Rita Mohd Said
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Preferred name
Rita Mohd Said
Official Name
Rita, Mohd Said
Alternative Name
Mohd Said, Rita
Said, Rita Mohd
Said, R. M.
Mohd Said, R.
Said, R. Mohd
Main Affiliation
Scopus Author ID
56353112100

Research Output
Now showing 1 - 2 of 2
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Publication

The effect of thermal annealing on the microstructure and mechanical properties of Sn-0.7Cu-xZn solder joint

2021 , Mohd Izrul Izwan Ramli , Mohd Arif Anuar Mohd Salleh , Rita Mohd Said , Mohd. Mustafa Al Bakri Abdullah , Dewi Suriyani Che Halin , Norainiza Saud , Marcin Nabiałek

The microstructural properties of a Pb-free solder joint significantly affect its mechanical behaviours. This paper details a systematic study of the effect of the annealing process on the microstructure and shear strength of a Zn-added Sn-0.7Cu solder joint. The results indicated that the IMC layer’s thickness at the solder/Cu interface increases with annealing time. The interfacial IMC layer of the Sn-0.7Cu solder joint gradually thickened with increasing annealing time and annealing temperature, while the interfacial IMC layer’s morphology changed from scallop-type to layer-type after the annealing process. However, the addition of 1.0 wt.% and 1.5 wt.% Zn in the Sn-0.7Cu effectively altered the interfacial IMC phase to Cu-Zn and suppressed the growth of Cu3Sn during the annealing process. The single-lap shear tests results confirmed that the addition of Zn decreased the shear strength of Sn-0.7Cu. The interfacial IMC of the Cu6Sn5 phase in Sn-0.7Cu changed to Cu-Zn due to the addition of Zn. The shear fractures in the annealed solder joint were ductile within the bulk solder instead of the interfacial IMC layer. Increased annealing time resulted in the increased presence of the Cu-Zn phase, which decreased the hardness and shear strength of the Sn-0.7Cu solder joint.

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Publication

Influence of 1.5 wt.% Bi on the microstructure, hardness, and shear strength of Sn-0.7Cu solder joints after isothermal annealing

2021 , Mohd Izrul Izwan Ramli , Mohd Arif Anuar Mohd Salleh , Andrei Victor Sandu , Siti Farahnabilah Muhd Amli , Rita Mohd Said , Norainiza Saud , Mohd. Mustafa Al Bakri Abdullah , Petrica Vizureanu , Adam Rylski , Jitrin Chaiprapa , Marcin Nabialek

This manuscript reports the isothermal annealing effect on the mechanical and microstructure characteristics of Sn-0.7Cu-1.5Bi solder joints. A detailed microstructure observation was carried out, including measuring the activation energy of the intermetallic compound (IMC) layer of the solder joints. Additionally, the synchrotron µX-ray fluorescence (XRF) method was adopted to precisely explore the elemental distribution in the joints. Results indicated that the Cu6Sn5 and Cu3Sn intermetallic layers thickness at the solder/Cu interface rises with annealing time at a rate of 0.042 µm/h for Sn-0.7Cu and 0.037 µm/h for Sn-0.7Cu-1.5Bi. The IMC growth’s activation energy during annealing is 48.96 kJ mol-1 for Sn-0.7Cu, while adding Bi into Sn-0.7Cu solder increased the activation energy to 55.76 kJ mol−1. The µ-XRF shows a lower Cu concentration level in Sn-0.7Cu-1.5Bi, where the Bi element was well dispersed in the β-Sn area as a result of the solid solution mechanism. The shape of the IMC layer also reconstructs from a scallop shape to a planar shape after the annealing process. The Sn-0.7Cu hardness and shear strength increased significantly with 1.5 wt.% Bi addition in reflowed and after isothermal annealing conditions.

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