JP2016031358A - Physical quantity sensor, electronic apparatus, and moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor capable of precisely detecting an acceleration if an acceleration sensor element is contained in vacuum space, and an electronic apparatus and a moving body having the physical quantity sensor.SOLUTION: A physical quantity sensor 1 includes an acceleration sensor 200 and a gyro sensor on a base substrate (substrate) 2. Further, the physical quantity sensor 1 includes an inner space (acceleration sensor element container) S2 containing the acceleration sensor 200 and an inner space (gyro sensor element container) containing the gyro sensor, the inner space S2 having protrusions 215 and 325 facing an acceleration sensor element 204 on the inner wall thereof.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a physical quantity sensor, an electronic device, and a moving object.

  2. Description of the Related Art Conventionally, as a physical quantity sensor including a vibration element using crystal, one that detects acceleration and angular velocity of a plurality of axes with one structure is known (for example, see Patent Document 1).

  In such a physical quantity sensor (combo sensor), since acceleration and angular velocities of a plurality of axes are detected with one structure, there is a concern that characteristics deteriorate due to the influence of multi-axis sensitivity. Therefore, it is desirable to form both the acceleration sensor and the gyro sensor on the same substrate.

  In this case, if each sensor is formed in a different atmosphere, the number of processes increases. Therefore, if each sensor is built in the same atmosphere by the same process, the following problems occur.

  In other words, it is preferable that the acceleration sensor has a large viscosity effect and the gyro sensor has a small viscosity effect. Therefore, the degree of vacuum is required to be low in the acceleration sensor and high in the gyro sensor. However, if the acceleration sensor and the gyro sensor are formed on the same substrate so as to be housed in the respective housing portions under the same atmosphere, the pressures in the housing portions are the same. Therefore, the relationship cannot be satisfied, and it is difficult to improve both sensor characteristics.

JP-A-10-239347

  An object of the present invention is to provide a physical quantity sensor capable of detecting acceleration with high accuracy even when an acceleration sensor element is accommodated in a vacuum space, and an electronic apparatus and a moving body including the physical quantity sensor.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The physical quantity sensor of the present invention includes an acceleration sensor element,
An acceleration sensor element storage portion for storing the acceleration sensor element,
The acceleration sensor element storage portion is provided with unevenness on the inner wall at a position facing the acceleration sensor element.

  As a result, even if the accelerometer element housing that houses the accelerometer is in a vacuum atmosphere, the viscosity effect can be increased in a virtually low vacuum state, so the accelerometer can detect acceleration with excellent accuracy. can do.

[Application Example 2]
The physical quantity sensor of the present invention includes an acceleration sensor element disposed on a substrate,
A gyro sensor element disposed on the substrate;
An acceleration sensor element storage portion for storing the acceleration sensor element;
A gyro sensor element storage portion for storing the gyro sensor element;
The acceleration sensor element storage portion is provided with unevenness on the inner wall at a position facing the acceleration sensor element.

  As a result, even if the acceleration sensor element storage portion for storing the acceleration sensor has a high degree of vacuum, the viscosity effect can be increased in a virtually low vacuum state. It can be detected with accuracy.

  Therefore, even if the degree of vacuum in the acceleration sensor element storage unit is set to be substantially the same as the degree of vacuum in the gyro sensor element storage unit, both the acceleration sensor and the gyro sensor included in the physical quantity sensor should be highly accurate. Can do.

[Application Example 3]
In the physical quantity sensor of the present invention, the acceleration sensor element storage portion and the gyro sensor element storage portion are respectively joined to the substrate so as to overlap the substrate, and correspond to the gyro sensor element and the acceleration sensor element. Preferably, the substrate is defined by a substrate having a first recess and a second recess, respectively.

  Thereby, the acceleration sensor element storage part and the gyro sensor element storage part can be easily formed.

[Application Example 4]
In the physical quantity sensor according to the aspect of the invention, each of the plurality of projections and depressions includes a projection that is disposed at a position overlapping with a region between the movable electrode and the fixed electrode included in the acceleration sensor element in a plan view of the substrate. It is preferable.

  Thereby, when a movable part displaces, it can reduce more that gas is extruded from between a movable electrode and a fixed electrode.

[Application Example 5]
In the physical quantity sensor of the present invention, it is preferable that both the acceleration sensor element storage portion and the gyro sensor element storage portion are arranged in the same space.

  Thus, even in the physical quantity sensor in which the acceleration sensor element storage portion and the gyro sensor element storage portion are arranged in the same space, according to the present invention, both the acceleration sensor and the gyro sensor are High accuracy can be achieved.

[Application Example 6]
In the physical quantity sensor of the present invention, it is preferable that the unevenness includes a glass material as a main material.

  Thereby, when the acceleration sensor element storage part provided with unevenness is formed by using an etching technique, a plurality of convex parts can be provided on the surface thereof.

[Application Example 7]
In the physical quantity sensor according to the aspect of the invention, it is preferable that the unevenness includes a plurality of protrusions on the surface thereof.

  As a result, the uneven surface becomes rough and the surface area increases. Therefore, when the movable part is displaced, it is possible to further reduce the gas being pushed out from between the movable electrode and the fixed electrode. Furthermore, it is possible to suppress or prevent the movable electrode from sticking to the unevenness when the movable portion is displaced.

[Application Example 8]
In the physical quantity sensor according to the aspect of the invention, it is preferable that the surface of the unevenness facing the movable electrode and the surface of the movable electrode facing the unevenness are not located on the same surface.

  Thereby, when a movable part displaces, it can suppress or prevent that a movable electrode sticks to an unevenness | corrugation, reducing pushing out of gas from between a movable electrode and a fixed electrode.

[Application Example 9]
In the physical quantity sensor according to the aspect of the invention, it is preferable that the degree of vacuum of the gyro sensor element housing portion and the degree of vacuum of the acceleration sensor element housing portion are uniform.

  Even if the degree of vacuum is uniform, by providing the unevenness, it is possible to make both the acceleration sensor and the gyro sensor highly accurate.

[Application Example 10]
In the physical quantity sensor of the present invention, it is preferable that the ceiling portions of the acceleration sensor element storage portion and the gyro sensor element storage portion are formed by the same etching process.

  Accordingly, the acceleration sensor element storage portion and the gyro sensor element storage portion can be formed to have a uniform ceiling height. Thus, since the acceleration sensor element storage part and the gyro sensor element storage part can be formed without variation, the quality of the obtained physical quantity sensor can be improved.

[Application Example 11]
In the physical quantity sensor of the present invention, it is preferable that the degree of vacuum of the acceleration sensor element storage portion and the gyro sensor element storage portion is 500 Pa or less.

  Even if the degree of vacuum of the acceleration sensor element storage portion and the gyro sensor element storage portion is within such a range, both the acceleration sensor and the gyro sensor can be highly accurate.

[Application Example 12]
In the physical quantity sensor of the present invention, it is preferable that the inside of the acceleration sensor element storage portion and the gyro sensor element storage portion is an inert atmosphere.

  Thereby, the secular change of an acceleration sensor and a gyro sensor can be reduced, and the reliability of a sensor can be improved.

[Application Example 13]
In the physical quantity sensor according to the aspect of the invention, it is preferable that the surface of the uneven acceleration sensor element facing the movable electrode is a convex surface.

  Thereby, when a movable part displaces, it can reduce more that gas is extruded from between a movable electrode and a fixed electrode.

[Application Example 14]
An electronic apparatus according to the present invention includes the physical quantity sensor according to the present invention.
Thereby, an electronic device with high reliability can be obtained.

[Application Example 15]
The moving body of the present invention includes the physical quantity sensor of the present invention.
Thereby, a mobile body with high reliability can be obtained.

It is a top view which shows typically 1st Embodiment of the physical quantity sensor of this invention. FIG. 2 is a cross-sectional view (a cross-sectional view taken along line AA in FIG. 1) of the gyro sensor of the physical quantity sensor shown in FIG. 1. It is sectional drawing (BB sectional drawing in FIG. 1) of the acceleration sensor of the physical quantity sensor shown in FIG. It is a top view (top view) of the functional element which the physical quantity sensor shown in FIG. 1 has. It is a top view (top view) of the functional element which the physical quantity sensor shown in FIG. 1 has. It is a top view (top view) of the functional element which the physical quantity sensor shown in FIG. 1 has. It is a top view (top view) of the functional element which the physical quantity sensor shown in FIG. 1 has. It is a top view (top view) of the functional element which the physical quantity sensor shown in FIG. 1 has. It is a top view (top view) of the functional element which the physical quantity sensor shown in FIG. 1 has. It is the elements on larger scale in the area | region C of the functional element shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the physical quantity sensor shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the physical quantity sensor shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the physical quantity sensor shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the physical quantity sensor shown in FIG. It is a top view which shows typically 2nd Embodiment of the physical quantity sensor of this invention. It is sectional drawing (DD sectional view taken on the line in FIG. 15) of the gyro sensor of the physical quantity sensor shown in FIG. It is sectional drawing (EE sectional view taken on the line in FIG. 15) of the gyro sensor and acceleration sensor of the physical quantity sensor shown in FIG. It is sectional drawing which shows an example of an electronic module provided with the physical quantity sensor of this invention. 1 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer to which an electronic apparatus of the present invention is applied. It is a perspective view which shows the structure of the mobile telephone (a smart phone, PHS etc. are included) to which the electronic device of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device of this invention is applied. It is a perspective view which shows the motor vehicle to which the mobile body of this invention is applied.

  Hereinafter, a physical quantity sensor, an electronic device, and a moving body of the present invention will be described in detail based on embodiments shown in the accompanying drawings.

1. Physical Quantity Sensor First, the physical quantity sensor of the present invention will be described.

<First Embodiment>
FIG. 1 is a plan view schematically showing a first embodiment of a physical quantity sensor of the present invention. 2 is a cross-sectional view (a cross-sectional view taken along line AA in FIG. 1) of the gyro sensor of the physical quantity sensor shown in FIG. 3 is a cross-sectional view of the acceleration sensor of the physical quantity sensor shown in FIG. 1 (a cross-sectional view taken along line BB in FIG. 1). 4 to 9 are plan views (top views) of functional elements included in the physical quantity sensor shown in FIG. 10 is a partially enlarged view (FIG. 10A is a plan view seen from the Z-axis direction and FIG. 10B is a cross-sectional view seen from the Y-axis direction) in the region C of the functional element shown in FIG. .

  1 to 3, the first functional element 101, the second functional element 102, the third functional element 103, the fourth functional element 204, the fifth functional element 205, and the sixth functional element 206 are illustrated in FIGS. Simplified and illustrated. 1 to 9 illustrate the X axis, the Y axis, and the Z axis as three axes orthogonal to each other. Furthermore, the direction parallel to the X axis (first axis) is called the X axis direction, the direction parallel to the Y axis (second axis) is called the Y axis direction, and the direction parallel to the Z axis (third axis) is called the Z axis direction. . A plane including the X axis and the Y axis is also referred to as an “XY plane”.

  As illustrated in FIGS. 1 to 3, the physical quantity sensor 1 includes a package 10 including a base substrate 2 and a lid 3, a gyro sensor 100, and an acceleration sensor 200.

  The gyro sensor 100 includes a first functional element 101, a second functional element 102, and a third functional element 103, and measures (detects) respective angular velocities around the X axis, the Y axis, and the Z axis. The functional elements 101, 102, and 103 are arranged in an internal space S <b> 1 provided in the package 10.

  The acceleration sensor 200 includes a fourth functional element 204, a fifth functional element 205, and a sixth functional element 206, and includes an X-axis direction (in-plane direction), a Y-axis direction (in-plane direction), and a Z-axis. This is a triaxial acceleration sensor that can measure the acceleration in each direction (vertical direction), and these functional elements 204, 205, and 206 are disposed in an internal space S <b> 2 provided in the package 10. Therefore, the physical quantity sensor 1 is a 6-axis combo sensor including both a 3-axis gyro sensor and a 3-axis acceleration sensor in the same package 10.

Hereinafter, each member with which this physical quantity sensor 1 is provided is demonstrated in detail.
-Base substrate 2-
On the upper surface of the base substrate (substrate) 2, functional elements (gyro sensor elements) 101, 102, 103 included in the gyro sensor 100, and functional elements (acceleration sensor elements) 204, 205, 206 included in the acceleration sensor 200 are provided. They are arranged and support these.

The base substrate (formation substrate) 2 is formed with recesses 13, 14, 15, 21, 22, and 23 that open to the upper surface. Among these, the recessed part 13 functions as an escape part for preventing contact between the first functional element 101 and the base substrate 2 disposed above. Similarly, the concave portion 14 functions as an escape portion for preventing contact between the second functional element 102 disposed above the concave portion 14 and the base substrate 2. Further, the recess 15 functions as an escape portion for preventing contact between the third functional element 103 disposed above the recess 15 and the base substrate 2. Furthermore, the concave portion 21 functions as a relief portion for preventing contact between the fourth functional element 204 disposed above and the base substrate 2. Similarly, the recess 22 functions as an escape portion for preventing contact between the fifth functional element 205 disposed above the recess 22 and the base substrate 2.
Further, the recess 23 functions as an escape portion for preventing contact between the sixth functional element 206 disposed above the recess 23 and the base substrate 2.

  Of these, the first fixed detection electrode portion 146 included in the first functional element 101 is disposed on the bottom surface of the recess 13, and the first fixed detection electrode portion 146 included in the second functional element 102 is disposed on the bottom surface of the recess 14. Is arranged. Furthermore, a first detection electrode 741 and a second detection electrode 742 included in the sixth functional element 206 are disposed on the bottom surface of the recess 23.

  Further, among these, the bottom surfaces of the recess 21 and the recess 22 are provided with a plurality of protrusions 215 extending in the Z-axis direction. That is, the bottom surfaces (inner walls) of the recess 21 and the recess 22 have irregularities.

  The arrangement and shape of the recesses 13, 14, 15, 21, 22, and 23 are not particularly limited, but in the present embodiment, the recesses 13, 14, and 15 are substantially rectangular (substantially square), and Y They are arranged side by side in the axial direction. Further, the recesses 21, 22, and 23 are longitudinal shapes in which the recesses 21 and 23 are arranged side by side in the X-axis direction on the −X-axis direction side of the recesses 13, 14, and 15, and both extend in the Y-axis direction. The concave portion 22 is arranged on the + Y-axis side of the concave portions 21 and 23 and has a longitudinal shape (substantially rectangular shape) extending in the X-axis direction. By setting it as such an arrangement | positioning and shape, the recessed parts 13, 14, 15, 21, 22, and 23 can be arrange | positioned in space-saving, and size reduction of the physical quantity sensor 1 can be achieved.

  Further, the base substrate 2 has a plurality of groove portions 211 that are routed so as to surround the recess portions 13, 14, 15, 21, 22, and 23, and wiring 721 is disposed on the bottom surface of each groove portion 211. ing. Each of the plurality of wirings 721 has one end electrically connected to the corresponding functional element 101, 102, 103, 204, 205, 206 via the conductive bump B11, and the other end. The portion is electrically connected to a corresponding terminal 721 a provided so as to be exposed at the edge of the base substrate 2. As a result, the terminals 721a can be used to electrically connect the functional elements 101, 102, 103, 204, 205, 206 to the outside (for example, an IC chip 102A described later).

  Such a base substrate 2 is formed using a glass material containing alkali metal ions (movable ions) (for example, borosilicate glass such as Pyrex glass (registered trademark)) as a main material. Thereby, the functional elements 101, 102, 103, 204, 205, 206 formed from the silicon substrate can be firmly bonded to the base substrate 2 by anodic bonding. Moreover, in the manufacturing method of the physical quantity sensor 1 to be described later, the recesses 21 and 22 including the protrusions 215 are formed by using an etching technique so that a plurality of protrusions (fine irregularities) are provided on the surface. Can do.

However, the constituent material of the base substrate 2 is not limited to a glass material, and for example, a high-resistance silicon material can be used. In this case, an insulating film is formed on the surface of the high resistance silicon and bonded to the functional elements 101, 102, 103, 204, 205, and 206. As the insulating film, SiO ₂ , SiN, or the like can be used.

  In addition, the constituent materials of the wiring 721 and the terminal 721a are not particularly limited as long as they have conductivity, and various electrode materials can be used. For example, simple metals such as Au, Pt, Ag, Cu, Al, In, Zn, Pt, and Sn, or alloys containing these, conductive oxides, and the like are preferably used.

-Lid 3
The lid (housing substrate) 3 is superposed on the base substrate (formation substrate) 2, so that the functional elements 101, 102, 103, 204, 205, 206, that is, the gyro sensor 100 and the acceleration arranged on the base substrate 2. This is for covering (sealing) the sensor 200.

  As shown in FIGS. 2 and 3, the lid (substrate) 3 has a concave portion 31 and a concave portion 32 that are open on the lower surface. Among these, the concave portion 31 corresponds to the functional elements 101, 102, and 103. The concave portion 32 is provided so as to correspond to the functional elements 204, 205, and 206. Then, the lid 3 is joined so as to overlap the base substrate 2, whereby an internal space (gyroscope) defined by the recess (first recess) 31 and the recesses 13, 14, 15 provided in the base substrate 2. The functional elements 101, 102, 103 (gyro sensor 100) are accommodated in the sensor element accommodating portion S1, and are defined by the concave portions (second concave portions) 32 and the concave portions 21, 22, 23 provided in the base substrate 2. Functional elements 204, 205, and 206 (acceleration sensor 200) are housed in an internal space (acceleration sensor element housing portion) S2.

  Of the recesses 31 and 32, the bottom surface of the recess 32 includes a plurality of protrusions 325 extending in the −Z-axis direction. That is, the bottom surface (inner wall) of the recess 32 has irregularities.

  Furthermore, it is preferable that the degree of vacuum in each of the internal space S1 that stores the functional elements 101, 102, and 103 and the internal space S2 that stores the functional elements 204, 205, and 206 is uniform. Even when the internal spaces S1 and S2 have the same degree of vacuum, the projections (convex portions) 215 and 325 are provided in the internal space S2, so that both the acceleration sensor 200 and the gyro sensor 100 are High accuracy can be achieved. The reason will be described in detail later.

  Moreover, specifically, the degree of vacuum in the internal spaces S1 and S2 is preferably set to 1000 Pa or less, more preferably 100 Pa to 500 Pa. Even if the degree of vacuum of the internal spaces S1 and S2 is within such a range, both the acceleration sensor 200 and the gyro sensor 100 can be made highly accurate.

  Furthermore, the atmosphere of the internal spaces S1 and S2 is not particularly limited, but is preferably an inert atmosphere such as nitrogen or argon. Thereby, the secular change of the acceleration sensor 200 and the gyro sensor 100 can be reduced, and the reliability of a sensor can be improved.

  Further, the lid 3 has a through hole 311 and a through hole 321 that penetrate in the thickness direction and communicate with the concave portion 31 and the concave portion 32, respectively. The through hole 311 and the through hole 321 are both For example, it is sealed with a sealing material 312 and a sealing material 322 made of a metal such as an Au—Ge alloy. Thereby, the internal space S1 and the internal space S2 are hermetically sealed. Although not shown, a metal layer for improving adhesion with the sealing materials 312 and 322 may be formed on the inner peripheral surfaces of the through holes 311 and 321.

  Further, the through holes 311 and 321 of the recesses 31 and 32 may not be provided. In this case, the internal spaces S1 and S2 are hermetically sealed in an atmosphere when a sealing film 8 described later is formed.

  Such a lid 3 is formed of a silicon substrate in the present embodiment. Thereby, the cover body 3 and the base substrate 2 can be firmly joined by anodic bonding.

In the state where the lid 3 is joined to the base substrate 2, the inside and outside of the internal spaces S 1 and S 2 communicate with each other through the groove portions 211 formed in the base substrate 2 in addition to the through holes 311 and 321. . Therefore, as described above, the through holes 311 and 321 are sealed with the sealing materials 312 and 322, and the groove 211 is closed with the sealing film 8 as shown in FIG. Thereby, the airtightness of internal space S1 and internal space S2 is ensured. As the material of the sealing film 8, an insulating film such as SiO ₂ or SiN is preferably used. These films are formed by a CVD method or the like. A metal film may be formed over the insulating film. By forming a metal film on the insulating film, the sealing performance can be further improved.

-Gyro sensor 100-
In the gyro sensor 100, a first functional element (gyro sensor element) 101 detects an angular velocity around the X axis, a second functional element 102 detects an angular velocity around the Y axis, and a third functional element 103 Detect the angular velocity around the axis.

  The first functional element 101, the second functional element 102, and the third functional element 103 are provided (arranged) on the base substrate 2 so as to correspond to the concave portion 13, the concave portion 14, and the concave portion 15, respectively. Yes. In the gyro sensor 100, as shown in FIGS. 1 and 2, the first functional element 101, the second functional element 102, and the third functional element 103 are arranged in a straight line, and the second functional element 102 and the second functional element 102 A first functional element 101 is provided between the three functional elements 103. That is, in the gyro sensor 100, the second functional element 102, the first functional element 101, and the third functional element 103 are arranged in a straight line in this order.

  In the example shown in FIG. 1, the functional elements 101, 102, and 103 are arranged in the Y-axis direction (along the Y-axis) in plan view (viewed from the Z-axis direction). The direction in which 103 is arranged is not particularly limited, and may be arranged in the Z-axis direction, for example.

  Hereinafter, the first functional element 101, the second functional element 102, and the third functional element 103 will be described.

(1) First functional element 101
First, the configuration of the first functional element 101 will be described.

  As shown in FIG. 4, the first functional element 101 includes a structure body 111. The structure 111 includes a vibrating body 134, a movable body 140, a first movable detection electrode part (first movable electrode part) 144, and a first fixed detection electrode part (first fixed electrode part) 146. ing. In FIG. 4, the structure 111 further includes a fixed portion 130, a drive spring portion 132, a movable drive electrode portion 136, fixed drive electrode portions 138 a and 138 b, and a beam portion 142.

  The fixed part 130, the drive spring part 132, the vibrating body 134, the movable drive electrode part 136, the movable body 140, the beam part 142, and the movable detection electrode part 144 are integrally provided, for example, by patterning a silicon substrate.

  The material of the fixed portion 130, the drive spring portion 132, the vibrating body 134, the movable drive electrode portion 136, the fixed drive electrode portions 138a and 138b, the movable body 140, the beam portion 142, and the movable detection electrode portion 144 is, for example, phosphorus or boron It is silicon to which conductivity is imparted by doping impurities such as.

  The vibrating body 134 is provided on the recess 13. In the example illustrated in FIG. 4, the vibrating body 134 is a rectangular frame in plan view, and includes a first extending portion 135 a extending in the Y-axis direction and a second extending extending in the X-axis direction. And a protruding portion 135b. A side surface in the Y-axis direction of the vibrating body 134 (a side surface having a perpendicular line parallel to the Y-axis) is connected to the drive spring portion 132. The vibrating body 134 can vibrate in the Y-axis direction (along the Y-axis) by the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b.

  The fixing unit 130 is fixed to the base substrate 2. The fixing unit 130 is bonded to the upper surface of the base substrate 2 by, for example, anodic bonding. In the illustrated example, four fixing portions 130 are provided.

  The drive spring portion 132 connects the fixed portion 130 (130a, 130b, 130c, 130d) and the vibrating body 134. In the illustrated example, the drive spring portion 132 has four springs 132a, 132b, 132c, and 132d. The spring 132a connects the fixed portion 130a and the vibrating body 134. The spring 132b connects the fixed portion 130b and the vibrating body 134. The spring 132c connects the fixed portion 130c and the vibrating body 134. The spring 132d connects the fixed portion 130d and the vibrating body 134.

  The springs 132a, 132b, 132c, and 132d extend in the Y-axis direction while reciprocating in the X-axis direction. The spring 132a and the spring 132b are provided symmetrically with respect to an axis α that passes through the center O of the vibrating body 134 and is parallel to the X axis in plan view. Similarly, the spring 132c and the spring 132d are provided symmetrically with respect to the axis α. In addition, the spring 132a and the spring 132c are provided symmetrically with respect to an axis β that passes through the center O of the vibrating body 134 and is parallel to the Y axis in plan view. Similarly, the spring 132b and the spring 132d are provided symmetrically with respect to the axis β. Thereby, the drive spring part 132 is restrained from being deformed in the X-axis direction and the Z-axis direction, and can smoothly expand and contract in the Y-axis direction, which is the vibration direction of the vibrating body 134.

  The movable drive electrode portion 136 is provided on the vibrating body 134. More specifically, the movable drive electrode portion 136 is connected to the first extension portion 135 a of the vibrating body 134. In the illustrated example, four movable drive electrode portions 136 are provided. As shown in FIG. 4, the movable drive electrode portion 136 includes a comb tooth having a trunk portion extending from the vibrating body 134 in the X-axis direction and a plurality of branch portions extending from the trunk portion in the Y-axis direction. Electrode.

  The fixed drive electrode portions 138 a and 138 b are fixed to the base substrate 2. The fixed drive electrode portions 138a and 138b are bonded to the upper surface of the base substrate 2 by, for example, anodic bonding. The fixed drive electrode portions 138a and 138b are provided to face the movable drive electrode portion 136, and the movable drive electrode portion 136 is disposed between the fixed drive electrode portions 138a and 138b. In the illustrated example, a fixed drive electrode portion 138 a is provided on the −Y axis direction side of the movable drive electrode portion 136, and a fixed drive electrode portion 138 b is provided on the + Y axis direction side of the movable drive electrode portion 136. As shown in FIG. 4, the movable drive electrode portion 136 has a comb-like shape, whereas the shapes of the fixed drive electrode portions 138 a and 138 b correspond to the shape of the movable drive electrode portion 136. Comb-shaped.

  The movable body 140 is provided on the recess 13. The movable body 140 is supported by the vibrating body 134 via the beam portion 142. The movable body 140 is provided inside the frame-shaped vibrating body 134 in plan view. The movable body 140 has a plate shape. The movable body 140 is connected to a side surface (a side surface having a perpendicular line parallel to the Y axis) of the vibrating body 134 (of the second extending portion 135b) by a beam portion 142 serving as a rotation axis.

  The beam portion 142 is provided at a position shifted from the center of gravity of the movable body 140. The beam portion 142 is provided along the Y axis. The beam portion 142 can be torsionally deformed, and the movable body 140 can be displaced in the Z-axis direction by the torsional deformation. In the illustrated example, the movable body 140 extends in the −X-axis direction from the beam portion 142, but the extending direction of the movable body 140 is not particularly limited.

  Although not shown, two beam portions 142 are provided, the movable body 140 extending from the one beam portion 142 in the −X axis direction, and the other beam portion 142 extending in the + X axis direction. A movable body 140 may be provided.

  The movable detection electrode unit 144 is provided on the movable body 140. In the illustrated example, the movable detection electrode unit 144 is a portion of the movable body 140 that overlaps the fixed detection electrode unit 146 in plan view. The movable detection electrode portion 144 is a portion that forms a capacitance between the movable body 140 and the fixed detection electrode portion 146. In the first functional element 101, the movable detection electrode unit 144 may be provided by configuring the movable body 140 with a conductive material, and the movable detection electrode made of a conductive layer such as a metal on the surface of the movable body 140. A portion 144 may be provided. In the example shown in the drawing, the movable detection electrode unit 144 is provided by the movable body 140 being made of a conductive material (silicon doped with impurities).

  The fixed detection electrode unit 146 is fixed to the base substrate 2 and is provided to face the movable detection electrode unit 144. For example, the fixed detection electrode unit 146 is provided on the bottom surface of the recess 13 (the upper surface of the base substrate 2 defining the recess 13). In the example illustrated in FIG. 4, the planar shape of the fixed detection electrode unit 146 is a rectangle.

  As the material of the fixed detection electrode unit 146, for example, a single metal such as Au, Pt, Ag, Cu, Al, In, Zn, Pt, Sn, or an alloy containing these, or a conductive oxide is preferably used. When the base substrate 2 is a transparent substrate (glass substrate) by using, for example, a transparent electrode material such as ITO (Indium Tin Oxide) as the fixed detection electrode unit 146, foreign matter or the like existing on the fixed detection electrode unit 146 Can be easily visually recognized from the lower side of the base substrate 2.

Next, the operation of the first functional element 101 will be described.
When a voltage is applied between the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b, an electrostatic force can be generated between the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b. Thereby, the vibrating body 134 can be vibrated in the Y-axis direction while the drive spring portion 132 is expanded and contracted in the Y-axis direction. The electrostatic force acting between the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b by reducing the distance (gap) between the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b. Can be increased.

  More specifically, the first alternating voltage is applied between the movable drive electrode portion 136 and the fixed drive electrode portion 138a, and the first alternating voltage and the phase are applied between the movable drive electrode portion 136 and the fixed drive electrode portion 138b. Is applied with a second alternating voltage shifted by 180 degrees.

  Since the movable body 140 is supported by the vibrating body 134 via the beam portion 142 as described above, the movable body 140 also vibrates in the Y-axis direction as the vibrating body 134 vibrates.

  When an angular velocity around the X axis (angular velocity about the X axis) ωx is applied to the first functional element 101 in a state where the vibrating body 134 is vibrating in the Y-axis direction, the Coriolis force acts, and the movable body 140 becomes Displacement in the Z-axis direction. When the movable body 140 is displaced in the Z-axis direction, the movable detection electrode unit 144 approaches or separates from the fixed detection electrode unit 146. For this reason, the capacitance between the movable detection electrode unit 144 and the fixed detection electrode unit 146 changes. By detecting the amount of change in capacitance between the movable detection electrode portion 144 and the fixed detection electrode portion 146, the angular velocity ωx around the X axis can be obtained.

  In the above description, the mode of driving the vibrating body 134 by electrostatic force (electrostatic driving method) has been described. However, the method of driving the vibrating body 134 is not particularly limited, and the piezoelectric driving method or the Lorentz force of the magnetic field is not limited. It is possible to apply an electromagnetic drive system using

(2) Second Functional Element Next, the second functional element 102 will be described.

  As shown in FIG. 5, the second functional element 102 includes a structure body 112. The structure 112 includes a vibrating body 134, a movable body 140, a second movable detection electrode portion (second movable electrode portion) 144, and a second fixed detection electrode portion (second fixed electrode portion) 146. ing. In FIG. 5, the second functional element 102 further includes a fixed portion 130, a drive spring portion 132, a movable drive electrode portion 136, fixed drive electrode portions 138 a and 138 b, and a beam portion 142. .

  The vibrating body 134 and the movable body 140 of the second functional element 102 are provided on the recess 14. The fixed detection electrode portion 146 of the second functional element is provided, for example, on the bottom surface of the recess 14 (the upper surface of the base substrate 2 that defines the recess 14).

  As shown in FIG. 5, the second functional element 102 has a form in which the first functional element 101 shown in FIG. 4 is rotated 90 degrees about the Z axis as a rotation axis. Therefore, the detailed description of the second functional element 102 is omitted.

  In the second functional element 102, the vibrating body 134 vibrates in the X axis direction, and the angular velocity around the Y axis (angular velocity about the Y axis) ωy in a state where the vibrating body 134 vibrates in the X axis direction. When C is applied, the Coriolis force acts and the movable body 140 is displaced in the Z-axis direction. Thereby, the electrostatic capacitance between the movable detection electrode part 144 and the fixed detection electrode part 146 changes, and the angular velocity ωy about the Y axis can be obtained.

(3) Third Functional Element Next, the configuration of the third functional element 103 will be described.

  Hereinafter, in the third functional element 103 shown in FIG. 6, members having the same functions as the constituent members of the first functional element 101 shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The third functional element 103 includes a structure 113 as shown in FIG. The structure 113 includes a vibrating body 134, a movable body 150, a third movable detection electrode part (third movable electrode part) 154, and a third fixed detection electrode part (third fixed electrode part) 156. ing. In FIG. 6, the structure 113 further includes a fixed portion 130, a drive spring portion 132, a movable drive electrode portion 136, fixed drive electrode portions 138 a and 138 b, and a detection spring portion 152.

  The movable body 150 is provided on the recess 15. The movable body 150 is supported by the vibrating body 134 via the detection spring portion 152. The movable body 150 is provided inside the frame-shaped vibrating body 134 in plan view. In the example illustrated in FIG. 6, the movable body 150 is a rectangular frame body in plan view, and includes a third extension portion 151 a extending in the Y-axis direction and a fourth extension extending in the X-axis direction. And an exit 151b. A side surface of the movable body 150 in the X-axis direction (a side surface having a perpendicular line parallel to the X-axis) is connected to the detection spring portion 152.

  The detection spring portion 152 connects the vibrating body 134 and the movable body 150. In the illustrated example, the detection spring portion 152 includes four springs 152a, 152b, 152c, and 152d. The springs 152a and 152b connect the movable body 150 and the first extending portion 135a disposed on the + X axis direction side of the movable body 150. The springs 152 c and 152 d connect the movable body 150 and the first extending portion 135 a disposed on the −X axis direction side of the movable body 150.

  The springs 152a, 152b, 152c, and 152d extend in the X-axis direction while reciprocating in the Y-axis direction. The spring 152a and the spring 152b are provided symmetrically with respect to an axis α that passes through the center O of the vibrating body 134 and is parallel to the X axis in plan view. Similarly, the spring 152c and the spring 152d are provided symmetrically with respect to the axis α. In addition, the spring 152a and the spring 152c are provided symmetrically with respect to an axis β that passes through the center O of the vibrating body 134 and is parallel to the Y axis in plan view. Similarly, the spring 152b and the spring 152d are provided symmetrically with respect to the axis β. Thereby, the deformation | transformation to the Y-axis direction and a Z-axis direction is suppressed, and the detection spring part 152 can be expanded-contracted smoothly in the X-axis direction which is a displacement direction of the movable body 150. FIG.

  The movable detection electrode unit 154 is provided on the movable body 150. The movable detection electrode unit 154 extends, for example, from one fourth extending portion 151b of the movable body 150 to the other fourth extending portion 151b in the Y-axis direction. In the illustrated example, two movable detection electrode portions 154 are provided.

  The fixed detection electrode unit 156 is fixed to the base substrate 2 and is provided to face the movable detection electrode unit 154. The fixed detection electrode unit 156 is bonded to the bottom surface of the recess 15 (the upper surface of the base substrate 2 defining the recess 15) by, for example, anodic bonding. The fixed detection electrode unit 156 is provided inside the frame-shaped movable body 150. In the illustrated example, the fixed detection electrode unit 156 is provided with the movable detection electrode unit 154 interposed therebetween.

  The fixed part 130, the drive spring part 132, the vibrating body 134, the movable drive electrode part 136, the movable body 150, the detection spring part 152, and the movable detection electrode part 154 are integrally provided, for example, by patterning a silicon substrate. The fixed portion 130, the drive spring portion 132, the vibrating body 134, the movable drive electrode portion 136, the fixed drive electrode portions 138a and 138b, the movable body 150, the detection spring portion 152, the movable detection electrode portion 154, and the fixed detection electrode portion 156 are: The material is, for example, silicon provided with conductivity by being doped with impurities such as phosphorus and boron.

Next, the operation of the third functional element 103 will be described.
When a voltage is applied between the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b, an electrostatic force can be generated between the movable drive electrode portion 136 and the fixed drive electrode portions 138a and 138b. Thereby, the vibrating body 134 can be vibrated in the Y-axis direction while the drive spring portion 132 is expanded and contracted in the Y-axis direction.

  Since the movable body 150 is supported by the vibrating body 134 via the detection spring portion 152 as described above, the movable body 150 also vibrates in the Y-axis direction as the vibrating body 134 vibrates.

  When an angular velocity around the Z axis (angular velocity about the Z axis) ωz is applied to the third functional element 103 in a state where the vibrating body 134 is vibrating in the Y axis direction, a Coriolis force is applied, and the movable body 150 , It is displaced in the X-axis direction. As the movable body 150 is displaced in the X-axis direction, the distance between the movable detection electrode unit 154 and the fixed detection electrode unit 156 changes. Therefore, the electrostatic capacitance between the movable detection electrode unit 154 and the fixed detection electrode unit 156 changes. By detecting the amount of change in capacitance between the movable detection electrode unit 154 and the fixed detection electrode unit 156, the angular velocity ωz around the Z axis can be obtained.

  As described above, the gyro sensor 100 detects angular velocities about three axes (Y axis, X axis, and Z axis) that are orthogonal to each other.

  Here, in the gyro sensor 100, the functional elements 101, 102, and 103 are arranged in a straight line, and the first functional element 101 is provided between the second functional element 102 and the third functional element 103. . Therefore, in the gyro sensor 100, in the adjacent functional elements among the functional elements 101, 102, 103, the vibration direction of the vibrating body 134 of one functional element and the displacement direction of the other movable body 140 (or the movable body 150). Unlike the (direction displaced by the Coriolis force), the displacement direction of the movable body 140 (or the movable body 150) of one functional element and the vibration direction of the vibration body 134 of the other functional element are different. That is, in the adjacent functional elements 101 and 102, the vibration direction (Y-axis direction) of the vibrating body 134 of the first functional element 101 and the displacement direction (Z-axis direction) of the movable body 140 of the second functional element 102 are: Differently, the displacement direction (Z-axis direction) of the movable body 140 of the first functional element 101 is different from the vibration direction (X-axis direction) of the vibrating body 134 of the second functional element 102. In the adjacent functional elements 101 and 103, the vibration direction (Y-axis direction) of the vibrating body 134 of the first functional element 101 and the displacement direction (X-axis direction) of the movable body 150 of the third functional element 103 are: Differently, the displacement direction (Z-axis direction) of the movable body 140 of the first functional element 101 is different from the vibration direction (Y-axis direction) of the vibrating body 134 of the third functional element 103.

  That is, in the gyro sensor 100, the first functional element 102 between the second functional element 102 in which the vibrating body 134 vibrates in the X-axis direction and the third functional element 103 in which the movable body 150 is displaced in the X-axis direction by Coriolis force. A functional element 101 is provided. Therefore, the distance between the second functional element 102 and the third functional element 103 can be increased, and the size can be reduced. Thereby, in the gyro sensor 100, it can suppress that the vibration of the vibrating body 134 of the 2nd functional element 102 influences the displacement by the Coriolis force of the movable body 150 of the 3rd functional element 103 via the base substrate 2. FIG. . More specifically, in the gyro sensor 100, the vibration of the vibrating body 134 of the second functional element 102 acts on the movable body 150 of the third functional element 103 (cross coupling), and the third functional element 103. It is possible to suppress an unnecessary vibration mode from being excited in the movable body 150 due to the vibration of the vibrating body 134 of the second functional element 102. As a result, the gyro sensor 100 can suppress deterioration in noise characteristics, and can have high detection accuracy while achieving downsizing.

-Acceleration sensor 200-
In the acceleration sensor 200, the fourth functional element 204 detects acceleration in the X-axis direction, the fifth functional element 205 detects acceleration in the Y-axis direction, and the sixth functional element 206 detects acceleration in the Z-axis direction. To detect.

  The fourth functional element 204, the fifth functional element 205, and the sixth functional element 206 are provided (arranged) on the base substrate 2 so as to correspond to the concave portion 21, the concave portion 22, and the concave portion 23, respectively. Yes. In the acceleration sensor 200, as shown in FIGS. 1 and 3, the fourth functional element 204 and the sixth functional element 206 are arranged in the X-axis direction with their longitudinal directions directed in the Y-axis direction. The fifth functional element 205 is provided on the + Y-axis direction side with respect to the fourth functional element 204 and the sixth functional element 206 with its longitudinal direction directed in the X-axis direction.

  Hereinafter, the fourth functional element 204, the fifth functional element 205, and the sixth functional element 206 will be described.

(4) Fourth functional element 204
First, the configuration of the fourth functional element 204 will be described.

  The fourth functional element 204 is an acceleration sensor element for detecting acceleration in the X-axis direction. As shown in FIG. 7, the fourth functional element 204 includes support parts 41 and 42, a movable part 43, connection parts 44 and 45, a plurality of first fixed electrode fingers 48, and a plurality of second elements. And a fixed electrode finger 49. In addition, the movable portion 43 includes a base portion 431 and a plurality of movable electrode fingers 432 protruding from the base portion 431 on both sides in the Y-axis direction. For example, the fourth functional element 204 is formed of a silicon substrate doped with impurities such as phosphorus and boron.

  The support portions 41 and 42 are respectively joined to the upper surface of the base substrate 2, and the support portion 41 is electrically connected to wiring (not shown). A movable portion 43 is provided between the support portions 41 and 42. The movable portion 43 is connected to the support portion 41 via the connection portion 44 on the −X axis side, and is connected to the support portion 42 via the connection portion 45 on the + X axis side. As a result, the movable portion 43 can be displaced in the X-axis direction as indicated by the arrow a with respect to the support portions 41 and 42.

  The plurality of first fixed electrode fingers 48 are arranged on one side in the X-axis direction of the movable electrode fingers 432 and are arranged in a comb-like shape that meshes with the corresponding movable electrode fingers 432 with a space therebetween. The plurality of first fixed electrode fingers 48 are bonded to the upper surface of the base substrate 2 at the base end portions.

  On the other hand, the plurality of second fixed electrode fingers 49 are arranged on the other side in the X-axis direction of the movable electrode fingers 432 so as to form a comb-tooth shape that meshes with the corresponding movable electrode fingers 432 with a space therebetween. Are lined up. The plurality of second fixed electrode fingers 49 are bonded to the upper surface of the base substrate 2 at the base end portion.

  Such a fourth functional element 204 detects the acceleration in the X-axis direction as follows. That is, when acceleration in the X-axis direction is applied to the physical quantity sensor 1, the movable portion 43 is displaced in the X-axis direction while elastically deforming the connecting portions 44 and 45 based on the magnitude of the acceleration. With such a displacement, the capacitance C1 between the movable electrode finger 432 and the first fixed electrode finger 48 and the capacitance C2 between the movable electrode finger 432 and the second fixed electrode finger 49 are increased. Changes. Therefore, acceleration can be detected based on the changes (differential signals) of these electrostatic capacitances C1 and C2.

  The fourth functional element 204 having such a configuration is accommodated in the internal space (acceleration sensor element accommodating portion) S2. In the base substrate 2 and the lid 3 that define the internal space S2, the fourth functional element 204 is provided. A plurality of projections 215 and projections 325 are formed in the recess 21 and the recess 32, respectively, at positions 204 are opposed to each other.

  Therefore, the capacitance C1 between the movable electrode finger 432 and the first fixed electrode finger 48 and the distance between the movable electrode finger 432 and the second fixed electrode finger 49 due to the displacement of the movable portion 43 in the X-axis direction. When detecting acceleration based on a change in the size of the capacitance C2 (differential signal), between the movable electrode finger 432 and the first fixed electrode finger 48 and between the movable electrode finger 432 and the second fixed electrode finger 49. Extrusion of gas from between the two can be reduced.

  Therefore, even if the internal space S2 in which the fourth functional element 204 is accommodated has a high degree of vacuum, the viscosity effect can be increased with a virtually low degree of vacuum. The axial acceleration can be detected with excellent accuracy.

  Therefore, as will be described in the method of manufacturing the physical quantity sensor 1 described later, the degree of vacuum in the internal space (acceleration sensor element storage portion) S2 in which the acceleration sensor 200 is stored is set to the internal space in which the gyro sensor 100 is stored (gyro sensor element storage). Part) Even if the degree of vacuum is set to be almost the same as the degree of vacuum in S1, both the acceleration sensor 200 and the gyro sensor 100 formed on the base substrate (same substrate) 2 included in the physical quantity sensor 1 are highly accurate. Can be.

  Further, in this embodiment, as shown in FIG. 10, the protrusion 215 and the protrusion 325 each have a convex surface facing the movable electrode finger (movable electrode) 432 and are viewed from the Z-axis direction (base A region between the movable electrode finger (movable electrode) 432 and the first fixed electrode finger (fixed electrode) 48 and the movable electrode finger 432 and the second fixed electrode finger (fixed electrode) 49. It arrange | positions corresponding to the position which covers the area | region between. Thereby, when the movable portion 43 is displaced in the X-axis direction, gas is pushed out from between the movable electrode finger 432 and the first fixed electrode finger 48 and between the movable electrode finger 432 and the second fixed electrode finger 49. Can be further reduced.

  Furthermore, it is preferable that the protrusion 215 and the protrusion 325 have a plurality of convex portions (fine irregularities) on the surface thereof. Protrusion 215 and protrusion 325 are provided with such a convex portion, so that the surface becomes rough and the surface area thereof increases. Therefore, when the movable portion 43 is displaced in the X-axis direction, gas is pushed out from between the movable electrode finger 432 and the first fixed electrode finger 48 and between the movable electrode finger 432 and the second fixed electrode finger 49. Can be further reduced. Furthermore, it is possible to suppress or prevent the movable electrode finger 432 from sticking to the protrusion 215 and the protrusion 325 when the movable portion 43 is displaced in the X-axis direction.

  In this case, the surface roughness Ra (specified in JIS B 0601) of the protrusion 215 and the protrusion 325 is preferably set to 0.01 μm or more and 1 μm or less. Thereby, the said effect can be exhibited notably.

  Further, as shown in FIG. 10B, the tip surface of the protrusion 325 and the upper surface of the movable electrode finger 432 are not located on the same surface but are separated from each other, and further, the tip of the protrusion 215 The surface and the upper surface of the movable electrode finger 432 are not located on the same surface and are separated from each other. Specifically, the distance between these surfaces is preferably 0.1 μm or more and 10 μm or less. Is set. Thereby, when the movable portion 43 is displaced in the X-axis direction, gas is pushed out from between the movable electrode finger 432 and the first fixed electrode finger 48 and between the movable electrode finger 432 and the second fixed electrode finger 49. It is possible to suppress or prevent the movable electrode finger 432 from sticking to the protrusion 215 and the protrusion 325 while reducing the occurrence of the protrusion.

(5) Fifth functional element 205
Next, the configuration of the fifth functional element 205 will be described.

  The fifth functional element 205 is an acceleration sensor element for detecting acceleration in the Y-axis direction. As shown in FIG. 8, the fifth functional element 205 has the same configuration as the fourth functional element 204 except that the fifth functional element 205 is arranged in a state rotated by 90 ° in plan view. That is, the fifth functional element 205 includes support portions 51 and 52, a movable portion 53, connecting portions 54 and 55, a plurality of first fixed electrode fingers 58, and a plurality of second fixed electrode fingers 59. doing. The movable portion 53 includes a base portion 531 and a plurality of movable electrode fingers 532 that protrude from the base portion 531 to both sides in the X-axis direction.

  Each of the support portions 51 and 52 is bonded to the upper surface of the base substrate 2. A movable portion 53 is provided between the support portions 51 and 52. The movable portion 53 is connected to the support portion 51 via the connecting portion 54 on the −Y axis side, and is connected to the support portion 52 via the connecting portion 55 on the + Y axis side. As a result, the movable portion 53 can be displaced in the Y-axis direction as indicated by the arrow b with respect to the support portions 51 and 52.

  The plurality of first fixed electrode fingers 58 are arranged on one side in the Y-axis direction of the movable electrode fingers 532 and are arranged in a comb-like shape that meshes with the corresponding movable electrode fingers 532 with a space therebetween. The plurality of first fixed electrode fingers 58 are bonded to the upper surface of the base substrate 2 at the base end portions.

  On the other hand, the plurality of second fixed electrode fingers 59 are arranged on the other side in the Y-axis direction of the movable electrode fingers 532 so as to form a comb-tooth shape that meshes with the corresponding movable electrode fingers 532 with a space therebetween. Are lined up. A plurality of such second fixed electrode fingers 59 are joined to the upper surface of the base substrate 2 at the base end portions.

  Such a fifth functional element 205 detects the acceleration in the Y-axis direction as follows. That is, when acceleration in the Y-axis direction is applied to the physical quantity sensor 1, the movable portion 53 is displaced in the Y-axis direction while elastically deforming the connecting portions 54 and 55 based on the magnitude of the acceleration. Along with such displacement, the capacitance C3 between the movable electrode finger 532 and the first fixed electrode finger 58 and the capacitance C4 between the movable electrode finger 532 and the second fixed electrode finger 59 are increased. Changes. Therefore, acceleration can be detected based on changes (differential signals) of these electrostatic capacitances C3 and C4.

(6) Sixth functional element 206
Next, the configuration of the sixth functional element 206 will be described.

  The sixth functional element 206 is an acceleration sensor element for detecting acceleration in the Z-axis direction (vertical direction). As shown in FIG. 9, the sixth functional element 206 has a pair of support portions 61 and 62, a movable portion 63, and a movable portion 63 that can swing with respect to the support portions 61 and 62. The movable portion 63 and the support portions 61 and 62 are coupled to each other, and the movable portion 63 swings with respect to the support portions 61 and 62 with the connection portions 64 and 65 as the axis J. It is configured to move.

  Each of the support portions 61 and 62 is bonded to the upper surface of the base substrate 2. A movable portion 63 is provided between the support portions 61 and 62. The movable part 63 includes a first movable part 631 located on the −X axis direction side with respect to the axis J, and a second movable part 632 located on the + X axis direction side with respect to the axis J. Further, the first movable portion 631 is disposed to face the first detection electrode 741, forms a capacitance Ca between the first detection electrode 741, and the second movable portion 632 includes the second detection electrode 742. The electrostatic capacitance Cb is formed between the second detection electrode 742 and the second detection electrode 742. For example, the sixth functional element 206 is formed of a silicon substrate doped with impurities such as phosphorus and boron.

  The first and second movable parts 631 and 632 have different rotational moments when acceleration in the vertical direction (Z-axis direction) is applied, and are designed so that a predetermined inclination occurs in the movable part 63 according to the acceleration. Has been. As a result, when vertical acceleration occurs, the movable portion 63 swings around the axis J. Specifically, in the present embodiment, the area (length) of the second movable part 632 is made larger than the area (length) of the first movable part 631 in plan view, thereby It is designed so that the rotational moment of the second movable part 632 is larger than the rotational moment.

  The sixth functional element 206 detects acceleration in the Z-axis direction as follows. That is, when vertical acceleration is applied to the physical quantity sensor 1, the movable portion 63 swings around the axis J. By such seesaw swinging of the movable portion 63, the separation distance between the first movable portion 631 and the first detection electrode 741 and the separation distance between the second movable portion 632 and the second detection electrode 742 change, and the static distance is accordingly changed. Capacitances Ca and Cb change. Therefore, the acceleration value can be detected based on the change amounts of the capacitances Ca and Cb (differential signals of the capacitances Ca and Cb), and the acceleration value can be detected from the change direction of the capacitances Ca and Cb. The direction can be specified.

  As described above, the acceleration sensor 200 detects accelerations in the directions of the three axes (Y axis, X axis, and Z axis) orthogonal to each other.

(Manufacturing method of physical quantity sensor 1)
Next, a method for manufacturing the physical quantity sensor 1 will be described with reference to FIGS. In addition, in FIGS. 11-14, sectional drawing corresponding to the AA line cross section in FIG. 1 is shown on the upper side, and sectional drawing corresponding to the BB line cross section in FIG. 1 is shown below. Therefore, in FIGS. 11 to 14, a part of the configuration of the physical quantity sensor 1 is not illustrated.

  The physical quantity sensor 1 is manufactured by a first step of placing the functional elements 101, 102, 103, 204, 205, 206 on the base substrate 2, and the functional elements 101, 102 between the lid 3 and the base substrate 2. , 103 and the functional elements 204, 205, 206, a second step of joining the lid 3 to the base substrate 2 so as to define an internal space S1 and an internal space S2 for accommodating the through-hole 311; And a third step of sealing 321 with sealing materials 312 and 322, respectively.

Hereinafter, these steps will be sequentially described.
[First step]
[1-1] First, as shown in FIG. 11A, a glass substrate 20 on which a plurality of base substrates 2 are integrally formed is prepared.

  The glass substrate 20 is obtained, for example, by forming the concave portions 13, 14, 15, 21, 22, 23 and the groove 211 on a plate-like glass substrate using a photolithography technique and an etching technique.

  At this time, the protrusions 215 are formed in the recesses 21 and 22 together with the formation of the recesses 13, 14, 15, 21, 22, 23 and the groove 211 in the same etching process. Thereby, the recessed parts 13, 14, 15, 21, 22, 23 and the groove part 211 can be formed as having a uniform depth. Thus, since each recessed part 13, 14, 15, 21, 22, 23 can be formed without variation, the quality of the obtained physical quantity sensor 1 can be improved.

  In addition, the wiring 721, the terminal 721a, the first and second detection electrodes 741 and 742, and the first fixed detection electrode portion 146 arranged on each base substrate 2 are formed on the upper surface of the glass substrate 20 by, for example, sputtering or vapor deposition. It is obtained by forming a metal film and patterning the metal film using a photolithography technique and an etching technique.

  [1-2] Next, as shown in FIG. 11B, the silicon substrate 40 is anodically bonded to the upper surface of the glass substrate 20. However, the bonding method is not limited to anodic bonding.

  [1-3] Next, as shown in FIG. 12A, the silicon substrate 40 is patterned by using a photolithography technique and an etching technique.

  Thereby, the functional elements 101, 102, 103, 204, 205, 206 are formed corresponding to the recesses 13, 14, 15, 21, 22, 23 of the base substrate 2, respectively. As a result, the functional elements 101, 102, 103, 204, 205, and 206 are bonded (arranged) on each base substrate 2 so as to overlap the concave portions 13, 14, 15, 21, 22, and 23.

[Second step]
[2-1] Next, a silicon substrate 30 on which a plurality of lids 3 are integrally formed is prepared, and the lower surface of the silicon substrate 30 is placed on the upper surface of the glass substrate 20 as shown in FIG. Join.

  As a result, an internal space S1 and an internal space S2 are formed between the silicon substrate 30 and the glass substrate 20 to accommodate the functional elements 101, 102, 103 and the functional elements 204, 205, 206, respectively.

  At this time, the internal space S1 and the internal space S2 are in communication with the external space via the through hole 311 and the through hole 321 respectively.

  However, the method for bonding the glass substrate 20 and the silicon substrate 30 is not limited to anodic bonding.

  Here, for example, the silicon substrate 30 is formed by patterning the silicon substrate from the upper surface side by using a photolithography technique and a wet etching technique to form the outer shape of each lid body 3 and the through holes 311 and 321. It is obtained by forming the recesses 31 and 32 by patterning from the lower surface side using a photolithography technique and a dry etching technique. Thus, by using the dry etching technique (anisotropic etching technique) for forming the recesses 31 and 32, the recesses 31 and 32 having straight side surfaces as shown in FIG. 12 can be easily formed. Can do.

  Further, when the recesses 31 and 32 are formed, the protrusions 325 are formed in the recesses 32 together with the formation of the recesses 31 and 32 in the same etching process. Thereby, the recessed parts 31 and 32 can be formed as what has the height of a uniform ceiling part. Thus, since each recessed part 31 and 32 can be formed without variation, the improvement of the quality of the physical quantity sensor 1 obtained is achieved.

[Third step]
[3-1] Next, as shown in FIG. 13A, the sealing film 8 is formed over the silicon substrate 30 and the glass substrate 20 by the CVD method, and the groove 211 is formed by the sealing film 8. Block it.

The sealing film 8 is preferably made of SiO ₂ , and this SiO ₂ film is formed by a CVD method using TEOS (Tetraethyl orthosilicate). Then, after the internal spaces S1 and S2 are made a predetermined atmosphere (depressurized atmosphere) through the through holes 311 and 321, the insides of the through holes 311 and 321 are sealed with sealing materials 312 and 322, respectively.

  As a result, the through holes 311 and 321 are sealed with the sealing materials 312 and 322 as shown in FIG.

  Here, as described above, when the internal spaces S1 and S2 are set to a predetermined atmosphere (depressurized atmosphere) and then the through holes 311 and 321 are sealed simultaneously, the internal space S1 and the internal space S2 respectively The degree of vacuum becomes uniform. In this case, in the present invention, the degree of vacuum is set high so that the gyro sensor 100 can detect the angular velocity with excellent accuracy. Usually, when the degree of vacuum is increased in this way, the acceleration detection sensitivity of the acceleration sensor tends to decrease, but as described above, the protrusions 215 and 325 are formed in the internal space S2. Therefore, even if the degree of vacuum in the internal space S2 becomes high, the viscosity effect can be increased in a virtually low degree of vacuum, so that the acceleration sensor 200 can detect acceleration with excellent accuracy. .

  Further, when the through holes 311 and 321 are not provided, the sealing is performed in the atmosphere when the sealing film 8 is formed. If the sealing film 8 is formed by the CVD method, it is sealed in a reduced pressure state.

  [3-2] Next, as shown in FIG. 13B, a part of the silicon substrate 30 (a region overlapping with the terminal 721a) is removed by half dicing using a dicing blade or the like, and the terminal 721a is removed. Is exposed to the outside.

[3-3] Next, for example, using a dicing saw, the glass substrate 20 is separated into pieces for each base substrate 2 as shown in FIG. Thereby, a plurality of physical quantity sensors 1 are obtained.
The physical quantity sensor 1 is manufactured through the above steps.

Second Embodiment
Next, a second embodiment of the physical quantity sensor of the present invention will be described.

  FIG. 15 is a plan view schematically showing a second embodiment of the physical quantity sensor of the present invention. 16 is a cross-sectional view (cross-sectional view taken along the line DD in FIG. 15) of the gyro sensor of the physical quantity sensor shown in FIG. 17 is a cross-sectional view (cross-sectional view taken along line EE in FIG. 15) of the gyro sensor and the acceleration sensor of the physical quantity sensor shown in FIG.

  Hereinafter, the physical quantity sensor 1 of the second embodiment will be described with a focus on differences from the physical quantity sensor 1 of the first embodiment, and description of similar matters will be omitted.

  A physical quantity sensor 1 shown in FIG. 15 houses an internal space (gyro sensor element housing portion) that houses functional elements 101, 102, and 103 (gyro sensor 100) and functional elements 204, 205, and 206 (acceleration sensor 200). The physical quantity sensor 1 is the same as the physical quantity sensor 1 shown in FIG. 1 except that the internal space (acceleration sensor element storage portion) is composed of the same internal space (closed space) S3.

  That is, in the physical quantity sensor 1 of the second embodiment, the internal space S1 and the internal space S2 in the physical quantity sensor 1 of the first embodiment are not defined separately by the base substrate 2 and the lid body 3, but communicate with each other. Then, an internal space S3 that is one closed space (space) is defined, and functional elements 101, 102, and 103 and functional elements 204, 205, and 206 are accommodated in the internal space S3.

  Thus, since the functional elements 101, 102, 103 (gyro sensor 100) and the functional elements 204, 205, 206 (acceleration sensor 200) are accommodated in the same internal space S3, the gyro that accommodates the gyro sensor 100 is naturally included. It can be said that the sensor element storage portion and the acceleration sensor element storage portion storing the acceleration sensor 200 have the same degree of vacuum.

  Even if both the functional elements 101, 102, 103 (gyro sensor 100) and the functional elements 204, 205, 206 (acceleration sensor 200) are accommodated in the internal space S3 that can be said to have a uniform degree of vacuum, the gyro Both the sensor 100 and the acceleration sensor 200 can be made highly accurate.

  Also by the physical quantity sensor 1 of the second embodiment, the same effect as that of the first embodiment can be obtained.

2. Next, an electronic module including the physical quantity sensor of the present invention will be described.

  FIG. 18 is a cross-sectional view showing an example of an electronic module including the physical quantity sensor of the present invention.

  An electronic module 100A shown in FIG. 18 includes a substrate 101A, a physical quantity sensor 1 fixed to the upper surface of the substrate 101A via an adhesive layer 103A, and an IC fixed to the upper surface of the physical quantity sensor 1 via an adhesive layer 104A. Chip (electronic component) 102A. The physical quantity sensor 1 and the IC chip 102A are molded with the molding material M in a state where the lower surface of the substrate 101A is exposed. As the adhesive layers 103A and 104A, for example, solder, silver paste, resin adhesive (die attach agent) or the like can be used. Further, as the molding material M, for example, a thermosetting epoxy resin can be used, and for example, it can be molded by a transfer molding method.

  A plurality of terminals 101a are arranged on the upper surface of the substrate 101A, and a plurality of mounting terminals 101b connected to the terminals 101a via internal wiring and castellation (not shown) are arranged on the lower surface. The substrate 101A is not particularly limited, and for example, a silicon substrate, a ceramic substrate, a resin substrate, a glass substrate, a glass epoxy substrate, or the like can be used.

  Further, the IC chip 102A includes, for example, a drive circuit that drives the physical quantity sensor 1, a detection circuit that detects acceleration in the X-axis, Y-axis, and Z-axis directions based on a signal from the physical quantity sensor 1, An output circuit that converts a signal from the detection circuit into a predetermined signal and outputs the signal is included. Such an IC chip 102A is electrically connected to the terminal 721a of the physical quantity sensor 1 via the bonding wire 105A, and is electrically connected to the terminal 101a of the substrate 101A via the bonding wire 106A.

  Since the electronic module 100A includes the physical quantity sensor 1, it has excellent reliability.

3. Next, the electronic device of the present invention will be described.

  FIG. 19 is a perspective view showing a configuration of a mobile (or notebook) personal computer to which the electronic apparatus of the present invention is applied.

  In this figure, a personal computer 1100 includes a main body 1104 having a keyboard 1102 and a display unit 1106. The display unit 1106 is supported by the main body 1104 via a hinge structure so as to be rotatable. Yes. Such a personal computer 1100 includes a physical quantity sensor 1 including a gyro sensor 100 and an acceleration sensor 200.

  FIG. 20 is a perspective view illustrating a configuration of a mobile phone (including a smartphone, a PHS, and the like) to which the electronic device of the present invention is applied.

  In this figure, a cellular phone 1200 includes an antenna (not shown), a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit is disposed between the operation buttons 1202 and the earpiece 1204. Has been. Such a cellular phone 1200 incorporates a physical quantity sensor 1.

  FIG. 21 is a perspective view showing the configuration of a digital still camera to which the electronic apparatus of the present invention is applied. In this figure, connection with an external device is also simply shown.

  A display unit is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit is a finder that displays an object as an electronic image. Function. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.

  When the photographer confirms the subject image displayed on the display unit and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 incorporates, for example, a physical quantity sensor 1 used for camera shake correction as a gyro sensor and an acceleration sensor.

  Since such an electronic apparatus includes the physical quantity sensor 1, it has excellent reliability.

  In addition to the personal computer of FIG. 19, the mobile phone of FIG. 20, and the digital still camera of FIG. 21, the electronic apparatus of the present invention includes, for example, an ink jet type ejection device (for example, an ink jet printer), a laptop personal computer, TV, video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring devices, instruments (for example, vehicles, aircraft, ships) Instruments), flight simulators, etc.

4). Next, the moving body of the present invention will be described.

FIG. 22 is a perspective view showing an automobile to which the moving body of the present invention is applied.
As shown in FIG. 22, the physical quantity sensor 1 is built in the automobile 1500. For example, the physical quantity sensor 1 can detect the posture and acceleration of the vehicle body 1501. The detection signal of the physical quantity sensor 1 is supplied to the vehicle body posture control device 1502, and the vehicle body posture control device 1502 detects the posture of the vehicle body 1501 based on the signal, and controls the stiffness of the suspension according to the detection result. The brakes of the individual wheels 1503 can be controlled. In addition, the physical quantity sensor 1 includes keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake system (ABS), airbag, tire pressure monitoring system (TPMS), engine It can be widely applied to electronic control units (ECUs) such as control, battery monitors of hybrid vehicles and electric vehicles.

  As described above, the physical quantity sensor, the electronic device, and the moving body of the present invention have been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each unit is an arbitrary configuration having the same function. Can be substituted. In addition, any other component may be added to the present invention.

  In the above-described embodiment, the configuration in which the physical quantity sensor has three functional elements for detecting the angular velocity and three functional elements for detecting the acceleration has been described. There is no limitation, and it is sufficient that there are at least one for detecting angular velocity and one for detecting acceleration.

DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor 2 ... Base substrate 3 ... Cover body 8 ... Sealing film 10 ... Package 13, 14, 15, 21, 22, 23, 31, 32 ... Recess 20 ... Glass substrate 30, 40 …… Silicone substrates 41, 42, 51, 52, 61, 62 …… Supporting portions 43, 53, 63 …… Moving portions 44, 45, 54, 55, 64, 65 …… Connecting portions 48, 58 …… No. 1 fixed electrode finger 49, 59 ... 2nd fixed electrode finger 100 ... gyro sensor 100A ... electronic module 101 ... 1st functional element 101A ... substrate 101a ... terminal 101b ... mounting terminal 102 ... 2nd function Element 102A... IC chip 103... Third functional elements 103A and 104A... Adhesive layer 105A... Bonding wire 106A ... Bonding wires 111, 112 and 113. 130a, 130b, 130c, 130d... Fixed part 132... Drive spring parts 132a, 132b, 132c, 132d... Spring 134 .. vibrating body 135a... First extension part 135b. ... movable drive electrode portions 138a, 138b ... fixed drive electrode portion 140 ... first movable body 142 ... beam portion 144 ... movable detection electrode portion 146 ... fixed detection electrode portion 150 ... movable body 151a ... third Extension part 151b ...... Fourth extension part 152 ...... Detection spring parts 152a, 152b, 152c, 152d ... Spring 154 ... Moveable detection electrode part 156 ... Fixed detection electrode part 200 ... Acceleration sensor 204 ... No. 4th functional element 205 ... 5th functional element 206 ... 6th functional element 211 ... Groove 215 ... Protrusion 311 321 ... Through-hole 312, 322 ... Sealing material 325 ... Projection 431 ... Base 432 ... Movable electrode finger 531 ... Base 532 ... Movable electrode finger 631 ... First movable part 632 ... Second movable part 721 ... Wiring 721a ... Terminal 741 ... First detection electrode 742... Second detection electrode 1100... Personal computer 1102... Keyboard 1104. Digital still camera 1302 ... Case 1304 ... Light receiving unit 1306 ... Shutter button 1308 ... Memory 1312 ... Video signal output terminal 1314 ... Input / output terminal 1430 ... TV monitor 1440 ... Personal computer 1500 ... Automobile 1501 ... ... Car body 1502 ... Car body attitude control device 150 3 ... Wheel B11 ... Conductive bump M ... Mold material S1 ... Internal space S2 ... Internal space S3 ... Internal space

Claims (15)

An acceleration sensor element;
An acceleration sensor element storage portion for storing the acceleration sensor element,
The physical quantity sensor according to claim 1, wherein the acceleration sensor element storage portion has an inner wall with irregularities at a position facing the acceleration sensor element. An acceleration sensor element disposed on the substrate;
A gyro sensor element disposed on the substrate;
An acceleration sensor element storage portion for storing the acceleration sensor element;
A gyro sensor element storage portion for storing the gyro sensor element;
The physical quantity sensor according to claim 1, wherein the acceleration sensor element storage portion has an inner wall with irregularities at a position facing the acceleration sensor element.   The acceleration sensor element storage portion and the gyro sensor element storage portion are joined to the substrate so as to overlap the substrate, respectively, and a first recess and a position corresponding to the gyro sensor element and the acceleration sensor element, respectively. The physical quantity sensor according to claim 2, wherein the physical quantity sensor is defined by a substrate having a second recess.   4. The plurality of concaves and convexes each have a convex portion arranged at a position overlapping with a region between the movable electrode and the fixed electrode included in the acceleration sensor element in a plan view of the substrate. Physical quantity sensor.   The physical quantity sensor according to any one of claims 2 to 4, wherein the acceleration sensor element storage portion and the gyro sensor element storage portion are both disposed in the same space.   The physical quantity sensor according to claim 2, wherein the unevenness includes a glass material as a main material.   The physical quantity sensor according to claim 2, wherein the unevenness includes a plurality of protrusions on a surface thereof.   The physical quantity according to any one of claims 2 to 7, wherein a surface of the unevenness facing the movable electrode and a surface of the movable electrode facing the unevenness are not located on the same surface. sensor.   The physical quantity sensor according to any one of claims 2 to 8, wherein a degree of vacuum of the gyro sensor element accommodation portion and a degree of vacuum of the acceleration sensor element accommodation portion are aligned.   The physical quantity sensor according to any one of claims 2 to 9, wherein each of the ceiling portions of the acceleration sensor element storage portion and the gyro sensor element storage portion is formed by the same etching process.   The physical quantity sensor according to any one of claims 2 to 10, wherein a degree of vacuum of the acceleration sensor element storage unit and the gyro sensor element storage unit is 500 Pa or less.   The physical quantity sensor according to any one of claims 2 to 11, wherein the acceleration sensor element storage section and the gyro sensor element storage section have an inert atmosphere inside.   The physical quantity sensor according to any one of claims 1 to 12, wherein a surface of the concavo-convex acceleration sensor element facing a movable electrode is a convex surface.   An electronic apparatus comprising the physical quantity sensor according to claim 1.   A moving body comprising the physical quantity sensor according to claim 1.

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