Stepped Metal Layer Design for Display Panel Corrosion Resistance

The patent applies local quality by creating a stepped structure where the second metal layer has different widths at different heights. The passivation protective layer is formed thicker at the stepped portion compared to the flat portion, providing enhanced local protection where corrosion is most likely to occur at the edges and corners of the metal layers.

The patent transitions from a two-dimensional uniform metal layer structure to a three-dimensional stepped structure by adding vertical height variation. This dimensional change allows the passivation protective layer to have varying thicknesses, creating overlapping coverage that enhances corrosion resistance without uniformly increasing material consumption across the entire structure.

The stepped structure enables the passivation protective layer to be thicker only at critical stepped portions where corrosion resistance is most needed, rather than uniformly increasing thickness across the entire metal layer. This localized thickening approach improves protection efficiency while controlling material consumption.

The patent applies partial action by providing excessive protection (thicker passivation layer) only at the stepped portions where it is most needed for corrosion resistance, rather than uniformly across the entire structure. This selective approach optimizes the balance between protection and material usage.