Effective diaphragm area of spring-supported capacitive MEMS microphone designs

Norizan Mohamad; Pio Iovenitti; Thurai Vinay

doi:10.1117/12.810575

30 December 2008 Effective diaphragm area of spring-supported capacitive MEMS microphone designs

Norizan Mohamad, Pio Iovenitti, Thurai Vinay

Proceedings Volume 7268, Smart Structures, Devices, and Systems IV; 726805 (2008) https://doi.org/10.1117/12.810575
Event: SPIE Smart Materials, Nano- and Micro-Smart Systems, 2008, Melbourne, Australia

Abstract

Capacitive (condenser) MEMS microphones have been developed using various design and fabrication techniques to improve performance. Mechanical sensitivity of a condenser MEMS microphone can be increased by reducing the residual stress of the diaphragm using several design approaches including corrugated diaphragms, and in recent years, various spring type diaphragms. The electrical sensitivity of the condenser microphone is proportional to the deflection of the diaphragm, however, the parabolic deflection of the diaphragm, and thus its effective diaphragm area, has reduced the sensitivity of parallel plate type capacitor on a condenser MEMS microphone. This paper presents the numerical analysis on the effective diaphragm area of several condenser MEMS microphone designs of 1.1mm x 1.1mm square. The analysis shows that the effective area of a spring-supported diaphragm is about 20% higher, and its capacitance value thus electrical sensitivity, is about 170% higher than a fully clamped flat diaphragm of an equal size. In addition, a flat deflection and higher effective diaphragm area of a spring-supported diaphragm can be achieved by carefully designed spring mechanisms.

Citation Download Citation

Norizan Mohamad, Pio Iovenitti, and Thurai Vinay "Effective diaphragm area of spring-supported capacitive MEMS microphone designs", Proc. SPIE 7268, Smart Structures, Devices, and Systems IV, 726805 (30 December 2008); https://doi.org/10.1117/12.810575

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available