Display Touch Sensor Structure for Conductive-Layer Reflection Control

The patent transitions from planar conductive layers to a three-dimensional reverse tapered structure. The touch insulating layer and second conductive layer form an inverted pyramid shape with the second conductive layer having a larger width than the first conductive layer below it. This dimensional change allows the side surfaces to be oriented at angles that minimize light reflection toward the viewer, while preserving the multi-layer conductive structure needed for touch sensing functionality.

The patent applies an anti-reflective coating on the side surfaces of the reverse tapered structure. This coating modifies the optical properties of the surface to reduce light reflection. The anti-reflective coating can change the refractive index gradient or create interference effects that minimize reflected light, thereby reducing the harmful visual impact while maintaining the structural integrity and electrical functionality of the multi-layer touch sensor.

The patent introduces a buffer layer positioned between the thin-film encapsulation layer and the touch sensor layer components. This buffer layer is formed in advance to provide a stable foundation and alignment reference for subsequent layers. By preparing this intermediate layer first, the manufacturing process gains an additional degree of freedom for alignment, reducing the precision requirements for direct integration while still achieving thin overall device thickness.

The buffer layer serves as an intermediary element that mediates between the thin-film encapsulation layer and the touch sensor components. This intermediate layer facilitates better alignment and integration by providing a suitable interface with appropriate mechanical and electrical properties. The buffer layer absorbs some of the alignment tolerance requirements, making the overall integration process more manufacturable while maintaining the thin-form-factor advantage.

The patent divides the touch sensor layer into distinct segmented components: a first conductive layer, a reverse tapered touch insulating layer, and a second conductive layer with larger width. This segmentation allows each component to be optimized independently for its specific function. The reverse tapered shape is applied specifically to the insulating layer to reduce parasitic capacitance, while the conductive layers maintain their electrical functionality. This segmented approach manages structural complexity by assigning specific geometric features to specific layers rather than making the entire structure complex.

The reverse tapered geometry is applied locally to the touch insulating layer rather than to the entire touch sensor structure. This localized application of the reverse tapered shape specifically addresses the parasitic capacitance issue in the insulating region while leaving the conductive layers with simpler geometries optimized for electrical performance. The second conductive layer has larger width only at its edges where it extends beyond the first conductive layer, providing local optimization rather than global complexity.