Laminated Magnetic Cores With Partially Conducting Interlayers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laminated magnetic cores face challenges with substantial eddy current losses at high operating frequencies, limiting their use in applications like DC-DC converters and power systems-on-chip, due to the skin depth of the materials being smaller than the thickness of the magnetic material.
Innovation Solution
The development of laminated magnetic cores with interlamination layers of balanced electrical conductivity, allowing for the suppression of eddy current losses while enabling subsequent electrodeposition of metal layers, using partially conducting materials like conductive polymers, and a method of sequential multilayer electrodeposition to simplify fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional insulating laminations are used to suppress eddy current losses, then high frequency performance is improved, but fabrication complexity increases
Solution Approach 1:
The patent changes the electrical conductivity parameter of the interlamination layer from extremely low (insulating) to partially conducting (10^-4 to 10^5 S/cm). This parameter change allows the interlamination layer to serve dual functions: suppressing eddy currents while enabling electrodeposition fabrication, thereby resolving the contradiction between energy loss suppression and fabrication simplicity
Solution Approach 2:
The patent uses composite interlamination layers made of partially conducting materials such as conductive polymers, metal oxides, or doped semiconductors. These composite materials provide balanced electrical properties that simultaneously achieve eddy current suppression and facilitate metal electrodeposition, eliminating the need for complex insulation processes
2Ease of manufacture
If interlamination layer conductivity is increased to enable electrodeposition, then fabrication complexity is reduced, but eddy current losses increase
Solution Approach 1:
The patent optimizes the conductivity parameter of the interlamination layer to a specific range (10^-4 to 10^5 S/cm), which is sufficiently high to enable electrodeposition but sufficiently low to suppress eddy currents. This precise parameter control resolves the contradiction between fabrication ease and energy loss
Solution Approach 2:
The patent applies partial conduction rather than full conduction or full insulation. The interlamination layer provides just enough conductivity to enable metal deposition while maintaining sufficiently low conductivity to suppress harmful eddy currents, achieving the optimal balance between the two competing requirements
3Productivity
If lamination thickness is increased to reduce fabrication steps, then manufacturing precision is improved, but high frequency performance deteriorates
Solution Approach 1:
The patent maintains fine segmentation of the magnetic core into multiple thin lamination layers separated by interlamination layers. This segmentation structure suppresses eddy currents by breaking current paths while the systematic stacking of layers maintains manufacturing efficiency, resolving the contradiction between manufacturing productivity and high frequency reliability
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 enables uncompromised high-frequency performance with reduced fabrication complexity, suppressing eddy current losses to levels comparable to or lower than hysteresis losses, facilitating the commercialization of miniaturized inductive components and reducing the form factor of end-products.
Implementation Method 1
substantial eddy current losses at high operating frequencies (e.g., the typical 0.1-10 MHz frequencies used in DC-DC converters, battery chargers, and handheld devices) where the skin depths of the materials are smaller than the thickness of the magnetic material limit the use of these materials. By creating stacks of micron or sub-micron thick layers of thin magnetic alloy sheets ('laminations') with interlamination layers of extremely low conductivity, the eddy current losses within the volume of the laminated alloys can be suppressed even at MHz frequencies
Implementation Method 2
The interlamination layer comprises a partially conducting material having a conductivity greater than or equal to 10−4 S/cm and less than or equal to 105 S/cm. The method includes depositing a second magnetic layer over the interlamination layer. The method can include sequentially depositing additional interlamination layers and additional magnetic layers in an alternating fashion to produce the laminated magnetic core
Data Source
AI summary
The subject matter described herein relates to laminated magnetic cores, methods of fabricating laminated magnetic cores, and electric devices using laminated magnetic cores. In some examples, a method for fabricating a laminated magnetic core includes depositing a first magnetic layer and depositing an interlamination layer of over the first magnetic layer. The interlamination layer comprises a partially conducting material having a conductivity greater than or equal to 10−4 S/cm and less than or equal to 105 S/cm. The method includes depositing a second magnetic layer over the interlamination layer. The method can include sequentially depositing additional interlamination layers and additional magnetic layers in an alternating fashion to produce the laminated magnetic core.