Thin EMI Shielding with Sputtered Ferrite Absorbers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern electronic devices face challenges in mitigating electromagnetic cross-talk due to inadequate shielding at lower frequencies, as conventional conductive materials like copper, silver, and nickel require thick films to effectively block electromagnetic interference (EMI) in the kHz range, which is impractical and costly in device fabrication.
Innovation Solution
Incorporating magnetic ceramic ferrites or iron-containing alloys as EMI absorber materials with a skin depth of less than 2 μm into the molding compound or as a thin conductive layer, which can be deposited using methods like sputtering or spraying, to provide effective EMI shielding without the need for thick films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conductive materials like copper, silver, and nickel are used for EMI shielding, then shielding effectiveness is achieved, but thick films are required which increase device size and manufacturing cost
Solution Approach 1:
The patent changes the material parameter from conventional conductive materials (copper, silver, nickel) to magnetic absorber materials (ferrites, iron-containing alloys) that have different electromagnetic properties. These magnetic materials achieve equivalent or superior EMI shielding at much thinner film thicknesses (less than 2 μm skin depth) compared to conventional materials, thereby resolving the contradiction between shielding effectiveness and film thickness
Solution Approach 2:
The patent employs composite material structures by combining magnetic absorber materials with molding compounds or creating multi-layer configurations. The magnetic particles or powders are embedded in a non-conductive molding compound matrix, creating a composite material that provides both EMI shielding and structural integration, achieving effective shielding without requiring thick pure metal films
2Object-affected harmful factors
If thick films of conventional conductive materials are used for low frequency EMI shielding, then EMI protection is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent merges the EMI shielding function with the existing molding compound structure by embedding magnetic particles directly into the molding material. This integration eliminates the need for separate thick metal film deposition processes, reducing manufacturing steps and complexity while maintaining effective low-frequency EMI protection
Solution Approach 2:
The patent uses cost-effective magnetic particle materials (ferrites and iron-containing alloys) that can be incorporated into molding compounds at low cost, replacing expensive thick films of precious metals like silver and nickel. This approach provides economical EMI shielding without complex 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
This approach significantly reduces EMI by up to 26.5 dBm more than conventional copper films, offering a cost-effective and practical solution for shielding electronic devices across various frequency ranges, including kHz, while maintaining device compactness and functionality.
Implementation Method 1
Incorporating magnetic ceramic ferrites or iron-containing alloys as EMI absorber materials with a skin depth of less than 2 μm
Implementation Method 2
magnetic ceramic ferrites or iron-containing alloys as EMI absorber materials
Implementation Method 3
deposited by sputtering or spraying
Implementation Method 4
having a skin depth of less than 2 μm for electromagnetic signals having frequencies in a kilohertz range
Data Source
AI summary
An electronic device includes an electromagnetic interference shield having a layer of conductive material covering at least a portion of the electronic device and having a skin depth of less than 2 μm for electromagnetic signals having frequencies in a kilohertz range.