Interfacial reaction and mechanical properties of Sn58Bi-XCr solder joints under isothermal aging conditions

Vacuum ◽  
2021 ◽  
Vol 194 ◽  
pp. 110559
Author(s):  
Qianqian Song ◽  
Wenchao Yang ◽  
Yitai Li ◽  
Jun Mao ◽  
Weiou Qin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Interfacial Reaction ◽  
Isothermal Aging ◽  
Solder Joints ◽  
Aging Conditions

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.

Formation and Evolution of Intermetallic Compounds in Solder Joint for Electronic Interconnect

2011 ◽  
Vol 687 ◽  
pp. 80-84
Author(s):  
Chang Hua Du ◽  
Hai Jian Zhao ◽  
Li Meng Yin ◽  
Fang Chen
Keyword(s):  
Mechanical Properties ◽  
Solder Joint ◽  
Intermetallic Compounds ◽  
Isothermal Aging ◽  
Solder Joints ◽  
Growth Behavior ◽  
Electronic Products ◽  
Formation And Evolution ◽  
Kirkendall Voids ◽  
Reliability Of Solder Joints

As solder joints become increasingly miniaturized to meet the severe demands of future electronic packaging, the thickness of intermetallic compounds (IMC) in solder joint continuously decreases, while, the IMC proportion to the whole solder joint increases. So IMC plays a more and more important role in the reliability of microelectronic structure and microsystems. In this paper, the formation and growth behavior, along with the composition of IMC at the interface of Sn-based solders/Cu substrate in soldering were reviewed comprehensively. The effect of isothermal aging, thermal-shearing cycling and electromigration on the interfacial IMC growth and evolution were also presented. Furthermore, the formation mechanism of Kirkendall voids during thermal aging was introduced. In addition, the effect of the interfacial IMC on mechanical properties of solder joints was in-depth summarized. Adopting an appropriate flux to control the thickness of the IMC to improve the reliability of solder joints and electronic products was proposed in the end of this paper.

Nanoindentation Measurements of the Mechanical Properties of Individual Phases Within Lead Free Solder Joints Subjected to Isothermal Aging

2018 ◽  
Author(s):  
Abdullah Fahim ◽  
Sudan Ahmed ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Mechanical Properties ◽  
Isothermal Aging ◽  
Solder Joints ◽  
Bulk Solder ◽  
Lead Free ◽  
Nanoindentation Test ◽  
Lead Free Solder ◽  
Free Solder ◽  
The Individual ◽  
Sac Solder

Exposure of lead free solder joints to high temperature isothermal aging conditions leads to microstructure evolution, which mainly includes coarsening of the intermetallic (IMC) phases. In our previous work, it was found that the coarsening of IMCs led to degradation of the overall mechanical properties of the SAC solder composite consisting of β-Sn matrix and IMC particles. However, it is not known whether the isothermal aging changes properties of the individual β-Sn and IMC phases, which could also be affecting to the overall degradation of properties. In this study, the aging induced variations of the mechanical properties of the β-Sn phase, and of Sn-Cu IMC particles in SAC solder joints have been explored using nanoindentation. SAC solder joints extracted from SuperBGA (SBGA) packages were aged for different time intervals (0, 1, 5, 10 days) at T = 125 °C. Nanoindentation test samples were prepared by cross sectioning the solder joints, and then molding them in epoxy and polishing them to prepare the joint surfaces for nanoindentation. Multiple β-Sn grains were identified in joints using optical polarized microscopy and IMCs were also observed. Individual β-Sn grains and IMC particles were then indented at room temperature to measure their mechanical properties (elastic modulus and hardness) and time dependent creep deformations. Properties measured at different aging time were then compared to explore aging induced degradations of the individual phases. The properties of the individual phases did not show significant degradation. Thus, IMC coarsening is the primary reason for the degradation of bulk solder joint properties, and changes of the properties of the individual phases making up the lead free solder material are negligible.

scholarly journals Interfacial Reaction and Mechanical Properties of Sn-Bi Solder joints

Materials ◽  
2017 ◽  
Vol 10 (8) ◽  
pp. 920 ◽  
Author(s):  
Fengjiang Wang ◽  
Ying Huang ◽  
Zhijie Zhang ◽  
Chao Yan
Keyword(s):  
Mechanical Properties ◽  
Interfacial Reaction ◽  
Solder Joints

scholarly journals Interface evolution and mechanical properties of Sn–36Pb–2Ag solder joints under different aging conditions

2021 ◽  
Vol 10 ◽  
pp. 868-881
Author(s):  
Rui Li ◽  
Sen Cong ◽  
Jiancheng Mei ◽  
Le Zhang ◽  
Zhuo Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solder Joints ◽  
Interface Evolution ◽  
Aging Conditions

Investigation and Comparison of Aging Effects in SAC305 and Doped SAC+X Solders Exposed to Isothermal Aging

2020 ◽  
Author(s):  
Jing Wu ◽  
Mohammad S. Alam ◽  
KM Rafidh Hassan ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Isothermal Aging ◽  
Solder Joints ◽  
Lead Free ◽  
Aging Effects ◽  
Solid Solution Strengthening ◽  
Solution Strengthening

Abstract Microstructural evolution occurs in lead free Sn-Ag-Cu (SAC) solder joints exposed to isothermal aging. Such changes lead to degradations in the mechanical properties and creep behavior of the solder, and can result in dramatic reductions in the board level reliability of lead-free electronic assemblies subjected to aging. In our recent research, Scanning Electron Microscopy (SEM) has been used to: (1) monitor aging induced microstructural changes occurring within fixed regions in selected lead-free solder joints, (2) create time-lapse imagery of the microstructure evolution, and (3) analyze the microstructural changes quantitatively and correlate to the observed mechanical behavior evolution. This approach has removed the limitations of many prior studies where aged and non-aged microstructures were taken from two different samples and could only be qualitatively compared. In our current study, the microstructural evolutions were observed in SAC305 (96.5Sn-3.0Ag-0.5Cu) and SAC_Q (SAC+Bi) exposed to isothermal conditions at T = 100 °C and 125 °C for several different regions from several different joints. The microstructures in several fixed regions of interest were recorded after predetermined time intervals of aging, which were 1 hour (up to 270 hours) and 250 hours (up to 7000 hours) for the long-term aging samples. The aging induced changes in microstructure have been correlated with the changes in mechanical behavior measured using uniaxial tensile testing. The area and diameter of each IMC particle were tracked during the aging process using the recorded images and imaging processing software. As expected, the analysis of the evolving SAC305 and SAC+X microstructures showed a significant amount of diffusion of silver and bismuth in the beta-tin matrix during aging. In particular, Ag3Sn particles coalesced during aging leading to a decrease in the number of particles. Any bismuth in the SAC+X microstructure was observed to quickly go into solution, resulting in solid solution strengthening. This primary occurred within the beta-Sn dendrites, but also in the Ag3Sn intermetallic rich regions between dendrites. The presence of bismuth in was also found to slow the diffusion process that coarsens the Ag3Sn IMC particles. The combination solid solution strengthening and a lower diffusion rate for Ag lead to reduced aging effects in the SAC+Bi alloy relative to the SAC305 solder alloy. The SAC_Q alloy was found to have significantly better high temperature mechanical properties relative to SAC305 at all prior aging conditions. In particular, the initial modulus and ultimate tensile strength of SAC305 experienced large degradations during high temperature aging, whereas the same properties of SAC_Q changed only slightly. These changes in mechanical behavior correlated well with the observed increases in the average IMC particle diameter and decreases in the number of IMC particles. The microstructural and material property degradations were especially large for SAC305 during the initial 50 hours of aging.

Sign in / Sign up

Export Citation Format

Share Document