Deformation Behavior of Leadless 60% Pb–40% Sn Solder Joints

1987 ◽  
Vol 108 ◽  
Author(s):  
Ravichandran Subrahmanyan ◽  
Donald Stone ◽  
Che-Yu Li
Keyword(s):  
Fatigue Life ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Bauschinger Effect ◽  
Solder Joints ◽  
Accurate Prediction ◽  
Temperature Deformation ◽  
Stress Strain ◽  
Cyclic Displacement

ABSTRACTRoom temperature deformation data of leadless solder joints are reported. The joints were sheared under cyclic, displacement controlled loading at frequencies between 0.001 and 0.01 Hz. A microplastic model was utilized to simulate the stress-strain loops, which demonstrated a pronounced Bauschinger effect. The implications of microplasticity on fatigue life of solder joints are discussed. This phenomenon must be taken into account in an accurate prediction of solder deformation at low strain ranges.

Room Temperature Deformation Behavior of Inconel718

2005 ◽  
Vol 475-479 ◽  
pp. 677-680 ◽  
Author(s):  
Fang Bian ◽  
Guoyue Su ◽  
Fan Ya Kong ◽  
Ke Yang
Keyword(s):  
Grain Size ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Tensile Tests ◽  
True Stress ◽  
Temperature Deformation ◽  
Stress Strain ◽  
Limit Value ◽  
Heat Treated ◽  
Work Hardening Rate

The deformation behavior of Inconel718 at room temperature was studied by tensile tests. Three kinds of specimens were tested, including cold rolled, heat treated with grain size ASTM5 and heat treated with grain size ASTM7. The true stress-strain curves were obtained based on the tensile test records. The true stress-strain relation can express the room temperature deformation behavior, which can be described by equations similar to the Voce equation. The limit value of the work-hardening rate θ0 is very sensitive to the microstructure of the alloy.

Extensive deformation behavior of an all-oxide Al2O3-TiO2 nanostructured multilayer ceramic at room temperature

2009 ◽  
Vol 24 (11) ◽  
pp. 3387-3396 ◽  
Author(s):  
Arcan F. Dericioglu ◽  
Y.F. Liu ◽  
Yutaka Kagawa
Keyword(s):  
Cross Sections ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Temperature Deformation ◽  
Relative Movement ◽  
Element Simulation ◽  
Columnar Grains ◽  
Multilayer Ceramic ◽  
Extensive Deformation ◽  
Indentation Response

An all-oxide Al2O3-TiO2 ceramic multilayer composed of 10–100 nm thick alternating layers was fabricated using the reactive magnetron sputtering process. Microindentation tests were carried out on the multilayer ceramic followed by microstructural observations of the cross-sections of the indented sites to characterize the indentation response of the system. During the observations, it was noted that an extensive room temperature “deformation” occurred in the multilayer ceramic material. The material shows a thickness reduction of as much as ∼40% under a conical indenter at 300 mN of load without microcracking and dislocation-assisted deformation. The room temperature deformation mechanism is governed by the relative movement and rearrangement of the anisotropic nanoscale columnar grains along the intergranular boundaries containing elongated voids. The relative sliding along the intergranular boundaries, and the subsequent granular rotation under indentation were well captured by finite element simulation.

A General Autofrettage Model of a Thick-Walled Cylinder Based on Tensile-Compressive Stress-Strain Curve of a Material

2005 ◽  
Vol 40 (6) ◽  
pp. 599-607 ◽  
Author(s):  
X. P Huang
Keyword(s):  
Strain Hardening ◽  
Compressive Stress ◽  
Bauschinger Effect ◽  
Strain Curve ◽  
Accurate Prediction ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Perfectly Plastic ◽  
Hardening Models ◽  
Elastic Perfectly Plastic

The basic autofrettage theory assumes elastic-perfectly plastic behaviour. Because of the Bauschinger effect and strain-hardening, most materials do not display elastic-perfectly plastic properties and consequently various autofrettage models are based on different simplified material strain-hardening models, which assume linear strain-hardening or power strain-hardening or a combination of these strain-hardening models. This approach gives a more accurate prediction than the elastic-perfectly plastic model and is suitable for different strain-hardening materials. In this paper, a general autofrettage model that incorporates the material strain-hardening relationship and the Bauschinger effect, based upon the actual tensile-compressive stress-strain curve of a material is proposed. The model incorporates the von Mises yield criterion, an incompressible material, and the plane strain condition. Analytic expressions for the residual stress distribution have been derived. Experimental results show that the present model has a stronger curve-fitting ability and gives a more accurate prediction. Several other models are shown to be special cases of the general model presented in this paper. The parameters needed in the model are determined by fitting the actual tensile-compressive curve of the material, and the maximum strain of this curve should closely represent the maximum equivalent strain at the inner surface of the cylinder under maximum autofrettage pressure.

scholarly journals Effect of Thermal Cyclic Loading on Stress-Strain Response and Fatigue Life of 3D Chip Stacking Structure

2020 ◽  
Author(s):  
Liang Zhang ◽  
Su-juan Zhong
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Low Temperature ◽  
Dwell Time ◽  
Maximum Stress ◽  
Solder Joints ◽  
Stress Strain ◽  
3D Chip Stacking ◽  
Stacking Structure

Abstract In this paper, the thermo-mechanical reliability of IMCs (Ni3Sn4, Cu3Sn, Cu6Sn5) solder joints and Sn-3.9Ag-0.6Cu solder joints were investigated systematically in 3D chip stacking structure subjected to an accelerated thermal cyclic loading based on finite element simulation and Taguchi method. Effects of different control factors, including high temperature, low temperature, dwell time of thermal cyclic loading, and different IMCs on the stress-strain response and fatigue life of solder joints were calculated respectively. The results indicate that maximum stress-strain can be found in the second solder joint on the diagonal of IMC solder joints array, for Sn-3.9Ag-0.6Cu solder joints array the corner solder joints shows the obvious maximum stress-strain, these areas are the crack propagated locations. The stress-strain and fatigue life of solder joints is more sensitive to dwell temperature, especially to high temperature, increasing the high temperature, dwell time, or decreasing the low temperature, can reduce the stress-strain and enlarge the fatigue life of solder joints. The optimal design in the 3D IC structure has the combination of the Cu6Sn5/Cu3Sn, 373K high temperature, 233K low temperature, and 10min dwell time.

A Study on Strain Concentration Around V Notch in Lead Free Solder Material and the Low Cycle Fatigue Life

2015 ◽  
Author(s):  
Takashi Kawakami ◽  
Takahiro Kinoshita ◽  
Hirokazu Oriyama
Keyword(s):  
Fatigue Life ◽  
Solder Joints ◽  
Low Cycle Fatigue ◽  
Lead Free ◽  
Design Rule ◽  
Lead Free Solder ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Test Pieces ◽  
Free Solder

Solder joints are sometimes opened under thermal cyclic loads as low cycle fatigue phenomena. The fatigue crack is usually initiated around the edge of the interface where stress and strain very severely concentrate, having stress strain singularity. In this study, Sn-3.0Ag-0.5Cu test pieces with V shape notch were supplied to low cycle fatigue tests at 100°C. And inelastic stress strain simulations, which were based on time-dependent non-unified material model, were carried out under several cyclic load levels to obtain strain distributions around the bottom of the V notch. By results of fatigue test and inelastic simulation, the depth from the bottom of the V notch, where the strain range agrees with the prediction of the fatigue life based on smooth test pieces on Coffin-Manson rule, was investigated as the mechanical design rule for lead free solder joints.

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