JP6303760B2 - Functional elements, physical quantity sensors, electronic devices, and moving objects - Google Patents

Description

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

  Conventionally, for example, as a physical quantity sensor provided with a functional element that detects a physical quantity such as acceleration and angular velocity, both ends of the weight part, which is provided with a movable part on the support substrate and can be displaced in a predetermined direction, along the displacement direction. Semiconductor mechanical quantities having a configuration in which anchor portions (hereinafter referred to as “fixed portions”) fixed to a support substrate are provided outside the portions, and the weight portions are connected to the fixed portions via beam portions having a spring function. A sensor is known (see, for example, Patent Document 1).

JP 2001-330623 A

In the semiconductor dynamic quantity sensor, the weight portion is between the beam portion connected to one fixed portion and the beam portion connected to the other fixed portion (in other words, one fixed portion and the other fixed portion (Between the fixed portion).
In the physical quantity sensor including the semiconductor dynamic quantity sensor, it is known that the physical quantity detection sensitivity is proportional to the mass of the weight part, and the physical quantity detection sensitivity is improved as the mass of the weight part is increased.

In order to increase the mass of the weight part, the semiconductor dynamic quantity sensor, for example, increases the distance between one fixed part and the other fixed part and lengthens the weight part. Due to the bending, the weight portion easily comes into contact with the support substrate, and there is a possibility that problems such as sticking of the weight portion to the support substrate (sticking) are likely to occur.
As another measure, for example, when the thickness of the weight portion is increased without changing the distance between one fixed portion and the other fixed portion, the total thickness of the semiconductor dynamic quantity sensor increases, and There is a risk that it will be difficult to reduce the thickness.

  As described above, the semiconductor dynamic quantity sensor (physical quantity sensor) having the above configuration has a limitation on the mass of the weight portion, and thus it may be difficult to improve the detection sensitivity of the physical quantity by increasing the mass of the weight portion. .

  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 A functional element according to this application example includes a substrate, a movable part disposed on the substrate and displaceable in a first direction, and one end side and the other end side of the movable part in the first direction. A fixed portion that is fixed to the substrate and connected to the movable portion via a flexible portion, from at least one end of the one end side and the other end side of the movable portion A mass part is extended outside the fixed part on the one end side and the other end side.

According to this, since the functional element has a mass portion extending from at least one end portion on one end side and the other end side of the movable portion to the outside between the fixed portions on the one end side and the other end side. The mass of the movable part including the mass part can be increased without increasing the distance between the fixed parts on the one end side and the other end side (corresponding to between the one fixed part and the other fixed part in Patent Document 1). .
As a result, the functional element can improve the detection sensitivity of the physical quantity, for example, as a functional element that detects the physical quantity.

  Application Example 2 In the functional element according to the application example described above, it is preferable that the mass portion extends along a second direction intersecting the first direction in a plan view.

According to this, the functional element includes the mass part while suppressing the size increase in the first direction because the mass part extends along the second direction intersecting the first direction in plan view. The mass of the movable part can be increased.
As a result, the functional element can improve the detection sensitivity of the physical quantity, for example, while suppressing the size increase in the first direction.

  Application Example 3 In the functional element according to the application example, the fixing portion extends along the second direction so as to face the mass portion, and at least one of the fixing portion and the mass portion is provided on the functional element. It is preferable that a protruding portion that protrudes toward the opposite side is provided.

  According to this, the functional element extends along the second direction so that the fixed portion faces the mass portion, and at least one of the fixed portion and the mass portion has a protruding portion that protrudes to the opposite side. Since the protrusion is in contact with the fixed part or the mass part, the displacement of the mass part in the first direction can be restricted, and the damage to the movable part including the mass part can be reduced.

  Application Example 4 In the functional element according to the application example described above, it is preferable that the protruding portion is provided on a distal end side in the second direction of the fixing portion or the mass portion.

  According to this, since the protrusion is provided on the distal end side in the second direction of the fixed part or the mass part, the functional element includes the mass part as compared with the case where it is provided on the root part side. It is possible to suppress the inclination in plan view with respect to the first direction at the time of displacement.

  Application Example 5 In the functional element according to the application example, the movable portion includes a movable electrode extending in a second direction intersecting the first direction in a plan view, and the movable electrode is provided on the substrate. It is preferable that a fixed electrode extending along the second direction is provided so as to oppose.

  According to this, the functional element has a movable electrode having a movable portion extending along a second direction intersecting the first direction in plan view, and the substrate is provided with a fixed electrode so as to face the movable electrode. Therefore, the displacement of the movable part can be detected as a change in capacitance between the movable electrode and the fixed electrode, for example.

  Application Example 6 In the functional element according to the application example described above, the mass unit includes an additional movable electrode extending along the second direction, and the substrate has the additional movable electrode facing the additional movable electrode. It is preferable that an additional fixed electrode extending along the second direction is provided.

According to this, since the functional element has the additional movable electrode whose mass part extends along the second direction, and the substrate is provided with the additional fixed electrode so as to face the additional movable electrode, The displacement of the movable part can be detected as a change in capacitance obtained by adding the capacitance between the additional movable electrode and the additional fixed electrode to the capacitance between the movable electrode and the fixed electrode.
As a result, for example, the functional element can further improve the detection sensitivity of the physical quantity.

  Further, since the functional element has the additional movable electrode in which the mass part extends in the second direction, the mass distribution of the movable part including the mass part is dispersed, for example, to the substrate of the movable part at the time of manufacture. Can be suppressed.

  Application Example 7 In the functional element according to the application example described above, it is preferable that the additional movable electrode is provided with a protruding portion that protrudes toward the fixed portion that faces the additional movable electrode.

  According to this, since the functional element is provided with the protruding portion that protrudes toward the fixed portion facing the additional movable electrode, the protruding portion comes into contact with the fixed portion, whereby the functional element moves in the first direction of the mass portion. The displacement of the movable part including the mass part can be reduced.

  Application Example 8 In the functional element according to the application example described above, it is preferable that the fixed portion is disposed so as to sandwich the movable portion along a second direction intersecting the first direction in a plan view. .

According to this, since the functional element is disposed so as to sandwich the movable part along the second direction in which the fixed part intersects the first direction in plan view, the movable part is disposed via the flexible part. It can be supported from both sides in the second direction.
As a result, the functional element can support the movable part in a stable state by the fixed part.

  Application Example 9 A physical quantity sensor according to this application example includes the functional element according to any one of the application examples described above.

  According to this, since the physical quantity sensor of this configuration includes the functional element described in any one of the application examples, a physical quantity sensor that exhibits the effect described in any one of the application examples is provided. Can do.

  Application Example 10 An electronic apparatus according to this application example includes the functional element described in any one of the application examples described above.

  According to this, since the electronic device of this configuration includes the functional element described in any one of the application examples, an electronic device that exhibits the effects described in any one of the application examples is provided. Can do.

  Application Example 11 A moving body according to this application example includes the functional element described in any one of the application examples.

  According to this, since the moving body of this structure is provided with the functional element as described in any one example of the said application example, providing the moving body which produces the effect as described in any one example of the said application example Can do.

It is a schematic diagram which shows schematic structure of the acceleration sensor of 1st Embodiment, (a) is a schematic plan view, (b) is a schematic cross section in the AA of (a). The schematic plan view explaining an example of the wiring of an acceleration sensor. It is a schematic diagram which shows schematic structure of the acceleration sensor of 2nd Embodiment, (a) is a schematic plan view, (b) is a schematic cross section in the AA of (a). The model perspective view which shows the structure of the mobile type (or notebook type) personal computer as an electronic device provided with a functional element. The model perspective view which shows the structure of the mobile telephone (PHS is also included) as an electronic device provided with a functional element. The model perspective view which shows the structure of the digital still camera as an electronic device provided with a functional element. The model perspective view which shows the motor vehicle as an example of the mobile body provided with the functional element.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.

First, an acceleration sensor as an example of a physical quantity sensor including a functional element will be described.
(First embodiment)
FIG. 1 is a schematic diagram illustrating a schematic configuration of the acceleration sensor according to the first embodiment. FIG. 1A is a schematic plan view, and FIG. 1B is a schematic cross-sectional view taken along line AA in FIG. In the plan view, the lid is omitted, and some components are hatched for easy understanding.
Moreover, in each figure after FIG. 1 including it, in order to make it intelligible, the dimension ratio of each component differs from actual. Further, the X axis, the Y axis, and the Z axis in the figure are mutually orthogonal coordinate axes, and the direction of the arrow is the + (plus) direction.

As shown in FIG. 1, the functional element provided in the acceleration sensor 1 includes a substantially rectangular flat plate-like substrate 10, a movable portion 20 that is disposed on the substrate 10 and can be displaced in the X-axis direction as the first direction. The movable unit 20 is positioned on one end side (− (minus) X side) and the other end side (+ X side) in the X-axis direction, fixed to the substrate 10, and connected to the movable unit 20 via the flexible unit 30. Fixing portions 40 and 41.
And the functional element with which the acceleration sensor 1 is equipped is the fixed part 40-fixed part 41 of the one end side and the other end side from the edge part of the one end side and other end side of the movable part 20 (here both). The mass parts 50 and 51 extended outside are provided, and the cover body 60 which covers each of these components. (Here, for convenience, description will be made assuming that the functional element is an acceleration sensor. The same applies to the following embodiments.)

The movable portion 20 extends in a beam shape along the X-axis direction, and extends along the Y-axis direction as a second direction intersecting the X-axis direction in plan view (viewed from the Z-axis direction). have.
The movable electrode 70 is comb-shaped and includes five movable electrode fingers 71 extending to the + Y side and five movable electrode fingers 72 extending to the −Y side.
A fixed electrode 80 extending along the Y-axis direction is provided on the substrate 10 so as to face the movable electrode 70 (movable electrode finger 71, movable electrode finger 72).
The fixed electrode 80 has a comb-like shape and is positioned on the + Y side of the movable portion 20 and faces the + X side of the movable electrode finger 71, and the −Y side of the movable portion 20. And four first fixed electrode fingers 82 that face the + X side of the movable electrode finger 72.
Further, the fixed electrode 80 has a comb-like shape, is positioned on the + Y side of the movable portion 20, and is disposed with four second fixed electrode fingers 83 facing the −X side of the movable electrode finger 71, and the movable portion 20. Four second fixed electrode fingers 84 positioned on the −Y side and facing the −X side of the movable electrode finger 72.

Thus, in the acceleration sensor 1, the first fixed electrode finger 81 and the second fixed electrode finger 83 are arranged between the adjacent movable electrode fingers 71-71, and the first fixed electrode finger is interposed between the adjacent movable electrode fingers 72-72. 82 and the second fixed electrode finger 84 are arranged.
A predetermined gap (gap) is provided between the electrode fingers so as to generate a predetermined capacitance.

  The fixed portions 40 and 41 are each paired, and are disposed so as to sandwich the movable portion 20 along the Y-axis direction. The fixed portions 40 and 41 each extend along the Y-axis direction, bend in the X-axis direction so that the tip end side (side away from the movable portion 20) surrounds the flexible portion 30, and the whole Are formed in an L shape (inverted L shape).

The flexible portion 30 corresponds to each of the four fixed portions 40 and 41, one on the + Y side and one on the one end side of the movable portion 20, and one on the + Y side on the other end side of the movable portion 20 and One is provided on the −Y side, and the movable part 20 and the fixed parts 40 and 41 are connected.
The four flexible portions 30 each extend along the X-axis direction while being folded back multiple times in the Y-axis direction (meandering in the Y-axis direction).
Thereby, the flexible portion 30 has flexibility (elasticity) in the X-axis direction, and the movable portion 20 connected to the flexible portion 30 can be displaced in the X-axis direction.

The mass parts 50 and 51 extend along the X-axis direction from both ends of the movable part 20 in the X-axis direction (here, the connection parts with the flexible part 30), and then the fixed parts 40 and 41 Extending in a substantially rectangular shape on the + Y side and the −Y side of the movable portion 20 along the Y-axis direction so as to face each other.
Thereby, the mass parts 50 and 51 as a whole are formed in a T shape that is rotated by 90 ° horizontally.

  The movable part 20, the flexible part 30, the fixed parts 40 and 41, the mass parts 50 and 51, the movable electrode 70, and the fixed electrode 80 are laminated on the substrate 10, for example, with a semiconductor material such as silicon as a main material. It is formed from a single semiconductor substrate with high accuracy using techniques such as photolithography and etching.

On the main surface 11 along the XY plane defined by the X axis and the Y axis of the substrate 10, a movable portion 20, a flexible portion 30, mass portions 50 and 51, and a movable electrode 70 (movable electrode finger 71, movable In order to avoid interference between the electrode fingers 72) and the substrate 10, a recess 12 is provided so that a gap is formed between these components and the substrate 10.
As a result, the fixed electrode 80 (the first fixed electrode finger 81, the first fixed electrode finger 82, the second fixed electrode finger 83, and the second fixed electrode finger 84) is moved to the movable electrode 70 (movable electrode finger 71, movable electrode finger 72). ) Is projected from the main surface 11 of the substrate 10 toward the recess 12 (overhangs).
In addition, it is preferable that the recessed part 12 is not provided in the part which overlaps with the fixing | fixed part 40 and 41 of the board | substrate 10 in planar view, in order to ensure the fixing strength to the board | substrate 10 of the fixing | fixed part 40 and 41.

A terminal portion 90 is provided at an end portion on the −X side of the main surface 11 of the substrate 10.
The terminal portion 90 is provided with a common terminal 91, a first terminal 92, and a second terminal 93 that are arranged in this order from the −Y side to the + Y side along the Y axis.
The common terminal 91 is electrically connected to the fixed portion 40 (41) by wiring provided in a groove portion (not shown) of the main surface 11 of the substrate 10, and the first terminal 92 is similarly connected to the first fixed electrode fingers 81 and The first fixed electrode finger 82 is electrically connected, and the second terminal 93 is similarly electrically connected to the second fixed electrode finger 83 and the second fixed electrode finger 84.
Thus, the common terminal 91 is electrically connected to the movable electrode 70 (movable electrode finger 71, movable electrode finger 72) of the movable portion 20 via the fixed portion 40 (41) and the flexible portion 30. become.

As a material of the substrate 10, an insulating material such as glass or high resistance silicon is preferably used. In particular, when the semiconductor substrate that becomes the movable part 20, the flexible part 30, the fixed parts 40 and 41, the mass parts 50 and 51, the movable electrode 70, and the fixed electrode 80 is mainly made of a semiconductor material such as silicon, As a material for the substrate 10, it is preferable to use glass containing alkali metal ions (movable ions) (for example, borosilicate glass such as Pyrex (registered trademark)).
Thereby, the acceleration sensor 1 can perform anodic bonding of the substrate 10 and the semiconductor substrate. Further, the acceleration sensor 1 can easily insulate and isolate the substrate 10 and the semiconductor substrate by using glass containing alkali metal ions for the substrate 10.

The substrate 10 does not necessarily have insulation, and may be a conductive substrate made of low resistance silicon, for example. In this case, an insulating film is sandwiched between the substrate 10 and the semiconductor substrate to insulate and separate them.
The material of the substrate 10 is preferably as small as possible in the difference in thermal expansion coefficient from the material of the semiconductor substrate. Specifically, the difference in thermal expansion coefficient between the material of the substrate 10 and the material of the semiconductor substrate is 3 ppm / ° C. or less. It is preferable that Thereby, the acceleration sensor 1 can reduce the residual stress between the substrate 10 and the semiconductor substrate.

The lid 60 has a substantially rectangular flat plate shape, has a recess 61 on the main surface 11 side of the substrate 10, and is fixed to the substrate 10 so as to cover the main surface 11 side of the substrate 10 excluding the terminal portion 90. Has been.
The lid 60 is fixed to the main surface 11 of the substrate 10 by using, for example, a bonding method using an adhesive, an anodic bonding method, a direct bonding method, or the like.
The movable part 20, the flexible part 30, the fixed parts 40 and 41, the mass parts 50 and 51, the movable electrode 70, and the fixed electrode 80 have a gap between the lid 60 and the recessed part 61 of the lid 60. .
The material of the lid body 60 is not particularly limited, but for example, a silicon material, a glass material, or the like can be suitably used.

The internal space S of the acceleration sensor 1 hermetically sealed by fixing the lid 60 to the substrate 10 is in a reduced pressure state (high vacuum state) or filled with an inert gas such as nitrogen, helium, or argon. It has become.
The internal space S includes the concave portion 12 of the substrate 10 and the concave portion 61 of the lid body 60, and includes a movable portion 20, a flexible portion 30, fixed portions 40 and 41, mass portions 50 and 51, and a movable electrode 70. And the fixed electrode 80 is accommodated.

Here, the wiring of the acceleration sensor 1 will be described.
FIG. 2 is a schematic plan view illustrating an example of the wiring of the acceleration sensor. The wiring is indicated by a broken line. Further, in the figure, ● represents a conduction portion between each wiring and each component.

As shown in FIG. 2, in the acceleration sensor 1, each terminal, the movable electrode 70, and the fixed electrode 80 are electrically connected by each wiring provided in a groove portion (not shown) of the main surface 11 of the substrate 10. ing.
Specifically, the movable electrode 70 passes along the peripheral portion on the −Y side of the concave portion 12 of the substrate 10 through the movable portion 20, the flexible portion 30, and the −Y side fixed portion 40 that are integrated. It is electrically connected to the common terminal 91 by the common wiring 13 extending to the −X side. Here, the fixed portion 40 on the −Y side is a conductive portion with the common wiring 13 on the movable electrode 70 side.

Among the fixed electrodes 80, the first fixed electrode fingers 81 and 82 are first formed by the first wiring 14 extending so as to surround the recess 12 counterclockwise from the −Y side along the peripheral edge of the recess 12 of the substrate 10. The terminal 92 is electrically connected.
The remaining second fixed electrode fingers 83 and 84 of the fixed electrode 80 extend from the outside of the first wiring 14 along the peripheral edge of the recess 12 of the substrate 10 so as to surround the recess 12 counterclockwise from the −Y side. The second wiring 15 is electrically connected to the second terminal 93.

The material of each wiring and each terminal is not particularly limited as long as it has conductivity, and various electrode materials can be used.
Specifically, oxides (transparent electrode materials) such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), In ₃ O ₃ , SnO ₂ , Sb-containing SnO ₂ , and Al-containing ZnO, Au, Pt, Ag , Cu, Al, or an alloy containing these, and one or more of these can be used in combination.

In the acceleration sensor 1, if the material of each wiring is a transparent electrode material (especially ITO), and the substrate 10 is transparent, the first fixed electrode fingers 81 and 82 and the second fixed electrode fingers 83 and 84 Foreign matter or the like existing on the surface on the substrate 10 side can be easily seen from the back side opposite to the main surface 11 of the substrate 10, and inspection can be performed efficiently.
In addition, the acceleration sensor 1 extends the first fixed electrode fingers 81 and 82 or the second fixed electrode fingers 83 and 84 to the vicinity of the first terminal 92 or the second terminal 93, so that the first wiring 14 or the second wiring 14 The wiring 15 may also be used.

Here, the operation of the acceleration sensor 1 will be described.
Returning to FIG. 1, in the acceleration sensor 1, a signal is applied to the common terminal 91, the first terminal 92, and the second terminal 93, whereby the first fixed electrode finger 81 (82) and the first fixed electrode finger 81. A first capacitor is formed between the movable electrode finger 71 (72) facing (82) from the -X side, and + X is applied to the second fixed electrode finger 83 (84) and the second fixed electrode finger 83 (84). A second capacitor is formed between the movable electrode finger 71 (72) facing from the side.

In this state, for example, when acceleration is applied to the acceleration sensor 1 in the −X direction, the movable portion 20 and the movable electrode finger 71 (72) are displaced in the + X direction due to inertia. At this time, since the distance between the first fixed electrode finger 81 (82) and the movable electrode finger 71 (72) becomes narrow, the capacitance of the first capacitor increases. In addition, since the distance between the second fixed electrode finger 83 (84) and the movable electrode finger 71 (72) is increased, the capacitance of the second capacitor is reduced.
Conversely, when acceleration is applied in the + X direction and the movable portion 20 and the movable electrode finger 71 (72) are displaced in the -X direction, the capacitance of the first capacitor decreases and the capacitance of the second capacitor increases. To do.

Therefore, the acceleration sensor 1 detects the change in the capacitance of the first capacitor detected between the common terminal 91 and the first terminal 92 and the second detected between the common terminal 91 and the second terminal 93. By detecting the difference from the change in the capacitance of the capacitor, the magnitude and direction of the acceleration applied to the acceleration sensor 1 can be detected.
And the acceleration sensor 1 becomes a structure which can detect an acceleration with high sensitivity by detecting the difference of the electrostatic capacitance change of two capacitors.

As described above, the acceleration sensor 1 according to the first embodiment is fixed to the one end side and the other end side of the movable portion 20 from the one end side and the other end side (both in this case). Mass portions 50 and 51 are extended outside the portion 41.
From this, the acceleration sensor 1 can increase the mass of the movable part 20 including the mass parts 50 and 51 without expanding the space between the fixed part 40 and the fixed part 41 on one end side and the other end side.
As a result, the acceleration sensor 1 avoids sticking to the substrate 10 due to the bending of the central portion of the movable portion 20 caused by expanding the space between the fixed portion 40 and the fixed portion 41 on the one end side and the other end side, while maintaining the physical quantity. As a functional element for detecting the acceleration, the acceleration detection sensitivity can be improved.

Moreover, since the mass parts 50 and 51 extend along the Y-axis direction that intersects (orthogonally) the X-axis direction in a plan view, the acceleration sensor 1 suppresses an increase in size in the X-axis direction, The mass of the movable part 20 including the mass parts 50 and 51 can be increased.
As a result, the acceleration sensor 1 can improve acceleration detection sensitivity while suppressing an increase in size in the X-axis direction.

Further, the acceleration sensor 1 has a movable electrode 70 (movable electrode fingers 71 and 72) in which the movable portion 20 extends in the Y-axis direction intersecting the X-axis direction in plan view. The fixed electrodes 80 (first fixed electrode fingers 81 and 82, second fixed electrode fingers 83 and 84) are provided so as to face each other.
From this, the acceleration sensor 1 detects the displacement of the movable part 20 by, for example, the movable electrode 70 (movable electrode fingers 71, 72) and the fixed electrode 80 (first fixed electrode fingers 81, 82, second fixed electrode fingers 83, 84) can be detected as a change in capacitance.

The acceleration sensor 1 is also possible because the fixed portions 40 and 41 are arranged so as to sandwich the movable portion 20 along the Y-axis direction that intersects the X-axis direction in a plan view. The movable part 20 can be supported from both sides in the Y-axis direction via the flexible part 30.
As a result, the acceleration sensor 1 can support the movable part 20 in a stable state by the fixed parts 40 and 41.
Note that the acceleration sensor 1 may have a configuration in which only one of the mass parts 50 and 51 is provided as long as there is no problem in acceleration detection.

(Second Embodiment)
Next, an acceleration sensor according to a second embodiment will be described.
FIG. 3 is a schematic diagram illustrating a schematic configuration of the acceleration sensor according to the second embodiment. FIG. 3A is a schematic plan view, and FIG. 3B is a schematic cross-sectional view taken along the line AA in FIG. In addition, the same code | symbol is attached | subjected to a common part with 1st Embodiment, detailed description is abbreviate | omitted, and it demonstrates centering on a different part from 1st Embodiment.

As shown in FIG. 3, the acceleration sensor 2 of the second embodiment is different from the first embodiment in the configuration of the mass parts 50 and 51.
The acceleration sensor 2 has an additional movable electrode 170 in which the mass parts 50 and 51 extend along the Y-axis direction, and the substrate 10 has an additional extension extending along the Y-axis direction so as to face the additional movable electrode 170. A fixed electrode 180 is provided.
The additional movable electrode 170 is comb-shaped, and includes four additional movable electrode fingers 171 extending to the + Y side of the mass parts 50 and 51 and four additional movable electrodes extending to the −Y side of the mass parts 50 and 51. And a finger 172.

The additional fixed electrode 180 has a comb-like shape, is positioned on the + Y side of the mass parts 50 and 51, and has three additional first fixed electrode fingers 181 facing the + X side of the additional movable electrode finger 171 and the mass part. And three additional first fixed electrode fingers 182 located on the −Y side of 50 and 51 and facing the + X side of the additional movable electrode finger 172.
Further, the additional fixed electrode 180 has a comb-tooth shape and is positioned on the + Y side of the mass parts 50 and 51 and includes three additional second fixed electrode fingers 183 facing the −X side of the additional movable electrode finger 171. And three additional second fixed electrode fingers 184 located on the −Y side of the mass parts 50 and 51 and facing the −X side of the additional movable electrode finger 172.

The acceleration sensor 2 extends along the Y-axis direction so that the fixed portions 40 and 41 face the additional movable electrode fingers 171 and 172 of the mass portions 50 and 51, and faces the fixed portions 40 and 41. Four protrusions 140 and 141 having a substantially semicircular planar shape that protrudes toward the additional movable electrode fingers 171 and 172 of the mass parts 50 and 51 are provided.
The four projecting portions 140 and 141 are provided on the distal end side (the side away from the movable portion 20) in the Y-axis direction of the fixed portions 40 and 41, respectively.

As described above, the acceleration sensor 2 of the second embodiment includes the additional movable electrode 170 in which the mass parts 50 and 51 extend along the Y-axis direction, and the substrate 10 is opposed to the additional movable electrode 170. An additional fixed electrode 180 is provided.
From this, the acceleration sensor 2 changes the displacement of the movable part 20 including the mass parts 50 and 51 to the electrostatic capacity between the movable electrode 70 and the fixed electrode 80, and the static between the additional movable electrode 170 and the additional fixed electrode 180. It can be detected as a change in capacitance with added capacitance.
As a result, the acceleration sensor 2 can further improve the acceleration detection sensitivity.

  Moreover, since the mass parts 50 and 51 have the additional movable electrode 170 extended along the Y-axis direction, the acceleration sensor 2 distributes the mass distribution of the movable part 20 including the mass parts 50 and 51, for example. The sticking of the movable part 20 to the substrate 10 during manufacturing can be suppressed.

The acceleration sensor 2 extends along the Y-axis direction so that the fixed portions 40 and 41 face the additional movable electrode fingers 171 and 172 of the mass portions 50 and 51, and faces the fixed portions 40 and 41. Protrusions 140 and 141 projecting toward the additional movable electrode fingers 171 and 172 of the mass parts 50 and 51 to be performed are provided.
From this, the acceleration sensor 2 regulates the displacement of the mass parts 50 and 51 in the X-axis direction by the protrusions 140 and 141 coming into contact with the additional movable electrode fingers 171 and 172 of the mass parts 50 and 51. Damage to the movable part 20 (particularly the movable electrode 70 and the additional movable electrode 170) including the mass parts 50 and 51, the fixed electrode 80, the additional fixed electrode 180, and the like during an impact can be reduced.

Further, in the acceleration sensor 2, since the protrusions 140 and 141 are provided on the distal end side in the Y-axis direction of the fixed portions 40 and 41, the mass parts 50 and 51 are more than those provided on the root side. The inclination in the plan view with respect to the X-axis direction at the time of displacement of the movable part 20 including can be suppressed.
Note that the protruding portions 140 and 141 may be provided so as to protrude from the additional movable electrode fingers 171 and 172 of the mass portions 50 and 51 to the opposing fixed portions 40 and 41 instead of the fixed portions 40 and 41. Alternatively, it may be provided on both the fixed portions 40 and 41 and the additional movable electrode fingers 171 and 172 of the mass portions 50 and 51.
Further, the protrusions 140 and 141 may be provided on the base part side (side closer to the movable part 20) in the Y-axis direction of the fixed parts 40 and 41 (additional movable electrode fingers 171 and 172 of the mass parts 50 and 51). It may well be provided on both the tip side and the root side.
Note that a plurality of protrusions 140 and 141 may be provided at one location.
Further, the protrusions 140 and 141 are also applicable to the first embodiment.

(Electronics)
Next, an electronic device including the above-described functional element will be described.
FIG. 4 is a schematic perspective view illustrating a configuration of a mobile (or notebook) personal computer as an electronic device including a functional element.
As shown in FIG. 4, the personal computer 1100 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1101. The display unit 1106 is connected to the main body portion 1104 via a hinge structure portion. And is rotatably supported.
Such a personal computer 1100 has a built-in acceleration sensor 1 (or 2) as a physical quantity sensor including a functional element.

FIG. 5 is a schematic perspective view illustrating a configuration of a mobile phone (including PHS) as an electronic device including a functional element.
As shown in FIG. 5, the cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1201 is disposed between the operation buttons 1202 and the earpiece 1204. .
Such a cellular phone 1200 incorporates an acceleration sensor 1 (or 2) as a physical quantity sensor including a functional element.

FIG. 6 is a schematic perspective view illustrating a configuration of a digital still camera as an electronic apparatus including a functional element. In FIG. 6, connection with an external device is also simply shown.
Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.
A display unit 1310 is provided on the back surface (front side in the figure) of the case (body) 1302 in the digital still camera 1300, and the display unit 1310 is configured to perform display based on an imaging signal from the CCD. Functions as a viewfinder that displays images as electronic images.
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 figure) of the case 1302.

When the photographer confirms the subject image displayed on the display unit 1310 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. 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, if 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 an acceleration sensor 1 (or 2) as a physical quantity sensor including a functional element.

Since such an electronic apparatus includes the physical quantity sensor including the above-described functional element, the effects described in the above embodiments are exhibited, and excellent performance can be exhibited.
In addition to the above, the electronic device provided with the above-described functional elements includes, for example, an ink jet discharge device (for example, an ink jet printer), a laptop personal computer, a television, a video camera, a video tape recorder, various navigation devices, Pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, video phone, TV monitor for crime prevention, electronic binoculars, POS terminal, medical device (for example, electronic thermometer, blood pressure monitor, Blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring instruments, instruments, flight simulator, and the like.
In any case, since these electronic devices are provided with the functional elements described above, the effects described in the above embodiments can be achieved, and excellent performance can be exhibited.

(Moving body)
Next, the moving body provided with the functional element described above will be described.
FIG. 7 is a schematic perspective view showing an automobile as an example of a moving object including a functional element.
The automobile 1500 uses the acceleration sensor 1 (or 2) as a physical quantity sensor including a functional element, for example, as an attitude detection sensor such as an installed navigation apparatus or attitude control apparatus.
According to this, since the automobile 1500 includes the physical quantity sensor including the above-described functional elements, the effects described in the above embodiments are exhibited, and excellent performance can be exhibited.

The functional elements described above are not limited to the automobile 1500, and are preferably used as main components of the posture detection sensor of a moving body including a self-propelled robot, a self-propelled transport device, a train, a ship, an airplane, an artificial satellite, and the like. In any case, the effects described in the above embodiments can be achieved, and a moving body that exhibits excellent performance can be provided.
In addition, the functional element of this structure is applicable to an angular velocity sensor etc. besides an acceleration sensor.

  DESCRIPTION OF SYMBOLS 1, 2 ... Acceleration sensor as a physical quantity sensor provided with a functional element, 10 ... Board | substrate, 11 ... Main surface, 12 ... Recessed part, 13 ... Common wiring, 14 ... 1st wiring, 15 ... 2nd wiring, 20 ... Movable , 30 ... flexible part, 40, 41 ... fixed part, 50, 51 ... mass part, 60 ... lid, 61 ... recessed part, 70 ... movable electrode, 71, 72 ... movable electrode finger, 80 ... fixed electrode, 81 82, first fixed electrode fingers, 83, 84, second fixed electrode fingers, 90, terminal portions, 91, common terminals, 92, first terminals, 93, second terminals, 140, 141, projecting portions, 170,. Additional movable electrode, 171, 172 ... Additional movable electrode finger, 180 ... Additional fixed electrode, 181, 182 ... Additional first fixed electrode finger, 183, 184 ... Additional second fixed electrode finger, 1100 ... Personal computer as an electronic device, 1101... Display unit, 1102 Keyboard 1104 ... Main unit 1106 Display unit 1200 Mobile phone as electronic device 1201 Display 1202 Operation button 1204 Earpiece 1206 Speaking mouth 1300 Digital still as electronic device Camera 1302 Case 1304 Light receiving unit 1306 Shutter button 1308 Memory 1310 Display unit 1312 Video signal output terminal 1314 Input / output terminal 1430 Television monitor 1440 Personal computer 1500 Automobile as a moving body, S ... Internal space

Claims (11)

A substrate,
A movable part disposed on the substrate and displaceable in a first direction;
A fixed portion located on one end side and the other end side in the first direction of the movable portion, fixed to the substrate, and connected to the movable portion via a flexible portion,
From at least one end of the one end side and the other end side of the movable part, a mass part extends outside the fixed part on the one end side and the other end side ,
The movable part has a movable electrode extending along a second direction intersecting the first direction in plan view,
The fixed parts are paired in two, and are arranged so as to sandwich the movable part along the second direction,
The two fixed portions that are paired extend in the second direction, bend in the first direction so that the distal end portion surrounds the flexible portion, and have an L shape as a whole. function element characterized in that it is formed. The functional element according to claim 1,
The mass element extends along a second direction intersecting the first direction in plan view. The functional element according to claim 2,
The fixing part extends along the second direction so as to face the mass part,
A functional element, wherein at least one of the fixed part and the mass part is provided with a protruding part that protrudes to the opposite side. In the functional element according to claim 3,
The functional element, wherein the protruding portion is provided on a distal end side in the second direction of the fixed portion or the mass portion. In the functional element according to any one of claims 1 to 4,
The functional element, wherein a fixed electrode extending along the second direction is provided on the substrate so as to face the movable electrode. The functional element according to claim 5,
The mass portion has an additional movable electrode extending along the second direction,
The functional element, wherein an additional fixed electrode extending along the second direction is provided on the substrate so as to face the additional movable electrode. The functional element according to claim 6,
The functional element, wherein the additional movable electrode is provided with a protruding portion protruding toward the fixed portion facing the additional movable electrode. In the functional element according to any one of claims 1 to 7,
The functional part, wherein the fixed part is arranged so as to sandwich the movable part along a second direction intersecting the first direction in plan view.   A physical quantity sensor comprising the functional element according to any one of claims 1 to 8.   An electronic device comprising the functional element according to claim 1.   A moving body comprising the functional element according to any one of claims 1 to 8.

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