Flexible Circuit ESD Protection for Display Modules
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Solution Overview
Problem
Conventional display modules face issues with electrostatic discharge (ESD) damage due to the lack of reliable ESD protection mechanisms, particularly in IPS LCD panels without conductive electrodes, leading to pinch mura defects and unreliable conductive tape attachments that can peel off under mechanical stress or in humid environments.
Innovation Solution
A display module incorporating a flexible circuit board as an ESD protection member, electrically grounded and sandwiched between the display panel's substrates, providing a reliable electrostatic discharge guiding path with improved conduction and resistance to mechanical stress and environmental conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive material is sandwiched between display panel and front bezel to guide electrostatic discharge, then ESD protection is provided, but pinch mura defect occurs due to pressure causing liquid molecular rotation
Solution Approach 1:
A conductive adhesive layer is introduced as an intermediary between the conductive material and the display panel. This adhesive layer serves as a mediator that provides ESD protection while avoiding direct pressure contact with the liquid crystal layer, thereby preventing pinch mura defects. The conductive adhesive layer transfers electrostatic discharge away from the display panel without transmitting mechanical pressure to the liquid crystals.
2Reliability
If conductive tape is connected between display panel and rear bezel to guide electrostatic discharge, then ESD protection is provided, but conductive tape peels off under mechanical shock or in humid environments
Solution Approach 1:
The patent employs a conductive adhesive layer that combines the electrical conductivity of conductive materials with the adhesive properties of bonding agents. This composite material provides both ESD protection and stable attachment to the display panel, preventing peeling under mechanical shock or in humid environments. The conductive adhesive layer integrates the functions of electrical conduction and mechanical bonding into a single stable component.
3Reliability
If pressure is applied by front bezel to ensure firm contact of conductive material with display panel, then ESD conduction is improved, but liquid molecular rotation occurs causing pinch mura defect
Solution Approach 1:
The conductive adhesive layer acts as an intermediary that decouples the mechanical pressure function from the electrical conduction function. It provides a compliant interface that maintains electrical contact for ESD protection without transmitting sufficient pressure to rotate liquid molecules. The adhesive layer's material properties allow it to bond surfaces while accommodating dimensional variations without exerting damaging force on the liquid crystal layer.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The flexible circuit board ESD protection member effectively reduces the risk of ESD damage by ensuring stable and reliable electrostatic discharge pathways, preventing pinch mura defects and maintaining attachment even under mechanical stress and in humid environments, thus enhancing the overall reliability of the display module.
Implementation Method 1
an electrostatic discharge guiding path which is with high reliability and has better electrical conduction performance is provided, so that ESD damage for the display panel can be avoided
Implementation Method 2
The ESD protection member, which is a flexible circuit board, is connected to the electrical connection layer and is electrically grounded
Data Source
AI summary
A display module is provided, which includes a display panel and an ESD protection member. The display panel includes a rear substrate, a front substrate, a front polarizer, and an electrical connection layer. The front substrate is stacked on the rear substrate and includes a manifesting area and a perimeter area surrounding the display area. The front polarizer is relative to the manifesting area and is disposed on the front surface of the front substrate. The electrical connection layer is relative to the manifesting area and the perimeter area and is sandwiched between the front polarizer and the front substrate. The ESD protection member, a flexible printed circuit, is connected to the electrical connection layer and is electrically grounded.