LCD Array Substrate Lead Protection Against Gold Finger Shorts

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Solution Overview

Problem

The existing array substrate design in LCD panels is prone to short circuits due to misalignment of gold fingers during bonding, which causes conduction between different signal leads when the protection layer is crushed.

Innovation Solution

Incorporating a second metal pattern layer in the protection layer above the bent signal leads to provide protection, ensuring the layer partially covers the signal leads and withstands bonding pressure, thereby preventing short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protection layer is provided above signal leads to prevent short circuits, then the signal leads are protected, but the protection layer can be crushed during gold finger bonding causing short circuits between different signal leads

Engineering Contradiction:
Improvesignal lead protectionVSAvoidshort circuit between signal leads
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A second metal pattern layer is introduced as an intermediary protective layer between the gold fingers and the signal leads. This metal pattern layer serves as a mediator that absorbs the bonding pressure and prevents direct contact between misaligned gold fingers and adjacent signal leads, thereby avoiding short circuits while maintaining the integrity of the original protection layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protection mechanism is enhanced by adding a layer in the vertical dimension (thickness direction) rather than only relying on the planar protection layer. The second metal pattern layer is disposed at a different height level, creating a multi-dimensional protective structure that prevents gold fingers from crushing the protection layer and causing short circuits.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If the routing direction of signal leads is designed perpendicular to conductive contacts to achieve narrow frame, then frame width is reduced, but misalignment of gold fingers causes them to extend beyond bonding area and contact adjacent signal leads

Engineering Contradiction:
Improveframe widthVSAvoidbonding alignment precision
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The second metal pattern layer acts as an intermediary barrier that prevents misaligned gold fingers from contacting adjacent signal leads. This intermediary layer compensates for the reduced alignment margin caused by the perpendicular routing design, allowing the narrow frame structure to maintain its reliability despite the increased risk of misalignment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The second metal pattern layer provides beforehand cushioning by being positioned to absorb potential misalignment errors before they can cause short circuits. This preventive measure cushions against the harmful effects of alignment deviations that may occur during the bonding process.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If a second metal pattern layer is added to protect signal leads, then short circuit prevention is improved, but manufacturing complexity and production cost increase

Engineering Contradiction:
Improveshort circuit preventionVSAvoidlayer structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The second metal pattern layer is merged with the existing TFT electrode structure, allowing it to be formed in the same fabrication process step. This merging approach adds the protective function without requiring a completely separate manufacturing process, thereby reducing the increase in manufacturing complexity and production cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The second metal pattern layer serves multiple functions: it acts as both a protective layer for signal leads and as part of the TFT electrode structure. This multi-functionality reduces the overall device complexity by combining protection and electrical function in a single layer rather than requiring separate dedicated protection and electrode layers.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4310820B1Array substrate, liquid crystal display panel, and liquid crystal display apparatus
Publication Date: 2025.12.03 MIANYANG HKC OPTOELECTRONICS TECH CO LTD
  • EP4310820B1 patent drawingFigure 1
  • EP4310820B1 patent drawingFigure 2
  • EP4310820B1 patent drawingFigure 3

AI summary

The present application provides an array substrate, an LCD panel and an LCD apparatus, and involves in the field of display technologies, and the array substrate (31) includes: a base substrate (300), a first metal pattern layer (310) and a protection layer (320) arranged as stacked in sequence; the array substrate (31) further includes: a display area (10) and a peripheral area (20) surrounding the display area (10), the peripheral area (20) includes a bonding area (210) and a non-bonding area (220), and the bonding area (210) is disposed on at least one side outside the display area (10); the first metal pattern layer (310) includes a plurality of conductive contacts (21) disposed in the bonding area (210) and arranged at intervals along a first direction and a plurality of signal leads (22) disposed in the non-bonding area (220) and having a bent shape; the protection layer (320) includes a first insulation layer (321) and a second metal pattern layer (323) arranged as stacked in sequence, and along a thickness direction of the base substrate (300), the first insulation layer (321) is disposed on a side of the second metal pattern layer (323) approaching the base substrate (300). In the present application, through adding the second metal pattern layer at least partially covering the signal leads in the protection layer, the signal leads can be protected and the short-circuiting problem caused by the gold fingers can be avoided.