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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. [DOI: 10.1115/1.4002727] Keywords: light emitting diode, thermo-ultrasonic flip-chip bonding, Taguchi method, principle component analysis, gray relational analysis

In its analysis of the impact of foreign investment on China's productivity, this article develops two empirical models: one using labor productivity and the other using total factor productivity (TFP). Using cross-provincial data on Chinese industries for 1993, 1994, and 1997 to regress the empirical models, it is concluded that the impact of investment differed depending on its source, with that from these overseas Chinese enterprises contributing to the spillover effect in regions with a high technology gap, whereas that from other foreign enterprises tending to improve productivity and TFP primarily in regions with a low technology gap. (JEL D24, F13, F15, L60), I. INTRODUCTION Since mainland China opened its doors to outside investment in 1979, strenuous efforts have been made to attract foreign investment, resulting in a significant increase in foreign direct [...]

This study aims at investigating the roles of house price expectations and mortgages in urban dwellers' subjective well‐being (SWB) in China. Using 3,717 urban householder respondents collected in the 2011 China Household Finance Survey and categorizing the sample into three subsamples: homeowners without and with a home loan, and nonhomeowners, the ordered logit models of the ordinal‐dependent variable SWB with and without considering the endogeneity problem are estimated using these three subsamples separately. The primary finding is that house price expectations have a negative influence on the likelihood of having a better SWB only for homeowners without a home loan. However, more houses can mitigate this negative influence. For homeowners with a home loan, mortgages have a negative impact on the likelihood of having a better SWB. Finally, the Beijing sample based on the 2017 data also supports the influences of house price expectations and mortgages on SWB. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the following two issues related to internal migration in Taiwan: one is the widely discussed issue of the existence of magnetic effects induced by welfare benefits and the other is a rarely discussed issue of the existence of phantom voters. Using panel data for 23 counties and cities from 1995 to 2010 and estimating three fixed-effects spatial Durbin models, the primary findings of this study are that, by keeping other factors constant and considering the spatial dependence of migration, welfare migration is found to exist, particularly for females, and the number of phantom voters in an election year can significantly affect internal migration in Taiwan. [ABSTRACT FROM AUTHOR]