High-Frequency LCR Heating Control for Gallium Oxide Crystal Growth

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Solution Overview

Problem

Existing methods for growing gallium oxide crystals face challenges such as high crucible material costs, instability in heating control due to impedance changes during melting, and fluctuations in high-frequency voltage and current, which hinder stable crystal growth and industrial mass production.

Innovation Solution

A high-frequency heating device with an LCR circuit, phase difference detector, frequency controller, and inverter is used to stabilize heating by controlling the driving frequency based on the phase difference between high-frequency voltage and current, enabling precise temperature distribution control during melting and crystal growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

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

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

Solution Approach 1:

The patent replaces the traditional mechanical contact heating method with electromagnetic induction heating. The induction heating coil generates a magnetic field that directly induces eddy currents in the crucible and material, heating them without mechanical contact. This allows the use of cheaper crucible materials that can withstand induction heating, eliminating the need for expensive iridium crucibles while maintaining the ability to grow large crystals.

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

Solution Approach 2:

The patent changes the heating parameter from conventional resistance heating to electromagnetic induction heating frequency control. By optimizing the induction heating frequency and power parameters, the system achieves efficient heating of large crucibles, enabling cost-effective production of large crystals without requiring expensive traditional heating equipment.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If high-frequency voltage and current are applied to melt gallium oxide, then melting is achieved, but heating control becomes unstable due to impedance changes during phase transition

Engineering Contradiction:
Improvemelting temperatureVSAvoidheating control stability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent implements a feedback control system that continuously monitors the impedance changes of the gallium oxide during heating and melting. The system detects the phase transition from solid to liquid and adjusts the induction heating power and frequency in real-time to maintain stable temperature control. This feedback mechanism compensates for the natural impedance variations that occur during melting, ensuring reliable and stable heating control throughout the phase transition process.

Inventive Principle:
Principle #23Feedback

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

Stabilizes the heating process, allowing for stable crystal growth and reducing costs by maintaining a controlled temperature distribution, thus facilitating industrial-scale production of gallium oxide crystals.

Implementation Method 1

heating is performed by controlling a driving frequency of induction heating

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

heating is performed by controlling a driving frequency of induction heating

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 3

the driving frequency of induction heating is controlled in at least one of a melting step and a crystal growing step

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4610410A1Crystal manufacturing method, high frequency heating device, and crystal manufacturing device
Publication Date: 2025.09.03 C&A CORP
  • EP4610410A1 patent drawingFigure 1
  • EP4610410A1 patent drawingFigure 2(A)~2(B)
  • EP4610410A1 patent drawingFigure 3

AI summary

The high-frequency heating device includes at least a phase difference detector, a frequency controller, an inverter, and an LCR circuit, and the phase difference detector detects the phase difference between the high-frequency voltage generated by the frequency controller and the high-frequency current flowing through the LCR circuit, and the inverter updates the driving frequency of the high-frequency voltage based on the phase difference to control the current in the LCR circuit.