MEMS Microphone Package Structure with Integrated Acoustic Cover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MEMS microphone modules lack protection for solder wires and are susceptible to external damp, leading to reliability issues and reduced performance due to the absence of a molding compound.
Innovation Solution
A package structure for MEMS microphones that includes a substrate with a connection pad, a MEMS microphone module electrically coupled to the substrate, an acoustic wave cover fixed on the chip without touching the sensing portion, and an encapsulant that protects the module and exposes the acoustic wave cover surface, replacing conventional top plates and support rings to reduce volume and enhance protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional top plate and support ring structures are used, then the MEMS microphone module lacks protection for solder wires and contacts, but the module volume remains larger
Solution Approach 1:
The patent merges the top plate, support ring, and acoustic wave cover into a single integrated acoustic wave cover structure. This unified structure simultaneously provides mechanical support, defines the acoustic cavity, and protects the MEMS chip and its connections, eliminating the need for separate protective components and reducing overall module volume.
Solution Approach 2:
The acoustic wave cover is designed to perform multiple functions: it serves as the enclosure for the acoustic cavity, provides mechanical support for the MEMS chip, protects the solder wires and contacts from external vibrations and damp, and defines the acoustic wave path. This multi-functional design eliminates the need for separate protective structures.
2Ease of manufacture
If no molding compound is used, then the manufacturing process is simpler, but the module is susceptible to external damp and vibrations
Solution Approach 1:
The patent employs the acoustic wave cover as a protective shell that encloses the MEMS microphone module. This cover acts as a barrier against external damp and vibrations while allowing acoustic waves to pass through, providing environmental protection without requiring additional molding compound layers.
3Volume of stationary object
If a larger acoustic wave cavity space is used, then the module volume increases, but the acoustic wave sensing range is limited
Solution Approach 1:
The patent optimizes the acoustic wave cavity by utilizing three-dimensional space efficiently within the compact acoustic wave cover structure. The cavity is designed with specific geometric dimensions and configurations that maximize acoustic wave propagation paths and sensing coverage within a minimal volume, expanding the effective sensing range without increasing overall module size.
Data Source
AI summary
A package structure of a micro-electromechanical system (MEMS) type microphone is disclosed. The MEMS microphone comprises a substrate, a MEMS chip, an acoustic wave cover, and an encapsulant. The substrate has connection pads. The MEMS chip is electrically coupled to the connection pads. The MEMS chip includes an acoustic wave sensing portion. The acoustic wave cover is fixed on the MEMS chip for covering without contacting the acoustic wave sensing portion and defining an acoustic wave cavity space. The acoustic wave cover has an opening for allowing an acoustic wave to enter or exit out of the acoustic cavity space. The encapsulant encapsulates the substrate, the MEMS chip, and the acoustic wave cover, wherein a surface of the acoustic wave cover is exposed. The exposed surface of the acoustic wave cover is along the same level as the surface of the encapsulant.