MEMS Microphone Conductive Case Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MEMS microphones on silicon dies are fragile and susceptible to physical damage, light, and electromagnetic interferences, requiring effective shielding without increasing production costs or causing peeling issues with thin conductive layers.
Innovation Solution
A MEMS microphone design featuring a conductive case that covers the cover and sidewall of the housing, forming a cavity with a conductive shield similar to a Faraday cage, protecting transducers from interference signals while maintaining structural integrity and reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If thin conductive layers are electroplated on non-conductive layers to form shields, then electromagnetic shielding is achieved, but production cost increases and the conductive layers peel off
Solution Approach 1:
The patent uses a composite structure combining conductive plastic material with non-conductive layers. The conductive plastic is integrated into the housing structure rather than being electroplated, creating a stable composite material that provides electromagnetic shielding without peeling issues and at lower production cost.
Solution Approach 2:
The patent replaces expensive electroplating processes with cost-effective conductive plastic material that can be molded directly into the housing. This eliminates the need for complex electroplating operations and reduces production costs while maintaining shielding effectiveness.
2Object-affected harmful factors
If thin conductive layers are used for shielding, then electromagnetic interference is blocked, but the layers are fragile and susceptible to physical damage
Solution Approach 1:
The patent uses a thin-walled housing structure made of conductive plastic that provides both flexibility and protection. The thin-walled design maintains electromagnetic shielding effectiveness while the integrated structure provides physical protection against damage to the fragile transducer.
Solution Approach 2:
The conductive plastic composite material combines the shielding properties of conductive layers with the mechanical strength and flexibility of plastic, creating a durable shielding structure that is both physically robust and electromagnetically protective.
3Object-affected harmful factors
If the silicon die is shielded to protect transducers, then interference protection is achieved, but device complexity increases
Solution Approach 1:
The patent merges the shielding function with the housing structure itself. The conductive plastic housing serves dual purposes: it provides mechanical protection for the transducer and simultaneously acts as the electromagnetic shield. This integration eliminates the need for separate shielding components, reducing overall device complexity.
Solution Approach 2:
The housing structure is designed to perform multiple functions simultaneously: mechanical support, electromagnetic shielding, and transducer protection. This multi-functional design reduces the number of separate components needed and simplifies the overall device architecture while maintaining comprehensive protection.
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 conductive case effectively shields the transducers from external interferences, enhancing durability and reducing production costs by preventing peeling issues with thin conductive layers, thus improving the protection and reliability of MEMS microphones.
Implementation Method 1
The conductive case defines a first part covering the cover, a second part extending from the first part for covering the sidewall and a third part perpendicularly extending from the second part for covering a periphery part of the base, the third part forming an opening
Implementation Method 2
a moveable diaphragm separated from the backplate for forming a capacitor. While external sound waves reach the diaphragm, the diaphragm will be activated to vibrate relative to the backplate, which changes the distance between the diaphragm and the backplate and changes the capacitance value
Data Source
AI summary
A MEMS microphone includes a cover, a housing engaging with the cover for forming a cavity, at least one transducer accommodated in the cavity, and a conductive case covering the cover and the sidewall of the housing. The housing includes a cover and a sidewall extending from the base. The conductive case defines a first part covering the cover, a second part extending from the first part for covering the sidewall and a third part perpendicularly extending from the second part for covering a periphery part of the base, the third part forming an opening.