Light Emitting Display Second Electrode Short Prevention

Solution Overview

Problem

In light emitting display devices, foreign materials can cause electrical shorts between electrodes, leading to dark spots and increased electrical resistance, which deteriorate optical characteristics and increase power consumption.

Innovation Solution

A light emitting device with a second electrode comprising multiple layers, including an insulating layer, is designed to reduce electrical resistance while preventing shorts, where the first layer has a smaller cross-sectional thickness and the second layer has a larger thickness, with the insulating layer positioned between them to prevent electrical contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cross-sectional thickness of the second electrode is reduced to prevent electrical short, then the occurrence of dark spots is reduced, but the electrical resistance of the second electrode increases

Engineering Contradiction:

Improveprevention of electrical shortVSAvoidelectrical resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The second electrode is divided into multiple layers (first metallic layer, insulating layer, second metallic layer) instead of being a single homogeneous layer. This segmentation allows the electrode to simultaneously achieve low electrical resistance through the metallic layers and electrical short prevention through the insulating layer barrier.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An insulating layer is introduced as an intermediary between the first metallic layer and the second metallic layer. This insulating layer acts as a barrier that prevents electrical short between electrodes while allowing the metallic layers to maintain low electrical resistance for efficient current conduction.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the cross-sectional thickness of the second electrode is reduced to prevent electrical short, then the occurrence of dark spots is reduced, but the optical characteristics deteriorate and driving voltage increases

Engineering Contradiction:

Improveprevention of electrical shortVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The second electrode is divided into multiple layers (first metallic layer, insulating layer, second metallic layer) instead of being a single homogeneous layer. This segmentation allows the electrode to simultaneously achieve low electrical resistance through the metallic layers and electrical short prevention through the insulating layer barrier.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An insulating layer is introduced as an intermediary between the first metallic layer and the second metallic layer. This insulating layer acts as a barrier that prevents electrical short between electrodes while allowing the metallic layers to maintain low electrical resistance for efficient current conduction.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9006722B2Light emitting display

Publication Date: 2015.04.14 SAMSUNG DISPLAY CO LTD

AI summary

A light emitting device includes a pixel defining layer including a plurality of pixel defining layer elements, on a substrate; a first electrode in a space defined by the substrate and the pixel defining layer; a light emitting layer in a space defined by the first electrode and the pixel defining layer; and a second electrode on the light emitting layer and the pixel defining layer. The second electrode includes a plurality of layers, and an insulating layer between the plurality of layers, overlapping the light emitting layer, and exposing a layer among the plurality of layers in an area corresponding to the pixel defining layer.