Micromechanical sensor device and corresponding manufacturing method

• US 9,725,309 B2
• Filed: 11/30/2015
• Issued: 08/08/2017
• Est. Priority Date: 12/01/2014
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Gonska, Julian, Reinmuth, Jochen
• Primary Examiner(s): Erdem, Fazli
• Application Number:
  US14/953,936
• Publication Number:
  US 20160152466A1
• Time in Patent Office: 617 Days
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: B81C 2203/0792 Forming interconnections between the electronic processing unit and the micromechanical structure

Abstract

A micromechanical sensor device includes: an ASIC substrate having a first front side and a first rear side; a rewiring element formed on the first front side and including multiple stacked conductor levels and insulating layers; a MEMS substrate having a second front side and a second rear side; a first micromechanical functional layer formed on top of the second front side; and a second micromechanical functional layer formed on top of the first micromechanical functional layer and connected to the rewiring element. In the second micromechanical functional layer, a movable sensor structure is anchored on one side via a first anchoring area, and an electrical connecting element formed in a second anchoring area is anchored on one side on the ASIC, and the first and second anchoring areas are elastically connected to one another via a spring element.

Claims

1. A micromechanical sensor device, comprising:

an ASIC substrate having a first front side and a first rear side;

a rewiring element formed on the first front side and including multiple stacked conductor levels and insulating layers;

a MEMS substrate having a second front side and a second rear side;

a first micromechanical functional layer formed on top of the second front side;

a second micromechanical functional layer formed on top of the first micromechanical functional layer and connected to the rewiring element via a bond connection;

a movable sensor structure formed in the second micromechanical functional layer and anchored on one side on the MEMS substrate via a first anchoring area formed in the second micromechanical functional layer;

an electrical connecting element which is formed in a second anchoring area of the second micromechanical functional layer and anchored on one side of the ASIC substrate via a contact area of the bond connection; and

a spring element formed in the second micromechanical functional layer and elastically connecting the first anchoring area and the second anchoring area to one another.

2. The micromechanical sensor device as recited in claim 1, wherein a further electrical contact element is formed in the first anchoring area.

3. The micromechanical sensor device as recited in claim 1, wherein the second anchoring area is electrically connected to the rewiring element via the contact area of the bond connection.

4. The micromechanical sensor device as recited in claim 1, wherein the second anchoring area is electrically connected to the rewiring element via an electrically insulating spacer area.

5. The micromechanical sensor device as recited in claim 1, wherein the electrical contact element has a perforation.

6. The micromechanical sensor device as recited in claim 4, wherein the electrical contact element and a conductor area formed in the first micromechanical functional layer together form a measuring capacitor structure.

7. The micromechanical sensor device as recited in claim 3, wherein the electrical contact element and a conductor area formed in the first micromechanical functional layer together form a short circuit test structure.

8. The micromechanical sensor device as recited in claim 1, wherein a cavity is formed between the first front side and the second front side, and wherein the first anchoring area and the second anchoring area are each delimited by the cavity on a respective unanchored side.

9. The micromechanical sensor device as recited in claim 8, wherein the bond connection includes a circumferential bond frame area.

10. The micromechanical sensor device as recited in claim 8, wherein the spring element is under pretensioning with respect to the first front side.

11. A manufacturing method for a micromechanical sensor device, comprising:

providing an ASIC substrate having a first front side and a first rear side;

forming a rewiring element which includes multiple stacked conductor levels and insulating layers on the first front side of the ASIC substrate;

providing a MEMS substrate having a second front side and a second rear side;

forming a first micromechanical functional layer on top of the second front side;

forming a second micromechanical functional layer on top of the first micromechanical functional layer;

forming a movable sensor structure in the second micromechanical functional layer and anchoring the movable sensor structure on one side on the MEMS substrate via a first anchoring area formed in the second micromechanical functional layer;

forming an electrical connecting element in a second anchoring area in the second micromechanical functional layer;

forming a spring element in the second micromechanical functional layer, wherein the spring element elastically connects the first anchoring area and the second anchoring area to one another; and

connecting the second micromechanical functional layer to the rewiring element via a bond connection, the second anchoring area being anchored on one side of the ASIC substrate via a contact area of the bond connection.

12. The manufacturing method as recited in claim 11, wherein a cavity is formed between the first front side and the second front side during the connection, so that the first anchoring area and the second anchoring area are each delimited by the cavity on a respective unanchored side.