Application of Plastic-Creep Separate Type of Inelastic Constitutive Model to Lead Free Solder Alloys

2002 ◽  
Vol 2002.2 (0) ◽  
pp. 431-432
Author(s):  
Kenichi OHGUCHI ◽  
Katsuhiko SASAKI
Keyword(s):  
Constitutive Model ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Separate Type ◽  
Free Solder ◽  
Plastic Creep

A Viscoplastic Constitutive Model and Estimation Method of Material Constants for Lead-Free Solder Alloys

2005 ◽  
Author(s):  
Ken-Ichi Ohguchi ◽  
Katsuhiko Sasaki
Keyword(s):  
Constitutive Model ◽  
Estimation Method ◽  
Fem Analysis ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Creep Tests ◽  
Simple Method ◽  
Material Constants ◽  
Free Solder

A viscoplastic constitutive model for lead-free solder alloys was proposed. The proposed model is the elasto-plastic-creep type which comprises the sum of the plastic, transient creep, and steady-state creep strains. To determine the material constants employed by the proposed constitutive model, a simple method to estimate the constants was also proposed. The method was applied to the lead-free solder alloy of Sn-3.0Ag-0.5Cu. Then, all the material constants for Sn-3.0Ag-0.5Cu employed by the constitutive model were estimated only by three tensile tests and one subsequent stress relaxation test. Using the constitutive model with the estimated constants, the ratcheting deformations of Sn-3.0Ag-0.5Cu under different strain rates were simulated. As a result, the simulations could predict the strain rate effect on the ratcheting deformation well. Therefore, the FEM analysis employing the constitutive model with the estimation method for material constants must be useful for the faster selection of the optimum lead-free solder alloys for electronic devices mounting because the material constants in the model can be estimated without conducting the long-time creep tests.

scholarly journals Electrochemical migration of lead-free solder alloys in Na2SO4 environment

2017 ◽  
Author(s):  
Balint Medgyes ◽  
Sandor Adam ◽  
Lajos Tar ◽  
Vadimas Verdingovas ◽  
Rajan Ambat ◽  
...  
Keyword(s):  
Lead Free ◽  
Electrochemical Migration ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Free Solder

scholarly journals The Influences Which Constitutive Models for Lead-Free Solder Alloys in General FEA Programs Give to Accumulated Inelastic Strain Behavior

2016 ◽  
Vol 5 (4) ◽  
pp. 266-274
Author(s):  
Takeharu HAYASHI ◽  
Hirohiko WATANABE ◽  
Masaaki TAKABE ◽  
Yoshinori EBIHARA ◽  
Tatsuhiko ASAI ◽  
...  
Keyword(s):  
Constitutive Models ◽  
Inelastic Strain ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Strain Behavior ◽  
Free Solder

Solder Joint Reliability of Sn-Cu and Sn-Ag-Cu Lead-Free Solder Alloys Solidified on Copper Substrates with Different Surface Roughnesses

2015 ◽  
Vol 830-831 ◽  
pp. 265-269
Author(s):  
Satyanarayan ◽  
K.N. Prabhu
Keyword(s):  
Solder Joint ◽  
Solder Matrix ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Cu Substrate ◽  
Cu Substrates ◽  
Free Solder ◽  
Substrate Surfaces ◽  
Lead Free Solders

In the present work, the bond strength of Sn-0.7Cu, Sn-0.3Ag-0.7Cu, Sn-2.5Ag-0.5Cu and Sn-3Ag-0.5Cu lead free solders solidified on Cu substrates was experimentally determined. The bond shear test was used to assess the integrity of Sn–Cu and Sn–Ag–Cu lead-free solder alloy drops solidified on smooth and rough Cu substrate surfaces. The increase in the surface roughness of Cu substrates improved the wettability of solders. The wettability was not affected by the Ag content of solders. Solder bonds on smooth surfaces yielded higher shear strength compared to rough surfaces. Fractured surfaces revealed the occurrence of ductile mode of failure on smooth Cu surfaces and a transition ridge on rough Cu surfaces. Though rough Cu substrate improved the wettability of solder alloys, solder bonds were sheared at a lower force leading to decreased shear energy density compared to the smooth Cu surface. A smooth surface finish and the presence of minor amounts of Ag in the alloy improved the integrity of the solder joint. Smoother surface is preferable as it favors failure in the solder matrix.

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