ELECTRO ACOUSTIC TRANSDUCER

• US 20120230523A1
• Filed: 11/10/2010
• Published: 09/13/2012
• Est. Priority Date: 11/10/2009
• Status: Active Grant

• Current Assignee: Göran Ehrlund
• Original Assignee: Göran Ehrlund
• Inventors: Ehrlund, Göran
• Granted Patent: US 8,891,345 B2
• Time in Patent Office: Days
• US Class Current: 381/174
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: Y10T 29/49005 Acoustic transducer

Abstract

The invention relates to a condenser microphone element (10) with an electrically conducting transducer membrane (15) having an acoustically active area (20) that is arranged to receive sound waves and to vibrate in response to said sound waves, wherein the membrane (15) is arranged in parallel with and at a distance from a back plate (60), which is formed from a non conductive base (61), which is provided with a conductive layer (65). The conductive layer has an active area (66) that is arranged opposite the acoustically active area (20) of the membrane (15) and has a shape that faces said acoustically active area (20), and is delimited by an area where no conductive layer is provided. The invention further relates to a microphone and to a method of producing the microphone element (10).

Claims

1-11. -11. (canceled)

12. A condenser microphone element (10) with an electrically conducting transducer membrane (15) having an acoustically active area (20) that is arranged to receive sound waves and to vibrate in response to said sound waves, wherein the membrane (15) is arranged in parallel with and at a distance from a back plate (60), which is formed from a non conductive base (61), which is provided with a conductive layer (65), wherein the conductive layer has an active area (66) that is arranged opposite the acoustically active area (20) of the membrane (15) and has a shape that faces said acoustically active area (20), and is delimited by an area provided as a gap (63), and that a conductive layer is provided both outside and inside of said gap (63).

13. The condenser microphone element (10) according to claim 12, wherein the acoustically active area (20) of the membrane (15) is larger than the active area (66) of the back plate (60).

14. The condenser microphone element (10) according to claim 12, wherein the membrane (15) is connected to ground and kept at potential 0 V.

15. The condenser microphone element (10) according to claim 12, wherein a spacer in the form of an adhesive film is attached to the upper surface of the back plate (60) to create the necessary distance between the active area (66) of the back plate (60) and the acoustically active area (20) of the membrane (15).

16. The condenser microphone element (10) according to claim 12, wherein the acoustically active area (20) of the transducer membrane (15) has an essentially triangular shape.

17. The condenser microphone element (10) according to claim 12, wherein an electrical connection (69) is arranged through the non conductive base (61) of the back plate (60), which connection (69) connects the active area (66) of the back plate (60) to an electrical contact (62).

18. The condenser microphone element (10) according to claim 12, wherein the non conductive base (61) is formed from a rigid material from the group of materials comprising ceramics, plastics and composites.

19. The condenser microphone element (10) according to claim 12, wherein the conductive layer (65) is a metallic layer that includes copper.

21. A method of producing a condenser microphone element (10) including an electrically conducting transducer membrane (15) having an acoustically active area (20) arranged in parallel with and at a distance from a back plate (60), wherein the back plate (60) is formed from a non conductive base (61), which is provided with a conductive layer (65), comprising forming the back plate (60) in the same way as a printed circuit board is produced, by adding a conductive layer (65) in form of metal foil to a non conductive base (61), wherein the conductive layer (65) is formed with an active area (66) that is to be arranged opposite the membrane (15), such that it faces the acoustically active area (20) of the membrane (15), and is delimited by an area (69) where no conductive layer is provided.