MEMS MICROPHONE MODULE AND METHOD THEREOF

• US 20080157238A1
• Filed: 11/21/2007
• Published: 07/03/2008
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: Advanced Semiconductor Engineering Inc (ASE Technology Holding Co., Ltd.)
• Original Assignee: Advanced Semiconductor Engineering Inc (ASE Technology Holding Co., Ltd.)
• Inventors: Hsiao, Wei-Min
• Granted Patent: US 7,808,060 B2
• Time in Patent Office: Days
• US Class Current: 257/416
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure

Abstract

A MEMS microphone module having an application specific IC and a microphone chip is disclosed. The application specific IC has a plurality of first vias and a plurality of first pads, and the first vias are connected to the first pads. The microphone chip has a resonant cavity, a plurality of second vias and a plurality of second pads, and the second vias are connected to the second pads. The microphone chip is disposed on a first surface of the application specific IC with an opening of the resonant cavity facing toward a first surface of the application specific IC. The second conductive vias of the microphone chip are also electrically connected to the first vias of the application specific IC. By placing the microphone chip on the first surface of the application specific IC, the present invention could reduce the package size and increase the reliability of the package.

Claims

1. A MEMS microphone module, comprising:

an application specific IC having a first surface, a second surface, a plurality of first pads, and a plurality of first vias, wherein the first pads are formed on the first surface of the application specific IC and the first vias are connected to the first pads; and

a microphone chip having an active surface, a back surface, a resonant cavity having an opening, a plurality of second vias, a vibrating film, and a plurality of second pads, wherein the vibrating film and the second pads are formed on the active surface of the microphone chip, the resonant cavity is formed on the back surface of the microphone chip, the second vias are connected to the second pads, the microphone chip is disposed on the first surface of the application specific IC with the opening of the resonant cavity facing toward the application specific IC, and the second vias of the microphone chip are electrically connected to the first vias of the application specific IC.

2. The MEMS microphone module of claim 1 further comprising a cover disposed on the active surface of the microphone chip.

3. The MEMS microphone module of claim 2, wherein the microphone chip comprises a surrounding wall, wherein the cover is disposed on the surrounding wall of the microphone chip.

4. The MEMS microphone module of claim 1, further comprising a first metal formed in the first vias of the application specific IC and a second metal formed in the second vias of the microphone chip, wherein the second metal protrudes from the back surface of the microphone chip.

5. The MEMS microphone module of claim 4, wherein the application specific IC comprises a first insulator formed between the inner sidewall of the first vias and the first metal and the microphone chip comprises a second insulator formed between the inner sidewall of the second vias and the second metal.

6. The MEMS microphone module of claim 1 further comprising an encapsulant formed between the application specific IC and the microphone chip.

7. The MEMS microphone module of claim 6, wherein the encapsulant is positioned with respect to the exterior side of the first vias of the application specific IC and the second vias of the microphone chip.

8. The MEMS microphone module of claim 6, wherein the encapsulant comprises a metal material.

9. The MEMS microphone module of claim 1 further comprising a sealing layer formed between the application specific IC and the microphone chip to electrically connect the first vias and the second vias.

10. The MEMS microphone module of claim 1, wherein the application specific IC further comprises a plurality of external pads formed on the second surface of the application specific IC and connected to the first vias.

11. The MEMS microphone module of claim 2, wherein the cover comprises at least one sound hole.

12. The MEMS microphone module of claim 2, wherein the cross-section of the cover comprises a “

-”

shape or a “

U”

shape.

13. A method for fabricating a MEMS microphone module, comprising:

providing a first wafer having a plurality of application specific IC, wherein each of the application specific IC comprises a first surface, a second surface, a plurality of first pads formed on the first surface, and a plurality of first vias connecting the first pads;

providing a second wafer having a plurality of microphone chips, wherein each of the microphone chips comprises an active surface, a back surface, a resonant cavity having an opening formed on the back surface of the microphone chip, a vibrating film and a plurality of second pads formed on the active surface of the microphone chip, and a plurality of second vias connected to the second pads; and

performing a bonding process to bond the second wafer and the first wafer by connecting the microphone chips of the second wafer to the application specific IC of the first wafer, wherein the opening of the resonant cavity is disposed to face toward the application specific IC and the first vias of the application specific IC are electrically connected to the second vias of the microphone chip.

14. The method of claim 13 further comprising forming a surrounding wall on the active surface of the microphone chip.

15. The method of claim 13 further comprising disposing a cover on the active surface of the microphone chip.

16. The method of claim 14 further comprising disposing a cover on the surrounding wall.

17. The method of claim 13 further comprising forming a first metal in the first vias of the application specific IC and a second metal in the second vias of the microphone chip, wherein the first metal protrudes from the second surface of the application specific IC and the second metal protrudes from the back surface of the microphone chip.

18. The method of claim 17 further comprising forming a first insulator between the inner sidewall of the first vias of the application specific IC and the first metal and a second insulator between the inner sidewall of the second vias of the microphone chip and the second metal.

19. The method of claim 13 further comprising forming an encapsulant between the application specific IC and the microphone chip.

20. The method of claim 19, wherein the encapsulant is positioned with respect to the exterior side of the first vias of the application specific IC and the second vias of the microphone chip.

21. The method of claim 13 further comprising forming a sealing layer between the application specific IC and the microphone chip to electrically connect the first vias and the second vias.

22. The method of claim 13 further comprising forming a plurality of external pads on the second surface of the application specific IC and electrically connecting the external pads and the first vias.

23. The method of claim 13 further comprising sawing the first wafer and the second wafer to form a plurality of MEMS microphone modules.