Auxiliary Coupling Layer for Display Panel Side Bonding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing display devices face challenges in achieving reliable electrical connections between flexible circuit members and display panels, leading to potential issues with signal transmission and device stability, particularly in reducing bezel width and enhancing coupling reliability.

Innovation Solution

The implementation of an electrically floating auxiliary layer on the side surface of the display panel, spaced apart from the pads, which is coupled with the circuit member to enhance the coupling force and stability of the connection, using ultrasonic bonding and anisotropic conductive films to secure the electrodes and auxiliary electrodes, thereby expanding the coupling area and improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pads and electrodes are connected using conventional methods (anisotropic conductive film or ultrasonic bonding), then the electrical connection is established, but the coupling reliability and stability are insufficient

Engineering Contradiction:
Improvecoupling reliabilityVSAvoidconnection structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The connection structure is divided into multiple independent bonding areas: a first bonding area between the pad and electrode, and a second bonding area between the auxiliary layer and auxiliary electrode. This segmentation allows each bonding area to independently contribute to coupling reliability, so that even if one bonding area experiences stress or degradation, the other maintains the connection stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection is extended from a single-plane bonding structure to a multi-dimensional structure by adding the auxiliary layer and auxiliary electrode that are spaced apart from the pad and electrode in the thickness direction. This creates additional bonding interfaces in the vertical dimension, distributing mechanical and electrical stress across multiple levels and improving overall coupling reliability.

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

2Length of stationary object

If the bezel width is reduced to minimize the boundary between adjacent display units, then the aesthetic appearance and connected screen effect are improved, but the coupling force and stability of the connection may be compromised

Engineering Contradiction:
Improvebezel widthVSAvoidcoupling force
Core Design Contradiction:
Length of stationary objectVSStrength

Solution Approach 1:

By introducing the auxiliary layer and auxiliary electrode spaced apart in the thickness direction, the connection strength is enhanced through additional bonding interfaces in the vertical dimension. This allows the bezel width to be reduced while maintaining coupling force, as the multi-level bonding structure compensates for the reduced lateral bonding area.

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

Solution Approach 2:

The connection structure employs composite bonding approaches, combining different bonding methods (anisotropic conductive film and ultrasonic bonding) in different bonding areas. This composite structure distributes mechanical loads across multiple material interfaces, maintaining coupling strength even when the bezel width is minimized.

Inventive Principle:
Principle #40Composite materials

3Area of stationary object

If the pads are positioned closer to the edge to reduce bezel width, then the display area is maximized, but the connection stability and signal transmission reliability may deteriorate

Engineering Contradiction:
Improvedisplay areaVSAvoidsignal transmission reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The connection structure is segmented into multiple bonding areas with the auxiliary layer and auxiliary electrode positioned at different locations. This segmentation provides redundant connection paths for signal transmission, ensuring that even when pads are positioned closer to the edge to maximize display area, the signal transmission reliability is maintained through multiple independent bonding interfaces.

Inventive Principle:
Principle #1Segmentation

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

This solution enhances the coupling reliability between the circuit units and the display panel, leading to improved stability and reduced bezel width, resulting in a more reliable and efficient display device with a minimized boundary between adjacent display units when forming a single connected screen.

Implementation Method 1

using ultrasonic bonding and anisotropic conductive films to secure the electrodes and auxiliary electrodes

Methodology Applied
Scientific EffectUltrasonic bonding: Ultrasonic Vibration

Implementation Method 2

using ultrasonic bonding and anisotropic conductive films to secure the electrodes and auxiliary electrodes

Methodology Applied
Scientific EffectAnisotropic conduction: Anisotropy

Data Source

PatentEP3786698B1Auxiliary coupling layer and display device having the same
Publication Date: 2023.10.18 SAMSUNG DISPLAY CO LTD
  • EP3786698B1 patent drawingFigure 1
  • EP3786698B1 patent drawingFigure 2
  • EP3786698B1 patent drawingFigure 3~4

AI summary

A display device includes a display panel including a side surface; on the side surface of the display panel: a pad through which an electrical signal is provided to the display panel from outside thereof; and an auxiliary layer in a same layer as the pad and spaced apart from the pad along a thickness direction of the display panel; and a circuit member facing the side surface of the display panel and coupled to both the pad and the auxiliary layer.