Characterization of Sn-Bi-Co low temperature solder alloy / Lina Syazwana Kamaruzzaman

• Main Author: Lina Syazwana , Kamaruzzaman
• Format: Thesis
• Published: 2023
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://studentsrepo.um.edu.my/15138/2/Lina_Syazwana.pdf; http://studentsrepo.um.edu.my/15138/1/Lina_Syazwana.pdf; http://studentsrepo.um.edu.my/15138/

Sn-Bi solder had Bi-rich phase that brittle and prone to fracture during service. As the result, the excessive hardness and brittleness of Sn-Bi solder alloy could easily deteriorate the solder mechanical properties which then strongly influence the solder joint and packaging components continuing reliability. Systematic investigation on the impact of alloying Co element using flux doping technique on both microstructure and mechanical properties of Sn-58Bi solder alloy and the study of the effect of Sn-58Bi-Co/Cu solder joints microstructure when varying aging duration are conducted. The melting temperature of the solder are evaluated using differential scanning calorimeter (DSC) while the solder microstructure and IMC is characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscope (EDX) and build-in image analyser. The crystalline structure of the solder was analysed using XRD. Tensile test and Vickers hardness test used to characterize the solder mechanical properties. All characterization of the Sn-Bi-Co solder are assessed and correlated with Sn-Bi solder to note to any enhancement. The microstructure of all Sn-58Bi-xCo solders did not show significant different compared to Sn-58Bi solder. Sn-58Bi-1.5Co solder shown excellence mechanical properties with 60.29 ± 0.18 MPa tensile strength and 19.52 ± 0.47 HV microhardness value. After 56 days of thermal aging, the IMC layer of Sn-58Bi-xCo/Cu solder joints become flattening. It is highly anticipated that this new Sn-Bi-Co alloy can be applied in low temperature soldering and heat sensitive electronic devices, thus replacing lead-containing solder alloy.