PCB Acoustic Channel for Microphone Placement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge in designing microphones for portable electronic devices lies in creating an effective acoustic channel within space-restricted environments, as existing solutions often require complex mechanical parts like microphone tubes that occupy significant space and interfere with other device components.

Innovation Solution

A printed circuit board (PCB) with an integrated acoustic channel is used, where the board body defines a channel extending between a microphone aperture and inlet openings, allowing for an acoustic waveguide that provides an acoustic path without the need for a traditional microphone tube, thus optimizing space and reducing interference with other components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional microphone tube is used to create an acoustic channel, then the acoustic path is established, but the space occupied by the microphone tube interferes with other device components and increases device complexity

Engineering Contradiction:
Improveacoustic channel functionalityVSAvoidmicrophone tube structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the acoustic channel function with the printed circuit board structure. The PCB itself forms the acoustic channel through strategically placed openings and cavities, eliminating the need for a separate microphone tube. This integration reduces device complexity while maintaining acoustic functionality, as the PCB serves dual purposes: electrical signal transmission and acoustic wave guidance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The printed circuit board is designed to perform multiple functions simultaneously: it provides electrical connections for the microphone, creates the acoustic channel for sound wave transmission, and structures the housing layout. This multi-functionality eliminates the need for dedicated microphone tubes and reduces the overall number of components in the device.

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

2Reliability

If a traditional microphone tube is used to create an acoustic channel, then the acoustic path is established, but the space occupied by the microphone tube increases the overall device size

Engineering Contradiction:
Improveacoustic channel functionalityVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The acoustic channel is merged into the PCB structure, utilizing the board's existing volume and spatial arrangement. The openings and cavities within the PCB create the acoustic path without requiring additional external space, thereby reducing the overall device volume while maintaining effective acoustic transmission from the microphone to the outlet.

Inventive Principle:
Principle #5Merging (Combining)

3Length of moving object

If the microphone is placed close to the microphone inlet, then the acoustic path is short, but the placement is restricted by other device components and design constraints

Engineering Contradiction:
Improveacoustic channel lengthVSAvoidmicrophone placement flexibility
Core Design Contradiction:
Length of moving objectVSAdaptability or versatility

Solution Approach 1:

The acoustic channel extends through the PCB in three-dimensional space, utilizing vertical and lateral dimensions within the board structure. This allows the microphone to be positioned at locations optimized for other design constraints (such as antenna placement or component layout) while the acoustic path routes sound waves through the PCB's internal openings and cavities to reach the outlet, providing placement flexibility without sacrificing acoustic efficiency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution enables the placement of microphones away from the microphone inlet, freeing up space on the PCB and improving design flexibility while maintaining effective acoustic performance, reducing the complexity and size requirements for acoustic channel creation.

Implementation Method 1

the printed circuit board defining an acoustic channel within the board body which extends between a microphone aperture in the board body and a plurality of inlet openings in the board body

Methodology Applied
Scientific EffectAcoustic wave propagation: Sound

Data Source

PatentEP2664221B1Printed circuit board with an acoustic channel for a microphone
Publication Date: 2019.04.10 BLACKBERRY LTD
  • EP2664221B1 patent drawingFigure 1
  • EP2664221B1 patent drawingFigure 2
  • EP2664221B1 patent drawingFigure 3~4

AI summary

A printed circuit board with an acoustic channel for a microphone and a portable electronic device having such a printed circuit board are provided. In accordance with one embodiment, there is provided a microphone assembly, comprising : a printed circuit board (PCB) comprising a board body having at least one signal trace, the printed circuit board defining an acoustic channel within the board body which extends between a microphone aperture in the board body and a plurality of inlet openings in the board body.