MEMS Loudspeaker with PCB-Integrated ASIC and Cavity

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Solution Overview

Problem

Existing MEMS loudspeakers have a relatively large construction volume, making them less compact and efficient for generating significant sound pressure levels.

Innovation Solution

A loudspeaker arrangement that integrates a MEMS loudspeaker and an ASIC within a printed circuit board, where the circuit board forms part of the loudspeaker's cavity and sound-conducting channel, allowing for a compact design and efficient sound amplification and direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If MEMS loudspeaker is used to generate sound waves, then sound pressure level can be achieved, but the construction volume becomes relatively large

Engineering Contradiction:
Improvesound pressure levelVSAvoidconstruction volume
Core Design Contradiction:
Stress or pressureVSVolume of stationary object

Solution Approach 1:

The patent merges the MEMS loudspeaker, ASIC, and printed circuit board into a single integrated assembly. The circuit board serves dual functions as both a structural support and part of the acoustic cavity, eliminating the need for separate housing components. This consolidation reduces the overall construction volume while maintaining the required sound pressure generation capability through the integrated driver-diaphragm-cavity system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ASIC is embedded within a cavity in the printed circuit board, and the MEMS loudspeaker is mounted on the board such that its cavity integrates with the board's structural cavities. This nesting arrangement allows multiple functional elements to occupy overlapping or adjacent spatial volumes, effectively reducing the external dimensions of the overall loudspeaker assembly while preserving internal functional volumes needed for sound pressure generation.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If ASIC is exposed to external influences, then accessibility is maintained, but reliability decreases due to external influences

Engineering Contradiction:
ImproveaccessibilityVSAvoidprotection from external influences
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The ASIC is integrated directly into the printed circuit board structure, merging the electronic component housing with the circuit board itself. This integration provides inherent protection as the ASIC becomes part of the rigid, enclosed board structure, shielding it from environmental factors such as dust, moisture, and physical damage, while maintaining electrical connectivity and functional accessibility through the board's circuit traces and connection points.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of stationary object

If MEMS loudspeaker and ASIC are integrated into printed circuit board, then compact design is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improvestructural volumeVSAvoidintegration complexity
Core Design Contradiction:
Volume of stationary objectVSDevice complexity

Solution Approach 1:

The printed circuit board is designed to serve multiple functions simultaneously: it provides structural support for the MEMS loudspeaker and ASIC, acts as an electrical connection medium through its circuit traces, forms part of the acoustic cavity volume, and provides mechanical mounting surfaces. This multi-functionality reduces the number of separate components needed, simplifying the overall manufacturing process despite the integrated design, as a single multi-functional board replaces what would otherwise require multiple separate parts.

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 solution enables a very compact and cost-effective loudspeaker design with enhanced sound pressure amplification and directional control, achieved through the integration of the MEMS loudspeaker and ASIC within the printed circuit board, reducing structural volume and simplifying manufacturing.

Implementation Method 1

the MEMS loudspeaker is driven electromechanically, electrostatically, and/or piezoelectrically

Methodology Applied
Scientific EffectElectromechanical actuation:

Implementation Method 2

the MEMS loudspeaker is driven electromechanically, electrostatically, and/or piezoelectrically

Methodology Applied
Scientific EffectElectrostatic actuation: Electrostatics

Implementation Method 3

the MEMS loudspeaker is driven electromechanically, electrostatically, and/or piezoelectrically

Methodology Applied
Scientific EffectPiezoelectric actuation: Piezoelectric Effect

Implementation Method 4

The circuit board has a second cavity, which includes an opening. The MEMS speaker extends over this opening, completely sealing it. Furthermore, the MEMS speaker extends over the opening in such a way that the second cavity forms at least part of the MEMS speaker's cavity. A 'cavity' is a hollow space that amplifies the sound pressure of the MEMS speaker.

Methodology Applied
Scientific EffectAcoustic amplification: Resonance

Data Source

PatentEP3135044B1Loud speaker arrangement with circuit-board-integrated asic
Publication Date: 2019.06.05 USOUND
  • EP3135044B1 patent drawingFigure 1~2
  • EP3135044B1 patent drawingFigure 3~4
  • EP3135044B1 patent drawingFigure 5~6

AI summary

The present invention relates to a loud speaker arrangement (1) with a circuit board (2), an MEMS loudspeaker (3) for producing sound waves in the audible wavelength spectrum, said MEMS loud speaker having a membrane (9) deflectable along a z-axis, a sound-conducting channel (21) adjacent to the MEMS loudspeaker (3) with an acoustic outlet opening (22) and an ASIC (4) electrically connected to the MEMS loudspeaker (3). Further, the circuit board (2) comprises a first circuit board cavity (11) in which the ASIC (4) is arranged so as to be fully integrated in the circuit board (2). Further, the circuit board (2) comprises a second circuit board cavity (13) with an opening (14), said opening being closed by means of the MEMS loudspeaker (3) so that the second circuit board cavity (13) forms at least one part of a cavity (15) of the MEMS loudspeaker (3). According to the invention, the sound-conducting channel (21) extends obliquely to the z-axis of the MEMS loudspeaker. Moreover, the acoustic outlet opening (22) is arranged on the lateral surface of the loudspeaker arrangement (1).