Conductive Resin Composition for High-Frequency EMI Shielding
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Solution Overview
Problem
Conventional resin molded bodies fail to provide sufficient electromagnetic wave shielding properties in the high-frequency region of 1 GHz or more, limiting their effectiveness in modern electronic devices.
Innovation Solution
A resin molded body comprising a thermoplastic resin, plate-like graphite, and at least one of carbon black and metal fibers, with specific ratios and properties to enhance electromagnetic wave shielding and thermal conductivity, thereby achieving excellent shielding and heat dissipation properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conductive materials (metal plates, conductive tape, plating) are used to improve electromagnetic wave shielding properties, then shielding effectiveness is enhanced, but product weight increases and costs increase
Solution Approach 1:
The invention changes the parameters of the resin composition by incorporating specific conductive fillers (graphite particles with aspect ratio 10-200 and carbon fibers with length 0.3-3mm) in optimized proportions (0.1-5 wt% graphite, 0.1-5 wt% carbon fibers) to achieve electromagnetic wave shielding without using heavy metal materials. This parameter optimization allows the resin to gain shielding properties while maintaining lightweight characteristics.
Solution Approach 2:
The invention creates a composite material system combining thermoplastic resin with multiple conductive fillers (graphite particles and carbon fibers). This composite structure synergistically enhances electromagnetic wave shielding properties through the combined effects of the resin matrix and conductive filler network, achieving shielding effectiveness without relying on traditional heavy metal materials.
2Weight of moving object
If conventional resin molded bodies with graphite particles are used to reduce weight, then product weight decreases, but electromagnetic wave shielding properties in high-frequency region (1 GHz or more) are insufficient
Solution Approach 1:
The invention optimizes critical parameters including graphite particle aspect ratio (10-200), carbon fiber length (0.3-3mm), and their content proportions (0.1-5 wt% each) to enhance high-frequency shielding. These parameter adjustments create an optimized conductive network structure that effectively shields electromagnetic waves in the 1 GHz and above frequency range while maintaining the lightweight advantage of resin materials.
Solution Approach 2:
The invention employs a composite material system combining thermoplastic resin with both graphite particles and carbon fibers. This dual-filler composite creates a more effective conductive network compared to single-filler systems, enabling superior high-frequency electromagnetic wave shielding while preserving the lightweight characteristics of polymer-based materials.
3Reliability
If carbon fibers and graphite powder are added to resin to improve shielding properties, then electromagnetic wave shielding is enhanced, but manufacturing complexity and material dispersion uniformity become challenging
Solution Approach 1:
The invention specifies precise parameter ranges for filler dimensions (graphite aspect ratio 10-200, carbon fiber length 0.3-3mm) and content proportions (0.1-5 wt% each) to optimize both shielding performance and dispersion characteristics. These controlled parameters ensure uniform distribution of conductive fillers within the resin matrix, simplifying manufacturing while achieving effective shielding.
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 resin molded body exhibits improved electromagnetic wave shielding effects of 20 dB or more at frequencies up to 75 GHz and increased thermal conductivity, addressing the limitations of conventional materials by providing reliable performance in high-frequency regions and heat dissipation.
Implementation Method 1
a resin molded body having excellent electromagnetic wave shielding properties in the high-frequency region of 1 GHz or more
Implementation Method 2
The resin molded body exhibits improved electromagnetic wave shielding effects of 20 dB or more at frequencies up to 75 GHz
Implementation Method 3
increased thermal conductivity, addressing the limitations of conventional materials by providing reliable performance in high-frequency regions and heat dissipation
Data Source
AI summary
Provided is a resin molded body having excellent electromagnetic wave shielding properties in a high-frequency region of 1 GHz or more. The resin molded body containing a thermoplastic resin, plate-like graphite, at least one of carbon black and metal fibers, the content of the plate-like graphite being 50 parts by weight or more and 200 parts by weight or less, relative to 100 parts by weight of the thermoplastic resin, the carbon black having a DBP oil absorption of 100 ml/100 g or more and 600 ml/100 g or less, the metal fibers having a diameter of 5 μm or more and 20 μm or less, the metal fibers having a fiber length of 2 mm or more and 12 mm or less, and the content of at least one of the carbon black and the metal fibers being 1 part by weight or more and 50 parts by weight or less, relative to 100 parts by weight of the thermoplastic resin.