Effect of Material Anisotropy on Deformation Behavior of Multiple Grained Sac305 Solder Joints

2021 ◽  
Author(s):  
Debabrata Mondal ◽  
Abdullah Fahim ◽  
KM Rafidh Hassan ◽  
Jeffrey Suhling ◽  
Pradeep Lall
Keyword(s):  
Deformation Behavior ◽  
Solder Joints ◽  
Material Anisotropy ◽  
Sac305 Solder

Deformation Behavior of SAC305 Solder Joints With Multiple Grains

2020 ◽  
Author(s):  
Debabrata Mondal ◽  
Abdullah Fahim ◽  
KM Rafidh Hassan ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Grain Size ◽  
Solder Joint ◽  
Deformation Behavior ◽  
Thermal Loading ◽  
Solder Joints ◽  
Lead Free ◽  
External Loading ◽  
Lead Free Solder ◽  
Material Anisotropy ◽  
Free Solder

Abstract Lead-free solder joints are the most widely used interconnects in electronic packaging industries. Usually solder joints in most of the electronic devices are exposed to an environment where variation of temperature exists, which indicates cyclic thermal loading to be a very common type of external loading. Moreover, due to difference in the coefficient of thermal expansion (CTE) among dissimilar contact materials, shear stress develops in junctions under thermal loading, which significantly deteriorates the overall reliability. Hence, characterization of lead-free solder materials under thermal loading is essential to predict the performance and deformation behavior of joints in practical applications. A significant portion of the studies in this field are concerned with thermal loading of lead-free solder interconnects, each of which has a very small diameter, in sub-millimeter range. Although the solder balls have very small dimensions, most of the analyses considered them as a bulk material with homogeneous and isotropic properties. However, with the decrease of specimen dimensions, size effects and material directionality play a significant role in deformation mechanisms. Since a very few grains exist in a small specimen, individual grain properties play a vital role on overall material response. Therefore, modeling from the grain structure and orientation point of view could be an effective and more accurate way to predict solder joint deformation behavior under thermal loading. In this study, the effect of grain size and orientation of SAC305 is investigated for predicting anisotropic behavior of solder joints under thermal load. A simplified three-dimensional model of beach-ball configuration solder joint was generated and simulated using ABAQUS finite element (FE) software. Experimentally obtained directional properties such as elastic modulus and CTE were assigned to the computational geometry to create material anisotropy. The effects of material anisotropy were studied for varying grain size specimens, as well as for specimens with varying grain orientation.

Deformation Behavior Sac305 Solder Joints With Multiple Grains

2021 ◽  
Author(s):  
Debabrata Mondal ◽  
Abdullah Fahim ◽  
KM Rafidh Hassan ◽  
Jeffrey Suhling ◽  
Pradeep Lall
Keyword(s):  
Deformation Behavior ◽  
Solder Joints ◽  
Sac305 Solder

Determination of Anand Parameters From Creep Testing of Sac305 Solder Joints

2021 ◽  
Author(s):  
Mohammad Ashraful Haq ◽  
Mohd Aminul Hoque ◽  
Jeffrey Suhling ◽  
Pradeep Lall
Keyword(s):  
Solder Joints ◽  
Creep Testing ◽  
Sac305 Solder

scholarly journals Shear Strength Degradation Modeling of Lead-Free Solder Joints at Different Isothermal Aging Conditions

2021 ◽  
Vol 18 (3) ◽  
pp. 137-144
Author(s):  
Dania Bani Hani ◽  
Raed Al Athamneh ◽  
Mohammed Aljarrah ◽  
Sa’d Hamasha
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Constant Strain Rate ◽  
Circuit Board ◽  
Sac305 Solder ◽  
Aging Conditions ◽  
Osp Surface Finish ◽  
Shear Strength Degradation

Abstract SAC-based alloys are one of the most common solder materials that are utilized to provide mechanical support and electrical connection between electronic components and the printed circuit board. Enhancing the mechanical properties of solder joints can improve the life of the components. One of the mechanical properties that define the solder joint structure integrity is the shear strength. The main objective of this study is to assess the shear strength behavior of SAC305 solder joints under different aging conditions. Instron 5948 Micromechanical Tester with a customized fixture is used to perform accelerated shear tests on individual solder joints. The shear strength of SAC305 solder joints with organic solderability preservative (OSP) surface finish is investigated at constant strain rate under different aging times (2, 10, 100, and 1,000 h) and different aging temperatures (50, 100, and 150°C). The nonaged solder joints are examined as well for comparison purposes. Analysis of variance (ANOVA) is accomplished to identify the contribution of each parameter on the shear strength. A general empirical model is developed to estimate the shear strength as a function of aging conditions using the Arrhenius term. Microstructure analysis is performed at different aging conditions using scanning electron microscope (SEM). The results revealed a significant reduction in the shear strength when the aging level is increased. An increase in the precipitates coarsening and intermetallic compound (IMC) layer thickness are observed with increased aging time and temperature.

Effect of Aging on the Properties of Intermetallic Layers in SAC+Bi Solder Joints

2021 ◽  
Author(s):  
Mohammad Ashraful Haq ◽  
Mohd Aminul Hoque ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Aging Condition ◽  
Sac305 Solder ◽  
The Poor ◽  
Free Solder ◽  
Lead Free Solders ◽  
Overall Reliability ◽  
Intermetallic Layers

Abstract A major problem faced by electronic packaging industries is the poor reliability of lead free solder joints. One of the most common methods utilized to tackle this problem is by doping the alloy with other elements, especially bismuth. Researches have shown Bismuth doped solder joints to mostly fail near the Intermetallic (IMC) layer rather than the bulk of the solder joint as commonly observed in traditional SAC305 solder joints. An understanding of the properties of this IMC layer would thus provide better solutions on improving the reliability of bismuth doped solder joints. In this study, the authors have used three different lead free solders doped with 1%, 2% and 3% bismuth. Joints of these alloys were created on copper substrates. The joints were then polished to clearly expose the IMC layers. These joints were then aged at 125 °C for 0, 1, 2, 5 and 10 days. For each aging condition, the elastic modulus and the hardness of the IMC layers were evaluated using a nanoindenter. The IMC layer thickness and the chemical composition of the IMC layers were also determined for each alloy at every aging condition using Scanning Electron Microscopy (SEM) and EDS. The results from this study will give a better idea on how the percentage of bismuth content in lead free solder affects the IMC layer properties and the overall reliability of the solder joints.

Effect of microwave operating power and reflow time on the microstructure and tensile properties of Sn–3.0Ag–0.5Cu/Cu solder joints

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mardiana Said ◽  
Muhammad Firdaus Mohd Nazeri ◽  
Nurulakmal Mohd Sharif ◽  
Ahmad Azmin Mohamad
Keyword(s):  
Tensile Properties ◽  
Design Methodology ◽  
Solder Joints ◽  
Reflow Time ◽  
Sac305 Solder ◽  
Cross Sectional ◽  
Content Type ◽  
Solder Reflow ◽  
Microwave Hybrid Heating ◽  
Si Wafer

Purpose This paper aims to investigate the morphology and tensile properties of SAC305 solder alloy under the influence of microwave hybrid heating (MHH) for soldering at different microwave parameters. Design/methodology/approach Si wafer was used as susceptor in MHH for solder reflow. Microwave operating power for medium and high ranging from 40 to 140 s reflow time was used to investigate their effect on the microstructure and strength of SAC305/Cu solder joints. The morphology and elemental composition of the intermetallic compound (IMC) joint were evaluated on the top surface and cross-sectional view. Findings IMC formation transformed from scallop-like to elongated scallop-like structure for medium operating power and scallop-like to planar-like structure for high operating power when exposed to longer reflow time. Compositional and phase analysis confirmed that the observed IMCs consist of Cu6Sn5, Cu3Sn and Ag3Sn. A thinner IMC layer was formed at medium operating power, 80 s (2.4 µm), and high operating power, 40 s (2.5 µm). The ultimate tensile strength at high operating power, 40 s (45.5 MPa), was 44.9% greater than that at medium operating power, 80 s (31.4 MPa). Originality/value Microwave parameters with the influence of Si wafer in MHH in soldering have been developed and optimized. A microwave temperature profile was established to select the appropriate parameter for solder reflow. For this MHH soldering method, the higher operating power and shorter reflow time are preferable.

scholarly journals Suppression of the Growth of Intermetallic Compound Layers with the Addition of Graphene Nano-Sheets to an Epoxy Sn–Ag–Cu Solder on a Cu Substrate

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 936 ◽  
Author(s):  
Min-Soo Kang ◽  
Do-Seok Kim ◽  
Young-Eui Shin
Keyword(s):  
Intermetallic Compound ◽  
Isothermal Aging ◽  
Solder Joints ◽  
Solder Paste ◽  
Shear Tests ◽  
Sac305 Solder ◽  
Epoxy Solder ◽  
The Relationship ◽  
Bonding Characteristics ◽  
Preventive Effects

This study investigated the suppression of the growth of the intermetallic compound (IMC) layer that forms between epoxy solder joints and the substrate in electronic packaging by adding graphene nano-sheets (GNSs) to 96.5Sn–3.0Ag–0.5Cu (wt %, SAC305) solder whose bonding characteristics had been strengthened with a polymer. IMC growth was induced in isothermal aging tests at 150 °C, 125 °C and 85 °C for 504 h (21 days). Activation energies were calculated based on the IMC layer thickness, temperature, and time. The activation energy required for the formation of IMCs was 45.5 KJ/mol for the plain epoxy solder, 52.8 KJ/mol for the 0.01%-GNS solder, 62.5 KJ/mol for the 0.05%-GNS solder, and 68.7 KJ/mol for the 0.1%-GNS solder. Thus, the preventive effects were higher for increasing concentrations of GNS in the epoxy solder. In addition, shear tests were employed on the solder joints to analyze the relationship between the addition of GNSs and the bonding characteristics of the solder joints. It was found that the addition of GNSs to epoxy solder weakened the bonding characteristics of the solder, but not critically so because the shear force was higher than for normal solder (i.e., without the addition of epoxy). Thus, the addition of a small amount of GNSs to epoxy solder can suppress the formation of an IMC layer during isothermal aging without significantly weakening the bonding characteristics of the epoxy solder paste.

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