Publication:
Effect of multiple reflow cycles and isothermal aging on shear strength in SAC305Sn58BiCu-OSP hybrid solder joint
Effect of multiple reflow cycles and isothermal aging on shear strength in SAC305Sn58BiCu-OSP hybrid solder joint
Date
2024-12
Authors
Muhammad Luqman Mokhtar
Flora Somidin
Mohd Arif Anuar Mohd Salleh
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Research Projects
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Abstract
This study investigates the effects of multiple reflow cycles and isothermal aging on the shear strength and microstructure of SAC305/Sn58Bi/Cu-OSP hybrid solder joints. The joints combine SAC305 solder spheres and Sn58Bi solder paste reflowed on Cu-OSP substrates. Microstructural analysis revealed two distinct regions: a Bi-rich phase at the bottom and an Ag-rich phase at the top. Reflow cycles and isothermal aging at 85 °C, 125 °C, and 150 °C for up to 120 hours were evaluated for their impact on mechanical performance and reliability. Shear tests at 100 mm/s and 2000 mm/s showed that hybrid joints outperformed conventional SAC305/Cu-OSP joints, even after multiple reflow cycles. Aging at 85 °C and 125 °C had minimal impact on shear strength, indicating good stability under moderate conditions. However, aging at 150 °C, above the melting point of Sn58Bi (138 °C), caused a significant decrease in strength. These findings highlight the potential of hybrid solder joints for improved mechanical performance and thermal stability, offering advantages over conventional solder joints for advanced electronic packaging.
Description
Keywords
SAC305/Sn58Bi,
Hybrid solder joint,
Cu-OSP,
Isothermal aging,
Thermal cycling,
Mechanical properties