Cavity-Embedded PCB Component with EMI Shielding

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Solution Overview

Problem

Modern printed circuit boards face challenges in accommodating miniaturized electronic components due to size limitations, often requiring costly redesigns or extended fabrication timelines, and existing solutions do not effectively address electromagnetic interference (EMI) shielding in compact configurations.

Innovation Solution

A printed circuit board with a cavity formed on one side to house an electronic component, where the cavity is lined with electrically-conductive metal for EMI shielding and optionally surrounded by conductive foam, allowing for reduced overall height and flexible component placement without direct electrical connection to the board.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If electronic components are mounted on the surface of a printed circuit board, then electrical connection is achieved, but the overall height of the assembly increases

Engineering Contradiction:
Improveoverall heightVSAvoidelectrical connection
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The electronic component is nested within a cavity formed in the printed circuit board substrate. The cavity has recessed walls that receive and hold the component, allowing it to be positioned below the surface level of the board. This nesting arrangement reduces the overall height of the assembly while maintaining secure mechanical support and electrical connection through conductive elements extending into the cavity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Volume of stationary object

If a cavity is formed in the printed circuit board to house a component, then space is saved, but electromagnetic interference shielding is compromised

Engineering Contradiction:
Improvespace utilizationVSAvoidelectromagnetic interference
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The cavity walls, which create the space-saving configuration, are lined with conductive material that serves dual purposes: providing structural support for the nested component and acting as an electromagnetic interference shield. The conductive lining converts the potential harm of the cavity opening (EMI exposure) into a beneficial shielding effect, protecting the component while maintaining the compact design.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The cavity structure combines the base printed circuit board substrate with an additional conductive material applied to the cavity walls. This composite construction integrates the mechanical support function of the substrate with the electromagnetic shielding function of the conductive coating, achieving both space utilization and EMI protection simultaneously.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If standard manufacturing tools are used to form a cavity, then fabrication complexity increases, but cost and time are reduced

Engineering Contradiction:
Improvefabrication complexityVSAvoidfabrication time
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The cavity is formed as an integral part of the printed circuit board during the standard manufacturing process, before final assembly. By incorporating cavity formation into the board fabrication itself using conventional tools, the need for subsequent complex post-processing operations is eliminated, reducing both fabrication complexity and overall production time.

Inventive Principle:
Principle #10Preliminary action

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 reduces the overall height of the component assembly, enables the use of components in space-constrained applications, and provides effective EMI shielding, while being economically viable and easily deployable using standard manufacturing tools.

Implementation Method 1

the cavity is lined with electrically-conductive metal for EMI shielding

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

optionally surrounded by conductive foam, allowing for reduced overall height

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP2779805B1Method and apparatus pertaining to a cavity-bearing printed circuit board
Publication Date: 2021.03.10 BLACKBERRY LTD
  • EP2779805B1 patent drawingFigure 1~2
  • EP2779805B1 patent drawingFigure 3~6
  • EP2779805B1 patent drawingFigure 7~9

AI summary

A printed circuit board has a cavity formed in at least one side thereof and an electronic component disposed at least partially within that cavity. Electromagnetic interference (EMI)-shielding material is disposed between the electronic component and at least one of the side walls and bottom of this cavity. So configured, the overall height of the combined structure is reduced as compared to a surface-mounted component.