Double-side mountable MEMS package

• US 20090218668A1
• Filed: 02/28/2008
• Published: 09/03/2009
• Est. Priority Date: 02/28/2008
• Status: Active Grant

• Current Assignee: Shandong Gettop Acoustic Company Limited (Weifang Gaoke Electronic Company Limited)
• Original Assignee: Silicon Matrix Pte., Ltd.
• Inventors: Zhe, Wang, Choong, Chong Ser
• Granted Patent: US 7,843,021 B2
• Time in Patent Office: Days
• US Class Current: 257/680
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 2207/095 through the lid
• CPC Class Codes: B81B 2207/096 through the substrate
• 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: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/1134 Stud bumping, i.e. using a wire-bonding apparatus
• CPC Class Codes: H01L 2224/11901 with repetition of the same manufacturing step
• CPC Class Codes: H01L 2224/1308 being stacked
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 2224/4824 Connecting between the body and an opposite side of the item with respect to the body
• CPC Class Codes: H01L 2224/48599 Principal constituent of the connecting portion of the wire connector being Gold (Au)
• CPC Class Codes: H01L 2224/73207 Bump and wire connectors
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/85444 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 23/055 : the leads having a passage through the base H01L23/057 takes precedence
• CPC Class Codes: H01L 24/11 : Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/13 : of an individual bump connector
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 25/165 : Containers
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/07811 : Extrinsic, i.e. with electrical conductive fillers
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1433 : Application-specific integrated circuit [ASIC]
• CPC Class Codes: H01L 2924/1461 : MEMS

Abstract

The MEMS package has a mounting substrate on which one or more transducer chips are mounted wherein the mounting substrate has an opening. A top cover is attached to and separated from the mounting substrate by a spacer forming a housing enclosed by the top cover, the spacer, and the mounting substrate and accessed by the opening. Electrical connections are made between the one or more transducer chips and the mounting substrate and/or between the one or more transducer chips and the top cover. A bottom cover can be mounted on a bottom surface of the mounting substrate wherein a hollow chamber is formed between the mounting substrate and the bottom cover, wherein a second opening in the bottom cover is not aligned with the first opening. Pads on outside surfaces of the top and bottom covers can be used for further attachment to printed circuit boards. The top and bottom covers can be a flexible printed circuit board folded under the mounting substrate.

Claims

1. A MEMS package comprising:

a mounting substrate on which one or more transducer chips are mounted wherein said mounting substrate has a first opening;

a top cover attached to and separated from said mounting substrate by a spacer forming a housing enclosed by said top cover, said spacer, and said mounting substrate and accessed by said opening; and

bonding wires forming electrical connections between one or more of;

said one or more of said transducer chips and said mounting substrate; and

said one or more of said transducer chips and said top cover.

2. The package according to claim 1 wherein said mounting substrate and said top cover each comprise a dielectric layer and patterned metal layers on both sides of said dielectric layer.

3. The package according to claim 1 wherein said one or more transducer chips comprise an integrated circuit chip and a MEMS sensing element, a single chip with integrated circuit and MEMS sensing elements integrated thereon, or a plurality of integrated circuit chips and a plurality of MEMS sensing chips.

4. The package according to claim 1 wherein said spacer comprises a metal ring frame or an organic ring frame with coated conductive films and is attached to said mounting substrate and to said top cover by a soldering process or by adhesive attachment wherein said adhesive is tape or paste adhesive.

5. The package according to claim 1 wherein said first opening underlies a MEMS sensor device.

6. The package according to claim 1 wherein said electrical connections comprise high loop height bonding wires between said one or more of said transducer chips and said mounting substrate wherein a conductive adhesive bonds said loop of said bonding wires to said top cover.

7. The package according to claim 1 wherein said electrical connections comprise vertical bonding wires between said one or more of said transducer chips and said top cover wherein a conductive adhesive bonds said vertical bonding wires to said top cover.

8. The package according to claim 1 wherein said top cover comprises a first portion of a flexible printed circuit board and wherein a second portion of said flexible printed circuit board is folded under said mounting substrate and attached to said mounting substrate.

9. The package according to claim 8 wherein said folded second portion of said flexible printed circuit board is attached to and electrically connected to said mounting substrate by solder, conductive adhesive, or Anisotropic Conductive Film.

10. The package according to claim 8 wherein said flexible printed circuit board has a second opening in said second portion and wherein a gap is formed between said flexible printed circuit board and said mounting substrate wherein said gap joins said first opening and said second opening wherein said first opening is not aligned with said second opening.

11. The package according to claim 8 wherein a gap is formed between said second portion of said flexible printed circuit board and said mounting substrate wherein said gap underlies said first opening and wherein said flexible printed circuit board has a second opening in said first portion of said flexible printed circuit board.

12. A MEMS package comprising:

a mounting substrate on which one or more transducer chips are mounted wherein said mounting substrate has a first opening;

a top cover overlying, attached to, and separated from said mounting substrate by a spacer;

a bottom cover underlying and joined to said mounting substrate wherein a gap is formed between said bottom cover and said substrate; and

electrical connections between one or more of;

said one or more transducer chips and said mounting substrate; and

said one or more of said transducer chips and said top cover.

13. The package according to claim 12 wherein said one or more transducer chips comprise an application specific integrated circuit chip and a MEMS sensing element, a single chip with integrated circuit and MEMS sensing elements integrated thereon, or a plurality of integrated circuit chips and a plurality of MEMS sensing chips.

14. The package according to claim 12 wherein said top cover has a second opening and said bottom cover has no opening.

15. The package according to claim 12 wherein said bottom cover has a second opening and said top cover has no opening, wherein said first opening is not aligned with said second opening.

16. The package according to claim 12 wherein said mounting substrate and said top cover each comprise a dielectric layer and patterned metal layers on both sides of said dielectric layer.

17. The package according to claim 12 wherein said spacer comprises a metal ring frame or an organic ring frame with coated conductive films and is attached to said mounting substrate and to said top cover by a soldering process or by adhesive attachment wherein said adhesive comprises tape or past adhesive.

18. The package according to claim 12 wherein said first opening underlies a MEMS sensor device.

19. The package according to claim 12 wherein said electrical connections comprise high loop height bonding wires between said one or more of said transducer chips and said mounting substrate wherein a conductive adhesive bonds said loop of said bonding wires to said top cover.

20. The package according to claim 12 wherein said electrical connections comprise vertical bonding wires between said one or more transducer chips and said top cover wherein a conductive adhesive bonds said vertical bonding wires to said top cover.

21. The package according to claim 12 wherein said electrical connections comprise stacked stud bumps between said one or more transducer chips and said top cover wherein a conductive adhesive bonds said stacked stud bumps to said top cover.

22. The package according to claim 12 wherein said electrical connections comprise bonding wires between said one or more transducer chips and said bottom cover through openings in said mounting substrate and between said mounting substrate and said bottom cover through openings in said mounting substrate.

23. The package according to claim 12 wherein said electrical connections comprise:

high loop height bonding wires between said one or more transducer chips and said bottom cover through openings in said mounting substrate wherein a conductive adhesive bonds said loop to said top cover; and

bonding wires between said mounting substrate and said bottom cover through openings in said mounting substrate.

24. A MEMS package comprising:

a mounting substrate on which one or more transducer chips are mounted wherein said mounting substrate has a first opening;

a top cover overlying, attached to, and separated from said mounting substrate by a spacer;

a bottom cover underlying and joined to said mounting substrate wherein said bottom cover has a second opening and wherein a gap is formed between said bottom cover and said mounting substrate wherein said gap joins said first opening and said second opening and wherein said first opening is not aligned with said second opening;

electrical connections between one or more of;

said one or more transducer chips and said mounting substrate;

said one or more transducer chips and said top cover; and

said one or more transducer chips and said bottom cover; and

pads on outside surfaces of said top and bottom covers used for further attachment to printed circuit boards.

25. A method for fabricating a MEMS package comprising:

providing a mounting substrate having a first opening;

mounting one or more transducer chips on a top surface of said mounting substrate;

mounting a spacer on said top surface of said mounting substrate;

mounting a top cover overlying, attached to, and separated from said mounting substrate by said spacer forming a housing enclosed by said top cover, said spacer, and said mounting substrate and accessed by said first opening; and

providing electrical connections between one or more of;

said one or more transducer chips and said mounting substrate; and

said one or more transducer chips and said top cover.

26. The method according to claim 25 wherein said first opening underlies a MEMS sensor device.

27. The method according to claim 25 further comprising:

mounting a bottom cover on a bottom surface of said mounting substrate wherein a hollow chamber is formed between said mounting substrate and said bottom cover, wherein a second opening in said bottom cover allows external fluid, acoustic energy or pressure to enter said hollow chamber wherein said second opening is not aligned with said first opening; and

providing electrical connections between one or more of;

said one or more transducer chips and said bottom cover; and

said one or more transducer chips and said top cover.

28. The method according to claim 25 wherein said top cover comprises a first portion of a flexible printed circuit board comprising mounting said first portion of said flexible printed circuit board on said spacer wherein an acoustic chamber is formed between said flexible printed circuit board and said mounting substrate, and wherein a second portion of said flexible printed circuit board is folded over and attached to the bottom of said mounting substrate wherein a hollow chamber is formed between said mounting substrate and said second portion of said flexible circuit board, wherein a second opening in said second portion of said flexible circuit board allows external fluid, acoustic energy or pressure to enter said hollow chamber wherein said second opening is not aligned with said first opening, and further comprising providing electrical connections between one or more of:

said one or more transducer chips and said mounting substrate; and

said one or more transducer chips and said flexible printed circuit board.

29. The method according to claim 25 wherein said top cover comprises a first portion of a flexible printed circuit board comprising mounting said first portion of said flexible printed circuit board on said spacer wherein a second opening in said first portion of said flexible circuit board allows external fluid, acoustic energy or pressure to enter said housing, and wherein a second portion of said flexible circuit board is folded over and attached to the bottom of said mounting substrate wherein a hollow chamber is formed between said mounting substrate and said second portion of said flexible circuit board, and further comprising providing electrical connections between one or more of:

said one or more transducer chips and said mounting substrate; and

said one or more transducer chips and said flexible printed circuit board.

30. The method according to claim 25 wherein said mounting said spacer and said top cover comprises:

screen printing or dispensing solder paste on said top surface of said mounting substrate;

attaching said bottom edges of said spacer to said solder paste on said mounting substrate using a solder reflow process;

screen printing or dispensing solder paste on a bottom surface of said top cover;

placing said top cover on the top of said spacer with said solder paste touching top edges of said spacer; and

attaching said top cover on top edges of said spacer using a solder reflow process.

31. The method according to claim 25 wherein said mounting said spacer and said top cover comprises:

applying adhesive on said top surface of said mounting substrate;

attaching bottom edges of said spacer to said adhesive on said mounting substrate;

applying adhesive on a bottom surface of said top cover; and

attaching said top cover to top edges of said spacer.

32. The method according to claim 25 wherein said providing electrical connections between said one or more transducer chips and said top cover comprises:

bonding wires with sufficient loop height between said one or more transducer chips and said mounting substrate wherein a conductive adhesive bonds said loop of said bonding wires to said top cover.

33. The method according to claim 25 wherein said providing electrical connections between said one or more transducer chips and said top cover comprises:

vertical bonding wires between said one or more transducer chips and said top cover wherein a conductive adhesive bonds said vertical bonding wires to said top cover.

34. The method according to claim 25 wherein said providing electrical connections between said one or more transducer chips and said top cover comprises:

providing stacked stud bumps between said one or more transducer chips and said top cover wherein a conductive adhesive bonds said stacked stud bumps to said top cover.

35. The method according to claim 27 wherein said providing electrical connections between said one or more transducer chips and said bottom cover comprises:

bonding wires between said one or more transducer chips and said bottom cover through openings in said mounting substrate and between said mounting substrate and said bottom cover through openings in said mounting substrate.

36. The method according to claim 27 wherein said providing electrical connections between said one or more transducer chips and said top cover and between said one or more transducer chips and said bottom cover comprises:

bonding wires with sufficient loop height between said one or more transducer chips and said bottom cover through openings in said mounting substrate wherein a conductive adhesive bonds said loop to said top cover; and

bonding wires between said mounting substrate and said bottom cover through openings in said mounting substrate.

37. The method according to claim 28 wherein said mounting said spacer and said flexible printed circuit board comprises:

screen printing or dispensing solder paste on said top surface of said mounting substrate;

attaching said bottom edges of said spacer to said solder paste on said mounting substrate using a solder reflow process;

screen printing or dispensing solder paste on a bottom surface of a first portion of said flexible printed circuit board;

placing said first portion of said flexible printed circuit board on the top of said spacer with said solder paste touching top edges of said spacer;

attaching said first portion of said flexible printed circuit board on top edges of said spacer using a solder reflow process;

screen printing or dispensing adhesives on the bottom of said mounting substrate; and

attaching said second portion of said flexible printed circuit board onto said bottom of said mounting substrate.

38. The method according to claim 28 wherein said mounting said spacer and said flexible printed circuit board comprises:

applying adhesive on said top surface of said mounting substrate;

attaching bottom edges of said spacer to said adhesive on said mounting substrate;

applying adhesive on a bottom surface of a first portion of said flexible printed circuit board;

attaching said first portion of said flexible printed circuit board to top edges of said spacer;

screen printing or dispensing adhesives on the bottom of said mounting substrate; and

attaching said second portion of said flexible printed circuit board onto said bottom of said mounting substrate.

39. The method according to claim 28 wherein said providing electrical connections between said one or more transducer chips and said flexible printed circuit board comprises:

bonding wires with sufficient loop height between said one or more transducer chips and said mounting substrate wherein a conductive adhesive bonds said loop of said bonding wires to said first portion of said flexible printed circuit board.

40. The method according to claim 29 wherein said mounting said spacer and said flexible printed circuit board comprises:

screen printing or dispensing solder paste on said top surface of said mounting substrate;

attaching said bottom edges of said spacer to said solder paste on said mounting substrate using a solder reflow process;

screen printing or dispensing solder paste on a bottom surface of said first portion of said flexible printed circuit board;

placing said first portion of said flexible printed circuit board on the top of said spacer with said solder paste touching top edges of said spacer;

attaching said first portion of said flexible printed circuit board on top edges of said spacer using a solder reflow process;

screen printing or dispensing solder paste or conductive adhesives on the bottom of said mounting substrate; and

attaching said second portion of said flexible printed circuit board onto said mounting substrate.

41. The method according to claim 29 wherein said mounting said spacer and said flexible printed circuit board comprises:

applying adhesive on said top surface of said mounting substrate;

attaching bottom edges of said spacer to said adhesive on said mounting substrate;

applying adhesive on a bottom surface of said first portion of said flexible printed circuit board;

attaching said first portion of said flexible printed circuit board to top edges of said spacer;

screen printing or dispensing solder paste or conductive adhesives on the bottom of said mounting substrate; and

attaching said second portion of said flexible printed circuit board onto said mounting substrate.

42. The method according to claim 29 wherein said providing electrical connections between said one or more transducer chips and said flexible printed circuit board comprises:

bonding wires between said one or more transducer chips and said mounting substrate wherein a conductive adhesive bonds said loop of said bonding wires to said first portion of said flexible printed circuit board;

screen printing or dispensing solder paste or conductive adhesives on the bottom of said mounting substrate; and

attaching said second portion of said flexible printed circuit board onto said bottom of said mounting substrate.