Browsing by Author "Peng, H. Y."

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Analysis of bump resistance and current distribution of ultra-fine-pitch microbumps
(2013-01-01)
Chang, Y. W.
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Peng, H. Y.
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Yang, R. W.
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Chen, Chih
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Chang, T. C.
To keep up with the demand of continuous increase in device densities, the integration of three-dimensional integrated circuits (3D-IC) has become the most probable solution, and the utilization of ultra-fine-pitch microbump has emerged as an essential component of 3D-IC technology. In this study, a Kelvin bump structure was fabricated and resistances measured at different angles on a 20.0 mu m microbump were investigated. The microbump resistance at 0 degrees, 60 degrees, 120 degrees, and 180 degrees are 74.7, 45.9, 14.6, and 13.7 m Omega, respectively. These high resistances in microbumps may result in high interconnect resistance and cause resistance/capacitance (RC) delay, and thus lower the electrical performance of 3D-IC. A series of finite-element-model (FEM) was built to analyze the distribution of electric field in microbump. The FEM results have shown that the current is distributed uniformly in the thin solder joint, but current crowding still occurs in the Cu under-bump-metallization (UBM). The finding of the current crowding in the Cu UBM is the main cause of high resistances in the microbump. Thickening the Al trace, for example, from 0.4 mu m to 1.5 mu m, is a direct solution to reduce the unexpected high microbump resistance. A numerical model which treated solder joints as a resistance network was also performed in this study. For comparison, both FEM and the numerical model show the same trend and agree with the measurement results from Kelvin bump structure. The results all point to one thing: thickening the Al trace turn out to be the most effective approach to reduce high microbump resistance. When the Al trace thickness is increased from 0.8 to 3.0 mu m, the microbump resistance is decreased to half of the original value, resulted from the alleviation of current crowding in the Cu UBM. (C) 2012 Elsevier Ltd. All rights reserved.
Examining the effects of learning motivation and of course design in an instructional simulation game
(2010)
Chang, Y. C.
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Peng, H. Y.
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Chao, H. C.
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教育研究所
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工業工程與管理學系
In recent years, games have been proven to be an effective tool in supplementing traditional teaching methods. Through game playing, students can strengthen their cognitive-recognition architecture and can gain satisfaction as well as a sense of achievement. This study presents a conceptual framework for examining various effective strategies by which instructors can both integrate games into courses and strengthen games' positive influence on students' learning motivations. We used a flexible web-based instructional game called the Simulation of Production and Logistics Environment (SIMPLE) game in three decision-science courses in industrial engineering. Through this use, we evaluated the perceptions and the learning motivation attributable to a group of students after they played the SIMPLE game. We also explored the relationships between the course design and the students' learning motivations. We collected data from 139 students in the three courses and analysed the materials by using descriptive statistics, an independent t-test, a multiple regression analysis, one-way analysis of variance and Pearson correlation. Results showed that instructors' teaching strategies enhanced students' motivation to play the SIMPLE game and that students' learning motivation affected the students' acceptance of the SIMPLE game. The results also showed a clear and strong relationship between students' background and students' acceptance of the SIMPLE game in these three courses. By combining appropriate approaches to adopting the SIMPLE game and appropriate approaches to teaching students about production and logistics decision-making situations, instructors can create an effective learning environment for peer interaction, for learning motivation and for course-directed learning interest.