elastic-plastic behavior in the thickness direction of paperboard was modeled assuming small-strain orthotropic linear elasticity and a quadratic yield function. Simulations using this yield function and an associative flow law showed good agreement with the test results.

scholarly journals Comparison of Test Setups for the Experimental Evaluation of the Primary Fixation Stability of Acetabular Cups

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3982
Author(s):  
Christian Schulze ◽  
Danny Vogel ◽  
Sina Mallow ◽  
Rainer Bader
Keyword(s):  
Test Methods ◽  
Load Test ◽  
Test Method ◽  
Artificial Bone ◽  
Acetabular Cup ◽  
Acetabular Bone ◽  
Press Fit ◽  
Orthopedic Surgeons ◽  
Fixation Stability

Sufficient primary fixation stability is the basis for the osseointegration of cementless acetabular cups. Several test methods have been established for determining the tilting moment of acetabular press-fit cups, which is a measure for their primary fixation stability. The central aim of this experimental study was to show the differences between the commonly used lever-out test method (Method 1) and the edge-load test method (Method 2) in which the cup insert is axially loaded (1 kN) during the tilting process with respect to the parameters, tilting moment, and interface stiffness. Therefore, using a biomechanical cup block model, a press-fit cup design with a macro-structured surface was pushed into three cavity types (intact, moderate superior defect, and two-point-pinching cavity) made of 15 pcf and 30 pcf polyurethane foam blocks (n = 3 per cavity and foam density combination), respectively. Subsequently, the acetabular cup was disassembled from the three artificial bone cavities using the lever-out and the edge-load test method. Tilting moments determined with Method 1 ranged from 2.72 ± 0.29 Nm to 49.08 ± 1.50 Nm, and with Method 2, they ranged from 41.40 ± 1.05 Nm to 112.86 ± 5.29 Nm. In Method 2, larger areas of abrasion were observed in the artificial bone cavity compared to Method 1. This indicates increased shear forces at the implant–bone interface in the former method. In conclusion, Method 1 simulates the technique used by orthopedic surgeons to assess the correct fit of the trial cup, while Method 2 simulates the tilting of the cup in the acetabular bone cavity under in situ loading with the hip resultant force.

scholarly journals Advancing Measurement Science to Assess Monitoring, Diagnostics, and Prognostics for Manufacturing Robotics

2020 ◽  
Vol 7 (3) ◽  
Author(s):  
Guixiu Qiao ◽  
Brian A. Weiss
Keyword(s):  
Method Development ◽  
Performance Metrics ◽  
Health Management ◽  
Test Methods ◽  
Test Method ◽  
Verification And Validation ◽  
Positional Accuracy ◽  
Measurement Science ◽  
Wide Range ◽  
Barriers And Challenges

Unexpected equipment downtime is a ‘pain point’ for manufacturers, especially in that this event usually translates to financial losses. To minimize this pain point, manufacturers are developing new health monitoring, diagnostic, prognostic, and maintenance (collectively known as prognostics and health management (PHM)) techniques to advance the state-of-the-art in their maintenance strategies. The manufacturing community has a wide-range of needs with respect to the advancement and integration of PHM technologies to enhance manufacturing robotic system capabilities. Numerous researchers, including personnel from the National Institute of Standards and Technology (NIST), have identified a broad landscape of barriers and challenges to advancing PHM technologies. One such challenge is the verification and validation of PHM technology through the development of performance metrics, test methods, reference datasets, and supporting tools. Besides documenting and presenting the research landscape, NIST personnel are actively researching PHM for robotics to promote the development of innovative sensing technology and prognostic decision algorithms and to produce a positional accuracy test method that emphasizes the identification of static and dynamic positional accuracy. The test method development will provide manufacturers with a methodology that will allow them to quickly assess the positional health of their robot systems along with supporting the verification and validation of PHM techniques for the robot system.

scholarly journals Emission Monitoring and Testing of Combustion Processes

1995 ◽  
Author(s):  
George H. Wagner
Keyword(s):  
Air Pollutants ◽  
Method Development ◽  
Combustion Process ◽  
Test Methods ◽  
Test Method ◽  
State Agencies ◽  
Hazardous Air Pollutants ◽  
Test Method Development ◽  
Air Quality Planning ◽  
Combustion Processes

An outline of the federal regulations which require toting and continuous monitoring of combustion process emissions is presented. A discussion of the NOx RACT regulations and the differences between selected state agencies is presented. A brief review of the components of the proposed enhanced monitoring rule is provided. The technology and types of continuous emission monitors (CEM) currently available for criteria and hazardous air pollutants are described. The new CEM technologies being developed for criteria and hazardous air pollutants are summarized. The factors to be considered in purchasing, installing, certifying and operating a CEM system are outlined. The approved EPA test methods, procedures for new test method development and the new EPA stationary source and analyses database are reviewed. The use of continues monitors to develop individual combustion curves for optimization of reduced emissions is summarized. The Office of Air Quality Planning and Standard (QAQPS) network of databases is introduced.

Study on tearing tests and the determination of fracture toughness of PVC-coated fabric

2021 ◽  
pp. 152808372199394
Author(s):  
Han Bao ◽  
Minger Wu ◽  
Xubo Zhang
Keyword(s):  
Fracture Toughness ◽  
Failure Modes ◽  
Membrane Surface ◽  
Finite Size ◽  
Theoretical Method ◽  
Test Methods ◽  
Gauge Length ◽  
Test Method ◽  
Single Edge ◽  
Tearing Resistance

In this study, detailed uniaxial in-plane tearing tests including uniaxial central, single-edge notched, and trapezoidal tearing tests of a type of polyvinylchloride (PVC)-coated polyester fiber fabric were conducted. Two types of tearing failure modes, brutal and progressive, were examined. In addition to differences in the descending sections of the stress–displacement curves and the membrane surface morphology near the crack, it was found that the uniaxial central tearing test could be replaced by the corresponding single-edge notched tearing test to minimize the usage of test materials. The configuration of the single-edge notched specimen, including the gauge length and width, was investigated to determine the conditions under which the tearing resistance of the practically nearly infinite membrane surface can be studied with finite-size specimens. To obtain the fracture toughness GIC, which characterizes the ability of materials to prevent crack growth, a theoretical method and two test methods were introduced. After comparing the methods, the test method based on the area of the parallelogram obtained from the zigzag wave in the descending section of the load–displacement curves was proved to be superior. The value of GIC obtained with this simple test method was relatively stable, and it could be used to evaluate the tearing resistance and calculate the tearing strength of the coated fabrics.

scholarly journals Effects of Gaseous and Particulate Contaminants On Information Technology Equipment Reliability - A Review

2021 ◽  
Author(s):  
Satyam Saini ◽  
Jimil M. Shah ◽  
Pardeep Shahi ◽  
Pratik V Bansode ◽  
Dereje Agonafer ◽  
...  
Keyword(s):  
Data Center ◽  
Failure Modes ◽  
Test Methods ◽  
In Situ Test ◽  
Equipment Reliability ◽  
Hardware Failures ◽  
Particulate Contaminants ◽  
The Cost ◽  
Scale Data

Abstract Over the last decade, several hyper-scale data center companies such as Google, Facebook, and Microsoft have demonstrated the cost-saving capabilities of airside economization with direct/indirect heat exchangers by moving to chiller-less air-cooled data centers. Under pressure from data center owners, IT equipment OEMs like Dell and IBM are developing IT equipment that can withstand peak excursion temperature ratings of up to 45°C, clearly outside the recommended envelope, and into ASHRAE's A4 allowable envelope. As popular and widespread as these cooling technologies are becoming, airside economization comes with its challenges. There is a risk of pre-mature hardware failures or reliability degradation posed by uncontrolled fine particulate and gaseous contaminants in presence of temperature and humidity transients. This paper presents an in-depth review of the particulate and gaseous contamination-related challenges faced by the modern-day data center facilities that use airside economization. This review summarizes specific experimental and computational studies to characterize the airborne contaminants and associated failure modes and mechanisms. In addition, standard lab-based and in-situ test methods for measuring the corrosive effects of the particles and the corrosive gases, as the means of testing the robustness of the equipment against these contaminants, under different temperature and relative humidity conditions are also reviewed. It also outlines the cost-sensitive mitigation techniques like improved filtration strategies and methods that can be utilized for efficient implementation of airside economization.

scholarly journals Reinforcement and Restoration Studies of the Edremit Ataturk House

2020 ◽  
Vol 10 (2) ◽  
pp. 5346-5351
Author(s):  
B. M. Bagbanci
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Dynamic Properties ◽  
Element Model ◽  
Test Methods ◽  
Test Method ◽  
Before And After ◽  
Vibration Tests ◽  
Non Destructive

Edremit Ataturk House has been restored under international restoration principles. Due to its importance, a systematic study was carried out to prevent the building from suffering damage. The current situation of the building was investigated by using slightly destructive and non-destructive test methods. Flat-jack and shear tests were used in order to identify the mechanical properties of masonry walls according to the ASTM standards. The operational modal analysis test method was used in order to understand its dynamic characteristics. After the diagnosis phase, a finite element model was prepared and calibrated according to the in-situ test results. The reinforcement studies were performed according to the finite element modal analysis results. Finally, the differences between the dynamic properties of the structure were evaluated by vibration tests before and after the restoration works.

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