Oxide Semiconductor Connection Section for Display Units

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Solution Overview

Problem

In top emission organic electroluminescence (EL) display units, the connection section between the upper electrode and external circuits is prone to oxidation, leading to increased contact resistance and potential electrical disconnection during etching processes, especially as substrate size increases or etching uniformity degrades, affecting the lighting state.

Innovation Solution

A display unit with a connection section incorporating an oxide semiconductor layer, which includes a low-resistance region on its surface side, reducing contact resistance and enhancing electrical connectivity between the second electrode and the connection section, while being resistant to damage during metal film processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a metal connection section (Al, Al-Nd alloy, or metal film laminate) is used, then electrical connection with the upper electrode can be established, but the connection section is easily oxidized during film formation, increasing contact resistance and potentially causing electrical disconnection

Engineering Contradiction:

Improveelectrical connection stabilityVSAvoidoxidation damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An oxide semiconductor layer is introduced as an intermediary material between the metal connection section and the upper electrode. This oxide semiconductor layer acts as a protective barrier that prevents oxidation of the metal connection section during sputtering film formation, while simultaneously providing good electrical conductivity to maintain low contact resistance. The oxide semiconductor layer mediates between the conflicting requirements of metal reactivity and oxidation resistance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The connection structure employs a composite material system consisting of a metal layer (Al or Al-Nd alloy) combined with an oxide semiconductor layer. This composite structure leverages the high electrical conductivity of metal while utilizing the oxidation resistance of the oxide semiconductor, creating a connection section that achieves both low contact resistance and high reliability in preventing oxidation damage.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If the substrate size is increased or etching uniformity is degraded, then manufacturing flexibility is improved, but electrical connection may not be secured due to increased variation in connection section integrity

Engineering Contradiction:

Improvesubstrate size scalabilityVSAvoidelectrical connection consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The composite structure of metal layer plus oxide semiconductor layer creates a more robust connection section that maintains consistent electrical properties across larger substrate areas. The oxide semiconductor layer provides uniform protection and conductivity throughout, compensating for variations that occur with increased substrate size or degraded etching uniformity, thereby securing reliable electrical connection consistently across the entire display panel.

Inventive Principle:

Principle #40Composite materials

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 oxide semiconductor layer in the connection section reduces contact resistance and minimizes damage during manufacturing, ensuring stable electrical connections and improved lighting performance by maintaining conductivity and resisting oxidation, thus securing favorable electrical connections.

Implementation Method 1

the connection section includes an oxide semiconductor layer including, in at least a portion on a surface side thereof, a low-resistance region with lower electrical resistance than that in a portion other than the low-resistance region

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

the connection section is allowed to secure electrical connection with the upper electrode... since titanium and molybdenum exhibit electrical conductivity even in oxidized form

Methodology Applied

Scientific EffectOxidation resistance: Oxidation

Data Source

PatentUS9466655B2Display unit and electronic apparatus

Publication Date: 2016.10.11 MAGNOLIA BLUE CORP

AI summary

A display unit includes: a drive substrate including a thin film transistor; a pixel section provided on the drive substrate and including a plurality of pixels, each of the pixels including a first electrode, an organic layer including a light-emitting layer, and a second electrode in this order; and a connection section provided in a peripheral region around the pixel section in the drive substrate and configured to be electrically connected to the second electrode, in which the connection section includes an oxide semiconductor layer including, in at least a portion on a surface side thereof, a low-resistance region with lower electrical resistance than that in a portion other than the low-resistance region.