Microelectromechanical system package with environmental and interference shield

• US 6,781,231 B2
• Filed: 09/10/2002
• Issued: 08/24/2004
• Est. Priority Date: 09/10/2002
• Status: Expired due to Term

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Minervini, Anthony D.
• Primary Examiner(s): Chambliss, Alonzo
• Application Number:
  US10/238,256
• Publication Number:
  US 20040046245A1
• Time in Patent Office: 714 Days
• Field of Search: 257/704, 257/723, 257/724, 257/728, 257/729, 257/730, 257/773, 438/22, 438/26, 438/48, 438/106, 438/121, 438/124
• US Class Current: 257/704
• 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 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 31/006 Interconnection of transducer parts of diaphragm and outer suspension by moulding H04R31/003

Abstract

A microelectromechanical system package has a microelectromechanical system microphone, a substrate, and a cover. The substrate has a surface for supporting the microelectromechanical microphone. The cover includes a conductive layer having a center portion bounded by a peripheral edge portion. A housing is formed by connecting the peripheral edge portion of the cover to the substrate. The center portion of the cover is spaced from the surface of the substrate to accommodate the microelectromechanical system microphone. The housing includes an acoustic port for allowing an acoustic signal to reach the microelectromechanical system microphone.

Claims

1. A microelectromechanical system package comprising:

a microelectromechanical system microphone;

a substrate comprising a surface for supporting the microelectromechanical microphone;

a cover comprising a conductive layer having a center portion bounded by a peripheral edge portion; and

a housing formed by connecting the peripheral edge portion of the cover to the substrate, the center portion of the cover spaced from the surface of the substrate to accommodate the microelectromechanical system microphone, the housing including an acoustic port for allowing an acoustic signal to reach the microelectromechanical system microphone wherein the housing provides protection from an interference signal.

2. A microelectromechanical system package for providing a shield from an interference signal, the microelectromechanical package comprising:

a silicon-based microphone;

a substrate including a surface at least partially covered by a first layer of a conductive material, the silicon-based microphone is electrically coupled to the layer of a conductive material;

a cover comprising a second layer of a conductive material, the cover electrically connected to the first layer of a conductive material and providing a chamber in which the silicon-based microphone is located, the chamber providing an acoustic front volume for the silicon-based microphone.

3. A package for a microelectromechanical system microphone, the package comprising:

a substrate of a non-conductive material having an upper surface;

a first layer of a conductive material at least partially covering the upper surface of the substrate;

a second layer of a conductive material electrically connected to the first layer of a conductive material, the second layer of a conductive material comprising a peripheral edge portion at least partially sealed to the substrate and a central portion spaced from the upper surface of the substrate to provide a chamber; and

a plurality of acoustic ports for allowing acoustic energy to enter the chamber.

4. A package for a microelectromechanical system microphone, the package comprising:

a substrate of a non-conductive material having an upper surface;

a first layer of a conductive material least partially covering the upper surface of the substrate;

a cover including a formed metal cup electrically connected to the first layer of a conductive material, the formed metal cup comprising a peripheral edge portion at least partially sealed to the substrate and a central portion spaced from the upper surface of the substrate to provide a chamber; and

a plurality of acoustic ports in communication with the chamber for allowing acoustic energy to enter the housing, the acoustic ports located along a surface of the cover.

5. A microelectromechanical system package comprising:

a microelectromechanical system microphone;

a substrate comprising a surface for supporting the microelectromechanical microphone;

a cover having a central portion bounded by a peripheral edge, the cover comprising a first formed metal cup and a second metal cup fit within the first metal cup in mating relationship, the cover further comprising an environmental barrier layer disposed between the first metal cup and the second metal cup; and

a housing formed by connecting the peripheral edge portion of the cover to the substrate, the center portion of the cover spaced from the surface of the substrate to accommodate the microelectromechanical system microphone, the housing including an acoustic port for allowing an acoustic signal to reach the microelectromechanical system microphone wherein the housing provides protection from an interference signal.

6. The microelectromechanical system package of claim 5 further comprising a sealant for sealing the cover to the substrate.

7. The microelectromechanical system package of claim 6 wherein the sealant is a solder.

8. The microelectromechanical system package of claim 6 wherein the sealant is a conductive adhesive.

9. The microelectromechanical system package of claim 6 further comprising a conductive layer on the substrate.

10. The microelectromechanical system package of claim 9 wherein the sealant comprises a conductive material for providing an electrical connection between the cover and the conductive layer on the substrate.

11. The microelectromechanical system package of claim 5 further comprising an environmental barrier layer within the acoustic port.

12. The microelectromechanical system package of claim 5 wherein the cover comprises a layer of non-conductive material.

13. The microelectromechanical system package of claim 12 wherein the cover comprises alternating layers of conductive and non-conductive material.

14. The microelectromechanical system package of claim 13 wherein an outer surface of the cover comprises a conductive layer.

15. The microelectromechanical system package of claim 14 wherein an inner surface of the cover comprises a conductive layer.

16. The microelectromechanical system package of claim 5 wherein the cover further comprises a non-conductive layer having a conductive layer plated thereon.

17. The microelectromechanical system package of claim 16 wherein the cover further comprises a second non-conductive layer having a second conductive layer plated thereon.

18. The microelectromechanical system package of claim 17 wherein the cover further comprises an environmental barrier layer between the conductive layer and second conductive layer.

19. The microelectromechanical system package of claim 5 wherein the microelectromechanical system microphone is a silicon-based microphone.

20. The microelectromechanical system package of claim 5 further comprising a plurality of microelectromechanical system devices supported on the surface of the substrate.

21. The microelectromechanical system package of claim 5 wherein the cover is acoustically sealed to the substrate.

22. The microelectromechanical system package of claim 5 further comprising an integrated circuit.