Improving The Light Leakage Phenomenon Of LCD Panel By Using Taguchi Method

Nowadays, more and more automobile are installed with LCD GPS system as the quick generation of automobile electrical system. But there are some non-uniform bright dots on the edge of LCD which called light leakage phenomenon(Mura Ring), that causes the image distortion and impacts the performance.Light leakage Mura is occurred upon the completion of chip-on-glass (COG) packaging of silicon IC driver to LCD circuit through the thermal bonding process. Use finite element analysis model to analysis the process, we can find the coefficient of thermal expansion (CTE) mismatch between glass substrate, silicon chips and other parts. Then the warpage of glass substrate is occurred due to different temperature. In mid-size TFT-LCD demanding low weight and thin sharp, the Mura defect deteriorated as thinner glass plates were introduced.In this study, we use ANSYS software to build the transient thermal conduct model and glass substrate warpage model, and find the factors of warpage after analysis and verification. Then use Taguchi method to optimize the combination of all factors. The result is to reduce thermal bonding temperature and use the low young's modulus ACF film which can effectively reduce warpage, eliminate the Light leakage defect. After verification, this is a low cost and effective solution for the Mura defect.