Integrated Particle Filter Grid for MEMS Microphone Protection

Solution Overview

Problem

Silicon microphones in MEMS devices are vulnerable to particle damage due to direct exposure, leading to costly and labor-intensive particle filter installation on each device.

Innovation Solution

A monolithically integrated particle filter structure with a grid is incorporated into the MEMS chip during manufacturing, utilizing the precision of semiconductor manufacturing to protect the microphone or loudspeaker module from particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a particle filter is inserted into the sound channel in front of the printed circuit board during manufacturing, then the membrane is protected from particle damage, but the manufacturing process becomes very costly and labor intensive

Engineering Contradiction:

Improvemembrane protection from particle damageVSAvoidmanufacturing cost and labor intensity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The particle filter structure is merged with the MEMS chip structure itself, forming an integrated unit where the grid is formed within the cavity of the MEMS device. This eliminates the need for separate filter installation steps and reduces manufacturing complexity while maintaining particle protection functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The grid structure serves multiple functions: it acts as both the cavity structure and the particle filter simultaneously. This multi-functionality reduces the number of separate components needed and simplifies the manufacturing process while providing both structural support and particle protection.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a particle filter is inserted into the sound channel in front of the printed circuit board, then the membrane is protected from particle damage, but the manufacturing process requires individual filter installation for each microphone

Engineering Contradiction:

Improvemembrane protection from particle damageVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The particle filter structure is merged with the MEMS chip structure itself, forming an integrated unit where the grid is formed within the cavity of the MEMS device. This eliminates the need for separate filter installation steps and reduces manufacturing complexity while maintaining particle protection functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The grid structure is formed as part of the MEMS chip manufacturing process itself, using standard semiconductor fabrication techniques. This preliminary integration of the filter function into the chip manufacturing eliminates the need for subsequent separate filter installation steps, significantly improving productivity.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the grid elements have height greater than width, then the particle filtering effectiveness is improved, but the manufacturing precision requirements increase

Engineering Contradiction:

Improveparticle filtering effectivenessVSAvoidgrid element dimensional precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The grid structure utilizes the cavity walls of the MEMS device itself as the filter elements. The cavity structure naturally provides the height greater than width configuration needed for effective particle filtering, while the standard MEMS fabrication processes automatically ensure the required dimensional precision without additional manufacturing steps.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The particle filter structure is merged with the MEMS chip structure itself, forming an integrated unit where the grid is formed within the cavity of the MEMS device. This eliminates the need for separate filter installation steps and reduces manufacturing complexity while maintaining particle protection functionality.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9565488B2Micro-electro-mechanical system devices

Publication Date: 2017.02.07 INFINEON TECHNOLOGIES AG

AI summary

In various embodiments, a micro-electro-mechanical system device is provided. The micro-electro-mechanical system device may include a carrier, a particle filter structure coupled to the carrier, the particle filter structure comprising a grid, wherein the grid comprises a plurality of grid elements, each grid element comprising at least one through hole, and a micro-electro-mechanical system structure disposed on a side of the particle filter structure opposite the carrier. A height of the plurality of grid elements is greater than a width of the corresponding grid elements.