MEMS Sound Transducer With Curved Base Contour for Load Distribution

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Solution Overview

Problem

Existing MEMS sound transducers suffer from local load peaks that lead to destruction of cantilever elements, particularly at high power levels, resulting in increased production rejects and costs, and limited operation at low power levels.

Innovation Solution

The MEMS sound transducer features a cantilever element with a base end having a curved first contour and a cavity wall with a corresponding concave second contour, ensuring even load distribution and allowing for higher force absorption, along with a flexible deflection section and multiple layers, including a piezoelectric transducer layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If tight manufacturing tolerances are maintained to prevent local load peaks, then reliability is improved, but manufacturing precision requirements increase and production costs increase

Engineering Contradiction:

Improveprevention of cantilever element destructionVSAvoidmanufacturing tolerances

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The base end of the deflection section is designed with a curved first contour instead of a straight or angular shape. This curvature distributes loads more evenly across the base end area, preventing local load peaks that would otherwise require tight manufacturing tolerances to avoid. The curved geometry inherently reduces stress concentration at corners or edges.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Reliability

If tight manufacturing tolerances are maintained to prevent local load peaks, then reliability is improved, but production costs increase

Engineering Contradiction:

Improveprevention of cantilever element destructionVSAvoidproduction costs

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The curved first contour at the base end is more tolerant to manufacturing variations. Even with moderate manufacturing tolerances, the curved geometry ensures adequate load distribution, unlike sharp corners or straight edges where small dimensional variations could create significant stress concentrations. This reduces production rejects and lowers manufacturing costs.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Power

If the cantilever element is designed to operate at high power levels, then performance is improved, but local load peaks cause destruction of the cantilever element

Engineering Contradiction:

Improveoperating power levelVSAvoidcantilever element durability

Core Design Contradiction:

PowerVSStrength

Solution Approach 1:

The curved first contour at the base end of the deflection section distributes the high mechanical loads generated at high power levels more evenly across the structure. This prevents localized stress concentrations that would otherwise lead to material failure, enabling the cantilever element to withstand high power operation without destruction.

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Ease of manufacture

If the base end has a straight contour, then manufacturing is simpler, but local load peaks occur causing element destruction

Engineering Contradiction:

Improvecontour manufacturing simplicityVSAvoidprevention of element destruction

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

While a curved contour requires slightly more complex manufacturing than a straight line, the curvature is achieved through standard MEMS fabrication processes. The benefit of preventing element destruction through even load distribution far outweighs the minor increase in manufacturing complexity, ultimately improving yield and reducing waste.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 design prevents damage from local load peaks, enables stable operation at higher forces, reduces manufacturing tolerances, and lowers production costs by allowing for greater alignment errors, thereby enhancing performance and efficiency.

Implementation Method 1

The MEMS sound transducer has at least one cantilever element having a base section firmly connected to the support and a flexible deflection section projecting beyond the cavity wall... a piezoelectric transducer layer

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

Each beam comprises alternating piezoelectric layers and electrode layers, wherein the piezoelectric layers are designed such that they convert an exerted pressure into a voltage

Methodology Applied

Scientific EffectPiezoelectric effect: Converse Piezoelectric Effect

Data Source

PatentEP4447489B1MEMS sound transducer with a curved contour of a cantilever element

Publication Date: 2025.09.24 USOUND

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AI summary

The invention relates to a MEMS transducer (1) for generating and/or detecting sound waves, comprising a carrier (2) having a cavity wall (4) that at least partially delimits a cavity (3) of the MEMS transducer (1), and at least one cantilever element (5, 6, 7, 8) having a base section (9) fixedly connected to the carrier (2) and a flexible deflection section (10) projecting beyond the cavity wall (4), wherein the deflection section (10) has a base end (11) facing the cavity wall (4) and a free end (12) that is deflectable relative to the carrier (2) in the direction of a stroke axis (H) of the MEMS transducer. According to the invention, the base end (11) of the deflection section (10) has a curved first contour (27) in a top view of the transducer.