Generating a MEMS device with glass cover and MEMS device

Patent metadata

Field	Value
Publication number	US-12534360-B2
Application number	US-202016890534-A
Country	US
Kind code	B2
Filing date	Jun 2, 2020
Priority date	Jun 7, 2019
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

In a method of generating a microelectromechanical system, MEMS, device, a MEMS substrate including a movable element is provided. A glass cover member including a glass cover is formed by hot embossing. The glass cover member is bonded to the MEMS substrate so as to hermetically seal by the glass cover a cavity in which the movable element is arranged.

First claim

What is claimed is:

1 . A method of generating a microelectromechanical system (MEMS) device, the method comprising:
providing a MEMS substrate comprising a plurality of movable elements; heating a glass to a transition temperature of the glass; performing hot embossing by utilizing a pre-structured pressing tool to press the heated glass to form a first glass cover member comprising a plurality of first glass covers,
wherein a surface roughness of the glass cover member is less than 4 nm;
bonding, during a frontend process occurring prior to pre-assembly of the MEMS device and prior to a process for assembly of a printed circuit board, the first glass cover member to a first side of the MEMS substrate; performing hot embossing to form a second glass cover member comprising a plurality of second glass covers; and bonding, after bonding the first glass cover member to the first side of the MEMS substrate, the second glass cover member to a second side of the MEMS substrate opposite the first side thereof, wherein the first glass cover member and the second glass cover member are bonded to the MEMS substrate so as to hermetically seal by a respective one of the first glass cover and the second glass cover one of a plurality of cavities, wherein one of the plurality of movable elements is arranged in each of the plurality of cavities and, by being arranged in each of the plurality of cavities, is separated from each of the plurality of movable elements from a remaining portion of movable elements of the plurality of movable elements, and wherein the plurality of movable elements comprise a plurality of movable mirrors for a light detection and ranging (LIDAR) application or a plurality of movable parts of an optical gas sensor, of an optical pressure sensor, or of an optical acceleration sensor.

2 . The method of claim 1 , further comprising:
singularizing the MEMS substrate and the first glass cover member bonded thereto into a plurality of MEMS devices, wherein the plurality of cavities remain hermetically sealed.

3 . The method of claim 1 ,
wherein bonding the first glass cover member to the first side of the MEMS substrate comprises using a laser microwelding method.

4 . The method of claim 1 ,
wherein each glass cover of the plurality of first glass covers comprises side walls extending in an angle of between 80° and 90° relative to a plane of the MEMS substrate.

5 . The method of claim 1 ,
wherein each glass cover of the plurality of first glass covers comprises sharp edges between different portions thereof and does not comprise rounded transitions between portions thereof.

6 . The method of claim 1 ,
wherein each glass cover of the plurality of first glass covers comprises a dome shaped structure.

7 . The method of claim 1 , further comprising:
providing a perforated spacer layer between the first glass cover member and the MEMS substrate prior to bonding the first glass cover member to the first side of the MEMS substrate.

8 . The method of claim 1 , further comprising:
bonding the first glass cover member to the first side of the MEMS substrate in a presence of an inert process gas.

9 . The method of claim 1 ,
wherein the plurality of movable elements are the plurality of movable mirrors for the LIDAR application.

10 . The method of claim 1 ,
wherein the plurality of movable elements are the plurality of movable parts of the optical gas sensor.

11 . The method of claim 1 ,
wherein forming the first glass cover member comprises forming a mechanical stop member protruding from each of the plurality of first glass covers inwards and representing a mechanical stop for a movement of each of the plurality of movable elements upon bonding the first glass cover member to the first side of the MEMS substrate.

12 . The method of claim 1 ,
wherein the plurality of movable elements are the plurality of movable parts of the optical pressure sensor.

13 . The method of claim 1 ,
wherein the plurality of movable elements are the plurality of movable parts of the optical acceleration sensor.

14 . A method of generating a microelectromechanical system (MEMS) device, the method comprising:
heating a glass to a transition temperature of the glass; performing hot embossing by utilizing a pre-structured pressing tool to press the heated glass to form a first glass cover member comprising a plurality of first glass covers,
wherein a surface roughness of the glass cover member is less than 4 nm;
bonding, during a frontend process occurring prior to pre-assembly of the MEMS device and prior to a process for assembly of a printed circuit board, the first glass cover member to a first side of a MEMS substrate; performing hot embossing to form a second glass cover member comprising a plurality of second glass covers; and bonding, after bonding the first glass cover member to the first side of the MEMS substrate, the second glass cover member to a second side of the MEMS substrate opposite the first side thereof, wherein the first glass cover member and the second glass cover member are bonded to the MEMS substrate so as to hermetically seal by a respective one of the first glass cover and the second glass cover one of a plurality of cavities, wherein one of a plurality of movable elements is arranged in each of the plurality of cavities and, by being arranged in each of the plurality of cavities, is separated from each of the plurality of movable elements from a remaining portion of movable elements of the plurality of movable elements, and wherein the plurality of movable elements comprise a plurality of movable mirrors for a light detection and ranging (LIDAR) application or a plurality of movable parts of an optical gas sensor, of an optical pressure sensor, or of an optical acceleration sensor.

15 . The method of claim 14 , further comprising:
singularizing the MEMS substrate and the first glass cover member bonded thereto into a plurality of MEMS devices, wherein the plurality of cavities remain hermetically sealed.

16 . The method of claim 14 ,
wherein bonding the first glass cover member to the first side of the MEMS substrate comprises:
using a laser microwelding method to bond the first glass cover member to the first side of the MEMS substrate.

17 . The method of claim 14 ,
wherein each glass cover of the plurality of first glass covers comprises side walls extending in an angle of between 80° and 90° relative to a plane of the MEMS substrate.

18 . The method of claim 14 ,
wherein each glass cover of the plurality of first glass covers comprises sharp edges between different portions thereof and does not comprise rounded transitions between portions thereof.

19 . The method of claim 14 ,
wherein each glass cover of the plurality of first glass covers comprises a dome shaped structure.

20 . The method of claim 14 , further comprising:
providing a perforated spacer layer between the first glass cover member and the MEMS substrate prior to bonding the first glass cover member to the first side of the MEMS substrate.

21 . The method of claim 14 , further comprising:
bonding the first glass cover member to the first side of the MEMS substrate in a presence of an inert process gas.

22 . The method of claim 14 ,
wherein the plurality of movable elements are the plurality of movable mirrors for the LIDAR application.

23 . The method of claim 14 ,
wherein the plura

Assignees

• Infineon Technologies Ag

Inventors

• Brockmeier Andre
• Janski Rafael
• Kirillov Boris
• Oldsen Marten
• Roessler Clemens
• Santos Rodriguez Francisco Javier
• Sgouridis Sokratis
• Sorschag Kurt

Classifications

• B81C2203/037

  Thermal bonding techniques not provided for in B81C2203/035 - B81C2203/036 · CPC title

• B81C2203/0118

  Bonding a wafer on the substrate, i.e. where the cap consists of another wafer · CPC title

• B81C2201/036

  Hot embossing · CPC title

• B81B2201/047

  Optical MEMS not provided for in B81B2201/042 - B81B2201/045 · CPC title

• B81B2201/042

  Micromirrors, not used as optical switches · CPC title