WATERPROOF MICROPHONE AND ASSOCIATED PACKING TECHNIQUES

• US 20200131029A1
• Filed: 12/31/2019
• Published: 04/30/2020
• Est. Priority Date: 11/18/2015
• Status: Active Grant

• Current Assignee: Darcet Company Limited
• Original Assignee: Innogrity Pte Ltd.
• Inventors: SOORIAKUMAR, Kathirgamasundaram, AUSTIN, Anu, BIHAG, Ian Rose
• Granted Patent: US 11,312,620 B2
• Time in Patent Office: Days
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2207/11 Structural features, others than packages, for protecting a device against environmental influences
• CPC Class Codes: B81B 2207/99 Microstructural systems or auxiliary parts thereof not provided for in B81B2207/01 - B81B2207/115
• 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 7/0061 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: H04R 1/04 Structural association of microphone with electric circuitry therefor in deaf-aid sets H04R25/00
• CPC Class Codes: H04R 1/2876 by means of damping material, e.g. as cladding damping material for tuning desired resonances H04R1/2807, e.g. in vents H04R1/2823, H04R1/2846
• CPC Class Codes: H04R 1/44 Special adaptations for subaqueous use, e.g. for hydrophone
• CPC Class Codes: H04R 17/02 Microphones
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 Mems transducers or their use

Abstract

Aspects of the disclosure provide a waterproof packaging technique for fabricating waterproof microphones in mobile devices. A device based on the waterproof packaging technique can include a microelectromechanical system (MEMS) device, a housing enclosing the MEMS device, and a liquid-resistant air inlet passive device (LRAPD) on the housing. The LRAPD can include at least one channel connecting an exterior of the housing with a chamber formed between the housing and the MEMS device. An inside surface of the channel can be coated with a liquid-repellant coating. In some examples, the liquid-repellant coating can be a self-assembled monolayer (SAM) coating.

Claims

1. A device, comprising:

a microelectromechanical system (MEMS) device;

a housing enclosing the MEMS device, wherein a chamber is formed between the housing and the MEMS device; and

a liquid-resistant air inlet passive device (LRAPD) attached to the housing, the LRAPD being a separate structure independent from the housing, the LRAPD including a channel fluidically connecting the exterior of the housing and the chamber.

2. The device of claim 1, wherein no part of the channel of the LRAPD is formed by the housing.

3. The device of claim 1, wherein the LRAPD is independently manufactured from the housing.

4. The device of claim 1, the channel of the LRAPD further including

a first section having a first length;

and

a second section having a second length;

wherein the first section and the second section is connected to each other at an angle.

5. The device of claim 4, wherein the first section and the second section is connected to each other without any object in between.

6. The device of claim 4, wherein the first length is shorter than the second length.

7. The device of claim 4, wherein the angle is substantially ninety degree.

8. The device of claim 4, the channel including a third section connected to the second section forming a zigzag pathway of the channel.

9. The device of claim 1, wherein an inside surface of the channel is hydrophobic.

10. The device of claim 1, wherein an inside surface of the channel is coated with a liquid-repellant coating.

11. The device of claim 9, wherein the liquid-repellant coating is a self-assembled monolayer (SAM) coating.

12. The device of claim 1, the channel being a zigzag.

13. A method of making a liquid-resistant air inlet passive device (LRAPD) comprising:

forming a first channel path in a first substrate;

bonding a second substrate to the first substrate; and

forming a second channel path through the second substrate,

wherein one end of the second channel path is connected to the first channel path.

14. The method of claim 13, wherein the first substrate and/or the second substrate is silicon substrate.

15. The method of claim 13, wherein a top surface of the first substrate and a bottom surface of the second substrate are bonded to each other.

16. The method of claim 13, wherein the first substrate and the second substrate are thermally bonded.

17. The method of claim 13, wherein the first channel path is etched on a top surface of the first substrate.

18. The method of claim 13 further including

coating a hydrophobic layer on a surface of the first channel path.

19. The method of claim 13 further including

forming a third channel path through the first substrate, one end of the third channel path being connected to the first channel path.

20. The method of claim 19, wherein the first channel path, the second channel path, and the third channel path forms a channel fluidically connecting a surface of the second substrate and a surface of the first substrate.