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

• US 8,765,530 B1
• Filed: 03/15/2013
• Issued: 07/01/2014
• Est. Priority Date: 11/28/2000
• Status: Expired due to Fees

• 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:
  US13/838,319
• Time in Patent Office: 473 Days
• Field of Search: None
• US Class Current: 438/125
• 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 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, each layer having a predetermined coefficient of thermal expansion, 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 disposed on the upper surface of the individual substrate;

a second plurality of metal pads disposed 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; and

one or more electrical traces disposed completely within the individual substrate, wherein the traces 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 individual substrate;

mounting a MEMS microphone die having an acoustic passage to the upper surface of each substrate in the unsingulated panel of substrates, wherein the acoustic passage positions a diaphragm of the MEMS microphone die away from the upper surface of the 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 having a predetermined shape that comprises a top region having a port that passes completely through the cover, and a substantially vertical sidewall region that adjoins the central region at a substantially perpendicular angle and that completely surrounds and supports the top region, the sidewall region having a predetermined height, an exterior sidewall surface, an interior sidewall 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 shape of each cover and the predetermined height of each sidewall region, in cooperation with the interior region of the upper surface of its respective substrate, forms a protective enclosure that defines an acoustic chamber for its respective MEMS microphone; 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 the one or more electrical traces in each substrate of the unsingulated panel of substrates are electrically coupled to one or more of the first plurality of metal pads or to one or more of the second plurality of metal pads with through-hole connections.

3. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, further comprising a metal pad formed on the upper surface of the substrate, wherein the MEMS microphone die is mounted to the metal pad.

4. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 1, wherein the non-conductive material in the unsingulated panel of substrates is 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, electromagnetic interference, 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 enclosure further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the 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, the 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 cover is acoustically coupled to the front volume of its respective acoustic chamber, and the acoustic passage of the MEMS microphone die and the upper surface of the substrate define a back volume.

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, each layer having a predetermined coefficient of thermal expansion, 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 disposed on the upper surface of the printed circuit board;

a second plurality of metal pads disposed on the lower surface of the 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; and

one or more circuit traces disposed completely within the printed circuit board, wherein the circuit traces 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, wherein the circuit traces are patterned in at least one conductive layer interposed between the multiple layers of non-conductive material;

mounting a MEMS microphone die having an acoustic passage to the upper surface of each printed circuit board in the unsingulated panel of printed circuit board, wherein the acoustic passage positions a diaphragm of the MEMS microphone die away from the upper surface of the 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 printed circuit board;

providing an unsingulated panel comprised of a plurality of individual covers, each cover being a single-piece cover having a predetermined shape that comprises a top region having a port that passes completely through the cover, and a substantially vertical sidewall region that adjoins the central region at a substantially perpendicular angle and that completely surrounds and supports the top region, the sidewall region having a predetermined height, an exterior sidewall surface, an interior sidewall 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;

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 shape of the cover and the predetermined height of the sidewall region, in cooperation with the interior region of the upper surface of the printed circuit board, forms a protective enclosure that defines an acoustic chamber for the MEMS microphone die; 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 the one or more circuit traces in each printed circuit board of the unsingulated panel of printed circuit boards are electrically coupled to one or more of the first plurality of metal pads or to one or more of the second plurality of metal pads with through-hole connections.

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 formed on the upper surface of the individual printed circuit board, wherein the MEMS microphone die is mounted to the metal pad.

12. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 9, wherein the non-conductive material in the unsingulated panel of printed circuit boards is 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, electromagnetic interference, 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 enclosure further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the 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, the 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 cover is acoustically coupled to the front volume of its respective acoustic chamber, and the acoustic passage of the MEMS microphone die and the upper surface of the substrate define a back volume.

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, each layer having a predetermined coefficient of thermal expansion, 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 disposed on the upper surface of the individual substrate;

a second plurality of metal pads disposed 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; and

one or more wiring traces disposed completely within the individual substrate, wherein the wiring traces 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, wherein the wiring traces are patterned in at least one conductive layer interposed between the multiple layers of non-conductive material;

physically coupling a MEMS microphone die having an acoustic passage to the upper surface of each substrate in the unsingulated panel of substrates, wherein the acoustic passage positions a diaphragm of the MEMS microphone die away from the upper surface of the 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 having a predetermined shape that comprises a central region having a port that passes completely through the cover, and a substantially vertical sidewall region that adjoins the central region and that completely surrounds and supports the central region, the sidewall region 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 creating a protective enclosure for each MEMS microphone die,

wherein the interior of each protective enclosure is an acoustic chamber having a volume defined by the predetermined height of its respective sidewall region, the predetermined shape of its respective cover, and the width and length of the central 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 the one or more wiring traces in each substrate of the unsingulated panel of substrates are electrically coupled to one or more of the first plurality of metal pads or to one or more of the second plurality of metal pads with through-hole connections.

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 formed on the upper surface of the individual substrate, wherein the MEMS microphone die is physically coupled to the metal pad.

20. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 17, wherein the non-conductive material in the unsingulated panel of substrates is 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, electromagnetic interference, 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 enclosure 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, the 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, and the acoustic passage of the MEMS microphone die and the upper surface of the substrate define a back volume.

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 non-conductive material has a predetermined coefficient of thermal expansion, and 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 disposed 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 disposed in the peripheral region of the upper surface of the individual printed circuit board;

a second metal layer disposed 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 attach and electrically couple the surface mount MEMS microphone device to pads on a surface of an external printed circuit board; and

one or more wiring traces disposed completely within the individual printed circuit board, wherein the wiring traces 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, wherein the wiring traces are patterned in at least one conductive layer interposed between two layers of non-conductive material;

physically coupling a MEMS microphone die having an acoustic passage to the upper surface of each printed circuit board in the unsingulated panel of printed circuit boards, wherein the acoustic passage positions a diaphragm of the MEMS microphone die away from the upper surface of the 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 printed circuit board;

providing an unsingulated panel comprised of a plurality of individual covers, each individual cover being a single-piece cover having a predetermined shape that comprises a central region having a port that passes completely through the cover, and a substantially vertical sidewall region that adjoins the central region and that completely surrounds and supports the central region, the sidewall region 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 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 creating a protective enclosure for each MEMS microphone die,

wherein the interior of each protective enclosure is an acoustic chamber having a volume defined by the predetermined height of its respective sidewall region, the predetermined shape of its respective cover, and the width and length of the central 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 formed on the upper surface of the individual printed circuit board, wherein the MEMS microphone die is mounted to the metal pad.

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 at least one passive electrical device disposed within 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 the enclosure protects the MEMS microphone die from at least one of light, electromagnetic interference, and physical damage.

29. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 25, wherein each individual enclosure further comprises acoustic material that substantially blocks environmental contaminants from entering the acoustic chamber through the port.

30. A method of manufacturing a plurality of solder reflow surface mount MEMS microphone devices according to claim 25, when the unsingulated panel of covers is physically coupled to the unsingulated panel of printed circuit boards, the 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 cover is acoustically coupled to the front volume of its respective acoustic chamber, and the acoustic passage of the MEMS microphone die and the upper surface of the substrate define a back volume.