Journal ArticleDOI
Thermal Fatigue of SnPb and SAC Resistor Joints: Analysis of Stress-Strain as a Function of Cycle Parameters
TLDR
In this paper, thermomechanical finite element (FE) models were used to analyze the stress/strain response of a resistor test vehicle during ATC testing under three accelerated test conditions: two ramp rates (14 degC/min and 95 degC /min) and two temperature ranges (DeltaT=0degC-100degC and -40degC −125degC), denoted 14-100 (ramp rate-temperature range), 95-100, and 95-165).Abstract:
Accelerated thermal cycling (ATC) has been widely used in the microelectronics industry for reliability assessment. The relative effects of thermal cycling parameters (temperature range, dwell time, and ramp rate) and the failure mechanisms they induce have been the subject of many studies; however, uncertainty remains, particularly regarding the role of a very high ramp rate such as encountered in a thermal shock chamber. In the present research, thermomechanical finite-element (FE) models were used to analyze the stress/strain response of a resistor test vehicle during ATC testing under three accelerated test conditions: two ramp rates (14 degC/min and 95 degC/min) and two temperature ranges (DeltaT=0degC-100degC and -40degC-125degC), denoted 14-100 (ramp rate-temperature range), 95-100, and 95-165. The temperature gradients through the thickness of the assemblies were measured during the ATC test with the high ramp rate and were used to create an FE model that included transient stresses and strains. The effect of the transient temperature gradients during thermal shock was found to be negligible in these resistor joints. The FE models were then used to simulate the above three ATC test conditions with either SnPb or Pb-free (SAC) solders and were compared with previously published thermal fatigue lives for this resistor test vehicle. For both SnPb and SAC resistors, the maximum total solder strains (sum of elastic, plastic, and creep) and strain energy dissipation per cycle predicted by the FE models in the 95-165 test condition were much greater than those in either the 14-100 or 95-100 test conditions, which produced almost identical strains and energy dissipation. In all cases, the strain energy density dissipation per cycle due to creep was much larger than that due to plastic deformation. The trend of these results was in accordance with the ATC tests, which showed that the thermal cycling lives decreased in the same order for both the SAC and SnPb solders; i.e., the fatigue life decreased as the predicted total strain increasedread more
Citations
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Journal ArticleDOI
IMC growth of Sn-3.5Ag/Cu system: Combined chemical reaction and diffusion mechanisms
Ousama M. Abdelhadi,Leila Ladani +1 more
TL;DR: In this paper, the growth kinetics of intermetallic (IMC) compound layers formed between Sn-3.5Ag solders and Cu substrate in soldering process are investigated experimentally and analytically.
Journal ArticleDOI
Reliability behavior of lead-free solder joints in electronic components
TL;DR: In this paper, the application and research status of constitutive equations and fatigue life prediction equations were reviewed, which provide theoretic guide for the reliability of lead-free solder joints.
Journal ArticleDOI
Effects of cerium on Sn-Ag-Cu alloys based on finite element simulation and experiments
TL;DR: In this paper, the effect of small addition of rare earth on Sn-Ag-Cu solder was investigated by finite element method based on creep model of low stress and high stress and experiments respectively.
Journal ArticleDOI
Effect of primary creep and plasticity in the modeling of thermal fatigue of SnPb and SnAgCu solder joints.
TL;DR: It was found that for the thermal profiles considered, the role of plasticity was negligible for trilayer assemblies with SnPb and SnAg Cu solder interlayers, and when primary creep was included for SnAgCu, the temperature-dependent yield strength was not exceeded and no plastic strains resulted.
Journal ArticleDOI
A Second-Level SAC Solder-Joint Fatigue-Life Prediction Methodology
TL;DR: In this article, an acceleration model is developed for relating existing second-level fatigue-life data of tin-silver-copper solder joints to untested environments, which retains the familiar canonical form of the Norris-Landzberg equation.
References
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Journal ArticleDOI
Applying Anand Model to Represent the Viscoplastic Deformation Behavior of Solder Alloys
TL;DR: In this paper, a unified viscoplastic constitutive law, the Anand model, was applied to represent the inelastic deformation behavior for solders used in electronic packaging.
Proceedings ArticleDOI
Constitutive behaviour of lead-free solders vs. lead-containing solders-experiments on bulk specimens and flip-chip joints
TL;DR: In this paper, two lead-free solders (sn96.5Ag3.5, Sn95.8Cu0.7, Sn63Pb37 Sn59Pb40Agl) were investigated and compared with each other in order to give an estimation of the reliability enhancement of the new leadfree soldering technology.
Proceedings ArticleDOI
Acceleration models, constitutive equations, and reliability of lead-free solders and joints
TL;DR: In this article, a set of fabrication nodes for lead-free solder joints is proposed and discussed and useful equations for the acceleration models, life distribution, and failure probability are also provided.
Journal ArticleDOI
A Damage Mechanics-Based Fatigue Life Prediction Model for Solder Joints
Hong Tang,Cemal Basaran +1 more
TL;DR: A thermomechanical fatigue life prediction model based on the theory of damage mechanics is presented in this article, where the damage evolution, corresponding to the material degradation under cyclic thermOMEchanical loading, is quantified thermodynamic framework.
Journal ArticleDOI
Effects of underfill material properties on the reliability of solder bumped flip chip on board with imperfect underfill encapsulants
TL;DR: In this paper, three different types of underfill imperfections were considered; i.e., (1) interfacial delamination between the underfill encapsulant and the solder mask on the PCB (crack initiated at the tip of under-fill fillet), (2) inter-interference between the chip and the underfilled encapsulants (cracks initiated at chip corner), and (3) the same as (2), but without the underfilling fillet.