Backplateless silicon microphone
US7346178B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2004 |
| Grant date | Mar 18, 2008 |
| Priority date | — |
| Expiry date | Sep 30, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A silicon based microphone sensing element and a method for making the same are disclosed. The microphone sensing element has a diaphragm with a perforated plate adjoining each side or corner. The diaphragm is aligned above one or more back holes created in a conductive substrate wherein the back hole has a width less than that of the diaphragm. Perforated plates are suspended above an air gap that overlies the substrate. The diaphragm is supported by mechanical springs with two ends that are attached to the diaphragm at a corner, side, or center and terminate in a rigid pad anchored on a dielectric spacer layer. A first electrode is formed on one or more rigid pads and a second electrode is formed at one or more locations on the substrate to establish a variable capacitor circuit. The microphone sensing element can be embodied in different approaches to reduce parasitic capacitance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.