Electromagnetic Wave Shielding Member for Wideband 60–90 GHz Absorption
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Solution Overview
Problem
Existing electromagnetic wave absorbing materials for millimeter waves exhibit narrowband absorption characteristics and high manufacturing costs due to complex multilayer structures, limiting their practical use and effectiveness in high-frequency bands.
Innovation Solution
An electromagnetic wave shielding member comprising an electromagnetic wave absorbing layer with a dielectric constant of 4 to 30 and a dielectric loss tangent of 0.1 to 2.0, and a reflection layer with a volume resistivity of 1×10 -4< to 1×10 -1< Ω·cm, containing 1 to 20 wt% electromagnetic wave absorbing filler, achieving wide absorption and shielding characteristics in the 60 to 90 GHz band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single dielectric layer filled with carbon-based filler is used, then the structure is simple and manufacturing cost is low, but the absorption band is narrow (about 10 GHz for 10 dB attenuation)
Solution Approach 1:
The patent applies parameter changes by carefully controlling the dielectric constant (4 to 30) and dielectric loss tangent (0.1 to 2.0) of the single dielectric layer, along with its thickness (0.1 to 1.0 mm), to achieve wideband absorption without requiring multiple layers. This resolves the contradiction by optimizing material parameters rather than increasing structural complexity.
2Adaptability or versatility
If two or more dielectric layers are used to obtain wide band absorption, then the absorption band width increases, but the device complexity and manufacturing cost greatly increase due to many parameter controls
Solution Approach 1:
The patent extracts the essential function of wideband absorption into a single dielectric layer by removing the need for multiple layers. It identifies and controls only the critical parameters (dielectric constant, dielectric loss tangent, and thickness) of one layer, thereby achieving wideband absorption while dramatically reducing structural complexity and manufacturing difficulty.
3Reliability
If conventional electromagnetic wave absorbing sheets are used, then narrowband absorption is achieved, but the shielding performance is limited and practical application is restricted
Solution Approach 1:
The patent uses composite materials by combining a carbon-based filler (electromagnetic wave absorbing filler) with a resin matrix to create a dielectric layer with specifically controlled electromagnetic properties. This composite structure enables both wideband absorption and reliable shielding performance, resolving the contradiction between shielding effectiveness and frequency band coverage.
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 shielding member provides excellent absorption and shielding characteristics in a wide frequency band, allowing for thinner installation and flexibility in accommodating devices with varying frequencies, thus enhancing communication equipment and semiconductor device performance.
Implementation Method 1
the electromagnetic wave absorbing layer has a dielectric constant of 4 to 30 and a dielectric loss tangent of 0.1 to 2.0
Implementation Method 2
the reflection layer has a volume resistivity of 1×10 -4 to 1×10 -1 Ω·cm
Data Source
Figure 1
AI summary
An electromagnetic wave shielding member having an electromagnetic wave absorbing layer containing an electromagnetic wave absorbing filler and a binder resin, and a reflection layer disposed on an opposite surface side of an electromagnetic wave incident surface of the electromagnetic wave absorbing layer, wherein the electromagnetic wave absorbing layer has a dielectric constant of 4 to 30 and a dielectric loss tangent of 0.1 to 2.0, the content of the electromagnetic wave absorbing filler is 1 to 20 wt% based on the total weight of the electromagnetic wave absorbing layer, and the reflection layer has a volume resistivity of 1 × 10-4 to 1×10-1 Ω·cm.