Silicon based condenser microphone and packaging method for the same

• US 7,903,831 B2
• Filed: 08/18/2006
• Issued: 03/08/2011
• Est. Priority Date: 08/20/2005
• Status: Expired due to Fees

• Current Assignee: BSE Company Limited (BSE Holdings Company Limited)
• Original Assignee: BSE Company Limited (BSE Holdings Company Limited)
• Inventors: Song, Chung Dam
• Primary Examiner(s): NGUYEN, TUAN DUC
• Application Number:
  US11/506,664
• Publication Number:
  US 20070041597A1
• Time in Patent Office: 1,663 Days
• Field of Search: 381/170, 381/174, 381/175, 381/190, 381/191
• US Class Current: 381/174
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• 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 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H04R 1/06 Arranging circuit leads; Relieving strain on circuit leads
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 31/006 Interconnection of transducer parts of diaphragm and outer suspension by moulding H04R31/003

Abstract

Disclosed are a silicon based condenser microphone and a packaging method for the silicon based condenser microphone. The silicon based condenser microphone comprises a metal case, and a board which is mounted with a MEMS microphone chip and an ASIC chip having an electric voltage pump and a buffer IC and is formed with a connecting pattern for bonding with the metal case, wherein the connecting pattern is welded to the metal case. The method for packaging a silicon based condenser microphone includes the steps of inputting a board which is mounted with a MEMS chip and an ASIC chip and is formed with a connecting pattern; inputting a metal case, aligning the metal case on the connecting pattern of the board, and welding an opened end of the metal case to the connecting pattern of the board. Thus, the metal case is welded to the board by the laser.

Claims

1. A silicon based condenser microphone comprising:

a metal case;

a board which is mounted with a Micro Electro Mechanical System (MEMS) microphone chip and an application specific integrated circuit (ASIC) chip having a electric voltage pump and a buffer IC and is formed with a connecting pattern for bonding with the metal case, the connecting pattern being welded to the metal case; and

at least one connecting terminal connected with the connecting pattern, the connecting terminal extending to a circumference of the board.

2. The silicon based condenser microphone according to claim 1, wherein the metal case has any one of a cylindrical shape and a rectangular parallelepiped shape.

3. The silicon based condenser microphone according to claim 2, wherein an opened end of the metal case has any one of a straight line shape and a skirt shape which is formed by bending the opened end outwardly.

4. The silicon based condenser microphone according to claim 1, wherein the board is any one selected from the group of a printed circuit board (PCB), a ceramic board, a flexible PCB (FPCB) and a metal PCB.

5. The silicon based condenser microphone according to claim 1, wherein the metal case is made of any one selected from the group of brass, aluminum and nickel alloy.

6. The silicon based condenser microphone according to claim 1, wherein the welding is laser welding.

7. The silicon based condenser microphone according to claim 1, wherein the welding is electric welding.

8. The silicon based condenser microphone according to claim 1, wherein the welding is soldering.

9. The silicon based condenser microphone according to claim 1, wherein the welding is bonding using a conductive adhesive.

10. The silicon based condenser microphone according to claim 1, wherein the board is formed with two to eight connecting terminals for connecting with an external device.

11. The silicon based condenser microphone according to claim 1, wherein the board is formed with a rear sound inlet hole for collecting a rear sound, whereby the microphone has directivity.

12. A method for packaging a silicon based condenser microphone, the method comprising the steps of:

inputting a board which is mounted with a Micro Electro Mechanical System (MEMS) microphone chip and an application specific integrated circuit (ASIC) and is formed with a connecting pattern and at least one connecting terminal;

inputting a metal case;

aligning the metal case on the connecting pattern of the board; and

welding an opened end of the metal case to the connecting pattern of the board, wherein the metal case and the connecting terminal are connected by way of the connecting pattern and the connecting terminal extends to a circumference of the board.

13. A silicon based condenser microphone comprising:

a metal case having a bottom surface which is closed; and

a board which is formed with a sound hole for collecting an external sound and a sealing terminal for sealing the sound hole by soldering to prevent distortion of a sound wave in the space between a main printed circuit board (PCB) and the microphone,

the board being mounted with a Micro Electro Mechanical System (MEMS) microphone chip and an application specific integrated circuit (ASIC) chip having an electric voltage pump and a buffer IC,

the board being formed with a connecting pattern for connecting with the metal case so that the metal case is bonded on the connecting pattern by welding;

at least one connecting terminal connected with the connecting pattern, the connecting terminal extending to a circumference of the board.

14. The silicon based condenser microphone according to claim 13, wherein the metal case has any one of a cylindrical shape and a rectangular parallelepiped shape.

15. The silicon based condenser microphone according to claim 13, wherein an opened end of the metal case has any one of a straight line shape and a skirt shape which is formed by bending the opened end.

16. The silicon based condenser microphone according to claim 13, wherein the board is any one selected from the group of a PCB, a ceramic board, a flexible PCB (FPCB) and a metal PCB.

17. The silicon based condenser microphone according to claim 13, wherein the metal case is made of any one selected from the group of brass, aluminum and nickel alloy.

18. The silicon based condenser microphone according to claim 13, wherein the board is formed with two to eight connecting terminals for connecting with an external device.

19. The silicon based condenser microphone according to claim 13, wherein the sound hole of the board is formed on a portion where the MEMS chip is mounted and is not formed in the central portion of the board.

20. The silicon based condenser microphone according to claim 19, wherein the case is formed with a sound hole for collecting an external sound and is mounted with a sound resister on the inside and outside of the sound hole, whereby the microphone has directivity.

21. A silicon based condenser microphone which is mounted on a main printed circuit board (PCB) having an inserting hole into which the condenser microphone is inserted and connecting pads, the condenser microphone comprising:

a metal case which is inserted into the inserting hole of the main PCB and has a closed bottom side;

a board which is broader than the metal case, the board being formed with a sound hole on a central portion thereof and mounted with a Micro Electro Mechanical System (MEMS) microphone chip and an application specific integrated circuit (ASIC) chip having an electric voltage pump and a buffer IC, the board being formed with a connecting pattern for bonding with the metal case so that the metal case is bonded to the connecting pattern; and

connecting terminals which are formed on a part side of the board which is mounted with the metal case to connect with the connecting pads of the main PCB, the connecting terminal extending to a circumference of the board.

22. The silicon based condenser microphone according to claim 21, wherein the metal case has any one of a cylindrical shape and a rectangular parallelepiped shape.

23. The silicon based condenser microphone according to claim 21, wherein an end of the metal case has any one of a straight line shape and a skirt shape which is formed by bending the end outwardly.

24. The silicon based condenser microphone according to claim 21, wherein the board is any one selected from the group of a PCB, a ceramic board, a flexible PCB (FPCB) and a metal PCB.

25. The silicon based condenser microphone according to claim 21, wherein the metal case is made of any one selected from the group of brass, aluminum and nickel alloy.

26. The silicon based condenser microphone according to claim 21, wherein the connecting terminals are formed with two to eight connecting terminals.

27. The silicon based condenser microphone according to claim 21, wherein the sound hole of the board is not formed in the central portion of the board, but formed on the position where the MEMS chip is mounted.

28. The silicon based condenser microphone according to claim 27, wherein the case is formed with a sound hole for collecting sound from the outside and is mounted with an additional sound resister on the inside and outside of the sound hole, whereby the condenser microphone has directivity.