Integrated PCB Voice Coil for Heat-Safe Magnet Actuators

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Solution Overview

Problem

Existing magnet actuators in electronic devices face challenges in manufacturing and assembly due to the small size of components, particularly the coil, which also generates undesired heat that can demagnetize magnets.

Innovation Solution

A printed wiring board (PWB) with an integrated voice coil, where the voice coil is formed integrally with the PWB, allowing for a single, easily mountable component that reduces heat impact on adjacent components and eliminates the need for additional support means.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the coil is made as a separate component (glued or wound around magnet), then the magnet actuator can be assembled, but the components are difficult to manufacture and assemble due to small size, and additional support means are required

Engineering Contradiction:
Improveease of manufactureVSAvoiddevice complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines the voice coil and printed wiring board into a single integrated component. The voice coil is formed directly on the printed wiring board using standard PCB manufacturing techniques (copper traces), eliminating the need for separate coil components, adhesives, and additional support structures. This merging resolves the contradiction by simplifying the overall device structure while maintaining manufacturability through conventional PCB processes.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If the coil is placed close to the magnet for efficient actuation, then the actuator performance is improved, but the coil generates undesired heat that can demagnetize the magnet

Engineering Contradiction:
ImprovereliabilityVSAvoidtemperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The printed wiring board serves as a thermal intermediary between the voice coil and the magnet. The PCB material conducts heat away from the coil, distributing it across the board's structure rather than allowing direct heat transfer to the magnet. This mediator function maintains reliable actuation performance while protecting the magnet from demagnetization due to thermal effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes the thermal conductivity properties of the printed wiring board material to manage heat flow. The PCB acts as a heat sink and distribution pathway, conducting thermal energy away from the coil-magnet interface. This thermal management approach allows close proximity for efficient actuation while preventing excessive temperature buildup that would demagnetize the magnet.

Inventive Principle:
Principle #37Thermal expansion

3Adaptability or versatility

If separate components (coil, support means, integrated circuits) are used, then functional requirements are met, but assembly is complex and additional support means are needed

Engineering Contradiction:
ImproveadaptabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The printed wiring board performs multiple functions simultaneously: it provides structural support, serves as the voice coil conductor through copper traces, acts as a heat sink, and mounts integrated circuits for signal processing. This multi-functionality eliminates the need for separate support structures and reduces assembly complexity while maintaining all necessary functional adaptability for the magnet actuator application.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 integrated voice coil on the printed wiring board enhances manufacturing and assembly efficiency, reduces heat-related issues, and provides a reliable component for electronic devices, such as improved sound wave generation and reduced risk of magnet demagnetization.

Implementation Method 1

the coil generates undesired heat

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the material of the printed wired board distributes heat approximately 10 times better than air

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the current causing at least one of the magnets to move such that the distance between the magnets decreases or increases

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 4

the magnet actuator may comprise magnets which either attract or repulse each other

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentEP3808100B1Printed wiring board for an electronic device and electronic device comprising said printed wiring board
Publication Date: 2025.02.19 HUAWEI TECH CO LTD
  • EP3808100B1 patent drawingFigure 1~2
  • EP3808100B1 patent drawingFigure 3~4
  • EP3808100B1 patent drawingFigure 5

AI summary

A printed wiring board (1) for use in an electronic device (10), the printed wiring board comprising at least one integrated circuit (15) and a voice coil (3), the voice coil (3) being formed integrally with the printed wiring board (1). Integrating the voice coil into the printed wiring board improves dissipation of heat generated by the voice (3) coil and removes the need for additional supporting means.