Papers by Author: Mohd Faridz Mod Yunoh

Abstract: This paper presents durability analysis using a new statistical-based method, called the Fatigue Integrated Kurtosis-based Algorithm for Z-notch filter (Fatigue I-kaz) technique. This method provides a three dimensional graphical representation of the data distribution of the signal at three different frequency range in order to measure the degree of data scattering. For validation, three road surfaces were used for data collection purposes. An experiment has been performed on the motorcycle frame. In this study, the strain signals were collected based on three different road surfaces. The strain gauges were fixed on the motorcycle frame to measure the variable strain amplitude loadings imposed. The strain signals were then analysed using Fatigue I-kaz coefficient. Residential road surfaces give a higher Fatigue I-kaz coefficient, _f than campus and off road surfaces which is 0.0120 which is 0.0079 and 0.0067

Abstract: This paper presents the convenient wavelet family for the fatigue strain signal analysis based on the wavelet coefficients. This study involves the Morlet and Daubechies wavelet coefficients using both the Continuous and Discrete Wavelet Transforms, respectively. The signals were collected from a front lower suspension arm of a passenger car by placing strain gauges at the highest stress locations. The car was driven over public road surfaces, i. e. pavé, highway and UKM roads. In conclusion, the Daubechies wavelet was the convenient wavelet family for the analysis. It was because the wavelet gave the higher wavelet coefficient values indicating that the resemblance between the wavelet and the signals was stronger, closer and more similar.

Abstract: This paper presents a methodology to determine the durability of Quad Flat No-Lead (QFN) package. The QFN package is useful for improving the reliability of the package. A mechanical fatigue test namely three points bending cyclic test and signal analysis were proposed in this paper. The three points bending cyclic test method is a test assembly that supports a specimen on two anvils or rollers, and symmetrically loads the specimen on the opposite surface with an anvil or roller using micro-tester machine. For strain signal collection, a strain gauge was connected to the dynamic data acquisition system, and it was used for each tested QFN package for determining the response of the captured cyclic strain signal. It was found that the sinusoidal amplitude pattern of signal response has been obtained during the constant three points bending cyclic test. The obtained response signals were then analysed using the Power Spectral Density.

Abstract: This paper discusses some issues in micromechanical property of a newly developed Quad Flat No-lead (QFN) 3D stacked die package using three-point bending test approach. The relevant test methodologies were carried out in order to observe the flexural stress, strain, maximum load and deflection of the package. While performing the test, these QFN packages were positioned on the three points test bench, and the specific applied load was then applied and moved down until the package was clearly bent and broken. The related findings indicated that the maximum load was found to be at 251.52 N and the maximum deflection was obtained at 0.41 mm. The results were important for setting related testing parameters (load, stress and strain) before applying the three point cyclic bending test on the QFN stacked die package as the future work.