电容式触摸屏气泡线不良的研究与改善

Research and improvement of bubble line in capacitive touch screen

在触控产品的制作过程中,气泡线不良严重影响着产品的外观品质.本文从气泡线的产生机理入手进行研究,发现该不良是由贴附偏光片时传感器保护层有机膜段差处与偏光片之间残留气泡导致.本文从设计面、工艺面对气泡线的影响因子进行了研究,实验发现有机膜边界设计位置、有机膜厚度、偏光片贴附相关工艺以及偏光片中PSA厚度对气泡线不良影响显著.其中有机膜边界设计位置远离显示区,降低有机膜与偏光片交叠宽度,可以使脱泡时气泡更容易排出而改善气泡线不良;降低有机膜厚度,可以减少偏光片贴附时有机膜断差位置气泡积累而改善气泡线不良;偏光片贴附相关工艺中增加贴附压力、降低贴附速度、增加脱泡时间,可以减少气泡积累以及增加排出而改善气泡线不良;增加偏光片中PSA胶层的厚度,可以在偏光片贴附时获得更大的弹性及压入量,减少气泡的积累而改善气泡线不良.研究结果表明,以上改善方法均能有效降低气泡线的发生率,实际生产时可采用组合对策,避免气泡线不良的发生.

In the process of producing touch products, the appearance quality of the product was seriously affected by the poor bubble line. In this paper, the formation mechanism of bubble line was researched. When the polarizer was attached, the residual bubbles existed between the organic film segment of the sensor protective layer and the polarizer, which thereby caused such defect. The influence factors of the bubble line were studied from the point of design and the process. It is found that the boundary design position of organic film, the thickness of organic film, the related attaching process of polarizer and the PSA thickness in the polarizer have a significant adverse effect on the bubble line. After making the boundary design position of organic film far away from the AA zone and reducing the overlapping width between the organic film and the polarizer, the bubble can be discharged more easily during defoaming and the poor bubble line is improved accordingly. When attaching the polarizer, if the thickness of the organic film is reduced, the bubble accumulation on the position of the organic film gap is also reduced and the poor bubble line is improved. Furthermore, increasing the adhesion pressure, reducing the adhesion speed and increasing the defoaming duration, the bubble accumulation can be reduced and the bubble discharge can be increased to improve the poor bubble line. If the thickness of the PSA glue layer in the polarizer is increased, greater elasticity and indentation can be obtained, so the accumulation of bubbles can be reduced and the poor bubble line can be improved. The research results show that the above improvement methods can effectively reduce the incidence of bubble lines.