Array Substrate with Oxide and Poly-Silicon Transistors

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Solution Overview

Problem

Current array substrates for display devices face challenges in achieving high refresh frequency and large-size displays due to poor electrical uniformity and high off-state leakage current in low temperature poly-silicon thin film transistors, which affect display quality and power consumption.

Innovation Solution

The array substrate incorporates a pixel region with an oxide thin film transistor and a peripheral region with a poly-silicon thin film transistor, utilizing different active layer materials to enhance electrical uniformity and mobility, allowing for improved contrast ratio and reduced power consumption, while the GOA gate drive circuit enables higher refresh frequency and driving capability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If low temperature poly-silicon thin film transistors are used in the pixel region, then the manufacturing process is simpler and cost is reduced, but the electrical uniformity deteriorates and off-state leakage current increases

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidelectrical uniformity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies different active layer materials to different regions: oxide semiconductor in the pixel region for high uniformity and low leakage, poly-silicon in the peripheral region for high mobility. This local differentiation resolves the contradiction by optimizing each region's performance characteristics according to its functional requirements.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The array substrate is segmented into pixel region and peripheral region with different transistor types. The pixel region uses oxide TFTs for display quality, while the peripheral region uses poly-silicon TFTs for driving capability, allowing each segment to be optimized independently for its specific function.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If low temperature poly-silicon thin film transistors are used, then manufacturing cost is reduced, but off-state leakage current increases affecting display quality

Engineering Contradiction:

Improvemanufacturing costVSAvoidoff-state leakage current

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

Oxide semiconductor active layers are used specifically in the pixel region where low leakage current is critical for display quality, while poly-silicon is used in the peripheral region where high mobility is more important. This local optimization eliminates the harmful leakage effect in the display area while maintaining manufacturing efficiency.

Inventive Principle:

Principle #3Local quality

3Reliability

If oxide thin film transistors are used in the pixel region, then electrical uniformity and contrast ratio are improved, but manufacturing complexity increases

Engineering Contradiction:

Improveelectrical uniformityVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Oxide TFTs are deployed only in the pixel region where their superior electrical uniformity directly improves display quality, while poly-silicon TFTs handle the peripheral driving functions. This selective application minimizes manufacturing complexity increases while maximizing performance benefits in the critical display area.

Inventive Principle:

Principle #3Local quality

4Speed

If poly-silicon thin film transistors are used in the peripheral region, then mobility and driving capability are improved, but electrical uniformity deteriorates

Engineering Contradiction:

Improvecarrier mobilityVSAvoidelectrical uniformity

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

Poly-silicon TFTs are used in the peripheral region where high carrier mobility is essential for driving capability and refresh frequency, while the less uniform electrical characteristics are acceptable since this region does not directly affect display quality. The pixel region uses oxide TFTs to maintain high uniformity for display performance.

Inventive Principle:

Principle #3Local quality

5Ease of manufacture

If GOA gate drive circuit is integrated on the array substrate, then production cost is decreased and narrow bezel is achieved, but the transistor performance requirements become more stringent

Engineering Contradiction:

Improveproduction costVSAvoidtransistor performance consistency

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The GOA gate drive circuit in the peripheral region uses poly-silicon TFTs for high mobility and driving capability, while the pixel region uses oxide TFTs for high uniformity and low leakage. This regional differentiation ensures that each transistor type is optimized for its specific function, meeting the stringent performance requirements of the integrated GOA circuit while maintaining manufacturing efficiency.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11469254B2Array substrate and manufacturing method thereof, display panel and electronic device

Publication Date: 2022.10.11 BEIJING BOE TECH DEV CO LTD

AI summary

An array substrate, a method of manufacturing an array substrate, a display panel, and an electronic device are provided. The array substrate includes a display area and a peripheral area; the display area includes a pixel region, the pixel region includes a first thin film transistor, and the first thin film transistor includes a first active layer; the peripheral area includes a second thin film transistor, and the second thin film transistor includes a second active layer; and the first active layer includes a material of oxide semiconductor, and the second active layer includes a material of poly-silicon semiconductor.