Attachment of a micromechanical microphone

• US 6,178,249 B1
• Filed: 06/17/1999
• Issued: 01/23/2001
• Est. Priority Date: 06/18/1998
• Status: Expired due to Fees

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Rusanen, Outi, Hietanen, Jarmo
• Primary Examiner(s): Kuntz, Curtis A.
• Assistant Examiner(s): Ni, Suhan
• Application Number:
  US09/335,419
• Time in Patent Office: 586 Days
• Field of Search: 381/173, 381/174, 381/190, 381/191, 381/356, 381/358, 381/361, 367/181, 367/188, 307/400
• US Class Current: 381/174
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence

Abstract

The invention relates to a method for attaching a micromechanical microphone (1) to be used in connection with a mobile station to a substrate (2), in which a diaphragm (4) and back electrode (6) for the microphone (1) are placed within a distance of each other, wherein an air gap (7) is formed between the diaphragm (4) and the back electrode (6). An insulation ring (12) is placed between the microphone (1) and the substrate, wherein the back electrode (6), the substrate (2) and the insulation ring (12) define a back chamber (13). The microphone (1) is attached to the substrate (2) with fixing means (11a, 11b), wherein the volume (Vb) of the back chamber (13) is adjusted by adjusting the height of the fixing means (11a, 11b).

Claims

1. A method for attaching a micromechanical microphone (1) used in connection with a mobile station to a substrate (2), in which a diaphragm (4) and a back electrode (6) for the microphone (1) are placed within a distance from each other, wherein an air gap (7) is formed between the diaphragm (4) and the back electrode (6), characterized in that an insulation ring (12) is placed between the microphone (1) and the substrate, wherein the back electrode (6), the substrate (2) and the insulation ring (12) define a back chamber (13), and that the microphone (1) is attached to the substrate (2) with fixing means (11a, 11b), wherein the volume (Vb) of the back chamber (13) is adjusted by adjusting the height of the fixing means (11a, 11b).

2. The method according to claim 1, characterized in that the micromechanical microphone (1) is produced on a semiconductor wafer, such as a silicon wafer.

3. The method according to claim 1, characterized in that an integrated circuit, such as an ASIC circuit is used as the substrate.

4. The method according to claim 2, characterized in that at least some of the circuits intended for processing of a microphone signal generated in the microphone (1) are integrated in the semiconductor wafer to be used in the fabrication of the micromechanical microphone (1).

5. A micromechanical microphone (1) for a wireless communication device, which is arranged to be attached to a substrate (2) and comprises a diaphragm (4) and a back electrode (6), placed within a distance from each other, wherein an air gap (7) is formed between them, characterized in that an insulation ring (12) is arranged to be placed between the microphone (1) and the substrate, wherein the back electrode (6), the substrate (2) and the insulation ring (12) define a back chamber (13), and that the microphone is arranged to be attached with fixing means, wherein the volume (Vb) of the back chamber (13) is arranged to be adjusted by adjusting the height of the fixing means (11a, 11b).

6. The micromechanical microphone (1) according to claim 5, characterized in that the insulation ring (12) is of polymer, such as silicone.

7. The micromechanical microphone (1) according to claim 5, characterized in that the height of the back chamber (13) is between 20 and 500 μ

m.

8. The micromechanical microphone (1) according to claim 5, characterized in that it is produced primarily of silicon compounds.

9. The micromechanical microphone (1) according to claim 5, characterized in that the substrate (2) is an integrated circuit, such as an ASIC circuit.

10. The micromechanical microphone (1) according to claim 5, characterized in that the fixing means (11a, 11b) are formed of metal flip-chips.