Anti-Interference Coil and Shielding Layout for PCB Magnetic Fields

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Solution Overview

Problem

Terminal devices, such as mobile phones, are susceptible to electromagnetic interference from changing magnetic fields generated by components like radio frequency circuits, which can disrupt the normal operation of electronic devices on the circuit board.

Innovation Solution

An anti-interference module is introduced, comprising a circuit board with an interfering source, a device disposing space, and an anti-interference component that includes a second coil and a magnetic field shielding element. The second coil generates a compensation magnetic field or consumes energy from the interference magnetic field, while the shielding element reduces the magnetic induction intensity in the device disposing space, thereby minimizing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a radio frequency circuit operates on the circuit board, then the terminal device provides communication functionality, but a changing magnetic field is generated that interferes with surrounding electronic devices

Engineering Contradiction:
Improvecommunication functionalityVSAvoidmagnetic field interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A magnetic shielding layer is introduced as an intermediary between the radio frequency circuit and surrounding electronic devices. This shielding layer, made of magnetic shielding material, intercepts and redirects magnetic field lines, preventing them from coupling with adjacent components like audio coils, thus eliminating the harmful interference while preserving communication functionality

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The circuit board is segmented into functional zones by introducing a magnetic shielding layer that physically divides the space between the radio frequency circuit and surrounding electronic devices. This segmentation isolates the magnetic field generated by the radio frequency circuit to a specific region, preventing it from affecting other components

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the circuit board layout becomes more complex to accommodate multiple functions, then more electronic devices can be integrated, but electromagnetic interference susceptibility increases

Engineering Contradiction:
Improvedevice integrationVSAvoidelectromagnetic interference susceptibility
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

Magnetic shielding layers are strategically placed between different functional modules on the circuit board, acting as intermediaries that allow multiple devices to coexist in close proximity while preventing electromagnetic interference between them, thus enabling higher device integration without increasing interference susceptibility

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Different regions of the circuit board are assigned different magnetic shielding properties. Magnetic shielding layers are selectively applied in areas where interference is most likely to occur, such as between radio frequency circuits and audio components, while leaving other areas open for signal transmission, thus enabling complex layouts with controlled interference

Inventive Principle:
Principle #3Local quality

3Reliability

If magnetic shielding material is added to reduce interference, then electromagnetic compatibility improves, but manufacturing complexity increases

Engineering Contradiction:
Improveelectromagnetic compatibilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The magnetic shielding layer is implemented as a thin film or flexible shielding structure that can be laminated onto the circuit board using existing manufacturing processes. This thin-film approach maintains electromagnetic compatibility while minimizing the impact on manufacturing complexity, as it can be integrated into standard PCB lamination processes

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The magnetic shielding layer is constructed using composite materials that combine magnetic shielding properties with structural integrity. These composite materials can be processed using standard manufacturing techniques, balancing the need for effective electromagnetic shielding with ease of manufacture

Inventive Principle:
Principle #40Composite materials

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 anti-interference module effectively reduces the magnetic induction intensity in the device disposing space, ensuring normal operation of electronic devices by compensating for or shielding the interfering magnetic field, thus enhancing the operational reliability of terminal devices.

Implementation Method 1

The second coil is disposed on a side of the device disposing space... configured to generate a compensation magnetic field that overlaps the interference magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

at least a part of the magnetic field shielding element is located between the second coil and the device disposing space... the shielding element reduces the magnetic induction intensity in the device disposing space

Methodology Applied
Scientific EffectMagnetic shielding: Magnetic Field

Data Source

PatentEP4164356B1Anti-interference module and terminal device
Publication Date: 2024.11.27 HONOR DEVICE CO LTD
  • EP4164356B1 patent drawingFigure 1
  • EP4164356B1 patent drawingFigure 2
  • EP4164356B1 patent drawingFigure 3

AI summary

This application discloses an anti-interference module and a terminal device, and relates to the field of terminal device technologies, so as to resolve a problem that an electronic device in the terminal device in a related technology is susceptible to interference from a magnetic field of an interfering source on a circuit board. The anti-interference module includes a circuit board, an interfering source, a device disposing space, and an anti-interference component. The interfering source is disposed on the circuit board, where the interfering source may generate a changing interference magnetic field; the device disposing space is provided on a side of the circuit board and is used to dispose an electronic device with a first coil; and the anti-interference component is configured to generate a compensation magnetic field that overlaps the interference magnetic field, or to consume electric energy generated by coupling between the interference magnetic field and the anti-interference component to reduce magnetic induction intensity of the device disposing space. This application may be applied to the terminal device such as a mobile phone.