System for protecting mems product under ESD event

Patent metadata

Field	Value
Publication number	US-11802040-B2
Application number	US-202117151654-A
Country	US
Kind code	B2
Filing date	Jan 18, 2021
Priority date	Jan 18, 2021
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

The present invention discloses a system for protecting a MEMS product from an ESD event, including, a control circuit; a MEMS product, electrically connected with the control circuit; an ESD protection device, electrically connected with the control circuit, and electrically connected with the MEMS product in parallel; wherein, the ESD protection device comprises: a top electrode assembly electrically connected with the control circuit; a flexible beam comprising a first electrode layer electrically connected with the control circuit, a second electrode layer electrically connected with the MEMS product, and a moving metal contact electrically connected with the second electrode layer; a bottom electrode assembly having a bottom electrode layer electrically connected with the MEMS product and a fixed metal contact electrically connected with the bottom electrode layer and facing the moving metal contact.

First claim

What is claimed is:

1. A system for protecting a MEMS product from an ESD event, comprising, a control circuit;
a MEMS product, electrically connected with the control circuit;
an ESD protection device, electrically connected with the control circuit, and electrically connected with the MEMS product in parallel; wherein, the ESD protection device comprises:
a top electrode assembly electrically connected with the control circuit;
a flexible beam comprising a first electrode layer electrically connected with the control circuit, a second electrode layer electrically connected with the MEMS product, and a moving metal contact electrically connected with the second electrode layer;
a bottom electrode assembly having a bottom electrode layer electrically connected with the MEMS product and a fixed metal contact electrically connected with the bottom electrode layer and facing the moving metal contact.

2. The system according to claim 1 , wherein, the ESD protection device further comprises a housing having a cavity, the beam received in the cavity and elastically supported by the housing.

3. The system according to claim 2 , wherein, the housing comprises a top wall, a bottom wall and a side wall connected between the top wall and the bottom wall, the top electrode assembly fixed to the top wall, the bottom electrode assembly fixed to the bottom wall, the beam fixed to the side wall.

4. The system according to claim 3 , wherein, the ESD protection device further comprises a flexible member, one end of the flexible member is connected with the beam, and the other end of the flexible member is connected with the side wall.

5. The system according to claim 1 , wherein, the top electrode assembly comprises a plurality of top electrodes spaced apart from each other, a top oxide layer encapsulating the top electrodes and at least one bump protruding toward the beam from the top oxide layer.

6. The system according to claim 5 , wherein, the beam further comprises a first oxide layer encapsulating the first electrode layer and a second oxide layer encapsulating the second electrode layer, the moving metal contact exposed out of the second oxide layer.

7. The system according to claim 6 , wherein, the first oxide layer and the second oxide layer are formed integrally.

8. The system according to claim 6 , wherein, the bottom electrode assembly further comprises a bottom oxide layer encapsulating the bottom electrode layer, and the fixed metal contact exposed out of the bottom oxide layer.

9. The system according to claim 1 , wherein, an area of the beam of the ESD protection device is larger than that of the MEMS product.

10. The system according to claim 1 , wherein, a contact resistance between the moving metal contact and the fixed metal contact is lower than that of the MEMS product.

11. The system according to claim 1 , wherein, the control circuit comprises a CMOS circuit and a high voltage input electrically connected with the CMOS circuit; the MEMS product and the ESD protection device both electrically connected with the high voltage input, and the CMOS circuit is configured to control the high voltage input to be electrically connected with the MEMS product or the ESD protection device.

Assignees

• Aac Tech Nanjing Co Ltd
• Aac Technologies Pte Ltd

Inventors

• Giles David Molinero

Classifications

• B81B7/0022 Primary

  Protection against electrostatic discharge (circuit arrangements for protecting electronic switching circuits used for pulse technique against overcurrent or overvoltage H03K17/08; electrostatic discharge protection for electronic semiconductor circuits H10D89/60) · CPC title

• B81B3/0086

  Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage · CPC title

• B81B7/0064

  for protecting against electromagnetic or electrostatic interferences · CPC title

• B81B2201/01

  Switches · CPC title

• B81B7/02 Primary

  containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] (B81B7/04 takes precedence) · CPC title