TFT-LCD摩擦工艺ESD研究与改善

摩擦工艺ESD(Electrostatic Discharge)是TFT-LCD制程中较为常见的一种不良,以317.5 mm(12.5 in)产品为例,摩擦工艺过程中ESD发生率20%,对产品良率影响较大。文章结合实际生产对摩擦工艺ESD的原因进行理论分析与实验验证,得出摩擦工艺发生ESD的原因为TFT基板上面有悬空的大块金属,在摩擦过程中电荷积累过多容易发生ESD,ESD进一步烧毁旁边金属电路导致面板点亮时画面异常。生产过程中通过工艺管控和产品设计两方面优化改善,工艺方面通过增加湿度,涂布防静电液以及管控摩擦布寿命进行改善,设计方面通过变更悬空的大块金属为小块金属,通过工艺设计优化最终生产过程中摩擦工艺ESD发生率由20%下降到0%,大大提高了产品品质,降低了生产成本。

Research and improvement on ESD of TFT-LCD rubbing process

Electrostatic discharge(ESD)is a common defect in TFT-LCD rubbing process,For example,the ratio of ESD is 20%at 317.5 mm(12.5 in)product,it is a great influence on the yield of products.The causes of ESD in rubbing process is studied with the theoretical analysis and experiment.Experiments show that the main reason for ESD is that there are large floating metal on the TFT substrate.In rubbing process,the charge is easy to accumulate on the TFT substrate and burning down the electric circuit,so the panel is abnormal.ESD can be reduced through controlling rubbing process and optimizing design.In process,increasing humidity and coating electrostatic prevention and controlling the life time of rubbing cloth can improve ESD.In design,by changing the large floating metal into small floating metal,ESD can be improved.By optimizing the process and design,the ESD ratio is reduced from 20%to 0%,which greatly improves the panel quality and reduced the product cost.