Rajendaran Vairavan

Wire Bond Shear Test Simulation on Sharp Groove Surface Bond Pad

Wire bonding process is first level interconnection technology used in the semiconductor packaging industry. The wire bond shear tests are used in the industry to examine the bond strength and reliability of the bonded wires. Hence, in this study thesimulation on wire bond shear test is performed on a sharp groove surface bond pad. ANSYS ver 11 was used to perform the simulation. The stress response of the bonded wires are investigated.The effects of three wire materials gold(Au), aluminum(Al) and copper(Cu) on the stress response during shear test were examined. The simulation results showed that copper wire bond induces highest stress and gold wire exhibits the least stress response.

Fabrication and characterisation of MEH-PPV/CdTe/CdS solar cell

Organic solar cell research has vastly developed in recent years. These organic solar cells however are still limited to low power conversion efficiencies. This has led to the generation of photovoltaic cells based on hybrid nanoparticle-organic polymer materials. The hybrid solar cell has the potential of bridging the efficiency gap which is present in organic and inorganic semiconductor materials. This paper focuses characterisation of fabricated hybrid active layer consisting of nanoparticles and organic polymer. The active layer was deposited on the substrate using the spin coating technique. Materials used in the active layer are poly (2-methoxy, 5 - (2 - ethyl hexyloxy) p-phenyl vinylene) MEH-PPV, cadmium telluride (CdTe) and cadmium sulphide (CdS). The fabricated solar cells with active layer of MEH-PPV only were found to have a power conversion efficiency of 0.1 % for 1 W, hybrid cell with active layer of MEH-PPV/CdTe has power conversion efficiency of 0.15 % for 1W and hybrid cell with active layer of MEH-PPV/CdTe/CdS has power conversion efficiency of 0.18 % for 1 W.

5mm X 5mm Copper-Diamond Composite Slug Stress Evaluation on LED

Light-emitting diodes (LEDs), have materialized as an innovative light source which features energy saving properties, good optical performance and efficacy which is added advantage over orthodox lighting systems. However, the efficacy of the LED is influenced by heat generated at the junction of the LED. Hence, in this study, the thermal and stress analysis of single chip LED package with copper diamond heat slug with dimension of 5mm x 5mm x 1mm was carried out through simulation under natural convection condition. Input power of 0.1W and 1W were applied to the single chip LED model. Result of the simulation indicates that at input power 1W, junction temperature of 107.02 °C and stress of 104.59 MPa were obtained.

Solid State Lighting Stress and Junction Temperature Evaluation on Operating Power

LEDs are being utilized as lighting source due to its superior advantages over incandescent lamps in terms of higher efficiency, brighter light emission and longer lifetime. However, the reliability and efficiency of the LED is dependent on the junction temperature of the LED chip. Hence, the heat dissipation of single chip LED package with aluminum heat slug was investigated through simulation in this study .The heat dissipation was evaluated in terms of junction temperature. The single chip LED was powered with input power of 0.1W and 1W. The Von Mises stress of the LED chip at both input power was evaluated. The maximum junction temperature of the LED at steady state is 119.43°C at input power of 1W.

High Power LED Thermal and Stress Simulation on Copper Slug

High power LED are captivating attention due to its cogent impacts on lighting industry in terms of efficacy, low power consumption, long lifetime and miniature physical size. Nonetheless, the efficiency and reliability of the LED is signified by the junction temperature. This work demonstrates the thermal and stress simulation of single chip LED package with 1mm x1mm x 1mm copper heat slug. The simulation was performed using Ansys version 11. The GaN LED chip was powered with input power of 0.1 W and 1 W. The simulation outcome exhibited that at the maximum junction temperature and stress of the LED chip were 115.81°C and 221.56MPa correspondingly for input power of 1W.

Stress and Temperature Simulation Using Copper-Diamond Composite Slug

A revolution to illumination industry, the high power light emitting diodes, LEDs have significant dominance in terms of optical performance, low power consumption and superior reliability over conventional lights. In spite of that the junction temperature of the LED is an imperative aspect which manipulates the consistency of the LED. This study discusses the thermal and stress analysis of single chip LED package with copper diamond heat slug. The simulation was carried out using Ansys version 11. In this simulation, input power of 0.1W and 1W were applied to the LED chip. The key findings of this study exhibited that the max junction temperature of 113.13 °C and stress of 116.36 MPa were gained.

3D mapping of breast surface using digital fringe projection

Optical sensing technique has inherited non-contact nature for generating 3D surface mapping where its application ranges from MEMS component characterization, corrosion analysis, and vibration analysis. In particular, the digital fringe projection is utilized for 3D mapping of objects through the illumination of structured light for medical application extending from oral dental measurements, lower back deformation analysis, monitoring of scoliosis and 3D face reconstruction for biometric identification. However, the usage of digital fringe projection for 3D mapping of human breast is very minimal. Thus, this paper addresses the application of digital fringe projection for 3D mapping of breast surface based on total non-contact nature. In this work, phase shift method is utilized to perform the 3D mapping. The phase shifted fringe pattern are displayed through a digital projector onto the breast surface, and the distorted fringe patterns are captured by a CCD camera. A phase map is produced, and phase unwrapping was executed to obtain the 3D surface mapping of the breast. The surface height profile from 3D fringe projection was compared with the surface height measured by a direct method using electronic digital vernier caliper. Preliminary results showed the feasibility of digital fringe projection in providing a 3D mapping of breast and its application could be further extended for breast carcinoma detection.

Structured light profilometry for designated breast surface coordinate variation analysis

Early detection of breast carcinoma is vital for effective treatment option and to enhance the survival rate. Existing breast imaging systems such as ultrasound, mammography, and magnetic resonance imaging (MRI) have been utilized for early detection of breast carcinoma which requires contact with the breast surface. However, these existing methods require contact to the breast surface, which causes discomfort to the test subject. Hence, there is a need for alternative modality, which exhibits a total non-contact nature. Structured light profilometry has developed into a vital system with its application in diverse fields of surface metrology analysis. Therefore, in this work structured light profilometry based on phase shift technique is setup to analyze the surface variation of the breast due to the presence of a lesion in the context of surface tension. The sinusoidal fringe pattern is projected through three step phase shift onto the surface of the breast, and a resulting phase map is produced. Pixel tracing was performed to evaluate the variation of surface changes on the breast based on surface marker coordinates. The comparison was made between breast with lump and breast without a lump. Maiden results have established that the structured light profilometry is capable of detecting breast surface changes at various locations on the breast.

A Brief on Breast Carcinoma and Deliberation on Current Non Invasive Imaging Techniques for Detection

BACKGROUND Breast carcinoma is a life threatening disease that accounts for 25.1% of all carcinoma among women worldwide. Early detection of the disease enhances the chance for survival. DISCUSSION This paper presents comprehensive report on breast carcinoma disease and its modalities available for detection and diagnosis, as it delves into the screening and detection modalities with special focus placed on the non-invasive techniques and its recent advancement work done, as well as a proposal on a novel method for the application of early breast carcinoma detection. CONCLUSION This paper aims to serve as a foundation guidance for the reader to attain birds eye understanding on breast carcinoma disease and its current non-invasive modalities.

Natural Heat Convection Analysis on Cylindrical Al Slug of LED

This paper presents the characterization of a single chip high power LED package through simulation. Ansys version 11 was used for the simulation. The characterization of the LED package with aluminum cylindrical heat slug was carried out under natural convection condition at ambient temperature of 25°C. The junction temperature and the stress of the LED chip was assesed. The LED chip was powered with input power of 0.1 W and 1 W and the heat dissipation was assesed. Results showed that that the junction temperature and the Von Mises Stress of the single chip LED package increases with the increased input power.