COP Display Chip Pad Structure for Mounting Pressure Distribution

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Solution Overview

Problem

The application of pressure during the mounting of a driving circuit chip on a flexible plastic substrate in COP technology can cause deformation and cracks in chip pads and lines on the display panel, leading to electrical defects and increased production energy and greenhouse gas emissions.

Innovation Solution

A display device with a pressure distribution structure made of organic insulating material, disposed between the chip pads and the driving circuit chip, which absorbs and distributes the mounting pressure, preventing cracks and reducing defect rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure is applied to mount the driving circuit chip on the display panel, then the chip is securely fixed, but cracks occur in the chip pads and lines due to substrate deformation

Engineering Contradiction:
Improvechip mounting reliabilityVSAvoidcracks in chip pads and lines
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A pressure distribution structure is introduced as an intermediary component between the driving circuit chip and the display panel substrate. This mediator distributes the mounting pressure across a larger area, preventing localized stress concentration that causes cracks in the chip pads and lines while still securing the chip firmly.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pressure distribution structure serves as a pre-configured cushioning element that anticipates and mitigates the harmful effects of mounting pressure before cracks can form. By distributing pressure in advance during the mounting process, it prevents substrate deformation and subsequent cracking of delicate pad and line structures.

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

2Reliability

If pressure is applied during chip mounting, then the chip is securely attached, but the flexible plastic substrate deforms causing electrical connection defects

Engineering Contradiction:
Improvechip attachment reliabilityVSAvoidsubstrate structural stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The pressure distribution structure acts as a mediator that decouples the direct contact between the chip and the flexible substrate. It provides a stable pressure distribution interface that secures the chip while preventing the transmission of deforming forces to the substrate, thereby maintaining substrate structural stability during mounting.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pressure distribution structure divides the concentrated mounting pressure into distributed forces across multiple contact points or a broader area. This segmentation of pressure prevents localized substrate deformation while achieving secure chip attachment, maintaining the substrate's structural integrity.

Inventive Principle:
Principle #1Segmentation

3Strength

If higher pressure is applied to ensure chip mounting quality, then attachment strength improves, but defect rate increases due to cracks and deformation

Engineering Contradiction:
Improvechip attachment strengthVSAvoidproduction defect rate
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The pressure distribution structure enables the application of higher mounting pressure to achieve strong chip attachment without increasing the defect rate. It mediates between the chip and substrate, distributing the high pressure to prevent crack formation and deformation, thus allowing high attachment strength with high manufacturing precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pressure distribution structure changes the pressure distribution parameters from concentrated high stress to distributed lower stress across a larger area. This parameter transformation allows the mounting process to achieve both high attachment strength and low defect rates by optimizing how pressure is applied rather than simply reducing the total force.

Inventive Principle:
Principle #35Parameter changes

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 pressure distribution structure effectively reduces cracks in chip pads and lines, lowering production defects and greenhouse gas emissions by distributing pressure and supporting the driving circuit chip during mounting.

Implementation Method 1

an anisotropic conductive film is used to mount the driving circuit chip on the display panel

Methodology Applied
Scientific EffectAnisotropic conduction: Anisotropy

Implementation Method 2

at least one pressure distribution structure vertically overlapping the driving circuit chip and disposed adjacent to at least one of the plurality of pad rows

Methodology Applied
Scientific EffectPressure distribution: Pressure Gradient

Data Source

PatentEP4704537A1Display device
Publication Date: 2026.03.04 LG DISPLAY CO LTD
  • EP4704537A1 patent drawingFigure 1
  • EP4704537A1 patent drawingFigure 2
  • EP4704537A1 patent drawingFigure 3

AI summary

A display device includes a substrate including a display area and a non-display area around the display area; a chip pad area disposed on the non-display area of the substrate, wherein a plurality of chip pads are disposed in the chip pad area and are arranged in a plurality of rows to constitute a plurality of pad rows; a driving circuit chip mounted on the chip pad area; and at least one pressure distribution structure vertically overlapping the driving circuit chip and disposed adjacent to each of the plurality of pad rows.