Purpose: The purpose of this paper is to publish on the review of the lead free solder for electronic packaging. This involved the basic principles of the solder, the lead solder and its legislation and the lead free solder with its mechanism. In addition, this paper also reviews on the lead free solder characteristics that focused on its wettability. Design/methodology/approach: This paper approach on the review of the solder wettability on the surface. It reviews on the solder especially on the contact angle and surface tension that is covered under the wettability of the solder. Findings: This paper also reviews on the lead free solder characteristics that focused on its wettability. Originality/value: This paper summarized finding from other researchers. The authors collect and summarize the useful data from other papers or journals. It is to create an understanding for the reader by discussion from the others research papers findings.

Polymer-dispersed liquid crystal (PDLC) film is an active smart film penetrating the market due to its unique functionalities. These functional characteristics include switchable tint capabilities, which shield building residents from the sun’s harmful ultraviolet (UV) rays, improve energy-saving features, and produce higher cost-efficiency. Although PDLC films are promising in several applications, there is still ambiguity on the performance of PDLC films. Particularly, the sizing effects’ (such as film thickness and area) correlation with visible light transmission (VLT), ultraviolet rejection (UVR), infrared rejection (IRR), light intensity, current consumption, and apparent power consumption is not well understood. Therefore, this study investigated the sizing effects of PDLC films, including the thickness effect on VLT, UVR, IRR, light intensity, and area influence on current and apparent power consumptions. The varying applied voltage effect on the light transmittance of the PDLC film was also effectively demonstrated. A 0.1 mm PDLC film was successfully presented as a cost-efficient film with optimal parameters. Consequently, this study paves the way for a clearer understanding of PDLC films (behavior and sizing effects) in implementing economic PDLC films for large-scale adoption in commercial and residential premises.

The spinning speed parameter plays a crucial role in determining the properties of an n-TiO₂/ZnO bilayer thin film fabricated using the sol–gel spin-coating technique, especially for solar cell applications. In this study, various spinning speeds were employed on an n-TiO₂/ZnO bilayer thin film, and characterizations were conducted, such as morphological, structural, and optical properties. The findings revealed that the optimal conditions for the thin film were achieved at a spinning speed of 3000 rpm. Under this condition, a homogenous and compact surface morphology was observed, with an even distribution of ZnO grains. The successful fabrication of an n-TiO₂/ZnO bilayer thin film was confirmed by the presence of characteristic peaks for both TiO₂ and ZnO. Obviously, three dominant ZnO orientation peaks, which included (100), (002), and (101) were identified. The prevalence of the (002)-ZnO orientation plane indicated a high-quality structure with excellent crystallinity. In terms of optical properties, the achievement of high transmittance up to 75% resembles the high transparency of the thin film. The optical energy of the n-TiO₂/ZnO bilayer thin film is estimated at 3.10 eV. In summary, the spinning speed parameter played a pivotal role in enhancing various properties of the thin film, making it a significant factor in its development for diverse applications.

In response to the growing demand for high-performance materials in industries such as automotive, aerospace, and construction, this study investigates the impact of jute cellulose nanofibers (CNFs) on the chemical, thermal, and morphological properties of thermoplastic polyurethane (TPU) nanocomposites. Jute CNFs were extracted using a chemo-mechanical method and incorporated into TPU through melt blending. Fourier transform infrared (FTIR) spectroscopy revealed notable changes in the chemical structure of the nanocomposites, including intensified O-H stretching vibrations and reduced C-H stretching vibrations upon the addition of 2 wt% and 4 wt% jute CNFs. Strong interfacial interactions between the jute CNFs and the TPU matrix were observed, particularly influencing the absorbance bands related to the -NH, C=O, and N-H groups. X-ray diffraction (XRD) analysis demonstrated enhanced crystallinity in the TPU nanocomposites, with new diffraction peaks and increased crystallite size correlating with higher jute CNF content. Field emission scanning electron microscopy (FESEM) revealed a uniform dispersion of the jute CNFs within the TPU matrix, contributing to improved interfacial adhesion and enhanced structural integrity. Thermal analysis using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed an increase in the thermal stability, with the onset of degradation occurring at higher temperatures in the TPU/jute CNF nanocomposites. The glass transition temperature (T_g) and melting temperature (T_m) exhibited minor shifts, reflecting improved thermal performance. These findings suggest that the incorporation of jute CNFs significantly enhances the crystallinity, thermal stability, and structural organization of TPU, offering a sustainable approach for developing robust materials with potential applications in structural, corrosion-resistant, and high-performance fields.

This study investigates the impact of strontium (Sr) additions on the corrosion resistance of an LM6 (A413) aluminium alloy. By incorporating varying concentrations of Sr (0.01 wt.% and 0.05 wt.%), the morphological and corrosion behaviours of the alloy were analysed under different corrosive environments, including sulphuric acid, sodium hydroxide, and sodium chloride solutions. The results demonstrate that Sr modifications significantly enhance the alloy’s corrosion resistance, with the most substantial improvement observed at 0.05 wt.% Sr. The analysis revealed that the weight loss of the alloy in sulphuric acid decreased by 2.5% with 0.05 wt.% Sr after 10 days of immersion, due to the formation of a stable passive oxide layer. In sodium hydroxide, however, the weight loss was reduced by 5% with 0.05 wt.% Sr after 10 days, indicating aggressive uniform corrosion. In the 3.5% sodium chloride solution, the corrosion rates remain relatively low, and the 0.05 wt.% Sr alloy showed a decrease in corrosion product formation over time, suggesting enhanced resistance. Detailed surface analyses, including 3D profiling and morphology assessments, revealed that Sr additions refine the eutectic silicon phase, transforming it from a coarse to a more desirable fibrous or lamellar structure, thus improving the alloy’s overall performance. The innovative findings underscore the potential of Sr as an effective microstructural modifier for enhancing the durability and longevity of Al-Si alloys in corrosive environments.

This study investigated the influence of reinforcing 0.50 wt.% of titanium oxide (TiO₂) and aluminium oxide (Al₂O₃) nanoparticles on the wettability performance of a Sn-3.0Ag-0.5Cu (SAC305) solder alloy. The thermal properties of the SAC305 nanocomposite solder are comparable with thos of an SAC305 solder with a peak temperature window within a range of 240 to 250 °C. The wetting behaviour of the non-reinforced and reinforced SAC305 nanocomposite solder was determined and measured using the contact angle and spreading area and the relationships between them were studied. There is an increment in the spreading area (5.6 to 7.32 mm) by 30.71% and a reduction in the contact angle (26.3 to 18.6°) by 14.29% with an increasing reflow time up to 60 s when reinforcing SAC305 solder with 0.50 wt.% of TiO₂ and Al₂O₃ nanoparticles. The SAC305 nanocomposite solder has a better wetting performance compared with the SAC305 solder. As the reflow time increased, the spreading area increased and the contact angle decreased, which restricted intermetallic compound growth and thus improved wettability performance