Spinel Ferrite Monolithic Component Co-Sintering

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Solution Overview

Problem

Current methods for manufacturing monolithic electromagnetic components using spinel ferrites are costly due to the need for noble metals and result in issues like delamination, cracks, and material diffusion, limiting their scalability and integration with semiconductors for high-power, high-frequency applications.

Innovation Solution

A method involving the use of spinel ferrites with a composition of Ni x Zn 1 -x-y-ε+δ Cu y Co ε Fe 2 -δ O 4, produced through a process of nanometric oxide grinding and calcination at lower temperatures, combined with cosintering of copper coils within the ferrite structure, to create a compact and efficient monolithic component.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sintering at 950°C is used to manufacture monolithic electromagnetic components, then good magnetic performance is achieved, but production cost increases due to requirement of noble metals (silver or palladium) for coils

Engineering Contradiction:
Improvemagnetic performanceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive noble metals (silver, palladium) with inexpensive base metals (copper, aluminum) for coil manufacturing. The ferrite substrate enables this substitution by providing adequate magnetic performance at lower sintering temperatures (900-1000°C), making the overall component cost-effective despite using cheaper materials that may have shorter operational lifetimes in extreme conditions

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent modifies the sintering temperature parameter to 900-1000°C (slightly lower than conventional 950°C) and adjusts ferrite composition to achieve optimal magnetic properties. This parameter optimization allows the use of base metals instead of noble metals while maintaining acceptable magnetic performance, thereby reducing production costs

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional manufacturing processes are used, then monolithic components can be produced, but process complexity increases due to numerous distinct steps carried out in places distinct from one another

Engineering Contradiction:
Improvemanufacturing capabilityVSAvoidprocess complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent integrates multiple manufacturing steps into a unified monolithic fabrication process. The ferrite substrate is prepared with embedded coil structures and magnetic paths in a single integrated component rather than assembling separate parts. This merging of functions reduces the number of distinct manufacturing steps and locations required, simplifying the overall production process

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If conventional manufacturing processes are used, then components can be produced, but material quality deteriorates due to delaminations, cracks, and material diffusion at interfaces

Engineering Contradiction:
Improvemanufacturing capabilityVSAvoidmaterial integrity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs composite material structures where ferrite substrates are specifically engineered with embedded coil structures and magnetic paths. The composite design ensures compatible thermal expansion coefficients and strong interfacial bonding between different materials, preventing delamination and cracks while minimizing material diffusion at interfaces during the sintering process

Inventive Principle:
Principle #40Composite materials

4Volume of moving object

If miniaturization is pursued to reduce component size, then integration density improves, but heat dissipation becomes more difficult

Engineering Contradiction:
Improvecomponent sizeVSAvoidheat dissipation
Core Design Contradiction:
Volume of moving objectVSLoss of energy

Solution Approach 1:

The patent utilizes ferrite materials with optimized microstructures that provide both miniaturization and effective heat dissipation. The porous or granular structure of the ferrite substrate increases surface area for heat transfer while maintaining compact dimensions. This allows high-power density operation in miniaturized components by improving thermal management through the material's inherent structure

Inventive Principle:
Principle #31Porous materials

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 reduces production costs, minimizes material handling errors, and achieves high-density, low-loss components suitable for high-frequency operations without the drawbacks of noble metal requirements, enabling efficient heat dissipation and integration with semiconductors.

Implementation Method 1

certain spinel ferrites are used to manufacture this type of component by conventional sintering at temperatures of the order of 950°C

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 2

dissipate heat more efficiently

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3039694B1Method for producing a monolithic electromagnetic component
Publication Date: 2021.12.22 CENT NAT DE LA RECH SCI (C N R S)
  • EP3039694B1 patent drawingFigure 1~5
  • EP3039694B1 patent drawingFigure 2A~2D
  • EP3039694B1 patent drawingFigure 3A~3C

AI summary

A method for producing a monolithic electromagnetic component comprising a plurality of elements including a base made from spinel ferrite and at least one planar coil comprising a plurality of windings. The method comprises the following series of steps: - during an initial step (110), obtaining a precursor (32) of the ferrite, - during a preparation step (120), in a mould, embedding the elements of the monolithic electromagnetic component including said at least one coil and other than the ferrite in the precursor (32), and - during a co-sintering step (130), rigidly connecting said precursor (32) to the other elements of the monolithic electromagnetic component including said at least one coil by co-sintering under load by means of a pulsed electric current.