Browsing by Author "Chang, Chin-Cheng"

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Effects of Localized Warpage and Stress on Chip-on-Glass Packaging Induced Light Leakage Phenomenon in 13-inch TFT-LCD
(2009)
Chang, Chin-Cheng
;
Leu, Jihperng
;
Lin, Mao-Hsing
;
Huang, Kun-Feng
;
材料科學與工程學系
Mura defect induced by chip-on-glass packaging in 13-inch LCD-TFT was investigated using contour measurement and numerical analysis. Excellent correlation between Mura defect and localized warpage/principal stress has been established Besides, the effects of ACF bonding temperatures and Si chip arrangement on Mura defect were studied and discussed.
Effects of localized warpage and stress on chip-on-glass packaging: Induced light-leakage phenomenon in mid-sized TFT-LCD
(2012-01-01)
Leu, Jihperng
;
Chang, Chin-Cheng
;
Chen, Alexander
;
Lin, Mao-Hsing
;
Huang, Kun-Feng
Mura defects become visible in a 13.3-in. TFT-LCD using chip-on-glass (COG) packaging when the thickness of the glass substrate is decreased from 0.5 to 0.3 mm. Mura, the non-uniform brightness in LCDs, is caused by COG packaging due to the mismatch of the coefficient of thermal expansion (CTE) and Young's modulus between the glass substrate and the IC-driver Si chips. In this paper, a 3-D finite-element-analysis (FEA) model, coupled with transient thermal analysis is first established to examine the warpage and stress behavior in the upper-glass-plate post-COG-package processing for identifying the root causes of the light-leakage phenomenon. Prior to that, the simulated warpage results are validated by surface-contour measurement. Data and modeling results show that a low bonding temperature together with a low modulus in novel ACF materials can effectively eliminate Mura. Besides, thinner silicon or a shorter length of Si chips as drivers offers enhanced reduction in the localized warpage, and thus can be a practical and low-cost solution for eliminating mura defects.