Bonding Pad Via Structure for LCD Array Substrate Corrosion Prevention
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Solution Overview
Problem
Metallic corrosion in the bonding pad via of LCD products occurs due to voids or gaps between the Indium Tin Oxide (ITO) layer and the Source/Drain electrode layer, allowing water moisture to contact the metal and cause electrochemical reactions, leading to defects such as line display and abnormal display issues.
Innovation Solution
A bonding pad configuration for an array substrate is developed, featuring a gate electrode, first and second insulation layers, and conductive layers with a bonding pad via that separates the second conductive layer from the Source/Drain layer, preventing water moisture from contacting the metal and thus avoiding corrosion. The method involves forming a first conductive layer, a Source/Drain electrode layer, a second insulation layer, and a second conductive layer, where the second conductive layer is electrically connected through the bonding pad via but remains separated from the Source/Drain layer, using Indium Tin Oxide and Passivation SiNx materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the second ITO layer is formed on the S/D layer surface, then electrical connection is achieved, but voids or gaps occur between the layers allowing moisture penetration and metal corrosion
Solution Approach 1:
The patent introduces a second insulation layer as an intermediary barrier between the S/D layer and the second conductive layer. This intermediate layer prevents direct contact between moisture and the metal S/D layer, blocking the corrosion pathway while still allowing electrical connection through the conductive layer configuration.
Solution Approach 2:
The patent segments the bonding pad structure into distinct functional layers: the S/D layer, second insulation layer, and second conductive layer. This segmentation isolates the metal S/D layer from moisture exposure by separating it with the insulation layer, preventing the formation of corrosive pathways while maintaining electrical functionality.
2Reliability
If the bonding pad via directly connects the second conductive layer to the first conductive layer, then electrical connection is achieved, but metal corrosion occurs due to moisture contact
Solution Approach 1:
The second insulation layer acts as a mediator that allows electrical connection through the bonding pad via while simultaneously blocking moisture from reaching the metal S/D layer. The insulation layer is positioned to span across the via opening, creating a protective bridge that maintains electrical continuity but prevents corrosive contact.
Solution Approach 2:
The patent converts the potential harm of having a via opening (which could allow moisture penetration) into a benefit by using the via structure to support the second insulation layer. The insulation layer is formed to cover the via opening, transforming the via from a potential corrosion pathway into a protected electrical connection point.
Data Source
AI summary
A bonding pad of an array substrate, comprising: a gate electrode formed on the array substrate; a first insulation layer formed on the gate electrode; a first conductive layer formed on the first insulation layer; a Source/Drain electrode (S/D) layer formed on the first conductive layer; a second insulation layer formed on the S/D layer; and a second conductive layer formed on the second insulation layer, wherein the second insulation layer is formed with a bonding pad via through which the second conductive layer is electrically connected to the first conductive layer, and the second conductive layer is separated from the S/D layer by the second insulation layer and does not contact the S/D layer. The present invention also discloses a method for producing the bonding pad, an array substrate comprising the bonding pad, and a liquid crystal display apparatus comprising the array substrate.