TiO Ceramic Composite EMI Shielding via Dielectric Loss
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Solution Overview
Problem
Existing electromagnetic interference (EMI) shielding materials, such as metal sheets, are inadequate at high frequencies like gigahertz, and ceramics are generally poor at absorbing EMI due to low dielectric loss.
Innovation Solution
Composite materials incorporating titanium monoxide (TiO) ceramic particles dispersed in a polymeric matrix, such as fluorocarbon-based polymers, exhibit high dielectric and magnetic loss tangents, effectively mitigating EMI across a broad frequency range by absorbing electromagnetic radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal sheets or foils are used to reflect EMI, then EMI blocking is achieved, but eddy currents reduce effectiveness at very high frequencies (GHz range)
Solution Approach 1:
The patent uses composite materials consisting of ceramic particles (such as titanium monoxide, barium ferrite, or other ferrites) dispersed in a polymer matrix. This composite structure combines the dielectric properties of ceramics with the mechanical flexibility of polymers, achieving effective EMI shielding at GHz frequencies without the eddy current problems that plague metal shields.
Solution Approach 2:
The patent changes the material parameters by selecting ceramic particles with specific dielectric loss tangents (tan δ ≥ 0.03 at 1 GHz, and preferably tan δ ≥ 0.1 or tan δ ≥ 0.3) and controlling their concentration in the polymer matrix (10-60 vol. %). This parameter optimization ensures high EMI attenuation through dielectric loss mechanisms rather than eddy currents.
2Reliability
If ceramics are used as shielding materials, then electrical insulation is provided, but dielectric loss is generally low making them poor at absorbing EMI
Solution Approach 1:
The patent fundamentally changes the material parameter by selecting specific ceramic materials (titanium monoxide, barium ferrite, other ferrites) that possess high dielectric loss tangents (tan δ ≥ 0.03 at 1 GHz, and preferably tan δ ≥ 0.1 or tan δ ≥ 0.3). This is contrary to conventional ceramics which have low dielectric loss. The high dielectric loss enables effective EMI absorption through conversion of electromagnetic energy to heat.
Solution Approach 2:
The patent copies the beneficial high-loss properties of specialized ceramic materials into a composite system by dispersing these ceramic particles throughout a polymer matrix, allowing the composite to exhibit high dielectric loss while maintaining the processability and flexibility of polymer materials.
3Reliability
If high concentration of ceramic particles is used to increase dielectric loss, then EMI absorption improves, but manufacturing complexity and material homogeneity become challenging
Solution Approach 1:
The patent optimizes the concentration parameter of ceramic particles within the range of 10-60 vol. % to achieve high EMI attenuation while avoiding excessive concentration that would cause agglomeration and processing difficulties. This parameter optimization balances performance with manufacturability.
Solution Approach 2:
The patent ensures uniform distribution of ceramic particles throughout the polymer matrix, creating local homogeneity in the composite material. This uniform dispersion prevents agglomeration and ensures consistent EMI shielding performance throughout the material, simplifying manufacturing by eliminating the need for complex mixing and distribution processes.
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 composite materials provide significant EMI attenuation at frequencies from 1 GHz to 60 GHz, surpassing the limitations of traditional shielding materials by offering substantial dielectric and magnetic loss, enhancing EMI shielding performance.
Implementation Method 1
certain ceramic materials, in particular titanium monoxide (TiO), either alone or in combination with one or more additional components, can provide a surprisingly high dielectric loss, magnetic loss, or both, even at gigahertz (GHz) frequencies
Implementation Method 2
The blocking, also known as shielding, can be achieved by reflection of the EMI, absorption of the EMI, or a combination of both
Data Source
AI summary
Compositions (120), which may be in the form of flexible films, molded bodies, or printable inks, can incorporate ceramic particles (122) comprising titanium monoxide (TiO) for purposes of electromagnetic interference (EMI) shielding at megahertz through gigahertz frequencies. One or more additional ceramic particles can also be included. The compositions comprise a composite material (120) which includes the ceramic particles (122) dispersed within a matrix material (121), such as a polymer. Methods associated with such compositions are also described.