JP-7855846-B2 - Physical quantity sensors and inertial measurement devices

JP7855846B2JP 7855846 B2JP7855846 B2JP 7855846B2JP-7855846-B2

Inventors

田中悟

Assignees

セイコーエプソン株式会社

Dates

Publication Date: 20260511
Application Date: 20211029

Claims (12)

When the three mutually orthogonal axes are defined as the X-axis, Y-axis, and Z-axis, A substrate including a first surface and a second surface that are perpendicular to the Z-axis and are in a front-back relationship with each other, The first element portion is located on the first surface of the substrate, On the first surface of the substrate, there is a second element portion which is arranged point-symmetrically with respect to the first element portion, Includes, The first element section is, The first fixing part fixed to the substrate, A first support beam connected to the first fixed part and extending in the Y-axis direction along the Y-axis, A first movable body is provided with respect to the first support beam, having a movable portion only on the negative side of the X-axis, and being pivotable relative to the substrate with the first support beam as the axis of rotation, Includes, The second element section is, The second fixing part fixed to the substrate, A second support beam connected to the second fixed part and extending in the Y-axis direction along the Y-axis, A second movable body is provided with respect to the second support beam, having a movable portion only on the positive side of the X-axis, and being able to swing with respect to the substrate with the second support beam as the axis of rotation, Includes, The first movable body is The other end of the first support beam is connected to a first connecting portion, A first movable electrode portion is positioned on the negative side of the X-axis relative to the first support beam, Includes, The second movable body is The second connecting portion to which the other end of the second support beam is connected, A second movable electrode portion is positioned on the positive side of the X-axis relative to the second support beam, Includes, The first connecting portion is, The other end of the first support beam is connected to a second portion that extends in the X-axis direction along the X-axis, The first portion is positioned on the negative side of the X-axis relative to the first support beam and extends in the Y-axis direction from the negative end of the Y-axis of the second portion, A third portion is positioned on the negative side of the X-axis than the first portion and extends in the Y-axis direction from the negative end of the Y-axis of the second portion, A first base movable electrode is positioned on the negative side of the X-axis than the third portion and extends in the Y-axis direction from the negative end of the Y-axis of the second portion, Includes, The second connecting portion is, The other end of the second support beam is connected to a fifth portion that extends in the X-axis direction along the X-axis, A fourth portion is positioned on the positive side of the X-axis than the second support beam and extends in the Y-axis direction from the positive end of the Y-axis of the fifth portion, A sixth portion is positioned on the positive side of the X-axis than the fourth portion and extends in the Y-axis direction from the positive end of the Y-axis of the fifth portion, A second base movable electrode is positioned on the positive side of the X-axis than the sixth portion and extends in the Y-axis direction from the positive end of the Y-axis of the fifth portion, Includes, The first element unit includes a first detection unit, The second element section includes a second detection section, The first detection unit is, The first fixed electrode portion includes a fixed portion fixed to the substrate and extending from the fixed portion in the Y-axis direction, The first movable electrode portion and, Composed of, The first movable electrode portion is, The first base movable electrode and, A group of first comb-tooth movable electrodes extending in the X-axis direction from the first base movable electrode, Includes, Each of the first movable electrode fingers of the first comb tooth movable electrode group, Each of the first fixed electrode fingers of the first comb-tooth fixed electrode group extending in the X-axis direction from the first fixed electrode portion, They are arranged so that they face each other alternately. The second detection unit is, The fixed portion includes a fixed portion fixed to the substrate, and a second fixed electrode portion extending from the fixed portion in the Y-axis direction, The above-described second movable electrode portion and Composed of, The second movable electrode portion is, The second base movable electrode and, A group of second comb-tooth movable electrodes extending in the X-axis direction from the second base movable electrode, Includes, Each of the second movable electrode fingers of the second comb tooth movable electrode group, Each second fixed electrode finger of the second comb-tooth fixed electrode group extending in the X-axis direction from the second fixed electrode portion, A physical quantity sensor characterized by having two elements arranged to face each other alternately.
In claim 1, The first movable electrode finger and the first fixed electrode finger face each other in the Y-axis direction, A physical quantity sensor characterized in that the second movable electrode finger and the second fixed electrode finger are facing each other in the Y-axis direction.
In claim 1 or 2, Each of the first movable electrode fingers is The first movable electrode comb teeth extend from the positive end of the first base movable electrode toward the positive side of the X-axis toward the positive side of the X-axis , The second movable electrode comb teeth extend from the negative end of the first base movable electrode in the X-axis direction toward the negative side of the X-axis, Includes, The first fixed electrode portion consists of a pair of first fixed electrode portions. The first fixed electrode finger is, A first fixed electrode comb tooth extending from one of the pair of first fixed electrode portions toward the negative side of the X-axis, A second fixed electrode comb tooth extending from the other of the pair of first fixed electrode portions toward the positive side of the X-axis, Includes, The first movable electrode comb teeth and the first fixed electrode comb teeth face each other in the Y-axis direction, A physical quantity sensor characterized in that the second movable electrode comb teeth and the second fixed electrode comb teeth are facing each other in the Y-axis direction.
In claim 3, Each of the aforementioned second movable electrode fingers is A third movable electrode comb tooth extending from the positive end of the second base movable electrode in the X-axis direction toward the positive side of the X-axis , A fourth movable electrode comb tooth extending from the negative end of the second base movable electrode in the X-axis direction toward the negative side of the X-axis, Includes, The second fixed electrode portion consists of a pair of second fixed electrode portions. The second fixed electrode finger is, A third fixed electrode comb tooth extends from one of the pair of second fixed electrode portions toward the negative side of the X-axis, A fourth fixed electrode comb tooth extending from the other of the pair of second fixed electrode portions toward the positive side of the X-axis, Includes, The third movable electrode comb teeth and the third fixed electrode comb teeth face each other in the Y-axis direction, A physical quantity sensor characterized in that the fourth movable electrode comb teeth and the fourth fixed electrode comb teeth are facing each other in the Y-axis direction.
In claim 1 or 2, The first fixed electrode portion is, First base fixed electrode and The first fixed electrode comb teeth extending in the X-axis direction from the first base fixed electrode, The second fixed electrode comb teeth extend from the first base fixed electrode in the opposite direction to the X-axis direction, Includes, The first movable electrode portion is, The first movable electrode comb teeth facing the first fixed electrode comb teeth, The second movable electrode comb teeth facing the second fixed electrode comb teeth, A physical quantity sensor characterized by including [something].
In claim 5, The second fixed electrode portion is, Second base fixed electrode, The third fixed electrode comb teeth extending in the X-axis direction from the second base fixed electrode, A fourth fixed electrode comb tooth extending from the second base fixed electrode in the opposite direction to the X-axis, Includes, The second movable electrode portion is, A third movable electrode comb tooth facing the third fixed electrode comb tooth, A fourth movable electrode comb tooth facing the fourth fixed electrode comb tooth, A physical quantity sensor characterized by including [something].
In any one of claims 1 to 6, When the first movable electrode portion and the second movable electrode portion are displaced to the positive side of the Z axis, the capacitance between the first movable electrode portion and the first fixed electrode portion decreases. A physical quantity sensor characterized in that when the first movable electrode portion and the second movable electrode portion are displaced to the negative side of the Z axis, the capacitance between the second movable electrode portion and the second fixed electrode portion decreases.
In claim 1 or 2, When the first movable electrode portion and the second movable electrode portion are displaced to the positive side of the Z axis, In the arrangement area of the first movable electrode portion and the first fixed electrode portion, the capacitance between the first movable electrode portion and the first fixed electrode portion arranged in the first region decreases, In the arrangement area of the second movable electrode portion and the second fixed electrode portion, the capacitance between the second movable electrode portion and the second fixed electrode portion located in the fourth region decreases, When the first movable electrode portion and the second movable electrode portion are displaced to the negative side of the Z axis, Of the arrangement areas of the first movable electrode and the first fixed electrode, the capacitance between the first movable electrode and the first fixed electrode, which are arranged in the second area, decreases. A physical quantity sensor characterized in that the capacitance between the second movable electrode portion and the second fixed electrode portion, which are located in a third region of the arrangement area of the second movable electrode portion and the second fixed electrode portion, decreases.
In claim 8, The first region and the second region are, This is a region in the arrangement area of the first movable electrode portion and the first fixed electrode portion that is aligned along the X-axis direction, The third and fourth regions are, A physical quantity sensor characterized in that the area where the second movable electrode portion and the second fixed electrode portion are arranged is a region aligned along the X-axis direction.
In claim 8, The first region and the second region are, This is a region in the arrangement area of the first movable electrode portion and the first fixed electrode portion that is aligned along the Y-axis direction, The third and fourth regions are, A physical quantity sensor characterized in that the area where the second movable electrode portion and the second fixed electrode portion are arranged is an area aligned along the Y-axis direction.
In any one of claims 1 to 10, In a plan view from the Z-axis direction along the Z-axis , the first movable electrode portion, the second fixed portion and the second support beam, the first fixed portion and the first support beam, and the second movable electrode portion are, A physical quantity sensor characterized in that the first movable electrode portion, the second fixed portion and the second support beam, the first fixed portion and the first support beam, and the second movable electrode portion are arranged in that order along the X-axis direction.
A physical quantity sensor according to any one of claims 1 to 11, A control unit that performs control based on the detection signal output from the physical quantity sensor, An inertial measuring device characterized by including [a certain element].

Description

This invention relates to a physical quantity sensor and an inertial measurement device, etc. Physical quantity sensors that detect physical quantities such as acceleration have been known for some time. For example, one such physical quantity sensor is the one disclosed in Patent Document 1. Patent Document 1 discloses a physical quantity sensor in which multiple sensor elements are arranged, each having a fixed electrode and a movable electrode, to detect physical quantities. Japanese Patent Publication No. 2021-32820 A plan view showing an example configuration of the physical quantity sensor of this embodiment.Diagram illustrating the placement of physical quantity sensors.Operational diagram of the detection unit.Operational diagram of the detection unit.Operational diagram of the detection unit.A plan view showing other configuration examples of physical quantity sensors.A plan view showing other configuration examples of physical quantity sensors.A plan view showing other configuration examples of physical quantity sensors.A plan view showing other configuration examples of physical quantity sensors.An exploded perspective view showing the schematic configuration of an inertial measurement device equipped with physical quantity sensors.Perspective view of the circuit board of a physical quantity sensor. The following describes this embodiment. Note that the embodiment described below does not unduly limit the scope of the claims. Furthermore, not all of the configurations described in this embodiment are necessarily essential components. 1. Physical Quantity Sensor An example of the configuration of the physical quantity sensor 1 of this embodiment will be described with reference to Figure 1, using an acceleration sensor that detects vertical acceleration as an example. Figure 1 is a plan view of the physical quantity sensor 1 in a direction perpendicular to the substrate 2. The physical quantity sensor 1 is a MEMS (Micro Electro Mechanical Systems) device, such as an inertial sensor. Note that in Figure 1 and Figures 6 to 9 described later, the dimensions of each component and the spacing between components are shown schematically for the sake of explanation, and not all components are shown. For example, electrode wiring and electrode terminals are omitted from the illustration. Furthermore, in the following explanation, the physical quantity detected by the physical quantity sensor 1 is mainly used as an example, but the physical quantity is not limited to acceleration and may be other physical quantities such as velocity, pressure, displacement, angular velocity, or gravity, and the physical quantity sensor 1 may be used as a pressure sensor or a MEMS switch, etc. Also, in Figure 1, the mutually orthogonal directions are referred to as the first direction DR1, the second direction DR2, and the third direction DR3. The first direction DR1, the second direction DR2, and the third direction DR3 are, for example, the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively, but are not limited to these. For example, the third direction DR3 corresponding to the Z-axis direction is, for example, the direction orthogonal to the substrate 2 of the physical quantity sensor 1, for example, the vertical direction. The first direction DR1, corresponding to the X-axis, and the second direction DR2, corresponding to the Y-axis, are perpendicular to the third direction DR3. The XY plane, which is the plane along the first direction DR1 and the second direction DR2, is, for example, aligned with the horizontal plane. Note that "perpendicular" includes not only planes that intersect at 90°, but also planes that intersect at an angle slightly inclined from 90°. The substrate 2 is, for example, a silicon substrate made of semiconductor silicon or a glass substrate made of a glass material such as borosilicate glass. However, the constituent material of the substrate 2 is not particularly limited, and a quartz substrate or an SOI (Silicon On Insulator) substrate may also be used. As shown in Figure 1, the physical quantity sensor 1 of this embodiment includes a first fixed electrode section 10, a first movable electrode section 20, a first connecting section 30, a first fixed section 40, and a first support beam 42. These first fixed electrode section 10, first movable electrode section 20, first connecting section 30, first fixed section 40, and first support beam 42 constitute the first element section 91 of the physical quantity sensor 1. The first element section 91 detects acceleration in the third direction DR3, which is, for example, the Z-axis direction, in the detection section Z1. The physical quantity sensor 1 also includes a second fixed electrode section 50, a second movable electrode section 60, a second connecting section 70, a second fixed section 80, and a second support beam 82. These second fixed electrode section 50, second movable electrode section 60, second connecting se