US 11,650,221 B2Granted

MEMS tri-axial accelerometer with one or more decoupling elements

AssigneeSTMicroelectronics S.r.l.

InventorsAlessandro Tocchio, Francesco Rizzini

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Abstract

A MEMS tri-axial accelerometer is provided with a sensing structure having: a single inertial mass, with a main extension in a horizontal plane defined by a first horizontal axis and a second horizontal axis and internally defining a first window that traverses it throughout a thickness thereof along a vertical axis orthogonal to the horizontal plane; and a suspension structure, arranged within the window for elastically coupling the inertial mass to a single anchorage element, which is fixed with respect to a substrate and arranged within the window, so that the inertial mass is suspended above the substrate and is able to carry out, by the inertial effect, a first sensing movement, a second sensing movement, and a third sensing movement in respective sensing directions parallel to the first, second, and third horizontal axes following upon detection of a respective acceleration component. In particular, the suspension structure has at least one first decoupling element for decoupling at least one of the first, second, and third sensing movements from the remaining sensing movements.

Claims16

Dependent claims

A device, comprising:

a substrate;
an anchor on the substrate;
a decoupling element including:
a plurality of first portions surrounding the anchor;
a plurality of second portions extending outward from the plurality of first portions;
and
a plurality of third portions extending from the plurality first portions transverse to the plurality of second portions;
a plurality of first elastic coupling elements, each one of the plurality of first elastic coupling elements is coupled to one of the plurality of first portions of the decoupling element;
a plurality of second elastic coupling elements, each one of the plurality of second elastic coupling elements is coupled to one of the plurality of second portions of the decoupling element;
a first and second plurality of fixed electrodes on the substrate;
an inertial mass including:
a first portion;
a second portion that is larger than the first portion;
a first opening in the first portion, and the decoupling element, the anchor and the first and second elastic coupling elements are within the first opening, the decoupling element is coupled to the mass by the plurality of first elastic coupling elements, and the decoupling element is coupled to the anchor by the plurality of second elastic coupling elements;
a first and second plurality of mobile electrodes extend from the mass;
a second opening, and the first plurality of fixed electrodes and the first plurality of mobile electrodes are in the second opening;
and
a third opening separated from the second opening by the first opening, the second plurality of fixed electrodes and the second plurality of mobile electrodes are in the third opening.

15 more elements

A device, comprising:

a substrate;
an inertial mass;
an anchor coupled to the substrate, the anchor including a center;
a decoupling element including:
a first portion surrounding the anchor;
a second portion extending outward from the first portion;
and
a third portion extending outward from the first portion transverse to the second portion;
a first elastic element coupling the first portion of the decoupling element to the anchor;
and
a second elastic element;
an inertial mass surrounds the decoupling element, the anchor, the first elastic element, and the second elastic element, the inertial mass is coupled to the second portion by the second elastic element, the inertial mass includes:
a center spaced apart from the center of the anchor;
a first portion with a first dimension extending from the first elastic element to a first end of the inertial mass;
a second portion with a second dimension extending from the first elastic element to a second end of the inertial mass opposite to the first end, the second dimension being less than the first dimension;
and
a centroid of the inertial mass within the first portion of the inertial mass.

14 more elements

A device, comprising:

a substrate including a surface;
an inertial mass overlapping and spaced apart from the surface of the substrate;
an anchor coupled to the substrate;
a decoupling element including:
a first portion surrounding the anchor;
a second portion extending outward from the first portion;
and
a third portion extending outward from the first portion transverse to the second portion;
a fourth portion extending outward from the first portion opposite to the second portion;
and
a fifth portion extending outward from the first portion opposite to the third portion;
a first elastic element coupling the first portion of the decoupling element to the anchor;
a second elastic element coupling the second portion of the decoupling element to the inertial mass;
a third elastic element coupling the fourth portion of the decoupling element to anchor;
a fourth elastic coupling element coupling the fifth portion of the decoupling element to the inertial mass;
and
a plurality of first fixed electrodes on the surface of the substrate, the plurality of first fixed electrodes are between the surface of the substrate, and the inertial mass, and the plurality of first fixed electrodes are in electrical communication with the inertial mass.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/986,056Filed 5 Aug 2020 · division
Priority: IT 1020160001103543 Nov 2016
Published: US 2020/0363448 A119 Nov 2020
Granted: 16 May 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01P 15/18
Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration: in two or more dimensions
G01P 15/097
With conversion into electric or magnetic values: by vibratory elements
G01P 15/125
With conversion into electric or magnetic values: by capacitive pick-up
G01P 2015/0845
Being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration: using…

Family

Application15/639,524Parent of this division · filed 30 Jun 2017
US 2020/0363448 A1Pre-grant publication · published 19 Nov 2020
US 10,768,199 B2Parent of this division
US 2018/0120342 A1Published application
US 11,650,221 B2This patent

From the US filing history. Foreign family members aren’t listed.