Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications
New mobile devices need microphones with a small size, low noise level, reduced cost and high stability respect to variations of temperature and humidity. These characteristics can be obtained using Microelectromechanical Systems (MEMS) microphones, which are substituting for conventional electret c...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-10-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/18/10/3545 |
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| author | Néstor N. Peña-García Luz A. Aguilera-Cortés Max A. González-Palacios Jean-Pierre Raskin Agustín L. Herrera-May |
| author_facet | Néstor N. Peña-García Luz A. Aguilera-Cortés Max A. González-Palacios Jean-Pierre Raskin Agustín L. Herrera-May |
| author_sort | Néstor N. Peña-García |
| collection | DOAJ |
| description | New mobile devices need microphones with a small size, low noise level, reduced cost and high stability respect to variations of temperature and humidity. These characteristics can be obtained using Microelectromechanical Systems (MEMS) microphones, which are substituting for conventional electret condenser microphones (ECM). We present the design and modeling of a capacitive dual-backplate MEMS microphone with a novel circular diaphragm (600 µm diameter and 2.25 µm thickness) supported by fifteen polysilicon springs (2.25 µm thickness). These springs increase the effective area (86.85% of the total area), the linearity and sensitivity of the diaphragm. This design is based on the SUMMiT V fabrication process from Sandia National Laboratories. A lumped element model is obtained to predict the electrical and mechanical behavior of the microphone as a function of the diaphragm dimensions. In addition, models of the finite element method (FEM) are implemented to estimate the resonance frequencies, deflections, and stresses of the diaphragm. The results of the analytical models agree well with those of the FEM models. Applying a bias voltage of 3 V, the designed microphone has a bandwidth from 31 Hz to 27 kHz with 3 dB sensitivity variation, a sensitivity of 34.4 mV/Pa, a pull-in voltage of 6.17 V and a signal to noise ratio of 62 dBA. The results of the proposed microphone performance are suitable for mobile device applications. |
| first_indexed | 2024-04-11T11:52:54Z |
| format | Article |
| id | doaj.art-46093c584d0b4fff8015b9982da5e3a6 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-11T11:52:54Z |
| publishDate | 2018-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-46093c584d0b4fff8015b9982da5e3a62022-12-22T04:25:15ZengMDPI AGSensors1424-82202018-10-011810354510.3390/s18103545s18103545Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device ApplicationsNéstor N. Peña-García0Luz A. Aguilera-Cortés1Max A. González-Palacios2Jean-Pierre Raskin3Agustín L. Herrera-May4Departamento de Ingeniería Mecánica, DICIS, Universidad de Guanajuato, Carr. Salamanca-Valle de Santiago km 3.5 + 1.8 km, Palo Blanco, Salamanca, Guanajuato 36885, MexicoDepartamento de Ingeniería Mecánica, DICIS, Universidad de Guanajuato, Carr. Salamanca-Valle de Santiago km 3.5 + 1.8 km, Palo Blanco, Salamanca, Guanajuato 36885, MexicoDepartamento de Ingeniería Mecánica, DICIS, Universidad de Guanajuato, Carr. Salamanca-Valle de Santiago km 3.5 + 1.8 km, Palo Blanco, Salamanca, Guanajuato 36885, MexicoInstitute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Université catholique de Louvain (UCL), 1348 Louvain-la-Neuve, BelgiumMicro and Nanotechnology Research Center, Universidad Veracruzana, Calzada Ruiz Cortines 455, Boca del Río, Veracruz 94294, MexicoNew mobile devices need microphones with a small size, low noise level, reduced cost and high stability respect to variations of temperature and humidity. These characteristics can be obtained using Microelectromechanical Systems (MEMS) microphones, which are substituting for conventional electret condenser microphones (ECM). We present the design and modeling of a capacitive dual-backplate MEMS microphone with a novel circular diaphragm (600 µm diameter and 2.25 µm thickness) supported by fifteen polysilicon springs (2.25 µm thickness). These springs increase the effective area (86.85% of the total area), the linearity and sensitivity of the diaphragm. This design is based on the SUMMiT V fabrication process from Sandia National Laboratories. A lumped element model is obtained to predict the electrical and mechanical behavior of the microphone as a function of the diaphragm dimensions. In addition, models of the finite element method (FEM) are implemented to estimate the resonance frequencies, deflections, and stresses of the diaphragm. The results of the analytical models agree well with those of the FEM models. Applying a bias voltage of 3 V, the designed microphone has a bandwidth from 31 Hz to 27 kHz with 3 dB sensitivity variation, a sensitivity of 34.4 mV/Pa, a pull-in voltage of 6.17 V and a signal to noise ratio of 62 dBA. The results of the proposed microphone performance are suitable for mobile device applications.http://www.mdpi.com/1424-8220/18/10/3545capacitive microphonedual backplateFEM modelelectret condenser microphonesspring-supported diaphragmSandia Ultra-Planar Multi-level MEMS Technology V (SUMMiT V) fabrication process |
| spellingShingle | Néstor N. Peña-García Luz A. Aguilera-Cortés Max A. González-Palacios Jean-Pierre Raskin Agustín L. Herrera-May Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications Sensors capacitive microphone dual backplate FEM model electret condenser microphones spring-supported diaphragm Sandia Ultra-Planar Multi-level MEMS Technology V (SUMMiT V) fabrication process |
| title | Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications |
| title_full | Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications |
| title_fullStr | Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications |
| title_full_unstemmed | Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications |
| title_short | Design and Modeling of a MEMS Dual-Backplate Capacitive Microphone with Spring-Supported Diaphragm for Mobile Device Applications |
| title_sort | design and modeling of a mems dual backplate capacitive microphone with spring supported diaphragm for mobile device applications |
| topic | capacitive microphone dual backplate FEM model electret condenser microphones spring-supported diaphragm Sandia Ultra-Planar Multi-level MEMS Technology V (SUMMiT V) fabrication process |
| url | http://www.mdpi.com/1424-8220/18/10/3545 |
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