Silicon condenser microphone and manufacturing method

• US 8,018,049 B2
• Filed: 04/30/2007
• Issued: 09/13/2011
• Est. Priority Date: 11/28/2000
• 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:
  US11/741,881
• Publication Number:
  US 20070201715A1
• Time in Patent Office: 1,597 Days
• Field of Search: None
• US Class Current: 257/704
• 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 and method for manufacture are disclosed. The silicon condenser microphone package includes a silicon condenser microphone die, a substrate comprising a conductive layer, and a cover having a conductive layer, where the conductive layers of the substrate and cover are electrically connected to form an electromagnetic interference shield for the silicon condenser microphone die. The method for manufacturing the silicon condenser microphone package involves placement of a plurality of silicon condenser microphone dies on a panel of printed circuit board material, placement of covers over each of the silicon condenser microphone dies, and then separating the panel into individual packages.

Claims

1. A silicon condenser microphone package comprising:

a package housing formed by connecting a multi-layer substrate comprising at least one layer of conductive material and at least one layer of non-conductive material, to a cover comprising at least one layer of conductive material;

a cavity formed within the interior of the package housing;

an acoustic port formed in the package housing; and

a silicon condenser microphone die disposed within the cavity in communication with the acoustic port;

where the at least one layer of conductive material in the substrate is electrically connected to the at least one layer of conductive material in the cover to form a shield to protect the silicon condenser microphone die against electromagnetic interference.

2. The silicon condenser microphone package of claim 1, further comprising:

an environmental barrier secured to the package housing covering the acoustic port.

3. The silicon condenser microphone package of claim 2,

the environmental barrier being disposed between layers of the package housing.

4. The silicon condenser microphone package of claim 3,

the environmental barrier being disposed between a first conductive layer and a second conductive layer package housing for forming a capacitor within the package housing.

5. The silicon condenser microphone package of claim 2,

the environmental barrier having acoustic properties.

6. The silicon condenser microphone package of claim 2,

the environmental barrier providing particle screening or moisture screening.

7. The silicon condenser microphone package of claim 2,

the environmental barrier providing optical screening.

8. The silicon condenser microphone package of claim 7,

the environmental barrier comprising one of a polymeric material and a sintered metal material.

9. The silicon condenser microphone package of claim 1,

the package housing comprising a second acoustic port, the second acoustic port being acoustically coupled to the silicon condenser microphone die.

10. The silicon condenser microphone package of claim 9, further comprising:

a second environmental barrier secured to the package housing covering the second acoustic port.

11. The silicon condenser microphone package of claim 1,

wherein the substrate and the cover are secured together by adhesive.

12. The silicon condenser microphone package of claim 11,

wherein the adhesive comprises a conductive adhesive.

13. The silicon condenser microphone package of claim 11,

wherein the adhesive comprises a patterned dry layer adhesive.

14. The silicon condenser microphone package of claim 11,

wherein the adhesive comprises a nonconductive patterned dry layer adhesive and a conductive adhesive.

15. The silicon condenser microphone package of claim 1,

where the substrate is 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.

16. The silicon condenser microphone package of claim 15,

wherein the element is formed within a layer of the substrate.

17. The silicon condenser microphone package of claim 1, further comprising:

a recess formed within the substrate adjacent the silicon condenser microphone die creating a back volume.

18. The silicon condenser microphone package of claim 17,

the recess being formed at least in part between layers of the substrate.

19. The silicon condenser microphone package of claim 1,

the internal cavity forming a back volume and being coupled to a first side of the silicon condenser microphone die and the acoustic port being coupled to a second side of the silicon condenser microphone die.

20. The silicon condenser microphone package of claim 1,

the package comprising a joined pair of microphones packages.

21. A method of manufacturing a silicon condenser microphone package comprising:

providing a panel comprising a plurality of interconnected package substrates, where each of the plurality of package substrates comprises at least one layer of conductive material and at least one layer of non-conductive material;

attaching a plurality of silicon condenser microphone dice to the plurality of package substrates, one die to each package substrate;

attaching a plurality of package covers, each comprising at least one layer of conductive material, to the panel, one package cover to each of the package substrates, where attaching the plurality of package covers to the panel comprises electrically connecting the at least one layer of conductive material in the package cover to the at least one layer of conductive material in the corresponding package substrate to form a shield to protect the silicon condenser microphone die against electromagnetic interference; and

separating the panel into a plurality of individual silicon condenser microphone packages.

22. The method of claim 21,

where each of the plurality of package substrates further comprises an acoustic port.

23. The method of claim 22,

where each silicon condenser microphone die is attached to its respective package substrate such that the die covers the acoustic port of its respective package substrate.

24. The method of claim 22,

where each silicon condenser microphone die is attached to its respective package substrate such that the die does not cover the acoustic port of its respective package substrate.

25. The method of claim 21,

where each of the plurality of package cover further comprises an acoustic port.

26. The method of claim 21,

where the panel comprises printed circuit board material.