Conductive Fabric Shielding for Compact PCB Interference Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional metal shielding cans used in electronic devices are bulky, making it difficult to achieve compact electromagnetic shielding, which is essential for devices with limited space, while omitting shielding can lead to unreliable performance due to electromagnetic interference.
Innovation Solution
The use of a metal frame covered with conductive fabric, featuring an insulating layer to prevent shorts and an elastomeric polymer cap for electrical isolation, along with the integration of shield cans with subscriber identity module shields to minimize volume and enhance shielding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional metal shielding cans are used, then electromagnetic shielding effectiveness is improved, but device volume increases
Solution Approach 1:
The patent replaces rigid metal shielding cans with flexible conductive fabric that can be stretched over a frame to create a thin, conformal shielding enclosure. This flexible film approach maintains electromagnetic shielding effectiveness while dramatically reducing the volume and thickness of the shielding structure compared to conventional rigid metal cans.
Solution Approach 2:
The patent employs composite material construction combining a rigid frame structure with flexible conductive fabric covering. This composite approach integrates the structural support function of the frame with the electromagnetic shielding function of the conductive fabric, achieving effective shielding in a compact configuration that neither material could accomplish alone.
2Volume of moving object
If shielding volume is reduced for compactness, then device space is saved, but shielding effectiveness may be compromised
Solution Approach 1:
The conductive fabric stretched over the frame creates a thin film shielding enclosure that achieves effective electromagnetic shielding without the bulky volume of conventional metal cans. The flexibility of the fabric allows it to conform closely to the components being shielded, maintaining shielding effectiveness in a compact form factor.
Solution Approach 2:
The patent changes the physical parameters of the shielding structure by transitioning from thick rigid metal walls to thin flexible fabric with a frame support system. This parameter change in wall thickness and structural rigidity allows volume reduction while maintaining the essential electromagnetic shielding function through the conductive properties of the fabric.
3Volume of moving object
If conductive fabric is used to cover the frame, then shielding volume is reduced, but electrical isolation requirements become more critical
Solution Approach 1:
The patent introduces insulating caps as intermediary elements positioned between the conductive fabric shielding and the electronic components. These caps serve as mediators that prevent direct electrical contact and potential shorts while allowing the conductive fabric to maintain its shielding function. This intermediary solution manages the electrical isolation requirement without compromising the compact fabric-based shielding design.
Solution Approach 2:
The patent extracts the electrical isolation function from the conductive fabric itself by separating it into distinct components: the conductive fabric provides shielding while separate insulating caps provide electrical isolation. This extraction of functions allows each component to specialize in its primary role, simplifying the overall design despite the added component.
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 configuration provides effective electromagnetic shielding in a compact form, allowing for efficient accommodation of components of varying heights without increasing the overall size of the shielding structure, thereby maintaining device performance while saving space.
Implementation Method 1
A shield may have a metal frame covered with a conductive fabric. The conductive fabric may cover an opening in the top of the frame. Electromagnetic shields may be mounted to the printed circuit over the components to suppress interference.
Data Source
AI summary
An electronic device may have a printed circuit to which electrical components are mounted. Electromagnetic shields may be mounted to the printed circuit over the components to suppress interference. A shield may have a metal frame covered with a conductive fabric. The conductive fabric may cover an opening in the top of the frame. An insulating layer may be formed on the lower surface of the conductive fabric to prevent shorts between components on the printed circuit and the conductive fabric. An insulating cap such as an elastomeric polymer cap may also be formed over each component to provide electrical isolation between the components and the conductive fabric. Shields may be formed by coupling shield cans to subscriber identity module shields or other metal structures in a device. Intervening wall structures may be removed to help provide additional shielding volume.