Display Signal Line Layout for Narrow-Bezel Screen Area

The patent transitions from conventional two-dimensional signal line routing to a three-dimensional architecture by stacking multiple substrate layers. First substrate contains first signal lines, second substrate contains second signal lines, and third substrate contains third signal lines, with vertical connections through connection holes. This multi-layer stacking enables signal routing in the vertical dimension, reducing the horizontal space required for non-display areas while maintaining complete signal connectivity pathways.

The patent implements a nested structure where multiple substrates are stacked and interconnected. The first substrate is positioned at a first position, the second substrate at a second position, and the third substrate at a third position, with each substrate containing signal lines that nest within the vertical stack. Connection holes penetrate through the stacked substrates to establish vertical electrical connections, creating a compact nested architecture that minimizes the horizontal footprint of non-display areas.

The patent segments the signal routing function across multiple independent substrates. Each substrate (first, second, and third substrates) contains specific signal lines dedicated to particular routing functions. This segmentation allows each substrate to be optimized independently for its specific signal routing requirements, simplifying the design and manufacturing of each individual layer while collectively achieving complex overall routing functionality.

The patent resolves routing complexity by moving signal lines from horizontal two-dimensional routing to vertical three-dimensional routing through stacked substrates. Connection holes provide direct vertical pathways between layers, eliminating the need for lengthy horizontal detours that would be required in conventional planar routing. This dimensional transition simplifies each individual routing segment while maintaining complete end-to-end connectivity.

The patent segments pad functions across multiple stacked substrates rather than concentrating all pads in a single boundary region. First pads are arranged on the first substrate, second pads on the second substrate, and third pads on the third substrate. This segmentation distributes the alignment requirements across multiple independent manufacturing layers, reducing the cumulative precision demands compared to arranging all pads in a single dense boundary region.

The patent introduces connection holes as intermediary structures that vertically connect pads across the stacked substrates. These connection holes serve as precise alignment references that mediate the positioning relationship between pads on different substrates. By establishing rigid vertical reference pathways through the stack, the system achieves high pad alignment precision without requiring excessively tight tolerances in individual pad placement operations.