High Frequency Magnetic Material via Precursor Heat Treatment
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Solution Overview
Problem
Conventional methods for manufacturing high frequency magnetic materials fail to achieve satisfactory long-term thermal stability and yield, resulting in high costs and inadequate performance in high frequency regions due to limitations in controlling permeability real and imaginary parts (μ′ and μ″) for applications like inductors and electromagnetic wave absorbers.
Innovation Solution
A method involving the preparation of precursor particles with specific compounds of Fe and Co, followed by heating in a reducing atmosphere to form insulating oxide particles with embedded magnetic metal particles, enhancing texture density and thermal stability, and allowing for precise control of particle size and composition to optimize magnetic characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thin film technologies (sputtering method) are used to manufacture inductance elements, then excellent characteristics in high frequency region are achieved, but large apparatus is needed and precise control of film thickness is required, resulting in insufficient cost performance and yield
Solution Approach 1:
The patent replaces complex thin film deposition equipment (sputtering apparatus) with a simple heat treatment process. By heating precursor particles in a reducing atmosphere, magnetic metal particles are formed directly without requiring sophisticated vacuum deposition equipment, thus substituting a mechanical/physical deposition system with a simpler thermal processing system.
Solution Approach 2:
The patent changes the approach from controlling film thickness during deposition to controlling particle size through heat treatment parameters. By adjusting heating temperature, time, and atmosphere composition, the particle size and magnetic properties are controlled, replacing precise mechanical control with thermal parameter control.
2Speed
If thin film technologies are used to manufacture inductors, then high frequency characteristics are improved, but long-term thermal stability of magnetic characteristics is insufficient under high temperature and high humidity conditions
Solution Approach 1:
The patent creates a composite structure where magnetic metal particles are embedded in an insulating oxide matrix. This composite structure provides both high frequency performance (from the magnetic particles) and thermal stability (from the stable oxide matrix), resolving the contradiction between speed and compositional stability.
Solution Approach 2:
The patent applies different properties to different parts: the magnetic metal particles provide high frequency magnetic characteristics while the surrounding insulating oxide provides thermal and environmental stability. Each component performs its specialized function, achieving both high frequency performance and long-term stability.
3Ease of manufacture
If binder forming method is used to manufacture electromagnetic wave absorbers, then manufacturing is simplified, but both μ′ and μ″ are extremely low in high frequency region of 1 GHz or more
Solution Approach 1:
The patent changes the particle size parameter to the nanometer scale (1-100 nm), which fundamentally improves the high frequency absorption characteristics. This parameter change enables the material to function effectively at 1 GHz and above while maintaining the simplicity of the binder forming manufacturing method.
Solution Approach 2:
The patent uses composite materials combining magnetic metal particles with insulating oxides in a binder matrix. This composite structure achieves both ease of manufacture (through binder forming) and high frequency performance (through the nanoscale magnetic particles with appropriate magnetic properties).
4Productivity
If mechanical alloying method is used to synthesize magnetic materials, then manufacturing process is achieved, but long-term thermal stability is insufficient and yield is low
Solution Approach 1:
The patent performs preliminary preparation of precursor particles with controlled composition and size before the final heat treatment. This preliminary action ensures that the subsequent thermal process produces consistent, high-yield results with excellent thermal stability, avoiding the variability and low yield associated with mechanical alloying.
Solution Approach 2:
The patent utilizes phase transition during heat treatment, where the precursor compounds transform into magnetic metal particles through controlled reduction. This phase transition approach provides better control over the final material properties and thermal stability compared to mechanical alloying, while achieving high yield.
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 approach results in high frequency magnetic materials with excellent long-term thermal stability, high permeability, and low loss, enabling their use as both inductors and electromagnetic wave absorbers across a wide frequency range, while reducing manufacturing costs and improving yield.
Implementation Method 1
heating the precursor particle in a reducing atmosphere to form an insulating particle made of an oxide of the metal element by decomposing the second compound
Implementation Method 2
heating the precursor particle in a reducing atmosphere to form an insulating particle made of an oxide of the metal element by decomposing the second compound, and to precipitate a particle of the magnetic metal in the insulating particle
Data Source
AI summary
A precursor particle having a particle size of 10 nm or more and 1 μm or less, and comprising a first compound selected from an alkoxide, a hydroxide, a sulfate, a nitrate, a carbonate, or a carboxylate of magnetic metal containing at least one metal of Fe and Co, and a second compound selected from an alkoxide or a hydroxide, a sulfate, a nitrate, a carbonate, or a carboxylate of a metal element for forming an oxide, is prepared. Then the precursor particle is heated in a reducing atmosphere to form an insulating particle made of an oxide of the metal element by decomposing the second compound, and to precipitate a particle of the magnetic metal in the insulating particle at a particle size of 1 nm or more and 100 nm or less, thereby manufacturing a high frequency magnetic material.