Solid state transducer for converting between an electrical signal and sound

• US 6,552,469 B1
• Filed: 05/08/2001
• Issued: 04/22/2003
• Est. Priority Date: 06/05/1998
• Status: Expired due to Fees

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Loeppert, Peter V., Pederson, Michael
• Primary Examiner(s): TAMAI, KARL I
• Application Number:
  US09/786,037
• Time in Patent Office: 714 Days
• Field of Search: 310/309, 251/129.17, 251/129.12, 381/190, 381/191
• US Class Current: 310/309
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence

Abstract

A solid state transducer is disclosed. The transducer comprises a micromachined electrostatic actuator formed of silicon, a support brace disposed about the actuator, and a membrane coupled to the support brace. The actuator is operatively coupled to the membrane. The transducer may be either a receiver or a microphone.

Claims

1. A solid state transducer for converting between an electrical signal and sound comprising:

an actuator comprising a silicon substrate having a doped portion, a metallization layer and an electrostatic cantilever disposed between the metallization layer and the silicon substrate wherein when a potential difference exists between the silicon substrate and the metallization layer a deflection force is incident upon the cantilever;

a support brace disposed about the actuator which supports the actuator; and

a membrane coupled to the support brace and to the cantilever.

2. The transducer of claim 1 wherein said transducer comprises a receiver.

3. The transducer of claim 1 wherein said transducer comprises a microphone.

4. The transducer of claim 1 wherein the actuator has a range of motion which is long compared to the thickness of the membrane.

5. The transducer of claim 1 wherein the cantilever is coupled to the membrane by a tip.

6. The transducer of claim 5 wherein the tip is made from nickel.

7. The transducer of claim 1 further comprising an end stop which prevents over-deflection of the cantilever in at least one direction.

8. The transducer of claim 1 wherein the cantilever comprises a corrugated portion.

9. Of The transducer of claim 1 further comprising an end stop to prevent over-deflection of the cantilever in at least one direction.

10. The transducer of claim 9 wherein the end-stop is made from nickel.

11. The transducer of claim 1 wherein the cantilever is attached to the membrane by a tip.

12. The transducer of claim 11 wherein the tip is made from nickel.

13. The transducer of claim 1 wherein the metallization layer is comprises a chrome/gold metallization layer.