Noise Suppression Sheet Composition for Low-Frequency Magnetic Shielding
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Solution Overview
Problem
Existing magnetic shields, such as those described in JP 2017-199871A, suffer from reduced permeability in the thickness direction due to the interposition of non-magnetic metal films, leading to inadequate shielding in low-frequency regions.
Innovation Solution
A noise suppression sheet with a first magnetic layer composed of alternating first and second regions, where the second region has a higher concentration of a third metal component than the first region, enhancing permeability and reducing resistance, thereby improving shielding effectiveness, especially in low-frequency regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a non-magnetic metal film is interposed between magnetic layers, then the structure is simplified and manufacturing is easier, but permeability in the thickness direction is reduced, causing lack of shielding effect in low-frequency region
Solution Approach 1:
The patent applies local quality by creating regions with different third metal component concentrations within the magnetic layer. High-concentration regions provide low resistance for electrical connectivity, while low-concentration regions maintain high permeability for magnetic field shielding, allowing each region to optimize its local function without requiring separate non-magnetic metal films
Solution Approach 2:
The patent uses composite materials by combining Ni-Fe alloy with varying concentrations of a third metal component (Cu, Ag, or Au) within a single magnetic layer. This composite structure achieves both low resistance and high permeability properties within one layer, eliminating the need for multi-layer constructions with non-magnetic separators
2Reliability
If multiple magnetic layers are stacked to improve shielding, then shielding effect is enhanced, but permeability in the thickness direction is reduced due to non-magnetic films, causing lack of shielding in low-frequency region
Solution Approach 1:
The patent applies parameter changes by varying the concentration of the third metal component within the magnetic layer to create a gradient structure. This continuous parameter variation allows optimization of both resistance and permeability without the discrete interruptions caused by non-magnetic films, maintaining stable permeability across the layer thickness
3Ease of manufacture
If uniform metal composition is used in magnetic layer, then manufacturing is simpler, but resistance is high and permeability is not optimized, reducing shielding effectiveness
Solution Approach 1:
The patent implements local quality by dividing the magnetic layer into regions with different third metal component concentrations. This allows different areas to have optimized properties: high-concentration regions for electrical conductivity and low-concentration regions for magnetic permeability, achieving superior shielding effectiveness without significantly complicating manufacturing
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 noise suppression sheet achieves a high shielding effect across a wide frequency range by alternately stacking regions with varying metal component concentrations, ensuring low resistivity and permeability, thus effectively dispersing magnetic fields and reducing magnetic saturation.
Implementation Method 1
effectively dispersing magnetic fields and reducing magnetic saturation
Implementation Method 2
a first magnetic layer... effectively dispersing magnetic fields
Implementation Method 3
shielding electromagnetic wave noise... achieving a high shielding effect
Data Source
AI summary
A noise suppression sheet that includes a first magnetic layer. The first magnetic layer includes a plurality of first regions stacked in a thickness direction of the noise suppression sheet and a second region positioned between the first regions. The first magnetic layer includes a first metal component of Ni, a second metal component of Fe, and a third metal component other than Ni and Fe. The concentration of the third metal component in the second region is higher than the concentration of the third metal component in the first regions.