Microphone U-Shaped Acoustic Path for Thinner Foldable Electronics

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Solution Overview

Problem

The challenge of further reducing the thickness of electronic devices, particularly foldable mobile phones, to enhance portability and tactile experience is hindered by the arrangement and structure of microphones, which occupy significant space and affect the overall thickness.

Innovation Solution

The implementation of a U-shaped sound pickup pipe formed by a first through hole, a second through hole, an air flow cavity, and a third through hole, where the microphone is positioned on one side of the circuit board, and a sealing hood on the opposite side, reduces the stack height by incorporating a sealing hood with specific dimensions and materials to minimize thickness while maintaining acoustic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a conventional microphone structure is used, then the microphone can perform sound pickup function, but the electronic device thickness increases

Engineering Contradiction:

Improveelectronic device thicknessVSAvoidmicrophone sound pickup performance

Core Design Contradiction:

Length of moving objectVSReliability

Solution Approach 1:

The sound pickup path is configured in a U-shape extending along the thickness direction of the circuit board, utilizing the third dimension (thickness direction) to route the sound path. This allows the microphone to achieve effective sound pickup performance while maintaining a compact footprint on the circuit board plane, thereby reducing overall device thickness without compromising acoustic performance.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The sealing hood is integrated with the circuit board structure, and the U-shaped sound pickup pipe is formed by combining through-holes in the circuit board with the air flow cavity in the sealing hood. This nested configuration allows multiple functional elements (sound path, sealing structure, air flow channel) to occupy overlapping spatial volumes, reducing the overall thickness requirement.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Device complexity

If the microphone is disposed on one side of the circuit board, then the structure is simplified, but stress concentration occurs on the circuit board

Engineering Contradiction:

Improvemicrophone arrangement structureVSAvoidcircuit board stress

Core Design Contradiction:

Device complexityVSStress or pressure

Solution Approach 1:

The microphone assembly is separated into two distinct locations: the microphone itself is mounted on one side of the circuit board while the sealing hood is positioned on the opposite side. This segmentation distributes the mechanical stress across different regions of the circuit board, preventing stress concentration at a single fastening point while maintaining structural simplicity.

Inventive Principle:

Principle #1Segmentation

3Length of moving object

If the sealing hood height is reduced, then the electronic device thickness is reduced, but acoustic wave impact on diaphragm increases

Engineering Contradiction:

Improveelectronic device thicknessVSAvoidacoustic wave impact on diaphragm

Core Design Contradiction:

Length of moving objectVSObject-affected harmful factors

Solution Approach 1:

The U-shaped sound pickup pipe configuration converts what would normally be harmful acoustic wave reflections and standing waves into beneficial effects. The U-shape creates a controlled acoustic path that manages pressure distribution, allowing the sealing hood to be made thinner while the acoustic wave dynamics within the U-shaped path prevent excessive impact on the diaphragm.

Inventive Principle:

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

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 allows for a reduction in the overall thickness of the electronic device, improving portability and tactile experience by optimizing the microphone's placement and reducing the impact of acoustic waves on the diaphragm, while maintaining or enhancing the microphone's peak frequency.

Implementation Method 1

the first through hole, the second through hole, the air flow cavity, and the third through hole form a U-shaped sound pickup pipe, and a sound signal outside the electronic device can be transmitted to the microphone through the U-shaped sound pickup pipe

Methodology Applied

Scientific EffectSound signal transmission: Sound

Implementation Method 2

to convert the sound signal into an electrical signal by using the microphone

Methodology Applied

Scientific EffectAcoustic to electrical energy conversion:

Data Source

PatentUS20250362720A1Electronic device

Publication Date: 2025.11.27 HONOR DEVICE CO LTD

AI summary

This application provides an electronic device, and relates to the field of electronic technologies. The electronic device includes a housing, a circuit board, a sealing hood, and a microphone. A first through hole is disposed on the housing. The circuit board includes a first surface and a second surface. A second through hole and a third through hole are disposed on the circuit board, and the second through hole is opposite to and communicated with the first opening. The sealing hood is located on a side that the second surface faces, the sealing hood and the circuit board enclose an air flow cavity, and the air flow cavity is communicated with the second through hole and the third through hole. The microphone is located on a side that the first surface faces, the microphone has a sound pickup hole that is opposite to and communicated with the third through hole.