Bottom port multi-part surface mount silicon condenser microphone package

• US 8,624,386 B1
• Filed: 12/31/2012
• Issued: 01/07/2014
• 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:
  US13/732,205
• Time in Patent Office: 372 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 of the electrostatic type H04R19/005
• 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

The present invention relates to a surface mount package for a silicon condenser microphone and methods for manufacturing the surface mount package. The surface mount package uses a limited number of components which simplifies manufacturing and lowers costs, and features a substrate that performs functions for which multiple components were traditionally required, including providing an interior surface on which the silicon condenser die is mechanically attached, providing an interior surface for making electrical connections between the silicon condenser die and the package, and providing an exterior surface for surface mounting the package to a device'"'"'s printed circuit board and for making electrical connections between package and the device'"'"'s printed circuit board.

Claims

1. A solder reflow surface mount microelectromechanical system (MEMS) microphone device, the device comprising:

a substrate having a planar upper surface and a planar lower surface, the upper surface having an interior region and a peripheral region that completely surrounds the interior region, the substrate further comprising;

a first plurality of metal pads formed on the upper surface of the substrate;

a second plurality of metal pads formed on the lower surface of the substrate and arranged within a perimeter of the lower surface of the substrate, wherein the second plurality of metal pads are configured to mechanically attach and electrically couple the surface mount MEMS microphone device to pads on a surface of an external printed circuit board;

one or more electrical pathways formed completely within the substrate, wherein the pathways electrically couple one or more of the first plurality of metal pads on the upper surface of the substrate to one or more of the second plurality of metal pads on the lower surface of the substrate; and

an acoustic port formed in the interior region of the substrate and passing completely through the substrate, wherein one of the second plurality of metal pads is a sealing ring that completely surrounds the acoustic port in the substrate;

a MEMS microphone die mounted on the upper surface of the substrate and electrically coupled to at least one of the first plurality of metal pads on the upper surface of the substrate, the MEMS microphone die being arranged directly over the acoustic port in the substrate;

a lid having an upper surface and a planar lower surface, the lower surface of the lid having an interior region and a peripheral region that completely surrounds the interior region of the lid;

a sidewall spacer having a top surface, a bottom surface, and a window having walls that extend between the top surface and the bottom surface of the sidewall spacer, wherein the sidewall spacer has a predefined thickness,

wherein the substrate, the sidewall spacer and the lid are attached to each other, wherein the bottom surface of the sidewall spacer is aligned to the peripheral region of the upper surface of the substrate, and the peripheral region of the lower surface of the lid is aligned to the top surface of the sidewall portion; and

wherein the interior region of the upper surface of the substrate, the window walls of the sidewall spacer, and the interior region of the lower surface of the lid, when attached, define an acoustic chamber that surrounds the MEMS microphone die; and

wherein the lid, sidewall spacer, and substrate of the MEMS microphone device form a rectangular-shaped housing that has surfaces substantially perpendicular to the lower surface of the substrate.

2. A surface mount MEMS microphone device according to claim 1, further comprising at least one passive electrical device formed within the substrate.

3. A surface mount MEMS microphone device according to claim 1, wherein the substrate is attached to the sidewall spacer with a conductive material.

4. A surface mount MEMS microphone device according to claim 1, wherein the rectangular-shaped housing protects the MEMS microphone die from at least one of light, electromagnetic interference, and physical damage.

5. A surface mount MEMS microphone device according to claim 1, wherein at least a portion of the window walls of the sidewall spacer is coated with conductive material.

6. A surface mount MEMS microphone device according to claim 5, wherein at least a portion of the lower surface of the lid is coated with conductive material.

7. A surface mount MEMS microphone device according to claim 6, wherein the conductive material on the window walls of the sidewall spacer is electrically coupled to the conductive material on the lower surface of the lid.

8. A surface mount MEMS microphone device according to claim 1, wherein the rectangular-shaped housing further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the acoustic port.

9. A solder reflow surface mount microelectromechanical system (MEMS) microphone device, the device comprising:

a bottom portion comprising multiple layers of non-conductive material and having a planar upper surface and a planar lower surface, the upper surface having an interior region and a peripheral region that completely surrounds the interior region, the bottom portion further comprising;

a first plurality of metal pads formed on the upper surface of the bottom portion;

a second plurality of metal pads formed on the lower surface of the bottom portion and arranged within a perimeter of the lower surface of the bottom portion, wherein the second plurality of metal pads are configured to mechanically attach and electrically couple the surface mount MEMS microphone device to pads on a surface of an external printed circuit board;

one or more electrical pathways formed completely within the bottom portion, wherein the pathways electrically couple one or more of the first plurality of metal pads on the upper surface of the bottom portion to one or more of the second plurality of metal pads on the lower surface of the bottom portion; and

an acoustic port formed in the interior region of the bottom portion and passing completely through the bottom portion, wherein one of the second plurality of metal pads is a sealing ring that completely surrounds the acoustic port in the bottom portion;

a MEMS microphone die mounted on the upper surface of the bottom portion and electrically coupled to at least one of the first plurality of metal pads on the upper surface of the bottom portion, the MEMS microphone die being arranged directly over the acoustic port in the bottom portion;

a top portion having an upper surface and a planar lower surface, the lower surface of the top portion having an interior region and a peripheral region that completely surrounds the interior region of the top portion;

a sidewall portion having a top surface and a bottom surface, and is comprised of at least one layer of non-conductive material having a predefined thickness, and wherein at least a portion of the top surface of the sidewall portion is coated with conductive material, and the sidewall portion further comprises an opening having walls that extend between the top surface and the bottom surface of the sidewall portion,

wherein the bottom portion, the sidewall portion and the top portion are mechanically attached to each other, wherein the bottom surface of the sidewall portion is aligned to the peripheral region of the upper surface of the bottom portion, and the peripheral region of the lower surface of the top portion is aligned to the top surface of the sidewall portion; and

wherein the interior region of the upper surface of the bottom portion, the opening walls of the sidewall portion, and the interior region of the lower surface of the top portion, when attached, define an acoustic chamber that surrounds the MEMS microphone die; and

wherein the top portion, sidewall portion, and bottom portion of the MEMS microphone device form a rectangular-shaped housing that has surfaces substantially perpendicular to the lower surface of the bottom portion.

10. A surface mount MEMS microphone device according to claim 9, further comprising at least one passive electrical device formed within the bottom portion.

11. A surface mount MEMS microphone device according to claim 9, wherein the bottom portion is mechanically attached to the sidewall portion with a conductive material.

12. A surface mount MEMS microphone device according to claim 9, wherein the rectangular-shaped housing protects the MEMS microphone die from at least one of light, electromagnetic interference, and physical damage.

13. A surface mount MEMS microphone device according to claim 9, wherein at least a portion of the opening walls of the sidewall portion is coated with conductive material.

14. A surface mount MEMS microphone device according to claim 13, wherein at least a portion of the lower surface of the top portion is coated with conductive material.

15. A surface mount MEMS microphone device according to claim 14, wherein the conductive material on the opening walls of the sidewall portion is electrically coupled to the conductive material on the lower surface of the top portion.

16. A surface mount MEMS microphone device according to claim 9, wherein the rectangular-shaped housing further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the acoustic port.

17. A solder reflow surface mount microelectromechanical system (MEMS) microphone device, the device comprising:

a substrate comprising multiple layers of non-conductive material and having a planar upper surface and a planar lower surface, the upper surface having an interior region and a peripheral region that completely surrounds the interior region, the substrate further comprising;

a first plurality of metal pads formed on the upper surface of the substrate;

a second plurality of metal pads formed on the lower surface of the substrate and arranged within a perimeter of the lower surface of the substrate, wherein the second plurality of metal pads are configured to mechanically couple and electrically couple the surface mount MEMS microphone device to pads on a surface of an external substrate; and

one or more electrical pathways formed completely within the substrate, wherein the pathways electrically couple one or more of the first plurality of metal pads on the upper surface of the substrate to one or more of the second plurality of metal pads on the lower surface of the substrate; and

an acoustic port formed in the interior region of the substrate and passing completely through the substrate, wherein one of the second plurality of metal pads is a sealing ring that completely surrounds the acoustic port in the substrate;

a MEMS microphone die physically coupled to the upper surface of the substrate and electrically coupled to at least one of the first plurality of metal pads on the upper surface of the substrate, the MEMS microphone die being arranged directly over the acoustic port in the substrate;

a lid having an upper surface and a planar lower surface, the lower surface of the lid having an interior region and a peripheral region that completely surrounds the interior region of the lid;

a sidewall spacer having a top surface and a bottom surface, and is comprised of at least one layer of non-conductive material having a predefined thickness, and wherein at least a portion of the top surface of the sidewall spacer is coated with conductive material, and the sidewall spacer further comprises a window having walls that extend between the top surface and the bottom surface of the sidewall spacer,

wherein the substrate, the sidewall spacer, and the lid are physically coupled to each other, wherein the bottom surface of the sidewall spacer is aligned to the peripheral region of the upper surface of the substrate, and the peripheral region of the lower surface of the lid is aligned to the top surface of the sidewall spacer; and

wherein the interior region of the upper surface of the substrate, the window walls of the sidewall spacer, and the interior region of the lower surface of the lid, when coupled, define an acoustic chamber that surrounds the MEMS microphone die; and

wherein the lid, sidewall spacer, and substrate of the MEMS microphone device form a rectangular-shaped housing that has surfaces substantially perpendicular to the lower surface of the substrate.

18. A surface mount MEMS microphone device according to claim 17, further comprising at least one passive electrical device formed within the substrate.

19. A surface mount MEMS microphone device according to claim 17, wherein the substrate is physically coupled to the sidewall spacer with a conductive material.

20. A surface mount MEMS microphone device according to claim 17, wherein the rectangular-shaped housing protects the MEMS microphone die from at least one of light, electromagnetic interference, and physical damage.

21. A surface mount MEMS microphone device according to claim 17, wherein at least a portion of the lower surface of the lid is coated with conductive material, and wherein at least a portion of the window walls of the sidewall spacer is coated with conductive material.

22. A surface mount MEMS microphone device according to claim 21, wherein the conductive material on the window walls of the sidewall spacer is electrically coupled to the conductive material on the lower surface of the lid.

23. A surface mount MEMS microphone device according to claim 22, wherein the conductive material on the window walls of the sidewall spacer is electrically coupled to at least one of the first plurality of metal pads on the upper surface of the substrate.

24. A surface mount MEMS microphone device according to claim 17, wherein the rectangular-shaped housing further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the acoustic port.

25. A solder reflow surface mount microelectromechanical system (MEMS) microphone device, the device comprising:

a printed circuit board having a multi-layer core of conductive and non-conductive materials, wherein the printed circuit board has a planar upper surface and a planar lower surface, the upper surface having an interior region and a peripheral region that completely surrounds the interior region, the printed circuit board further comprising;

a first metal layer formed on the upper surface of the printed circuit board and patterned into a first plurality of metal pads, wherein at least one pad of the first plurality of metal pads is formed in the peripheral region of the upper surface of the printed circuit board;

a second metal layer formed on the lower surface of the printed circuit board and patterned into a second plurality of metal pads, the second plurality of metal pads arranged within a perimeter of the lower surface of the printed circuit board, wherein the second plurality of metal pads are configured to mechanically couple and electrically couple the surface mount MEMS microphone device to pads on a surface of an external printed circuit board;

one or more electrical pathways formed completely within the printed circuit board, wherein the pathways electrically couple one or more of the first plurality of metal pads on the upper surface of the printed circuit board to one or more of the second plurality of metal pads on the lower surface of the printed circuit board; and

an acoustic port formed in the interior region of the printed circuit board and passing completely through the printed circuit board, wherein one of the second plurality of metal pads is a sealing ring that completely surrounds the acoustic port in the printed circuit board;

a MEMS microphone die physically coupled to the upper surface of the printed circuit board and electrically coupled to at least one of the first plurality of metal pads on the upper surface of the printed circuit board, the MEMS microphone die being arranged directly over the acoustic port in the printed circuit board;

a top portion having an upper surface and a planar lower surface, the lower surface of the top portion having an interior region and a peripheral region that completely surrounds the interior region of the top portion, wherein at least a portion of the lower surface of the top portion is coated with conductive material;

a sidewall portion having a top surface and a bottom surface, and is comprised of at least one layer of non-conductive material having a predefined thickness, and wherein at least a portion of the top surface of the sidewall portion is coated with conductive material, and the sidewall portion further comprises an opening having walls that extend between the top surface and the bottom surface of the sidewall portion,

wherein the printed circuit board, the sidewall portion and the top portion are physically coupled to each other, wherein the bottom surface of the sidewall portion is aligned to the peripheral region of the upper surface of the printed circuit board, and the peripheral region of the lower surface of the top portion is aligned to the top surface of the sidewall portion; and

wherein the interior region of the upper surface of the printed circuit board, the opening walls of the sidewall portion, and the interior region of the lower surface of the top portion, when coupled, define an acoustic chamber that surrounds the MEMS microphone die; and

wherein the top portion, sidewall portion, and printed circuit board of the MEMS microphone device form a rectangular-shaped housing that has surfaces substantially perpendicular to the lower surface of the printed circuit board.

26. A surface mount MEMS microphone device according to claim 25, further comprising at least one passive electrical device formed within the printed circuit board.

27. A surface mount MEMS microphone device according to claim 25, wherein the printed circuit board is physically coupled to the sidewall portion with a conductive material.

28. A surface mount MEMS microphone device according to claim 25, wherein the rectangular-shaped housing protects the MEMS microphone die from at least one of light, electromagnetic interference, and physical damage.

29. A surface mount MEMS microphone device according to claim 25, wherein at least a portion of the opening walls of the sidewall portion is coated with conductive material, and the conductive material on the opening walls of the sidewall portion is electrically coupled to the conductive material on the lower surface of the top portion;

and

wherein the conductive material on the opening walls of the sidewall portion is electrically coupled to at least one metal pad formed in the peripheral region of the upper surface of the printed circuit board.

30. A surface mount MEMS microphone device according to claim 25, wherein the rectangular-shaped housing further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the acoustic port.