MnZn Ferrite Composition for Low Core Loss and High-Temp Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MnZn-based ferrites used in high-temperature electronic components face challenges with high magnetic core loss and time-dependent changes in magnetic properties, which are not adequately addressed by existing compositions and manufacturing methods.
Innovation Solution
A MnZn-based ferrite composition containing specific amounts of Fe, Mn, Zn, Si, Ca, Co, Bi, and optional Ta, Nb, Ti, and Sn, along with a controlled calcination process to optimize magnetic core loss and stability, is developed to maintain low magnetic core loss and suppress time-dependent changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the minimum temperature of magnetic core loss is set to 100°C or lower for consumer electronics, then the ferrite performs well in low-temperature environments, but it cannot withstand high-temperature environments for on-vehicle use
Solution Approach 1:
The patent changes the chemical composition parameters of the ferrite by adding specific amounts of Bi2O3 (0.01-0.05 mass%), TiO2 (0.01-0.1 mass%), and SnO2 (0.01-0.1 mass%) to shift the minimum temperature of magnetic core loss to a higher range (120-180°C), enabling the material to withstand high-temperature on-vehicle environments while maintaining low loss characteristics
2Loss of energy
If Bi2O3 is added to obtain low magnetic core loss in a wider temperature range, then the temperature dependence of magnetic core loss is improved, but the time-dependent change of magnetic property increases under high-temperature environment
Solution Approach 1:
The patent creates a composite material system combining Bi2O3 with TiO2 and SnO2 in specific proportions. This composite approach allows Bi2O3 to reduce magnetic core loss while TiO2 and SnO2 work synergistically to suppress the time-dependent degradation of magnetic properties under high-temperature conditions, resolving the contradiction between low loss and stability
3Stability of the object's composition
If the ambient oxygen concentration is strictly controlled during calcination to suppress time-dependent change, then magnetic property stability is improved, but the magnetic core loss increases
Solution Approach 1:
The patent changes the calcination atmosphere parameters by controlling oxygen concentration at 5-21% (volume basis) during the high-temperature maintaining step. This optimized oxygen level, combined with the specific Bi-Ti-Sn composite composition, allows the ferrite to achieve both low magnetic core loss and suppressed time-dependent magnetic property changes, resolving the trade-off between stability and loss
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 solution achieves a low magnetic core loss and stable magnetic properties over a wide temperature range, reducing the rate of change in magnetic core loss and maintaining low losses even after exposure to high temperatures.
Implementation Method 1
the magnetic core loss has a minimum value at that temperature, usually, a temperature at which the magnetic core loss is the minimum is adjusted with the crystal magnetic anisotropy constant K1
Implementation Method 2
which prevents the ferrite from losing magnetism due to thermal run-away
Implementation Method 3
As a method of suppressing the time-dependent change of the magnetic property of the MnZn-based ferrite, Patent Document 2 and Patent Document 3 disclose to control an ambient oxygen concentration in calcination
Data Source
Figure 1~2
Figure 3
AI summary
Provided are: a MnZn-based ferrite which allows to have a low magnetic core loss and to suppress a time-dependent change of magnetic property under a high-temperature environment by a control of ambient oxygen concentration and an increase of the magnetic core loss, and a method for manufacturing the same. The MnZn-based ferrite is characterized in that Fe ranges from 53.25 mol% or more to 54.00 mol% or less on the basis of Fe2O3, Zn ranges from 2.50 mol% or more to 8.50 mol% or less on the basis of ZnO and Mn is the remainder on the basis of MnO, Si ranges from more than 0.001 mass% to less than 0.02 mass% on the basis of SiO2, Ca ranges from more than 0.04 mass% to less than 0.4 mass% on the basis of CaCO3, Co is less than 0.5 mass% on the basis of Co3O4, Bi is less than 0.05 mass% on the basis of Bi2O3, Ta is less than 0.05 mass% on the basis of Ta2O5, Nb is less than 0.05 mass% on the basis of Nb2O5, Ti is less than 0.3 mass% on the basis of TiO2, and Sn is less than 0.3 mass% on the basis of SnO2, and note that the converted total amount of Ta2O5 and Nb2O5 is less than 0.05 mass% and the converted total amount of TiO2 and SnO2 is less than 0.3 mass%.