Linear Evaporation Source with Independent Heating and Mixing Chambers

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Solution Overview

Problem

Current linear evaporation sources in OLED manufacturing face challenges in achieving uniform thickness of vapor deposition films due to limited space for vapor mixing and uniformization, especially in crucibles filled with material, leading to non-uniform film deposition and complex heating modes.

Innovation Solution

A linear evaporation source design featuring a heating chamber, a separate mixing chamber above it, and a channel connecting the two, with heaters on the peripheries of the chambers and nozzles, allowing for independent heating and mixing of vapor deposition material vapor, ensuring uniform film thickness through controlled flow and zigzag-shaped middle plates within the channel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional point evaporation source is used, then the system is simple and easy to manufacture, but the beam uniformity and coating quality are poor

Engineering Contradiction:
Improvebeam uniformityVSAvoidsource structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The evaporation source is divided into multiple independent linear evaporation zones (first, second, third linear evaporation zones) arranged in series. Each zone contains separate evaporation materials that can be independently controlled, allowing the beam to be segmented into multiple sub-beams that are then combined to form a uniform wide-area coating beam.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a conventional point-source evaporation (zero-dimensional) to a linear array evaporation source (one-dimensional), and further to a two-dimensional array configuration with multiple linear zones. This dimensional expansion enables uniform coverage across wide areas while maintaining controlled evaporation characteristics.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If a rotating evaporation source is used to achieve uniform coating, then the beam uniformity improves, but the coating speed decreases and production efficiency is low

Engineering Contradiction:
Improvecoating uniformityVSAvoidcoating speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

Instead of using a single rotating source, the invention segments the evaporation process into multiple stationary linear zones. Each zone contributes to a specific portion of the coating width, eliminating the need for rotation while achieving uniformity through the combined output of multiple controlled evaporation regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple linear evaporation beams from different zones are merged in space to form a single wide-area uniform coating beam. The evaporation materials in different zones evaporate simultaneously and their beams combine on the substrate, achieving both uniformity and high-speed coating without rotation.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If a wide-area linear evaporation source is used, then the coating efficiency increases, but the beam uniformity and material utilization rate decrease

Engineering Contradiction:
Improvecoating efficiencyVSAvoidbeam uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The wide-area source is segmented into multiple independent linear zones with separate evaporation materials. Each zone produces a controlled beam that can be independently optimized, and when combined, they form a uniform wide-area coating pattern with improved material utilization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different linear zones use different evaporation materials optimized for specific local requirements. Each zone's evaporation characteristics are tailored to its position in the array, ensuring optimal beam uniformity and material utilization across the entire wide-area coating process.

Inventive Principle:
Principle #3Local quality

4Area of stationary object

If multiple evaporation sources are arranged in parallel, then the coating width increases, but the system complexity and alignment difficulty increase

Engineering Contradiction:
Improvecoating widthVSAvoidsource arrangement
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

Instead of arranging multiple point sources in parallel (increasing system complexity), the invention uses a linear array configuration where evaporation sources are arranged in series along a line. This one-dimensional arrangement naturally provides the required coating width while simplifying alignment and reducing system complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Multiple linear evaporation zones are merged into a single integrated source structure with a common vacuum chamber and substrate positioning system. This unified design reduces the number of separate alignment requirements while achieving wide-area coating capability.

Inventive Principle:
Principle #5Merging (Combining)

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

This design enhances the uniformity of vapor deposition film thickness by allowing for independent heating and mixing in separate spaces, simplifying the heating mode and ensuring even vapor distribution, resulting in improved material utilization and film quality.

Implementation Method 1

a first linear evaporation zone, a second linear evaporation zone and a third linear evaporation zone are respectively and correspondingly arranged on the evaporation source

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

each linear evaporation zone comprises an evaporation material and a heating component corresponding to the evaporation material

Methodology Applied
Scientific EffectThermal emission: Thermionic Emission

Data Source

PatentEP3241923B1Linear evaporation source
Publication Date: 2019.09.04 KUNSHAN GO VISIONOX OPTO ELECTRONICS CO LTD
  • EP3241923B1 patent drawingFigure 1~2
  • EP3241923B1 patent drawingFigure 3~4
  • EP3241923B1 patent drawingFigure 5~6

AI summary

The present invention provides a linear evaporation source, comprising: a heating chamber for containing a vapor deposition material, a mixing chamber located above the heating chamber and used to mix the vapor deposition material vapor, and a channel used to communicate the heating chamber and the mixing chamber, wherein one end of the mixing chamber communicates with the heating chamber through the channel, and the other end is provided with a plurality of nozzles for spraying the vapor deposition material vapor; and heaters are provided at peripheries of the heating chamber, the mixing chamber, the channel and the nozzles. The linear evaporation source of the present invention can control the thickness of the vapor deposition film to have a better uniformity, because the heating of the vapor deposition material and the mixing of the material vapor are conducted in two independent spaces.