Ong Tee Say

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.

High density printing paper quality investigation

Light has been used to examine the quality of the products or surface finishing of most products by the industries in recent times. In this research, a lab module tester was designed and built to investigation on the different type of printing paper quality which available commercially was done. Laser light was utilized as a manipulator to distinguish the quality of printing paper and the light reflectance element was used. The photodiode was used as sensing element to detect the reflected light from the surface of printing paper. The both of laser diode and photodiode were placed in a light box. The laser was used to emit light on the sample and the photodiode detects light intensity from the surface printing paper in the light box. Different level of intensity correlates to different voltage output. The investigation on the different type of printing paper including of 70 g/m2, 80 g/m2 and 100 g/m2 were done respectively. The result showed that the 100 g/m2 printing paper has a higher reflected voltage output compared to 80 g/m2 and 70 g/m2 printing paper.

Fibrous Material Density Difference Analysis Using Light Reflectance

The objective of this work is designed and fabricated a lab module tester to differentiate the different type of printing paper quality which available commercially was done. Laser light source was used to differentiate the quality of printing paper. The concept light reflectance on surface material was used in this study. The photodiode was used as photo detector to detect the reflected light from the surface of printing paper. The laser diode and photodiode were placed in a box which the box named light box. The laser was used to emit light on the sample and the photodiode detects light intensity from the surface printing paper in the light box. Different level of intensity will have different value of voltage output. The differentiation on the different type of printing paper including of 70 g/m2, 80 g/m2 and 100 g/m2 were done respectively. The result showed that the 100 g/m2 printing paper has a higher reflected voltage output compared to 80 g/m2 and 70 g/m2 printing paper.

Fibrous Material Surface Reflectance Analysis

The light inspection on surface finishing of most product measurement is an important feature in the industries. In this study, a lab module tester for examination on the different type quality of tissue paper quality was done. The light reflectance element was used in this study to differentiate the quality of tissue paper. The laser diode and photodiode was used as manipulator to differentiate the tissue paper and photo detector to detect the reflected light from the surface of tissue paper. The both of laser diode and photodiode were placed in a light box. Different level of intensity reflected from the surface material will have different voltage output. The result showed that the total ply high quality tissue paper has a higher reflected voltage output compared to low quality tissue paper.

Analysis on Surface Roughness and Surface Reflectance through DOE

The Lambda 950 spectrometers are designed to investigate and examine surface coating on test specimen by using the light source. The objective of this research is to investigate the factors that affect the surface roughness and reflectance after different parameter of Reactive Ion Etching (RIE) process. There are four parameters to control the RIE process which is temperature, vacuum, RF (Radio Frequency) power and gas flow. The parameters in this research are using a Full Factorial Experimentation technique, the Design of Experiment (DOE). The AFM (Atomic Force Microscope) and Lambda 950 spectrometer are used to analyse the surface roughness and light reflectance of the specimen. The result showed all four parameters of RIE were give effect on surface roughness and surface reflectance. The parameter of gas flow is the most influence factor for surface roughness and surface reflectance compared to other parameters in this work.

Deposition Time Variation Analysis on Indium Tin Oxide Film

Indium Tin Oxide (ITO) is a transparent conducting material. The particular electrical and optical properties of the ITO make it becomes an important material that being applied in optoelectronic filed. In this paper, investigation on various parameters in time of deposition and ITO layer on specimen was done. The AFM (Atomic Force Microscope) was used to investigate grain size on specimen. It shows more layer deposition of ITO, it will increase grain size on the specimen. In addition, grain size on specimen was increased after annealing process compared test specimen before annealing process. Besides that, semiconductor parametric analyser was used to examine resistance on ITO films. The higher value of resistance is showed on test specimen after heat treatment compared to test specimen before heat treatment.

Metallic Layer Reflectance Analysis Using Design of Experiment

In this work, a Full Factorial Experimentation technique, Design of Experiment (DOE) was developed and used to control the parameter of RIE (Reactive Ion Etching) process on a silicon wafer with aluminium layer. The objective of this work is to examine the Reactive Ion Etching (RIE) process on aluminium with different parameter, which are temperature, vacuum, RF (Radio Frequency) power and gas flow. Then, AFM (Atomic Force Microscope) and Lambda 950 spectrometer are used to analyse the grain size and light reflectance on the test specimen after RIE process. From the result, all four parameters of RIE were give an effect on grain size and surface reflectance on the test specimen. The parameter of gas flow is the most influence factor for grain size and surface reflectance in RIE process for aluminium layer compared to other parameters in this work.

Shearing Speed Stress Comparison between Sn-3.9Ag-0.6Cu and Sn-3.5Ag-0.7Cu Solder Ball

The reliability of the solder joints of Ball Grid Array is severely tested during the exposure of thermal operation due to coefficient of thermal expansion (CTE). Different thermal expansion due to this mismatch causes shearing effects to the solder joints. This paper compares the shearing speed on stress and strain between Sn-3.9Ag-0.6Cu and Sn-3.5Ag-0.7Cu solder ball. A full factorial design of experiment was used to compute the interactions between the factors on each response using a finite element analysis software, Ansys. It is found out that Sn-3.5Ag-0.7Cu solder ball contributes higher stress. On the other hand, Von-Mises stress and equivalent plastic strain increases in parallel with the increasing of the shear speed.

Shear Height Analysis Study on Sn-3.9Ag-0.6Cu by Using SSF Method

Shear height has substantial effect on the solder ball shear strength. In recent times, taking environmental issue into consideration, Lead free solder joint must be developed. In this paper, the load effect of different shear heights with fixed shear speed of a single solder joint on Ball Grid Array (BGA) is presented through simulation. A Lead free material, Sn-3.9Ag-0.6Cu was adopted as solder ball attachment. The effect of dynamic stress response on a single solder joint was simulated using Ansys version 11. The results from the plotted graph showed that shear force reduced with the increasing of shear ram height.

Different Shear Height Stress Evaluation on -0.7Cu Based Lead Free Solder

Interconnection technology has improved by leaps and bounds since the advent of solder reflow. This has made surface mount technology more robust. Ball Grid Array (BGA) is a demanding surface mount chip package in Integrated Circuits (IC) which uses a grid of solder balls as its connectors. In this preliminary study, load effects of shear test on a single solder joint with varied parameters are briefly discussed. A suitable lead-free solder is used in this study which is Sn-3.5Ag-0.7Cu. Simple Single Factor (SSF) method was used to execute this experimental study. Ansys software was used to simulate and investigate the stress response on a single solder ball joints. The results shows that when the shear height is high the shear stress is reduced.