Multi-Objective Optimization of Thermo-Ultrasonic Flip-Chip Bonding Process for High-Brightness Light Emitting Diodes

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Chung-Feng Jeffrey Kuo ◽  
Hui-Ta Chen ◽  
Te-Li Su ◽  
Jr-Da Huang
Keyword(s):  
Taguchi Method ◽  
Flip Chip ◽  
Processing Parameters ◽  
Quality Characteristics ◽  
Gray Relational Analysis ◽  
Light Emitting ◽  
Relational Analysis ◽  
Optimal Processing ◽  
Multiple Quality Characteristics ◽  
Flip Chip Bonding

Flip-chip bonding is a kind of chip packaging technology, which can make fabricated chips lighter and smaller. Thermo-ultrasonic flip-chip bonding is a technology that directly joins gold pad and gold bump. This study combines principle component analysis and gray relational analysis to determine the optimal processing parameters for multiple quality characteristics of light emitting diodes (LEDs). The quality characteristics of this experiment include the candle light, forward voltage, and leakage current of LED and thrust value. First, this study determines the processing parameters that may affect the thermo-ultrasonic flip-chip bonding with the L18 orthogonal array, including substrate temperature, bonding downforce, ultrasonic working time, ultrasonic power, and rising and delay time of tool head bonding. Then, the gray relational analysis is applied to indicate the optimal processing parameters for the multiple quality characteristics of LED. Since the Taguchi method only takes one single quality characteristic into consideration, this study applies the Taguchi method to reduce the number of thermo-ultrasonic flip-chip bonding experiments. The experimental results prove that the optimal LED has good integral quality, which is above industrial standard.

A study of multi-quality processing parameter optimization for sueded fabric

2016 ◽  
Vol 87 (4) ◽  
pp. 389-398 ◽  
Author(s):  
Chung-Feng Jeffrey Kuo ◽  
Wen-Tsung Lin
Keyword(s):  
Taguchi Method ◽  
Color Difference ◽  
Processing Parameters ◽  
Quality Characteristics ◽  
Gray Relational Analysis ◽  
Processing Parameter ◽  
Optimum Processing ◽  
Multiple Quality Characteristics ◽  
Response Table ◽  
Fabric Surface

Sueded fabric quality control depends on the processing parameter settings. The quality characteristics considered in this study are surface softness and color difference. The Taguchi method was combined with gray relational analysis (GRA) to optimize the multi-quality sueding processing parameter combinations. First, an orthogonal array is designed by using the design of experiments of the Taguchi method for the major processing parameters of the sueding machine. The signal/noise ratio and analysis of variance are calculated from the measured fabric surface softness and color difference data, significant factors influencing the quality characteristics obtained, and GRA used to remedy the deficiency in the Taguchi method, which is only applicable to single-quality characteristics. The optimum processing parameters of multiple-quality characteristics are obtained from the response table and response diagram of GRA. The quality of suede fabric can be controlled effectively by using the optimum processing parameters to set the processing parameters, and the 95% confidence interval validates the reliability and reproducibility of the experiment.

Design of an optical lens for LED lighting using a hybrid principal components analysis–Taguchi method

2018 ◽  
Vol 51 (5) ◽  
pp. 788-802 ◽  
Author(s):  
WS Yip ◽  
S To ◽  
WK Wang
Keyword(s):  
Taguchi Method ◽  
Principal Components ◽  
Principal Component ◽  
Quality Characteristics ◽  
Quality Characteristic ◽  
Optical Lens ◽  
Light Emitting ◽  
Multiple Quality Characteristics ◽  
Optimum Parameters ◽  
Components Analysis

Optical lenses are extensively used to enhance the performance of light-emitting diodes. Both uniformity and efficiency are important performance indicators in lens design; however, improving uniformity always lowers efficiency. In this study, the Taguchi method and principal component analysis (PCA) are integrated to optimise the lens shape for two quality objectives, namely, uniformity and efficiency. The Taguchi method was conducted twice to establish the signal/noise ratio of the two quality characteristics for calculating the principal components in PCA. Then, the optimum parameters obtained by the Taguchi method were processed by PCA. The correlated individual responses were converted to the principal components which explained most of the dataset and were considered as the single quality characteristic for the optimisation. The combined method resolved the difficulties of optimising multiple quality characteristics without sacrificing any particular quality characteristic while the traditional Taguchi method can only be applied to the single quality characteristic. A LED light source fitted with a secondary lens designed by the proposed method showed over 92% light efficiency and an improvement in uniformity.

Optimization of Mechanical Properties of UV-cut Polyester Fiber Using a Hybrid Taguchi and Fuzzy Approach

2015 ◽  
Vol 10 (2) ◽  
pp. 155892501501000
Author(s):  
Te-Li Su ◽  
Yu-Lin Kuo
Keyword(s):  
Melt Spinning ◽  
Processing Parameters ◽  
Quality Characteristics ◽  
Fuzzy Approach ◽  
Optimal Conditions ◽  
Maximal Strength ◽  
High Quality ◽  
Optimal Processing ◽  
Multiple Quality Characteristics ◽  
Spinning Process

This goal of this study was to find the optimal processing parameters for PET/TiO2 UV-cut fiber in order to work out its maximal strength. UV-cut means PET/TiO2 fiber attenuates the transmission of UV-radiation. The hybrid Taguchi and fuzzy approach was applied to resolve the problem as regards optimization of multiple quality characteristics, and further discover the optimal conditions for PET/TiO2 UV-cut fiber. First, the Taguchi approach was employed to plan the melt-spinning process parameters and reduce the number of experiments to 27, thus decreasing experimental cost and time. The fuzzy approach was adopted to optimize multiple quality characteristics. The analysis of variance and response surface methodology found the factors significantly affecting the quality characteristics of PET/TiO2 UV-cut fiber were die temperature and winding speed. According to the experimental results, the PET/TiO2 UV-cut fiber can absorb UVA and UVB, and thus has been widely used in sportswear, high-quality parasols, work clothes, hats, tents, and curtains to reduce the risk of skin cancer.

Optimizing parameters for continuous electrospinning of polyacrylonitrile nanofibrous yarn using the Taguchi method

2017 ◽  
Vol 48 (3) ◽  
pp. 559-579 ◽  
Author(s):  
Chang-Mou Wu ◽  
Ching-Hsiang Hsu ◽  
Ching-Iuan Su ◽  
Chun-Liang Liu ◽  
Jiunn-Yih Lee
Keyword(s):  
Principal Component Analysis ◽  
Taguchi Method ◽  
Flow Rate ◽  
Draw Ratio ◽  
Principal Component ◽  
Quality Characteristics ◽  
Optimal Parameters ◽  
Signal To Noise ◽  
Multiple Quality Characteristics ◽  
Nanofibrous Yarn

In this study, the Taguchi method, analysis of variance, and principal component analysis were used to design the optimal parameters with respect to different quality characteristics for the continuous electrospinning of polyacrylonitrile nanofibrous yarn. The experiment was designed using a Taguchi L9(34) orthogonal array. The Taguchi method is a unique statistical method for efficiently evaluating optimal parameters and the effects of different factors on quality characteristics. The experimental results obtained by this method are more accurate and reliable than one-factor-at-a-time experiments. The control factors discussed in this work include the draw ratio, nozzle size, flow rate, and draw temperature. The quality characteristics taken into consideration are fiber diameter, fiber uniformity, and fiber arrangement. The parameters to optimize the different quality characteristics were obtained from the main effect plot of the signal-to-noise ratios, after which analysis of variance and confidence intervals were applied to confirm that the results were acceptable. Multiple quality characteristics were analyzed by principal component analysis from the normalized signal-to-noise ratios and the principal component score. Combining the experimental and analysis results, the optimum parameters for multiple quality characteristics were found to be a draw ratio of 2.0, a nozzle number of 22 G, a flow rate of 7 ml/h, and a draw temperature 120℃.

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