EMI Shield With Integrated Decoupling for Compact PCB Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional EMI shields require a continuously exposed ground plane around the perimeter of a PCB for effective shielding, leading to increased PCB size and production costs, and may not adequately shield all electronic components due to cutouts or slots that reduce shielding effectiveness.
Innovation Solution
An EMI shield with integrated decoupling, filtering, or matching components electrically connected between the shield and electrically-conductive traces or power planes on a PCB, allowing the shield to be connected via any exposed conductive material without a continuous ground plane, thereby reducing PCB size and production costs while providing comprehensive shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a continuously exposed ground plane is used around the PCB perimeter for EMI shielding, then shielding effectiveness is improved, but PCB size and production costs increase
Solution Approach 1:
The ground plane is segmented into discrete ground contact points rather than requiring a continuous perimeter ground plane. The EMI shield is divided into multiple sections with individual ground connections, allowing shielding without a continuous ground ring around the PCB perimeter.
Solution Approach 2:
Decoupling, filtering, and matching components are introduced as intermediary elements between the EMI shield and the PCB traces/power planes. These components provide the necessary electrical connection and signal conditioning without requiring direct ground plane contact, enabling shielding with reduced PCB area.
2Ease of operation
If cutouts or slots are added to the EMI shield for trace access, then trace connectivity is improved, but shielding effectiveness decreases
Solution Approach 1:
Decoupling, filtering, and matching components serve as intermediary elements that maintain electrical connectivity for traces crossing the EMI shield perimeter without requiring physical cutouts or slots. These components provide signal paths through the shield structure while preserving the continuous shielding enclosure.
Solution Approach 2:
The connection method transitions from a two-dimensional planar connection (traces on PCB surface) to a three-dimensional connection through the shield structure (using vertical decoupling components). This allows trace connectivity without compromising the shielding enclosure integrity.
3Ease of manufacture
If the EMI shield is connected directly to the PCB ground plane, then electrical connection is improved, but the need for continuous ground plane increases PCB complexity
Solution Approach 1:
The ground connection is segmented into multiple discrete points rather than requiring a continuous ground plane. The EMI shield connects to the PCB through multiple separated ground contact points, simplifying the PCB ground structure while maintaining effective electrical connection for shielding purposes.
Solution Approach 2:
The design uses standard, readily available decoupling, filtering, and matching components that are inexpensive and easily manufactured. These common electronic components provide the necessary electrical connection functionality without requiring complex custom PCB ground plane structures.
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 solution effectively reduces electromagnetic interference on electrically-conductive traces and power planes, allows for use with various PCB layouts, and eliminates the need for a continuous ground plane, resulting in smaller, less expensive PCBs with enhanced shielding capabilities.
Implementation Method 1
a plurality of decoupling, filtering, or matching components electrically connected between the EMI shield and the plurality of electrically-conductive traces and/or power planes such that the plurality of decoupling, filtering, or matching components are configured to filter or match signals or shunt noise
Implementation Method 2
The EMI shield is sized and shaped to form a perimeter around at least one of the plurality of electronic components on the PCB... to encapsulate and electromagnetically isolate the plurality of electronic components
Data Source
AI summary
An electronic assembly includes a printed circuit board (PCB) and an electromagnetic interference (EMI) shield. The PCB includes a plurality of electronic components and a plurality of electrically-conductive traces. The EMI shield is sized and shaped to form a perimeter around at least one of the plurality of electronic components on the PCB. The plurality of electrically-conductive traces cross the perimeter formed by the EMI shield. The EMI shield includes a plurality of decoupling, filtering, or matching components electrically connected between the EMI shield and the plurality of electrically-conductive traces such that the plurality of decoupling, filtering, or matching components are configured to shunt signal noise from the plurality of electrically-conductive traces. The EMI shield is electrically connected to the PCB via the plurality of decoupling, filtering, or matching components to encapsulate and electromagnetically isolate the plurality of electronic components.