OLED Encapsulation and Touch Sensor Layout for Lower RC Delay

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Solution Overview

Problem

Existing electronic devices face challenges in improving process reliability and downsizing while incorporating touch sensors without using metal masks, and there is a need for efficient manufacturing methods that reduce RC delay and simplify layer formation.

Innovation Solution

The electronic device includes a barrier rib with conductive portions separated by an insulating layer, a light emitting element with a cathode connected to one conductive portion, and touch sensors with conductive layers between encapsulation layers, allowing for reduced thickness and simplified manufacturing processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If metal masks are used in the manufacturing process, then manufacturing precision can be improved, but device complexity and production cost increase

Engineering Contradiction:
Improvelight emitting pattern formation precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent removes the metal mask from the manufacturing process entirely. Instead of using a metal mask to define the light emitting pattern, the invention uses a pixel defining film with a light emitting opening that is formed through standard photolithography processes. This extraction of the metal mask eliminates the associated complexity and cost while maintaining manufacturing precision through the pixel defining film structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical metal mask system with a photolithography-based pixel defining film system. The metal mask, which requires mechanical alignment and handling, is substituted with a photolithographically patterned film that can be precisely defined through photoresist processing and etching, thereby reducing mechanical complexity while maintaining precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If encapsulation layers are made thicker to protect conductive layers, then reliability is improved, but RC delay increases

Engineering Contradiction:
Improveconductive layer protectionVSAvoidRC delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the electrical parameters of the encapsulation system by introducing a conductive layer within the encapsulation structure. This conductive layer compensates for the capacitive effects of the encapsulation layers, effectively reducing the RC delay while maintaining the protective function. The parameter change involves transforming the encapsulation from a purely insulating structure to one with controlled conductivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The conductive layer acts as an intermediary element between the sensor electrodes and the external circuitry. It provides a low-impedance path that mediates the signal transmission, reducing the overall RC time constant of the sensor system while still allowing the encapsulation layers to provide their protective function.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If product size is reduced for downsizing, then adaptability is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveproduct size flexibilityVSAvoidfeature size control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent segments the device into modular components with standardized interfaces. The pixel defining film, barrier rib, and encapsulation layers are designed as discrete, repeatable structures that can be manufactured with consistent precision across different device sizes. This segmentation allows the same manufacturing processes to be applied regardless of the overall device scale.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs parameter scaling techniques where the dimensions of key structures (such as the light emitting opening, barrier rib width, and encapsulation layer thickness) are proportionally adjusted based on the target device size. This allows manufacturing precision requirements to be maintained at absolute levels while the relative dimensions change to accommodate different product sizes.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4486095B1Electronic device and method of manufacturing the same
Publication Date: 2026.04.22 SAMSUNG DISPLAY CO LTD
  • EP4486095B1 patent drawingFigure 1
  • EP4486095B1 patent drawingFigure 2
  • EP4486095B1 patent drawingFigure 3

AI summary

An electronic device is disclosed that includes a base layer, a pixel defining film disposed on the base layer and having a light emitting opening defined therein, a barrier rib disposed on the pixel defining film, having conductivity, and including a first portion having a first barrier rib opening corresponding to the light emitting opening and a second portion insulated from the first portion, a light emitting element disposed in the light emitting opening and including an anode, an intermediate layer disposed on the anode, and a cathode disposed on the intermediate layer and connected to the first portion, a first encapsulation layer covering the cathode, a second encapsulation layer covering the light emitting opening and the first barrier rib opening, a third encapsulation layer disposed on the second encapsulation layer, and a sensor disposed on the light emitting element and including a first sensor electrode and a second sensor electrode, wherein the sensor includes a first conductive layer disposed between the second encapsulation layer and the third encapsulation layer and a second conductive layer disposed on the third encapsulation layer, and the first conductive layer is electrically connected to the second portion through the first encapsulation layer.