Light-Emitting Device Auxiliary Wiring and Parasitic Capacitance Reduction

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Solution Overview

Problem

Existing light-emitting device structures face challenges in efficiently utilizing space where pixel electrodes are not formed and in reducing parasitic capacitance at wiring intersections.

Innovation Solution

The introduction of auxiliary wiring, connection wiring, and capacitor electrodes in regions not occupied by pixel electrodes, along with strategically placed opening portions in conductive layers to minimize overlap and thereby reduce parasitic capacitance at wiring intersections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the pixel electrode is the only conductive layer on the insulating layer, then the structure is simple, but the space in regions where the pixel electrode is not formed is wasted

Engineering Contradiction:

Improvestructure simplicityVSAvoidspace utilization

Core Design Contradiction:

Device complexityVSArea of stationary object

Solution Approach 1:

The patent combines multiple functions into the same conductive layer structure. The pixel electrode and auxiliary wiring are integrated into the same conductive layer (first conductive layer), allowing the auxiliary wiring to utilize spaces where the pixel electrode is not formed while maintaining structural simplicity. This merging approach resolves the contradiction by making the single conductive layer serve dual purposes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The first conductive layer is designed to serve multiple functions: it acts as the pixel electrode in regions where light emission is required, and as auxiliary wiring in regions where the pixel electrode is not formed. This multi-functionality allows efficient use of space without adding complex additional structures.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If wiring intersection portions are covered with insulating layers, then wiring protection is achieved, but parasitic capacitance increases at intersection portions

Engineering Contradiction:

Improvewiring protectionVSAvoidparasitic capacitance

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the conductive layers at wiring intersection portions by providing opening portions in the insulating layers. This segmentation allows certain conductive layers to be electrically disconnected at intersections, thereby reducing parasitic capacitance while maintaining wiring protection through the insulating layer structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extracts (removes) the insulating layer material at specific intersection portions to create opening portions. This extraction reduces the dielectric material between conductive layers at intersections, thereby reducing parasitic capacitance while the remaining insulating layer structure continues to provide wiring protection.

Inventive Principle:

Principle #2Taking out (Extraction)

3Productivity

If multiple conductive layers are added to utilize space and reduce parasitic capacitance, then performance improves, but device complexity increases

Engineering Contradiction:

Improvedevice performanceVSAvoidnumber of conductive layers

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the pixel electrode and auxiliary wiring functions into the same first conductive layer, avoiding the need for separate additional conductive layers. This merging approach improves space utilization and reduces parasitic capacitance without significantly increasing device complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The first conductive layer is designed with multi-functionality to serve as both pixel electrode and auxiliary wiring. This universal design improves device performance by efficient space utilization while maintaining relatively simple structure, as no additional conductive layers are required.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS8912547B2Light-emitting device, display device, and semiconductor device

Publication Date: 2014.12.16 SEMICON ENERGY LAB CO LTD

AI summary

A light-emitting device which includes a semiconductor layer; a first insulating layer over the semiconductor layer; a gate electrode and a first conductive layer over the first insulating layer; a second insulating layer over the gate electrode and the first conductive layer; source and drain electrodes and a second conductive layer over the second insulating layer; a third insulating layer over the source and drain electrodes and the second conductive layer; a first electrode and a third conductive layer over the third insulating layer; a planarization film covering an end portion of the first electrode; an electroluminescent layer over the first electrode; and a second electrode over the electroluminescent layer and the planarization film is provided. The second electrode is electrically connected to the third conductive layer through an opening portion provided in the planarization film. The opening portion overlaps with the first, second, and third conductive layers.