Soft Magnetic Powder Multilayer Coating for Heat-Stable Insulation
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Solution Overview
Problem
Existing soft magnetic powders experience a drastic reduction in insulation resistance and low heat resistance when exposed to high temperature environments due to the formation of insulating films on the surface of soft magnetic metal particles, as described in Patent Literatures 1 and 2.
Innovation Solution
A multilayer inorganic insulating film is formed on the surface of soft magnetic metal particles, comprising a first coating part with phosphorus and oxygen, a second coating part with silicon and oxygen, and optionally an intermediate layer with phosphorus and silicon, with controlled thickness ratios to maintain high insulation resistance and permeability under high temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer insulating film (phosphate or silica) is formed on the surface of soft magnetic metal particles, then insulation resistance is improved, but heat resistance deteriorates under high temperature environments
Solution Approach 1:
The insulating film is divided into two distinct layers: a phosphate compound layer (first coating part) in contact with the metal particle surface and a silica layer (second coating part) formed on the outer side. This segmentation allows each layer to perform its specialized function - the phosphate layer provides strong adhesion to the metal surface while the silica layer provides high-temperature stability and insulation, thereby resolving the contradiction between insulation resistance and heat resistance
Solution Approach 2:
The patent employs a composite insulating film structure combining two different materials (phosphate compound and silica) with complementary properties. The phosphate compound provides good adhesion to metal surfaces, while silica offers superior heat resistance and electrical insulation. This composite approach allows the film to simultaneously achieve high insulation resistance and maintain stability under high temperature conditions
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 multilayer insulating film effectively prevents the reduction of insulation resistance and maintains high permeability in soft magnetic powders even after exposure to high temperature environments for extended periods, enhancing the heat resistance of the core material.
Implementation Method 1
a first coating part in contact with a surface of the soft magnetic metal particle, and a second coating part formed at an outer side of the first coating part
Data Source
AI summary
A soft magnetic powder capable of maintaining high insulation resistance even after exposure to a high-temperature environment, a dust core, and an electronic component is provided with the dust core. A soft magnetic powder including soft magnetic metal particles, the surfaces of which are covered by an inorganic insulating coating, the inorganic insulating coating having a first coating part in contact with the surfaces of the soft magnetic metal particles, and a second coating part formed on the outside of the first coating part, the first coating part including phosphorus and oxygen, and the second coating part including silicon and oxygen.