Stress reduction during laser resealing through a temperature increase

Patent metadata

Field	Value
Publication number	US-11084716-B2
Application number	US-201615776341-A
Country	US
Kind code	B2
Filing date	Oct 12, 2016
Priority date	Dec 8, 2015
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A method for producing a micromechanical component having a substrate and a cap that are connected to each other and that enclose a first cavity, where a first pressure prevails inside the first cavity and a first gas mixture having a first chemical composition is enclosed within the first cavity, includes, in a first method step, developing in the substrate or cap an access opening connecting the first cavity to an environment of the micromechanical component, in a second method step, setting the first pressure and/or the first chemical composition in the first cavity, in a third method step, sealing the access opening using a laser by introduction of energy or heat into an absorbing part of the substrate or the cap, and, in a fourth method step, performing a thermal treatment of the substrate or the cap, thereby reducing temperature gradients in the substrate or in the cap.

First claim

What is claimed is:

1. A method for producing a micromechanical component that includes a substrate and a cap that are connected to each other and that enclose a first cavity, a first pressure prevailing in the first cavity, and a first gas mixture having a first chemical composition being enclosed within the first cavity, the method comprising:
in a first step, forming in the substrate or in the cap an access opening that connects the first cavity to an environment external to the micromechanical component;
in a second method step, setting at least one of the first pressure and the first chemical composition in the first cavity;
in a third method step, laser sealing the access opening by introducing energy or heat into an absorbing part of the substrate or the cap, thereby liquefying the absorbing part, the liquefied absorbing part thereafter cooling and solidifying; and
in a fourth method step, which is carried out temporally at least one of before, during, and after the third method step, performing a thermal treatment of the substrate or the cap at least in a region that is adjacent to the absorbing part and that does not liquefy in the third method step, the thermal treatment reducing temperature gradients in the substrate or in the cap between the absorbing part and the region that is adjacent to the absorbing part.

2. The method of claim 1 , wherein the thermal treatment includes raising a temperature of an entirety of the substrate or the cap.

3. The method of claim 1 , wherein the thermal treatment is carried out on a heating plate.

4. The method of claim 1 , wherein the thermal treatment is carried out using a spatially restricted heat source.

5. The method of claim 1 , wherein the thermal treatment is carried out using at least one of a laser, a light-emitting diode (LED), a laser diode, and a flash lamp.

6. The method of claim 1 , wherein the thermal treatment is performed includes raising the temperature of only the region that is adjacent to the absorbing part, the region consisting of a surface of the substrate or the cap that faces away from the first cavity.

7. The method of claim 1 , wherein the thermal treatment is carried out using a homogenous irradiation.

8. The method of claim 1 , wherein the fourth method step is carried out before the third method step.

9. The method of claim 1 , wherein the fourth method step is carried out during the third method step.

10. The method of claim 1 , wherein the fourth method step is carried out after the third method step.

11. The method of claim 1 , further comprising, in a fifth method step that is carried out prior to the first method step, bonding the substrate and the cap to each other.

12. The method of claim 1 , further comprising, in a fifth method step that is carried out after the first method step, bonding the substrate and the cap to each other.

Assignees

• Bosch Gmbh Robert

Inventors

• Amthor Julia
• Ametowobla Mawuli
• Kappe Philip

Classifications

• B81C2203/0145

  Hermetically sealing an opening in the lid · CPC title

• B81B7/02

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

• B81B2201/0235

  Accelerometers · CPC title

• B81C1/00293 Primary

  maintaining a controlled atmosphere with processes not provided for in B81C1/00285 · CPC title

• B81B2201/0242

  Gyroscopes · CPC title