Induction Coil Positioning for Crucible-Free Gallium Oxide Crystal Growth

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing gallium oxide crystals, such as the Edge-Defined Filmfed Growth (EFG) and skull melt methods, face challenges in achieving stable crystallinity, growth rate, and cost-effectiveness, particularly due to the need for large, expensive crucibles and lack of specific production conditions for industrial-scale production.

Innovation Solution

A production device and method utilizing high-frequency induction heating with a high-frequency induction-heating coil, positioning it 5 mm or less from the liquid surface, and controlling the positional relationship to form a molten zone for crystal growth, allowing for efficient and cost-effective production of gallium oxide crystals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the crucible size is increased to grow larger crystals, then the crystal size increases, but the manufacturing cost increases due to expensive crucible materials

Engineering Contradiction:
Improvecrystal sizeVSAvoidmanufacturing cost
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent extracts the crucible from the crystal growth system entirely, using direct induction heating of the raw material in a crucible-free configuration. This eliminates the need for expensive crucible materials while enabling larger crystal growth volumes, directly resolving the contradiction between crystal size and manufacturing cost.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the thermal conduction-based heating system (which requires crucibles) with an electromagnetic induction heating system. The induction coil directly heats the raw material through electromagnetic fields, eliminating mechanical contact with crucibles and enabling cost-effective large-scale crystal production.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Volume of moving object

If the crucible size is increased to grow larger crystals, then the crystal size increases, but the device complexity increases

Engineering Contradiction:
Improvecrystal sizeVSAvoiddevice complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

By removing the crucible component entirely and using direct induction heating, the patent simplifies the device structure while enabling larger crystal growth. The induction coil can be positioned directly around the raw material charge, reducing structural complexity compared to large crucible systems.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If high-frequency induction heating is used with the coil positioned 5 mm or less from the liquid surface, then the growth rate and crystallinity improve, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvegrowth rateVSAvoidpositional precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs a movable positioning mechanism that allows dynamic adjustment of the induction coil's position relative to the molten material surface. This enables maintenance of the optimal 5 mm or less distance throughout the crystal growth process, accommodating surface level changes while preserving high growth rates and crystallinity without excessive precision constraints.

Inventive Principle:
Principle #15Dynamics

4Productivity

If high-frequency induction heating is used with the coil positioned 5 mm or less from the liquid surface, then the growth rate and crystallinity improve, but the device complexity increases

Engineering Contradiction:
Improvegrowth rateVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The movable positioning mechanism enables the system to maintain optimal heating conditions throughout crystal growth without requiring complex fixed positioning structures. This dynamic adjustment capability achieves high growth rates and crystallinity while keeping the overall device configuration relatively simple.

Inventive Principle:
Principle #15Dynamics

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

The method enables industrially advantageous crystal production with improved crystallinity and growth rate, reducing the need for costly crucibles and enabling larger molten zones for enhanced crystal growth.

Implementation Method 1

forming a molten zone of a raw material solution by using high-frequency induction heating with a high-frequency induction-heating coil

Methodology Applied
Scientific EffectHigh-frequency induction heating: Electromagnetic Induction

Implementation Method 2

producing a crystal by crystal growth in a longitudinal direction of the molten zone

Methodology Applied
Scientific EffectCrystal growth: Crystallisation

Data Source

PatentEP4671419A1Manufacturing device and manufacturing method
Publication Date: 2025.12.31 C&A CORP
  • EP4671419A1 patent drawingFigure 1
  • EP4671419A1 patent drawingFigure 2A
  • EP4671419A1 patent drawingFigure 2B

AI summary

[Problem] To provide a production device and a production method capable of producing a crystal in an industrially advantageous manner. [Solution] Producing a crystal by using a production device for a crystal, which includes at least a high-frequency induction-heating coil, the production device being configured to form a molten zone of a raw material solution by using high-frequency induction heating, and produce a crystal by crystal growth in a longitudinal direction of the molten zone. In the production device, an upper end of the high-frequency induction-heating coil is disposed at a depth position of 5 mm or less from a liquid surface of the raw material melt, and the production device includes a positional relationship holding unit that performs the crystal growth while maintaining a positional relationship between the depth position and the upper end.