Wafer level assembly of a MEMS sensor device and related MEMS sensor device

Patent metadata

Field	Value
Publication number	US-9628919-B2
Application number	US-201414265053-A
Country	US
Kind code	B2
Filing date	Apr 29, 2014
Priority date	Apr 30, 2013
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

An assembly of a MEMS sensor device envisages: a first die, integrating a micromechanical detection structure and having an external main face; a second die, integrating an electronic circuit operatively coupled to the micromechanical detection structure, electrically and mechanically coupled to the first die and having a respective external main face. Both of the external main faces of the first die and of the second die are set in direct contact with an environment external to the assembly, without interposition of a package.

First claim

The invention claimed is:

1. A MEMS sensor device assembly comprising:
a single first semiconductor die having an internal surface and an opposite, external surface, a micromechanical detection structure integrated in the first semiconductor die at the internal surface; and
a single second semiconductor die having an internal surface and an opposite, external surface, an ASIC embedded in the second semiconductor die, the ASIC being operatively coupled to said micromechanical detection structure, the internal surface of the second semiconductor die coupled to the internal surface of said first semiconductor die, the external surfaces of the first and second semiconductor dice being exposed outer surfaces of the assembly, at least one of the external surfaces being configured to be placed in direct contact with a structure external to the assembly, the second semiconductor die having a cavity that at least partially receives the micromechanical detection structure of the first semiconductor die.

2. The assembly according to claim 1 , wherein said external surfaces of said first and second semiconductor dice are in respective parallel planes, and said first and second semiconductor dice are coupled in a direction that is transverse to said planes.

3. The assembly according to claim 1 , wherein said first and second semiconductor dice are configured to be mechanically and electrically coupled to the structure external to the assembly without interposition of packaging material.

4. The assembly according to claim 1 , wherein the internal surface of the second semiconductor die is directly coupled to the internal surface of the first semiconductor die by electrical connection elements.

5. The assembly according to claim 1 , wherein said external surface that is configured to be coupled directly to the structure external to the assembly includes a first electrical-connection element configured to electrically couple the assembly to said structure.

6. The assembly according to claim 5 , further comprising:
a second electrical-connection element located between said internal surfaces of said first and second semiconductor dice and electrically coupling said micromechanical detection structure to said electronic circuit;
a conductive through via that extends through one of said first and second semiconductor dice; and
a third electrical-connection element located between said internal surfaces of said first and second semiconductor dice and configured to electrically couple to the first electrical-connection elements by the conductive through via.

7. The assembly according to claim 1 , comprising a coupling ring between said first and second semiconductor dice that couples the first and second semiconductor dice together, the coupling ring surrounding said micromechanical detection structure.

8. The assembly according to claim 1 , wherein said micromechanical detection structure is an acoustic transducer, and includes a substrate of semiconductor material having a first cavity, a membrane suspended over the first cavity, and a rigid plate capacitively coupled to the membrane.

9. The assembly according to claim 8 , wherein:
the first semiconductor die includes a through opening that places the first cavity in fluid contact with an environment that is external to the assembly and allows acoustic-pressure waves to enter said assembly.

10. The assembly according to claim 1 , wherein said micromechanical detection structure is a pressure sensor, and includes a substrate of semiconductor material having a membrane suspended over a buried cavity; wherein said pressure sensor further includes elastic elements that couple said membrane to said substrate, said membrane being suspended on one side by a cavity in the first semiconductor die.

11. The assembly according to claim 1 , wherein said first and second semiconductor dice have external side surfaces that are transverse to said external surfaces and internal surfaces and are configured to be placed in direct contact with an external structure.

12. A MEMS sensor device assembly comprising:
a single first semiconductor die having an internal surface and an opposite, external surface, a first micromechanical detection structure integrated in the first semiconductor die at the internal surface;
a single second semiconductor die having an internal surface and an opposite, external surface, an ASIC embedded in the second semiconductor die, the ASIC being operatively coupled to said first micromechanical detection structure, the internal surface of the second semiconductor die coupled to the internal surface of said first semiconductor die, the external surfaces of the first and second semiconductor dice being exposed outer surfaces of the assembly, and at least one of the external surfaces being configured to be placed in direct contact with a structure external to the assembly, wherein said second semiconductor die includes a cavity that is located proximate the first micromechanical detection structure; and
a third semiconductor die integrating a second micromechanical detection structure, the third semiconductor die being secured to the internal surface of the second semiconductor die, housed within said cavity in said second semiconductor die, and facing, at a distance, said first micromechanical detection structure and being electrically coupled to said ASIC.

13. The assembly according to claim 12 , wherein said cavity in said second semiconductor die has side walls, the assembly further comprises conductive paths having respective portions located on the side walls, respectively, and said second micromechanical detection structure in said third semiconductor die is coupled to said ASIC by the conductive paths.

14. The assembly according to claim 13 , comprising a fourth semiconductor die integrating a third micromechanical detection structure, the fourth semiconductor die secured to the internal surface of the second semiconductor die and housed within said cavity in said second semiconductor die, said third micromechanical detection structure being electrically coupled to said ASIC.

15. An electronic apparatus, comprising:
a MEMS sensor device including:
a single first semiconductor die having a first surface, a second, opposite surface, and a micromechanical detection structure integrated in the first semiconductor die at the first surface; and
a single second semiconductor die having a first surface and a second, opposite surface, an ASIC integrated in the second semiconductor die at the first surface, the ASIC being operatively coupled to said micromechanical detection structure, the first surface of the second semiconductor die being coupled to the first surface of the first semiconductor die, the second surface of the first semiconductor die and the second surface of the second semiconductor die forming external surfaces of the assembly, the second semiconductor die having a cavity that at least partially receives the micromechanical detection structure of the first semiconductor die;

a printed circuit board coupled to conductive elements of one of the second surfaces of the first and second semiconductor dice without the interpositioning of packaging material.

16. The electronic apparatus according to claim 15 , wherein the micromechanical detection structure is a pressure sensor that includes a semiconductor substrate, a suspended membrane that is elastically coupled to the substrate, and a rigid electrode that is capacitively coupled to the suspended membrane.

17. The electronic apparatus according to claim 15 , wherein the first mi

Assignees

• St Microelectronics Srl

Inventors

• Conti Sebastiano
• Perletti Matteo
• Carminati Roberto
• Baldo Lorenzo
• Morcelli Alessandro

Classifications

• H01L29/84

  Electricity · mapped topic

• H04R1/04

  Structural association of microphone with electric circuitry therefor (in electric hearing aids H04R25/00) · CPC title

• H04R19/04

  Microphones (H04R19/01 takes precedence) · CPC title

• H04R19/005 Primary

  using semiconductor materials · CPC title

• H10D48/50

  Devices controlled by mechanical forces, e.g. pressure · CPC title