为提高产能, 笔记本电脑超高级超维场开关(HADS)显示产品的聚酰亚胺(PI)膜涂布方式从滚筒涂布的感光树脂转印版 (APR)转印变更为喷墨打印, 涂布方式的变更造成了PI液滴在面板周边Vcom过孔和走线密集处扩散困难, 难以扩散的PI液滴在面板边缘聚集形成周边黑线不良。首先, 通过变更PVX(passivation SiNx, 钝化层)掩膜版解决Vcom过孔周边PI液扩散不均问题,即通过改变面板周边过孔周期、尺寸以及距离像素区间距来减小过孔存在的影响, GP (Gate pad)侧过孔数量变为原来1/8, 过孔面积比原来减小了98%, DP (Date pad)侧过孔数量变为原来的1/9, 过孔面积比原来减小99%, 同时DP侧过孔与像素区间距增大60%, PVX掩膜版变更极大地改善了PI液滴在过孔周围的扩散均匀性, 最终周边黑线发生率从100%减小为6.6%。其次, 通过变更喷墨打印涂布工艺来减小面板周边PI液积聚程度, 我们开发出喷墨打印边缘补正功能, 即保持像素区膜厚不变, 面板边缘区域膜厚减少。 边缘区域PI液的减少降低了该区域PI液积聚的可能性, 边缘补正功能使得周边黑线发生率从6.6%降至0.5%。再次, 阵列基板采用条形涂覆方式, 即GP侧PI液全涂覆, 周边黑线不良发生率降至0.05%。通过变更PVX掩膜版设计和喷墨打印涂布工艺参数, 周边黑线不良发生率从100%减小为0.05%, 满足量产需求。

To improve the production capacity, the PI (polyimide) film coating method of High Advanced Dimension Switch (HADS) products is changed from APR transfer printing ( Roller Coater) to inkjet printing(Inkjet Printer). The change of coating method causes the accumulation of polyimide (PI) solution near the Vcom via hole and Vcom line which exists in the peripheral zone, which causes a failure named “peripheral black line”. Firstly, we can solve the diffusion problem of PI solution by changing PVX (passivation SiNx) mask, that is, to reduce the influence of via hole by changing the cycle, size and distance between via hole and active area. we reduce the cycle of Vcom via hole near gate pad (GP) area by a factor of eight, the occupied area of Vcom via hole decreases by 98% than before. In the meanwhile, we reduce the cycle of Vcom via hole near date pad (DP) area by a factor of nine, the occupied area of Vcom via hole decreases by 99%, the distance between via hole of GP area and AA area increases by 60% than before. The changing of PVX mask greatly improves the diffusion of PI solution, eventually, the failure rate of black line reduces from 100% to 6.6%. Secondly, we develop an edge compensation function of inkjet printer to reduce the accumulation of PI solution in peripheral area, that is, the PI thickness of peripheral area is half the active area, the reduction of PI solution in the EM area reduces the possibility of accumulation in the area, and then the failure rate of black line reduces from 6.6% to 0.5%. Thirdly, we change the coating mode from pattern coating to strip-type coating, that is, the GP area is filled with PI solution in all area, which reduces the failure rate from 0.5% to 0.05%. By changing the PVX mask design and process parameters of Inkjet printer, the incidence of peripheral black line defects are reduced from 100% to 0.05%, meeting the mass production needs.