Transducer package with transducer die unsupported by a substrate

• US 7,825,509 B1
• Filed: 08/18/2009
• Issued: 11/02/2010
• Est. Priority Date: 06/13/2009
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: MWM Acoustics LLC (Samsung Electronics Co. Ltd.)
• Inventors: Michel, Alan Dean, Welsh, Christopher Todd, Barber, Joshua R., McAteer, Jeffrey Phillip, Baumhauer, John Charles Jr.
• Primary Examiner(s): CLARK, SHEILA V
• Application Number:
  US12/543,309
• Time in Patent Office: 441 Days
• Field of Search: 357/723, 357/724, 357/787, 357/414
• US Class Current: 257/724
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0271 Resonators; ultrasonic resonators
• CPC Class Codes: B81C 1/0023 Packaging together an electronic processing unit die and a micromechanical structure die MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48237 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

A surface mountable transducer package is provided, the design of which allows a thin package profile to be achieved. An encapsulation layer bonds to a surface of each of the terminal pads and encapsulates a portion of the transducer and at least a portion of the signal processing IC.

Claims

1. A transducer package, comprising:

a MEMS transducer;

a signal processing integrated circuit (IC), wherein said MEMS transducer is electrically connected to said signal processing IC;

a plurality of terminal pads, wherein said plurality of terminal pads are unsupported by a substrate, and wherein said signal processing IC is electrically connected to said plurality of terminal pads;

an encapsulation material, wherein at least a portion of an upper surface of each of said plurality of terminal pads is bonded to said encapsulation material, wherein a portion of said MEMS transducer is encapsulated by said encapsulation material, and wherein at least a portion of said signal processing IC is encapsulated by said encapsulation material; and

a cover attached to a peripheral portion of one of said plurality of terminal pads.

2. The transducer package of claim 1, wherein an external mounting surface of said transducer package is formed by at least a portion of a lower surface of each of said plurality of terminal pads, a portion of said MEMS transducer, a portion of said encapsulation material extending between said MEMS transducer and an adjacent terminal pad of said plurality of terminal pads, and regions of said encapsulation material extending between adjacent terminal pads of said plurality of terminal pads.

3. The transducer package of claim 1, wherein said cover is electrically connected and mechanically coupled to said peripheral portion of said one of said plurality of terminal pads.

4. The transducer package of claim 3, further comprising a solder joint, wherein said solder joint electrically connects and mechanically couples said peripheral portion of said one of said plurality of terminal pads to said cover.

5. The transducer package of claim 1, wherein said peripheral portion of said one of said plurality of terminal pads corresponds to said upper surface of said one of said plurality of terminal pads.

6. The transducer package of claim 1, wherein an acoustic chamber volume within said transducer package is substantially defined by an inner surface of said cover, a portion of said MEMS transducer, and a surface of said encapsulation material.

7. The transducer package of claim 6, said cover further comprising an acoustic port in acoustic communication with said acoustic chamber volume.

8. The transducer package of claim 7, wherein said acoustic port is offset from and not overlapping with said MEMS transducer.

9. The transducer package of claim 6, further comprising an acoustic port in acoustic communication with said acoustic chamber volume, wherein said acoustic port passes through a portion of said encapsulation material.

10. The transducer package of claim 1, wherein a portion of an outer surface of said transducer package is comprised of an acoustic aperture of said MEMS transducer, and wherein said acoustic aperture of said MEMS transducer is exposed to ambient environment.

11. The transducer package of claim 1, wherein said signal processing IC is completely encapsulated by said encapsulation material.

12. The transducer package of claim 1, wherein said signal processing IC is an analog device.

13. The transducer package of claim 1, wherein said signal processing IC is a digital device.

14. The transducer package of claim 1, wherein said MEMS transducer is electrically connected to said signal processing IC via a first plurality of wire bonds, and wherein said signal processing IC is electrically connected to said plurality of terminal pads via a second plurality of wire bonds.

15. The transducer package of claim 1, wherein said MEMS transducer is a MEMS microphone transducer.

16. The transducer package of claim 1, wherein said MEMS transducer is a MEMS speaker transducer.

17. The transducer package of claim 1, wherein said MEMS transducer is a MEMS ultrasonic transducer.

18. The transducer package of claim 1, wherein said cover is comprised of a metal, wherein said metal is selected from the group consisting of steel, tin-plated steel, copper, brass, nickel, aluminum, tin-plated aluminum, or copper-plated aluminum.

19. The transducer package of claim 1, wherein said cover is comprised of at least one layer of an electrically conductive material, wherein said electrically conductive material is selected from the group consisting of conductive plastics, conductive polymers, or conductive coatings applied to a non-conductive material.

20. The transducer package of claim 1, wherein said plurality of terminal pads are comprised of a first material, and wherein said upper surface of each of said plurality of terminal pads are plated with a second material prior to encapsulation, said second material selected to promote wire bonding.

21. The transducer package of claim 20, wherein said second material is a metal.

22. The transducer package of claim 20, wherein said first material is comprised of copper, and wherein said second material is selected from the group consisting of tin and tin alloys.

23. The transducer package of claim 1, wherein a surface of said signal processing IC is bonded to one of said plurality of terminal pads.

24. The transducer package of claim 1, wherein a surface of said signal processing IC forms a portion of an exterior surface of said transducer package.

25. The transducer package of claim 1, wherein a total package height corresponding to said transducer package is less than 0.85 millimeters.

26. The transducer package of claim 1, wherein a total package height corresponding to said transducer package is less than 0.7 millimeters.

27. The transducer package of claim 1, further comprising a protective cap covering an aperture of said MEMS transducer.

28. The transducer package of claim 1, further comprising a transducer package mounting structure, wherein said transducer package mounting structure is comprised of a flexible PCB, wherein a portion of said flexible PCB is coupled to at least a portion of an exterior surface of said plurality of terminal pads, and wherein said portion of said flexible PCB leaves unobstructed an acoustic aperture of said MEMS transducer.

29. The transducer package of claim 28, wherein said flexible PCB is bent in an arc with an included angle of greater than 30 degrees.