Institut Farmaseutikal & Nutraseutikal Malaysia - Tesis

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Materials characterization and aiaided defect classification of pad discoloration in semiconductor wafer fabrication
(2025-09-16)
_Izzuddin Iskandar, Norizan
The discoloration of metal bond pads in semiconductor wafer fabrication is a constant problem because it can be caused by a number of things, from harmless native oxide formation and copper wrinkling to severe corrosion, embedded residues, or surface contamination that make wire bonding less reliable. Automated Optical Inspection (AOI) systems can see color changes, but they can't always tell the difference between low-risk and high-risk defects. This means that they might miss important defects or lose yield. This study gets around this problem by combining advanced material characterization with an AI-enhanced AOI classification framework to improve wafer yield without lowering reliability. We collected AOI images from separate diode and IGBT wafers and put them into seven groups based on the types of defects they had: Non-Visible, Pad Residue, Corrosion, Particle, Copper Wrinkling, Pad Deformation, and Scratches. We used optical microscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), and focused ion beam (FIB) cross-sectioning to find out how bad the defects were. Then we used Failure Mode and Effects Analysis (FMEA) to measure how bad they were. We used these FA-derived classifications to teach a ResNet-18 convolutional neural network (CNN) model on the carefully chosen AOI dataset. The trained AI model was 98.5% accurate overall, 94.8% accurate at selective inking, and had a 0.07% chance of an escapee. Grad-CAM visualizations showed that the network always focused on the right defect features, making it strong against changes in image brightness, contrast, and surface texture. The AI-powered classification system increased wafer yield from 65% to 85%, cut down on false positives, and kept strict detection of high-risk defects. This study shows that combining FA-based defect knowledge with AI-enhanced AOI makes it possible to tell the difference between cosmetic and critical pad discoloration in real time and on a large scale. This is a solution for semiconductor quality control that balances yield optimization with reliability assurance and sets the stage for more AI use in high-volume wafer manufacturing.
Investigation on mechanical and physical properties: a study on vickers hardness, density, and porosity of alumina through the addition of tungsten trioxide
(2025-09-17)
Ibrahim, Maina
Alumina (Al2O3) cutting tools are widely used in high-speed machining mainly because of their intrinsic properties, high hardness, high melting point, and wear resistance; however, the cutting tool often fails when encountering hard material due to its inherent brittleness. Tungsten trioxide (WO₃) is a dense, thermally stable oxide that serves as a hard dispersoid and effective sintering aid in Al₂O₃ matrices. The influence of WO3 addition (0-1 wt.%), on the microstructure, phase formation, and mechanical properties of alumina (Al2O3) was investigated. The Design of Experiment (DOE) is utilized through Response Surface Methodology (RSM), including Central Composite Design (CCD), to optimize two variables among WO3 additions and sintering heating rate. The sintering temperature is fixed at 1600 ℃. The study was designed with target values of approximately 3.9 g/cm³ density, 1600 HV hardness, and porosity below 1%, which are desirable for high-performance Al₂O₃ ceramics. The optimized variables resulted in achieving the desired responses for the hardness, density, and porosity of Al2O3 ceramics. Empirical models are found for responses, and their quality is checked using Analysis of Variance (ANOVA) and other parameters. The microstructure, phase formation, density, and hardness properties were characterized through a field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Archimedes' principle, and Vickers indentation technique, respectively. Although the incorporation of WO3 into the alumina matrix was intended to improve the composite’s mechanical and physical properties, the experimental results revealed a decrease in hardness and density, from 1386.7HV at 0 wt.% to 415.2 HV at 1.0 wt.%, and density from 3.83g/cm3 to 3.01g/cm3, accompanied by an increase in porosity from 0.26 to 18.21. This suggests that the addition of WO3 may have disrupted particle packing efficiency and hindered densification during sintering, leading to weaker interparticle bonding and a less compact microstructure.
Computational Design And Synthesis Of Potential Ns2b-Ns3 Dengue Protease Inhibitors
(2024-06)
Salin, Nurul Hanim
DENV2, the type of dengue virus commonly found in Southeast Asia, is a major public health concern. In week 6 of 2024, Malaysia reported with 3,631 dengue cases and 10 deaths due to DENV2, marking a 68.75 % increase from the same period in 2023, as reported by the World Health Organization (WHO). Despite the high number of cases, there is currently no clinically proven drug available to inhibit the virus replication, primarily due to the limited availability of 3D crystal structures of targetable protein-protein interactions for drug activation, including the NS2B-NS3 protease from DENV2 and West Nile virus (WNV). To address this issue, docking and pharmacophore modelling have been used with the ligands from DENV2 NS2B-NS3 protease and West Nile Virus. The Systematic Literature Review (SLR) analysis identified 9 active compounds from 2 types of in vitro DENV NS2B-NS3 protease assays i.e. 21 compound classes from cell-free-based assays and 9 compound classes from cell-based assays. 2 of the 9 scaffolds' molecules were identified as the best pharmacophore model based on their high Area Under the Curve (AUC) and Enrichment Factor (EF) values, which were close to 1 and 100% respectively, and were further used as a model for pharmacophore validation.
Model of speed control electric wheelchair
(2009-03-01)
Lim, Ching Chin
The main objective of this project was to design and develop a speed control electric wheelchair’s model. The wheelchair’s model will be used to investigate the characteristic of a speed control electric wheelchair. The project consists of building the wheelchair’s model body, designing the electronic print circuit boards (PCBs), and writing the control system coding. The body consists of a wooden strip board that holds the motor gearbox and PCB boards. The embedded electronics consists of two microcontrollers, which are connected by an I2C bus. A pair of optical encoder was used for speed or position feedback and a LCD was used for user’s display and guidance. One ultrasonic sensor added for obstacle or object sensing. The user will control the wheelchair’s model through a RF wireless remote control. The system is designed for expandability, additional I2C device can be added to the I2C bus and additional sensor can be added to the unused pins of the microcontroller. The system works as expected; we are able to control the wheelchair’s model navigation properly. Through the encoder feedback, we are able to get the running speed in RPM or the distance run in cm for both drive wheels. The encoder readings were proved to be accurate by comparison with tachometer’s readings. As a conclusion, all objectives in this project are successfully achieved.
Industrialization And Work Values In Kedah, Penang And Great Britain: A Study From The Convergence-Divergence-Crossvergence Perspective
(2021-08)
Yap Chee Yeong
The lack of discovery of the influence of industrialization on work values in Malaysian societies deters the further understanding of the reaction of Malaysians’ values to macro-level social changes. The review of prior studies shows that the influence of industrialization on work values is not consistent across societies, suggesting that it depends on the kind of society. This study aims to determine the Convergence-Divergence-Divergence (CDC) condition of work values in Malaysian societies to learn more about the influence of industrialization on Malaysians’ work values and the reaction of Malaysians’ values to macro-level social changes. In this context, work values are conceptualized into four dimensions: extrinsic work orientation, intrinsic work orientation, work centrality, and work-life balance. To test the convergence, divergence, and crossvergence hypotheses, the CDC framework was employed. 532 respondents from three regions with different extents of industrialization were involved. 175 Kedah respondents and 177 Penang respondents were recruited using convenience sampling through a face-to-face survey and an online survey, while 180 Great Britain respondents were obtained from secondary data. The responses were analyzed using the Mann-Whitney U Test and Kruskal-Wallis H Test. The results support the crossvergence hypothesis. Two out of four dimensions of work values in Penang do not differ significantly from that in Kedah and three out of four dimensions of work values in Penang do not differ significantly from that in Great Britain. This study suggests a verdict of crossvergence in work values in Malaysian societies. The extent of industrialization is influential on some dimensions of work values while some are not influenced. This implies that Malaysian societies are somewhere in the middle between adaptive and resistant when dealing with macro-level social changes.

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