Mardiana Said, Muhammad Firdaus Mohd Nazeri, Nurulakmal Mohd Sharif and Ahmad Azmin Mohamad
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…
Abstract
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.
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Abu Seman Anasyida and Mohd Sharif Nurulakmal
This study aims to develop and evaluate an inexpensive and durable metal cutting wheel using thermal spraying and polymer binding to enhance the wheel’s cutting capability by…
Abstract
Purpose
This study aims to develop and evaluate an inexpensive and durable metal cutting wheel using thermal spraying and polymer binding to enhance the wheel’s cutting capability by bonding hard particles (abrasives) onto the wheel.
Design/methodology/approach
Thermal spraying was used to deposit the coating powder (chromium and silicon carbide) onto high carbon substrate. Wear loss and depth of cut as function of load, time and speed were evaluated on uncoated and coated wheel.
Findings
The coated cutting wheel performed better than the uncoated cutting wheel in terms of wear performance. However, the coated cutting wheel experienced coating peel off at higher load and cutting speed, leading to a decrease in wear resistance of the cutting wheel. Thus, optimally cutting should be performed either at low cutting speed and high load or at high cutting speed and low load to prolong the wheel’s lifetime.
Originality/value
The outcome of the study will be beneficial for academicians and industrial working on cutting wheel process.
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Muhammad Asyraf Abdullah and Siti Rabiatull Aisha Idris
Pb-free solders have been developed to replace the standard Sn–Pb eutectic solder since the prohibition on Pb used in solders. The Sn–Ag–Cu series of lead-free solders is the most…
Abstract
Purpose
Pb-free solders have been developed to replace the standard Sn–Pb eutectic solder since the prohibition on Pb used in solders. The Sn–Ag–Cu series of lead-free solders is the most extensively used in the electronics industry. The Ag3Sn, which forms during isothermal ageing, can significantly degrade solder joint reliability. Sn–Ag–Cu solder’s high price further hindered its use in the electronics industry. This paper aims to investigate different copper percentages into Sn–xCu solder alloy to improve its microstructure and strength performance.
Design/methodology/approach
The solder alloys used in this work were Sn–xCu, where x = 0.0, 0.3, 0.5, 0.7, 1.0 Wt.%, which was soldered onto electroless nickel immersion gold (ENIG) substrate using carbon dioxide (CO2) gas laser. Then these samples were subjected to isothermal aging for 0, 200, 500, 1,000 and 2,000 h. The Sn–xCu solder alloy was fabricated through a powder metallurgy process.
Findings
Microstructure characterization showed that Cu addition resulted in fine and rounded shape of Cu–Sn–Ni particles. Shear strength of Sn–xCu solder joints was increased with increasing Cu content, but at aging duration of 1,000 h, it dropped slightly. It is believed that the strength improved due to the increment of diffusion rate during isothermal aging.
Practical implications
In a Cu–Sn solder, the recommended amount is 1.0 Wt.% of Cu. In extensive aging procedures, it was discovered that Sn1.0Cu solder improved the reliability of solder joints. The findings indicated that the innovative solder alloys might satisfy the needs of high-reliability applications.
Originality/value
The study shows that the right amount of Cu enhances the solidification of Sn–Cu solder, increasing the shear force of the Cu–Sn solder joint. The Sn1.0Cu exhibits a ductile fracture on the top microstructure, improving the joint’s average shear strength.