Folded MEMS Speaker Package for Higher Audio Output in Less Space
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Solution Overview
Problem
MEMS speakers face challenges in achieving substantial audio volume and maintaining sound quality due to their small size, as increasing the number of speakers to enhance volume increases overall package size, violating spatial constraints and diminishing efficiency.
Innovation Solution
A package design featuring two or more MEMS speakers on a substrate, connected by flexible sections and a spacer, forming an acoustic chamber with shared front chamber and isolated back chambers, ensuring efficient air movement and acoustic isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple MEMS speakers are used to increase audio volume, then air volume moved is improved, but package size increases
Solution Approach 1:
Multiple MEMS speaker packages are merged into a single integrated package structure, sharing common components including the rigid substrate, flexible substrate, acoustic chamber, and sealing structures. This consolidation allows multiple speakers to operate simultaneously while maintaining a compact overall package size that would be smaller than individual separate packages.
Solution Approach 2:
The MEMS speaker diaphragms are nested within the acoustic chamber formed by the rigid and flexible substrates. The flexible substrate folds back to create an acoustic chamber that encloses the speaker components, with vent apertures positioned to allow air movement while maintaining compact nesting of all speaker elements within a small volume.
2Volume of stationary object
If package size is reduced for compact devices, then spatial constraints are improved, but audio volume output deteriorates
Solution Approach 1:
The package utilizes three-dimensional space efficiently by folding the flexible substrate back onto itself to create an acoustic chamber. The vent apertures are positioned on opposite sides of the package, allowing air to move through the acoustic chamber in a path that maximizes the use of available vertical and lateral space within the compact package footprint.
Solution Approach 2:
The flexible substrate serves multiple functions: it seals the acoustic chamber, provides structural support, and creates the back surface of the acoustic chamber when folded. This thin flexible film allows the package to maintain a compact form factor while still enclosing sufficient air volume within the acoustic chamber for adequate sound output.
3Quantity of substance
If MEMS speaker size is increased to improve audio output, then air volume moved is improved, but form factor constraints are violated
Solution Approach 1:
The speaker package is segmented into distinct functional components: the MEMS speaker die, the rigid substrate with vent apertures, the flexible substrate forming the acoustic chamber, and the sealing structures. This segmentation allows each component to be optimized for its specific function while maintaining a compact overall size, as the air volume is distributed across multiple small speakers rather than requiring one large speaker.
Solution Approach 2:
The package combines rigid and flexible substrates to create a composite structure that provides both structural support and acoustic enclosure. The rigid substrate provides stiffness and defines vent aperture positions, while the flexible substrate provides sealing and forms the acoustic chamber, together enabling compact speaker construction with sufficient air volume for adequate audio output.
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 design effectively multiplies air volume without multiplying package size, enhancing audio performance and manufacturability, suitable for compact form-factor devices like mobile phones and earbuds.
Implementation Method 1
a first flexible section attached between and providing electrical continuity between the first rigid section and the second rigid section
Implementation Method 2
by moving air according to a frequency the speaker is to generate a noise audible to an ear or an electronic receiver
Data Source
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AI summary
A package for multiple MEMS-based speakers in a compact form factor is provided. One package includes: a first rigid section defining a first vent aperture; a second rigid section defining a second vent aperture; a first speaker die attached to the first rigid section and covering the first vent aperture; a second speaker die attached to the second rigid section and covering the second vent aperture; a first flexible section attached between and providing electrical continuity between the first rigid section and the second rigid section; and a spacer defining an acoustic port, where the first rigid section is attached to a first side of the spacer, and the second rigid section is attached to a second side of the spacer, where the first speaker die faces the second speaker die.