OLED Pixel Defining Layer Alignment for Accurate Inkjet Printing

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Solution Overview

Problem

Inkjet printing in OLED display panels often results in ink droplets being misaligned, leading to defects such as bright lines, dark lines, or color crossover, reducing display quality due to poor matching between the print head and the pixel defining layer.

Innovation Solution

A display panel structure with a marking pattern and pixel defining layer that allows for accurate positioning of ink droplets, combined with a correction process for the print head or carrier based on deviations between target and actual positions, ensuring precise alignment of functional layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If inkjet printing is used to form functional layers, then productivity and manufacturing flexibility are improved, but manufacturing precision deteriorates due to ink droplet misalignment

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidink droplet placement accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The pixel defining layer is formed with predetermined openings at exact target positions before the inkjet printing step. These openings serve as pre-established guides that ensure ink droplets are deposited precisely where needed, eliminating misalignment issues while maintaining the flexibility of inkjet printing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The pixel defining layer acts as an intermediary structure between the substrate and the functional layers. It provides a physical template with openings that mediates the positioning of ink droplets, ensuring accurate placement without requiring complex print head positioning systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If conventional inkjet printing without positioning structures is used, then device complexity is reduced, but manufacturing precision deteriorates due to lack of alignment reference

Engineering Contradiction:

Improvestructure complexityVSAvoidalignment accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The pixel defining layer serves multiple functions simultaneously: it defines the pixel boundaries, provides alignment references for inkjet printing, and acts as a structural support layer. This multi-functionality improves precision without adding separate positioning structures or increasing overall device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12543446B2Display panel and manufacturing method thereof, and display device

Publication Date: 2026.02.03 HEFEI BOE ZHUOYIN TECH CO LTD

AI summary

Provided are a display panel and a manufacturing method thereof, and a display device. The display panel includes: a base substrate; anodes and a mark pattern including at least one first mark pattern; a pixel defining layer having openings, wherein the orthographic projection of each opening on the base substrate at least partially overlaps with that of a corresponding anode, and the orthographic projection of the mark pattern on the base substrate is located within that of the pixel defining layer; at least one group of ink droplets including one or more ink droplets, and the orthographic projection of each ink droplet on the base substrate is located within that of the pixel defining layer; a functional layer including at least one sub-layer including a light-emitting layer, and the material of each group of ink droplets is the same as that of a sub-layer; and a cathode.