MEMS microphone, production method and method for installing

• US 8,229,139 B2
• Filed: 11/06/2006
• Issued: 07/24/2012
• Est. Priority Date: 11/10/2005
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: Epcos AG (TDK Corporation)
• Inventors: Pahl, Wolfgang
• Primary Examiner(s): Tran, Long
• Application Number:
  US12/092,423
• Publication Number:
  US 20080279407A1
• Time in Patent Office: 2,087 Days
• Field of Search: 381/71.7, 381/122, 381/150, 381/162, 381/355
• US Class Current: 381/150
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 7/0064 for protecting against electromagnetic or electrostatic interferences
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49109 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 2225/49 Reducing the effects of electromagnetic noise on the functioning of hearing aids, by, e.g. shielding, signal processing adaptation, selective (de)activation of electronic parts in hearing aid

Abstract

A microphone in a miniaturized form is described herein. The microphone includes a flat carrier substrate having a first recess extending through the carrier substrate. The microphone includes a first electro-acoustic transducer on a first surface of the carrier substrate and at least partially overlapping the first recess. The microphone also includes a cap on a second surface opposite the first surface having a tight seal with the second surface and spanning the first recess. The cap includes at least one metallic layer for electromagnetic shielding.

Claims

1. A microphone in a miniaturized form, comprising:

a flat carrier substrate having a first recess extending through the carrier substrate,

a first electro-acoustic transducer on a first surface of the carrier substrate and at least partially overlapping the first recess, and

a cap on a second surface opposite the first surface, the cap being configured to form a tight seal with the second surface and span the first recess, the cap comprising at least one metallic layer for electromagnetic shielding.

2. The microphone of claim 1, wherein the first electro-acoustic transducer comprises a micro-electromechanical system (MEMS) component on a silicon wafer.

3. The microphone of claim 1, wherein the cap comprises a multi-layer structure, wherein an outmost layer of the multi-layer structure comprises the metallic layer.

4. The microphone of claim 3, wherein an innermost layer of the cap comprises a plastic film.

5. The microphone of claim 1, further comprising solderable contacts electrically connected to one or more terminals of the first electro-acoustic transducer and/or one or more integrated components on the first surface of the carrier substrate.

6. The microphone of claim 1, further comprising at least one electrical component electrically connected to the first electro-acoustic transducer and selected from the group consisting of an impedance transducer, amplifier, low-pass filter, signal processor, A/D converter, and fuse component, the at least one electrical component being on the second surface of the carrier substrate under the cap.

7. The microphone of claim 1, wherein the carrier substrate comprises at least one metallization layer including electrical connection lines.

8. The microphone of claim 7, wherein the carrier substrate is comprises a multi-layered structure that includes at least one additional metallization layer, wherein the metallization layers are separated by one or more electrically insulating layers and connections between the metallization layers by via contacts form circuitry.

9. The microphone of claim 1, wherein the first electro-acoustic transducer includes at least one piezoelectric layer comprising transducer electrodes for electrically converting sound signals.

10. The microphone of claim 1, further comprising a shielding layer comprising metal on the first surface of the carrier substrate and on parts of the first electro-acoustic transducer.

11. The microphone of claim 1, wherein further comprising a second electro-acoustic transducer above a second recess on the first surface of the carrier substrate.

12. The microphone of claim 11, wherein each of the first and the second electro-acoustic transducers has a body comprising crystalline silicon and having on its surface away from the first surface of the carrier substrate, a sound entrance opening closed with a porous, metallized membrane.