Silicon Condenser Microphone and Manufacturing Method

• US 20070201715A1
• Filed: 04/30/2007
• Published: 08/30/2007
• Est. Priority Date: 11/28/2000
• Status: Active Grant

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Minervini, Anthony
• Granted Patent: US 8,018,049 B2
• Time in Patent Office: Days
• US Class Current: 381/355
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2207/092 Buried interconnects in the substrate or in the lid
• CPC Class Codes: B81B 3/0021 Transducers for transforming electrical into mechanical energy or vice versa dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81B 7/0058 for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
• CPC Class Codes: B81B 7/0061 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81B 7/0064 for protecting against electromagnetic or electrostatic interferences
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 3/00 Assembling of devices or systems from individually processed components
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 23/15 Ceramic or glass substrates H01L23/142, H01L23/145, H01L23/147 take precedence
• 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: H01L 2924/1461 MEMS
• CPC Class Codes: H04R 1/04 Structural association of microphone with electric circuitry therefor in deaf-aid sets H04R25/00
• CPC Class Codes: H04R 1/222 for microphones H04R1/24, H04R1/26 take precedence
• CPC Class Codes: H04R 1/2892 Mountings or supports for transducers
• CPC Class Codes: H04R 19/005 : using semiconductor materials
• CPC Class Codes: H04R 19/016 : for microphones
• CPC Class Codes: H04R 19/04 : Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 : Mems transducers or their use
• 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
• CPC Class Codes: H04R 23/00 : Transducers other than those covered by groups H04R9/00 - H04R21/00 diaphragms for transducers of the distributed-mode type H04R7/045
• CPC Class Codes: H04R 2410/03 : Reduction of intrinsic noise in microphones
• CPC Class Codes: H04R 3/00 : Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: H04R 31/006 : Interconnection of transducer parts of diaphragm and outer suspension by moulding H04R31/003
• CPC Class Codes: Y10T 29/49005 : Acoustic transducer
• CPC Class Codes: Y10T 29/4908 : Acoustic transducer
• CPC Class Codes: Y10T 29/49798 : Dividing sequentially from leading end, e.g., by cutting or breaking

Abstract

A silicon condenser microphone package is disclosed. The silicon condenser microphone package comprises a transducer unit, substrate, and a cover. The substrate includes an upper surface having a recess formed therein. The transducer unit is attached to the upper surface of the substrate and overlaps at least a portion of the recess wherein a back volume of the transducer unit is formed between the transducer unit and the substrate. The cover is placed over the transducer unit and includes an aperture.

Claims

1. A microphone comprising:

a composite wall housing defining an internal cavity, the composite wall housing having a conductive portion providing an interference shield around the internal cavity;

an acoustic port formed in the housing; and

a transducer disposed within the cavity in communication with the acoustic port.

2. The microphone of claim 1, comprising an environmental barrier secured to the housing covering the acoustic port.

3. The microphone of claim 2, the composite wall housing comprising a multi-layer wall housing, the environmental barrier being disposed between layers of the multi-layer wall housing.

4. The microphone of claim 3, the environmental barrier being disposed between a first conductive layer and a second conductive layer of the multi-layer wall housing for forming a capacitor within the multi-layer housing.

5. The microphone of claim 2, the environmental barrier having acoustic properties.

6. The microphone of claim 2, the environmental barrier providing particle screening or moisture screening.

7. The microphone of claim 2, the environmental barrier providing optical screening.

8. The microphone of claim 7, the environmental barrier comprising one of a polymeric material and a sintered metal material.

9. The microphone of claim 1, the housing comprising a second acoustic port, the second acoustic port being acoustically coupled to the transducer.

10. The microphone of claim 9, comprising a second environmental barrier secured to the housing covering the second acoustic port.

11. The microphone of claim 1, the composite wall housing comprising a multi-layer wall housing, wherein the multi-layer wall housing comprises secured together a bottom layer and a top layer.

12. The microphone of claim 11, wherein the bottom layer and the top layer are secured together by adhesive.

13. The microphone of claim 12, wherein the adhesive comprises a conductive adhesive.

14. The microphone of claim 12, wherein the adhesive comprises a patterned dry layer adhesive.

15. The microphone of claim 12, wherein the adhesive comprises a non-conductive patterned dry layer adhesive and a conductive adhesive.

16. The microphone of claim 11, wherein the bottom layer and the top layer each comprise a conductive portion, the conductive portions being electrically coupled.

17. The microphone of claim 11, at least one of the bottom layer and top layer being formed to include an element selected from the group of elements consisting of:

circuitry, ground planes solder pads, ground pads, power planes, capacitors and through hole pads.

18. The microphone of claim 17, wherein the element is formed within a layer of the multi-layer wall housing.

19. The microphone of claim 1, comprising a recess formed within the composite wall housing adjacent the transducer creating a back volume.

20. The microphone of claim 19, the composite wall housing comprising a multi-layer wall housing the recess being formed between layers of the multi-layer wall housing.

21. The microphone of claim 1, the internal cavity forming a back volume and being coupled to a first side of the transducer and the acoustic port being coupled to a second side of the transducer.

22. The microphone of claim 1, the microphone comprising a joined pair of microphones.