Sequential Source Ampules for Thermal Degradation in OVJP

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Solution Overview

Problem

Conventional organic vapor jet printing (OVJP) systems face challenges in maintaining the quality of OLED materials due to thermal degradation during long deposition campaigns, as source materials can decompose when exposed to high temperatures for extended periods, leading to compromised film quality and reduced uptime in manufacturing processes.

Innovation Solution

The OVJP system employs multiple sequentially heated source ampules, allowing for the use of small amounts of material that are heated only when in use, minimizing thermal degradation and enabling longer deposition campaigns by switching between sources before degradation occurs, and using a control manifold to manage gas flow and pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If source materials are heated continuously for long deposition campaigns, then productivity is improved, but thermal degradation of OLED materials occurs leading to compromised film quality

Engineering Contradiction:
Improvedeposition campaign durationVSAvoidfilm quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system divides the source material supply into multiple separate ampules (first source ampule, second source ampule, etc.) connected to a single jet head. This segmentation allows the deposition process to switch between multiple material sources without heating a large quantity of material continuously, thereby maintaining film quality while extending overall deposition campaign duration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple source ampules are prepared in advance and loaded into the system before the deposition campaign begins. The control system pre-configures the sequence of ampule usage, allowing the process to switch between ampules before any single one degrades, thus preventing thermal degradation while maintaining continuous productivity.

Inventive Principle:
Principle #10Preliminary action

2Duration of action of stationary object

If source materials are heated for extended periods, then uptime is improved, but material decomposition occurs leading to reduced manufacturing efficiency

Engineering Contradiction:
ImproveuptimeVSAvoidmanufacturing efficiency
Core Design Contradiction:
Duration of action of stationary objectVSProductivity

Solution Approach 1:

The system uses multiple source ampules that can be sequentially activated and discarded after use. Each ampule contains a limited amount of material that is heated only when needed, then replaced with a fresh ampule. This approach maintains high uptime by eliminating lengthy heating cycles while preserving manufacturing efficiency through continuous availability of fresh material sources.

Inventive Principle:
Principle #34Discarding and recovering

3Device complexity

If a single source ampule is used, then device complexity is reduced, but deposition campaign duration is limited due to thermal degradation

Engineering Contradiction:
Improvesource configurationVSAvoiddeposition campaign duration
Core Design Contradiction:
Device complexityVSDuration of action of stationary object

Solution Approach 1:

The source configuration is segmented into multiple ampules connected to a single jet head through a control manifold with valves. This segmentation extends deposition campaign duration by allowing sequential use of multiple ampules while maintaining relatively simple device architecture through the use of a shared delivery system and centralized control mechanism.

Inventive Principle:
Principle #1Segmentation

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 approach prevents thermal degradation of OLED materials, allows for longer and more efficient deposition campaigns, and maintains high film quality by ensuring that each source ampule is used before degradation sets in, thereby enhancing the uptime and reducing production costs.

Implementation Method 1

heating a first source ampule of the plurality of source ampules to a deposition temperature... depositing the first source material

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

a source of carrier gas... in fluid communication with the first source ampule... transporting the first source material vapor

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3584351B1Sequential material sources for thermally challenged OLED materials
Publication Date: 2022.08.03 UNIVERSAL DISPLAY CORP
  • EP3584351B1 patent drawingFigure 1
  • EP3584351B1 patent drawingFigure 2~3
  • EP3584351B1 patent drawingFigure 4A~4B

AI summary

Systems and techniques for deposition such as via OVJP using multiple source ampules are provided. The source ampules are arranged and controlled such that carrier gas may be fed through each source ampule sequentially, thereby allowing for more continuous operation and use of materials that otherwise would be subject to thermal degradation.