Methods of manufacture of bottom port surface mount silicon condenser microphone packages

• US 8,629,005 B1
• Filed: 03/15/2013
• Issued: 01/14/2014
• 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:
  US13/839,119
• Time in Patent Office: 305 Days
• Field of Search: None
• US Class Current: 438/125
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2207/097 Interconnects arranged on the substrate or the lid, and covered by the package seal
• 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 7/0061 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: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 1/00309 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81C 1/00333 Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325
• CPC Class Codes: B81C 3/002 Aligning microparts
• 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 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 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 3/00 : Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: Y10T 29/49005 : Acoustic transducer
• CPC Class Codes: Y10T 29/4908 : Acoustic transducer

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 method of manufacturing a plurality of solder reflow surface mount microelectromechanical system (MEMS) microphone devices, the method comprising:

providing an unsingulated panel comprised of a plurality of individual substrates, each 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, each individual substrate further comprising;

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

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

an acoustic port formed in the interior region of the individual substrate and passing completely through the individual substrate, wherein one of the second plurality of formed metal pads has an opening that completely surrounds the acoustic port in the substrate, the opening in the formed metal pad being larger than the acoustic port;

mounting a MEMS microphone die to the upper surface of each substrate in the unsingulated panel of substrates, each MEMS microphone die being arranged directly over the acoustic port in its respective substrate;

electrically coupling each MEMS microphone die to at least one of the first plurality of metal pads on the upper surface of its respective substrate;

providing an unsingulated panel comprised of a plurality of individual covers, each cover being a single-piece cover that has a top region and a sidewall region, the sidewall region adjoining the top region at a substantially perpendicular angle and having a predetermined height, an exterior surface, an interior surface, and a bottom surface;

attaching the unsingulated panel of covers to the unsingulated panel of substrates,

wherein the bottom surface of the sidewall region of each single-piece cover is aligned with and attached to the peripheral region of the upper surface of its respective substrate, and

wherein the predetermined height and interior surface of the sidewall region and interior surface of the top region of each cover, in cooperation with the interior region of the upper surface of its respective substrate, forms a protective enclosure for the MEMS microphone die that reduces electromagnetic interference and defines an acoustic chamber for its respective MEMS microphone die disposed on the upper surface of its respective substrate in the unsingulated panel of substrates; and

singulating the attached panels into a plurality of individual MEMS microphone devices.

2. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, wherein each individual substrate in the unsingulated panel of substrates further comprises a metal pad with an opening, wherein the opening surrounds the acoustic port in the individual substrate, and the metal pad is interposed between the MEMS microphone die and the upper surface of the individual substrate when the MEMS microphone die is mounted on the individual substrate.

3. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, wherein each individual substrate in the unsingulated panel of substrates further comprises a metal pad with an opening, wherein the opening surrounds the acoustic port in the individual substrate, and the MEMS microphone die contacts the metal pad when mounted on the upper surface of the individual substrate.

4. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, wherein each individual substrate in the unsingulated panel of substrates further comprises FR-4 material.

5. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, wherein each individual substrate in the unsingulated panel of substrates further comprises at least one passive electrical device disposed within the individual substrate.

6. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, wherein the enclosure protects the MEMS microphone die from at least one of light and physical damage.

7. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 6, wherein each individual substrate in the unsingulated panel of substrates further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the acoustic port.

8. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, wherein, when the unsingulated panel of covers is attached to the unsingulated panel of substrates, a diaphragm of each MEMS microphone die within each acoustic chamber defines a front volume and a back volume in its respective acoustic chamber, and the acoustic port disposed in each individual substrate is acoustically coupled to the front volume of its respective acoustic chamber.

9. A method of manufacturing a plurality of solder reflow surface mount microelectromechanical system (MEMS) microphone devices, the method comprising:

providing an unsingulated panel comprised of a plurality of individual printed circuit boards, each printed circuit board 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, each individual printed circuit board further comprising;

a first plurality of metal pads formed on the upper surface of the individual printed circuit board;

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

an acoustic port formed in the interior region of the individual printed circuit board and passing completely through the individual printed circuit board, wherein one of the second plurality of formed metal pads has an opening that completely surrounds the acoustic port in the printed circuit board, the opening in the formed metal pad being larger than the acoustic port;

mounting a MEMS microphone die to the upper surface of each printed circuit board in the unsingulated panel of printed circuit board, each MEMS microphone die being arranged directly over the acoustic port in its respective printed circuit board;

electrically coupling each MEMS microphone die to at least one of the first plurality of metal pads on the upper surface of its respective printed circuit board;

providing an unsingulated panel comprised of a plurality of individual covers, each cover being a single-piece cover that has a top region and a sidewall region, the sidewall region adjoining the top region at a substantially perpendicular angle and having a predetermined height, an exterior surface, an interior surface, and a bottom surface,

wherein each cover has a first length and a first width, and its respective printed circuit board has a second length and a second width, and

wherein the first length of each cover and second length of its respective printed circuit board are substantially equal, and the first width of each cover and second width of its respective printed circuit board are substantially equal;

mechanically attaching the unsingulated panel of covers to the unsingulated panel of printed circuit boards, wherein the bottom surface of the sidewall region of each single-piece cover is aligned with and mechanically attached to the peripheral region of the upper surface of its respective printed circuit board, and

wherein the predetermined height and interior surface of the sidewall region and interior surface of the top region of each cover, in cooperation with the interior region of the upper surface of its respective substrate, forms a protective enclosure for the MEMS microphone die that reduces electromagnetic interference and that defines an acoustic chamber for its respective MEMS microphone die disposed on the upper surface of its respective substrate in the unsingulated panel of substrates; and

singulating the attached panels into a plurality of individual MEMS microphone devices.

10. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises a metal pad with an opening, wherein the opening surrounds the acoustic port in the individual printed circuit board, and the metal pad is interposed between the MEMS microphone die and the upper surface of the individual printed circuit board when the MEMS microphone die is mounted on the individual printed circuit board.

11. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises a metal pad with an opening, wherein the opening surrounds the acoustic port in the individual printed circuit board, and the MEMS microphone die contacts the metal pad when mounted on the upper surface of the individual printed circuit board.

12. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises FR-4 material.

13. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises at least one passive electrical device disposed within the individual printed circuit board.

14. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein the enclosure protects the MEMS microphone die from at least one of light and physical damage.

15. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the acoustic port.

16. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein, when the unsingulated panel of covers is attached to the unsingulated panel of printed circuit boards, a diaphragm of each MEMS microphone die within each acoustic chamber defines a front volume and a back volume in its respective acoustic chamber, and the acoustic port disposed in each individual printed circuit board is acoustically coupled to the front volume of its respective acoustic chamber.

17. A method of manufacturing a plurality of solder reflow surface mount microelectromechanical system (MEMS) microphone devices, the method comprising:

providing an unsingulated panel comprised of a plurality of individual substrates, each 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, each individual substrate further comprising;

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

a second plurality of metal pads formed on the lower surface of the individual substrate and arranged within a perimeter of the lower surface of the individual 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 printed circuit board; and

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

an acoustic port formed in the interior region of the individual substrate and passing completely through the individual substrate, wherein one of the second plurality of formed metal pads has an opening that completely surrounds the acoustic port in the substrate, the opening in the formed metal pad being larger than the acoustic port;

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 disposed directly over the acoustic port in the substrate; and

providing an unsingulated panel comprised of a plurality of individual covers, each cover being a single-piece cover that has a top region and a sidewall region, the sidewall region adjoining the top region at a substantially perpendicular angle and having a predetermined height, an exterior surface, an interior surface, and a bottom surface;

physically coupling the unsingulated panel of covers to the unsingulated panel of substrates,

wherein the bottom surface of the sidewall region of each single-piece cover is aligned with and physically coupled to the peripheral region of the upper surface of its respective substrate, thereby forming a protective enclosure for the MEMS microphone die that reduces electromagnetic interference, and

wherein the interior of each protective enclosure is an acoustic chamber having a volume defined by the predetermined height of the sidewall region of its respective cover, and the width and length of the top region of its respective cover; and

singulating the coupled panels into a plurality of individual MEMS microphone devices.

18. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein each individual substrate in the unsingulated panel of substrates further comprises a metal pad with an opening, wherein the opening surrounds the port in the individual substrate, and the metal pad is interposed between the MEMS microphone die and the upper surface of the individual substrate when the MEMS microphone die is physically coupled on the individual substrate.

19. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein each individual substrate in the unsingulated panel of substrates further comprises a metal pad with an opening, wherein the opening surrounds the port in the individual substrate, and the MEMS microphone die contacts the metal pad when physically coupled on the upper surface of the individual substrate.

20. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein each individual substrate in the unsingulated panel of substrates further comprises FR-4 material.

21. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein each individual substrate in the unsingulated panel of substrates further comprises at least one passive electrical device disposed within the individual substrate.

22. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein the enclosure protects the MEMS microphone die from at least one of light and physical damage.

23. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein each individual substrate in the unsingulated panel of substrates further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the port.

24. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein, when the unsingulated panel of covers is physically coupled to the unsingulated panel of substrates, a diaphragm of each MEMS microphone die within each acoustic chamber defines a front volume and a back volume in its respective acoustic chamber, and the port disposed in each individual substrate is acoustically coupled to the front volume of its respective acoustic chamber.

29. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein the enclosure protects the MEMS microphone die from at least one of light and physical damage.

30. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the acoustic port.

25. A method of manufacturing a plurality of solder reflow surface mount microelectromechanical system (MEMS) microphone devices, the method comprising:

providing an unsingulated panel comprised of a plurality of individual printed circuit boards, each 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, each individual printed circuit board further comprising;

a first metal layer formed on the upper surface of the individual 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 individual printed circuit board;

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

an acoustic port formed in the interior region of the individual printed circuit board and passing completely through the individual printed circuit board, wherein one of the second plurality of formed metal pads has an opening that completely surrounds the acoustic port in the printed circuit board, the opening in the formed metal pad being larger than the acoustic port;

physically coupling a MEMS microphone die to the upper surface of each printed circuit board in the unsingulated panel of printed circuit boards, each MEMS microphone die being arranged directly over the acoustic port in its respective printed circuit board;

electrically coupling each MEMS microphone die to at least one of the first plurality of metal pads on the upper surface of its respective printed circuit board;

providing an unsingulated panel comprised of a plurality of individual covers, each individual cover being a single-piece cover that has a top region and a sidewall region, the sidewall region adjoining the top region at a substantially perpendicular angle and having a predetermined height, an exterior sidewall surface, an interior sidewall surface, and a bottom surface;

physically coupling the unsingulated panel of covers to the unsingulated panel of printed circuit boards,

wherein the bottom surface of the sidewall region of each single-piece cover is aligned with and physically coupled to the peripheral region of the upper surface of its respective printed circuit board, thereby forming a protective enclosure for the MEMS microphone die that reduces electromagnetic interference, and

wherein the interior of each protective enclosure is an acoustic chamber having a volume defined by the predetermined height of the sidewall region of its respective cover, and the width and length of the top region of its respective cover; and

singulating the coupled panels into a plurality of individual MEMS microphone devices.

26. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 25, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises a metal pad with an opening, wherein the opening surrounds the acoustic port in the individual printed circuit board, and the metal pad is interposed between the MEMS microphone die and the upper surface of the individual printed circuit board when the MEMS microphone die is physically coupled on the individual printed circuit board.

27. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 25, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises a metal pad with an opening, wherein the opening surrounds the acoustic port in the individual printed circuit board, and the MEMS microphone die contacts the metal pad when physically coupled on the upper surface of the individual printed circuit board.

28. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 25, wherein each individual printed circuit board in the unsingulated panel of printed circuit boards further comprises at least one passive electrical device disposed within the individual printed circuit board.