Display Panel Notch Layout for Bonding Resistance Inspection

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Solution Overview

Problem

Bonding resistance between the display panel and the chip on film affects the performance of display devices, leading to potential performance issues and inefficiencies in manufacturing.

Innovation Solution

A display device with a notch structure in the display panel and substrates, featuring multiple test pads and points for measuring bonding resistance, allowing for improved inspection and monitoring of bonding quality between the chip on film and the display panel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bonding resistance is increased to a reference value or higher, then performance of the display device may be negatively affected, but adding test pads and test points increases device complexity

Engineering Contradiction:
Improvebonding qualityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bonding interface is segmented into multiple measurement points (first-1 test pad, first-2 test pad, second-1 test pad, second-2 test pad) distributed at different locations. This segmentation allows localized bonding quality assessment without requiring a single complex measurement system, thereby maintaining reliability while managing device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Test pads and test points serve as intermediary elements between the bonding interface and measurement equipment. These intermediaries enable indirect measurement of bonding resistance through connection pads and lines, allowing quality assessment without direct intervention in the bonding process itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple test pads and connection pads are added to measure bonding resistance, then bonding quality inspection is improved, but manufacturing process becomes more complex

Engineering Contradiction:
Improvebonding resistance measurementVSAvoidmanufacturing process
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Multiple measurement functions are merged into a unified test structure where first-1 test pad, first-2 test pad, second-1 test pad, and second-2 test pad work together with connection pads and lines. This merging allows comprehensive bonding resistance measurement across multiple locations through a coordinated system rather than separate independent measurements, improving measurement precision while streamlining the manufacturing process.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The test pad structure serves multiple functions: electrical connection for bonding resistance measurement, mechanical support for the bonding interface, and alignment reference for the bonding process. This multi-functionality reduces the need for separate dedicated measurement components, thereby improving measurement capability without proportionally increasing manufacturing complexity.

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

3Reliability

If test structures are added to monitor bonding quality, then reliability is improved, but manufacturing efficiency decreases

Engineering Contradiction:
Improvebonding quality monitoringVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Test pads, connection pads, and test points are incorporated into the bonding structure during the manufacturing process itself, before actual bonding occurs. This preliminary integration allows bonding resistance measurement to be performed immediately after bonding without requiring separate post-bonding inspection steps, thereby maintaining reliability while preserving manufacturing efficiency.

Inventive Principle:
Principle #10Preliminary action

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

Enhances the reliability and manufacturing efficiency of display devices by ensuring uniform bonding quality and identifying potential bonding issues, thereby improving overall performance.

Implementation Method 1

an adhesive resin containing a plurality of conductive particles may be applied to an end portion of the display panel, and the chip on film may be positioned on the end portion of the display panel to which the adhesive resin is applied. The chip on film and the display panel may be compressed together, and the display panel and the chip on film may be electrically connected by the conductive particles contained in the adhesive resin.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4700465A1Display device and electronic device including the same
Publication Date: 2026.02.25 SAMSUNG DISPLAY CO LTD
  • EP4700465A1 patent drawingFigure 1
  • EP4700465A1 patent drawingFigure 2A~2B
  • EP4700465A1 patent drawingFigure 2C~2D

AI summary

A display device includes a display panel including a non-bonding area formed at an end portion thereof and defining first and second sides of the end portion the display panel; a first substrate having a notch formed therein to correspond to the non-bonding area, and includes a driving element for driving the display panel; and a second substrate connected with a second end portion of the first substrate, wherein the display panel includes a first-1 test pad at the first side of the panel, the first substrate includes a first-1 connection pad bonded with the first-1 test pad, a second-1 connection pad connected with the first-1 connection pad through first lines, the second substrate includes a second-1 test pad bonded with the second-1 connection pad, and a first test point connected with the second-1 test pad, and a portion of the first lines overlap the driving element.