Constitutive modeling of lead-free solders

Pei, Min; Qu, Jianmin

doi:10.1109/isapm.2005.1432043

Cited by 49 publications

(9 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pang [8] has shown that young's modulus and yield stress of Sn-Pb are highly depended on strain rate and temperature. Pei [9] executed tensile tests over a wide range of temperatures and low strain rates (10-S 10-3 10-1 per sec) with two types of lead free materials (96.SSn3.SAg and 9S.SSn3.8AgO.7Cu). Although a large numbers of researchers focus on low strain rates, the constitution models of those materials at high strain rates are scarce.…”

Section: Introductionmentioning

confidence: 99%

Material behavior of SAC305 under high strain rate at high temperature

Lall¹,

Zhang²,

Yadav³

et al. 2014

Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)

View full text Add to dashboard Cite

Leadfree solders have been used as interconnects in electronic packaging, due to its environmental friendly chemical property. However, those materials may experience high strain rates when subjected to shock and vibration. Consequently, failure will occur to electronics in those situations. Therefore, knowing the material properties of lead free solders are extremely important, but research on mechanical behaviors of those solder alloys at high strain rates are scarce. Anand's viscoplastic constitutive model has been widely used to describe the inelastic deformation behavior of solders in electronic components under thermo-mechanical deformation. However, Anand's model constants for the transient dynamic strain rates are scarce. In this paper, the nine material parameters to fit the Anand viscoplastic model at high strain rates have been presented. In order to develop the constants for this model, uniaxial tensile tests at several strain rates and temperatures have been completed. A constrant strain rate impact hammer which enables attaining strain rates around 1 to 100 per sec has been employed to implement tensile tests and a small thermal chamber is applied to control testing temperature. High speed cameras operating at 70,000 fps have been used to capture images of specimen and then digital image correlation method is used to calculate tensile strain. Uniaxial stress-strain curves have been plotted over a wide range of strain rates (f: =10, 35, 50, 75 /sec) and temperatures (T = 25, 50, 75, 100, 125°C). Anand viscoplasticity constants have been calculated by non-linear fitting procedures. In addition, the accuracy of the extracted Anand constants has been evaluated by comparing the model prediction and experimental data.

show abstract

Section: Introductionmentioning

confidence: 99%

Material behavior of SAC305 under high strain rate at high temperature

Lall¹,

Zhang²,

Yadav³

et al. 2014

Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)

View full text Add to dashboard Cite

show abstract

“…In addition, Pei and coworkers [27] have calculated the nine parameters of the Anand model by conducting tensile testing of Sn3.5Ag and Sn3.8Ag0.7Cu lead free solders at several temperatures and strain rates.…”

Section: Introductionmentioning

confidence: 99%

The effects of silver content and solidification profile on the Anand constitutive model for SAC lead free solders

Basit

Motalab

Roberts

et al. 2014

Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)

View full text Add to dashboard Cite

In the electronic packaging industry, it is important to be able to make accurate predictions of board level solder joint reliability during thermal cycling exposures. The Anand viscoelastic constitutive model is often used to represent the material behavior of the solder in finite element simulations. This model is defined using nine material parameters, and the reliability prediction results are often highly sensitive to the Anand parameters. In this work, an investigation on the Anand constitutive model and its application to SAC solders of various Ag contents (i.e. SACN05, with N = 1, 2, 3, 4) has been performed. For each alloy, both water quenched (WQ) and reflowed (RF) solidification profiles were utilized to establish two unique specimen microstructures, and the same reflow profile was used for all four of the SAC alloys so that the results could be compared and the effects of Ag content could be studied systematically.The nine Anand parameters were determined for each unique solder alloy and microstructure from a set of stressstrain tests performed at several strain rates and temperatures. Testing conditions included strain rates of 0.001, 0.0001, and 0.00001 (sec -1 ), and temperatures of 25, 50, 75, 100, and 125 C. The Anand parameters were calculated from each set of stress-strain data using an established procedure that is described in detail in the paper. Using the calculated results for the various SAC alloys and microstructures, a set of empirical models have been established to describe the effects of SAC alloy Ag content on the Anand model parameters.As expected, the mechanical properties (modulus and strength) increase with the percentage of Ag content, and these changes strongly affect the Anand parameters. The sensitivity of the mechanical properties and Anand parameters to silver content is higher at lower silver percentages (1-2%). Also, the observed mechanical properties of water quenched samples were better (higher in magnitude) than the corresponding mechanical properties of the reflowed samples. Although the differences in elastic modulus between the water quenched and reflowed samples are small, significant differences are present for the yield and ultimate tensile stresses of all four SAC alloys. After deriving the Anand parameters for each alloy, the stress-strain curves have been calculated for various conditions, and excellent agreement was found between the predicted results and experimental stress-strain curves.

show abstract

“…A FOR-TRAN subroutine, calculating the stress increment and material Jacobian matrix, knowing the strain field, was written. Simulations and verifications with various solders revealed that there are good agreements between the user subroutine and bibliography results presented in [16,17]. Table 4 lists hereafter the two solders constitutive laws parameters.…”

Section: Solders Jointsmentioning

confidence: 66%

Reliability of the connections used in IGBT modules, in aeronautical environment

Zéanh

Dalverny

Karama

et al. 2008

Int. J. Simul. Multidisci. Des. Optim.

View full text Add to dashboard Cite

-In this paper, two IGBT modules assembling technologies with double side cooling capabilities and high level of integration were proposed for aeronautic applications after a state of the art and failures analysis. These technologies are compared using design of experiment based on non-linear finite element analysis with various materials, with respect to their potential failures under thermal and power loading profiles. The configurations optimizing the lifetime and reliability level were pointed out by loading profile and failure mode. Recommendations were then done in order to choose the optimal configuration of assembly for each application. Finally, these design rules were followed by the study of parts dimensions effects on the design outputs in order to help dimensioning the IGBT modules.

show abstract

Constitutive modeling of lead-free solders

Cited by 49 publications

References 6 publications

Material behavior of SAC305 under high strain rate at high temperature

Material behavior of SAC305 under high strain rate at high temperature

The effects of silver content and solidification profile on the Anand constitutive model for SAC lead free solders

Reliability of the connections used in IGBT modules, in aeronautical environment

Contact Info

Product

Resources

About