Failure Analysis of Yellow Banding on Optically Bonded Touch Screen

Yellow banding is a phenomenon occurring at an edge(s) in an electronic optical touch screen when the display module emits certain background light. Although it is commonly recognized that the discoloration turns yellowish due to display liquid crystal (LC) cell gap change, the mechanism to create the color change can be different depending on the display designs. This paper discusses an approach to investigate a particular mechanism of forming yellow banding caused by uncured edge fill UV adhesive.