JP2014016182A - Physical quantity sensor and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor which achieves high measurement accuracy.SOLUTION: A physical quantity sensor 100 includes: a substrate 10; a movable part 86 provided on the substrate 10; a movable electrode part 87 which extends from the movable part 86; fixed electrode parts 88, 89 which at least have a portion fixed to the substrate 10 and extend so as to face the movable electrode part 87; and wires 20, 22 which are provided on the substrate 10 and extend in a direction that intersects a direction in which the fixed electrode parts 88, 89 extend. Further, the wires 20, 22 are electrically connected to the fixed electrode parts 88, 89. As seen in planar view, the fixed electrode parts 88, 89 have portions that intersect the wires 20, 22. In these portions, recesses 8a, 8b are provided through which the wires 20, 22 are passed.

Description

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

In recent years, for example, silicon MEMS (Micro Electro Mechanical)
A technology that realizes a small and highly sensitive physical quantity sensor by using the (System) technology has attracted attention.

  For example, Patent Document 1 forms a movable electrode that operates in accordance with a physical quantity and a fixed electrode that is arranged to face the movable electrode with a gap by processing a semiconductor substrate using MEMS technology. A physical quantity sensor that can detect various physical quantities such as acceleration and angular velocity based on the capacitance between the electrode and the fixed electrode is disclosed.

JP 2008-292428 A

  Here, in the physical quantity sensor of Patent Document 1, the fixed electrode has a cantilever support structure in which only one end is fixed and most of the fixed electrode is separated from the substrate. In such a physical quantity sensor, a portion of the fixed electrode that is separated from the substrate may be bent by its own weight or electrostatic attraction, or may be displaced when acceleration is applied. As a result, there is a problem that the capacitance between the movable electrode and the fixed electrode fluctuates and the measurement accuracy of the sensor decreases.

  An object of some aspects of the present invention is to provide a physical quantity sensor that can have high measurement accuracy. Another object of some embodiments of the present invention is to provide an electronic device 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 aspects or application examples.

[Application Example 1]
The physical quantity sensor according to this application example is
A substrate,
A movable part disposed on the substrate;
A movable electrode portion extending from the movable portion;
A fixed electrode portion that is at least partially fixed to the substrate and extends to face the movable electrode portion;
Wiring provided on the substrate, extending in a direction intersecting with the extending direction of the fixed electrode portion, and electrically connected to the fixed electrode portion;
Including
The fixed electrode portion is provided with a recess through which the wiring passes at a portion intersecting with the wiring in a plan view.

According to such a physical quantity sensor, the fixed electrode portion is provided with a recess through which the wiring passes at a portion intersecting with the wiring in a plan view. Therefore, in the extending direction of the fixed electrode portion, the length of the portion fixed to the substrate of the fixed electrode portion can be set to ½ or more of the total length of the fixed electrode portion. Therefore, it is possible to suppress a change in capacitance between the movable electrode portion and the fixed electrode portion due to the displacement of the fixed electrode portion. Thereby, it is possible to have high measurement accuracy.

[Application Example 2]
In the physical quantity sensor according to this application example,
In the extending direction of the fixed electrode portion, a length of a portion of the fixed electrode portion fixed to the substrate may be ½ or more of an entire length of the fixed electrode portion.

  According to such a physical quantity sensor, the capacitance between the movable electrode portion and the fixed electrode portion can be prevented from changing due to the displacement of the fixed electrode portion. Thereby, it is possible to have high measurement accuracy.

[Application Example 3]
In the physical quantity sensor according to this application example,
The thickness of the movable electrode part may be smaller than the thickness of the fixed electrode part.

  According to such a physical quantity sensor, erroneous detection due to displacement of the movable electrode portion in the thickness direction can be prevented, and detection accuracy can be further improved.

[Application Example 4]
In the physical quantity sensor according to this application example,
One surface of the fixed electrode portion may be fixed to the substrate.

  According to such a physical quantity sensor, it is possible to further suppress a change in the capacitance between the movable electrode portion and the fixed electrode portion due to the displacement of the fixed electrode portion.

[Application Example 5]
In the physical quantity sensor according to this application example,
The joint surface of the fixed electrode portion and the formation surface of the wiring may be on the same plane.

  According to such a physical quantity sensor, the manufacturing process can be simplified.

[Application Example 6]
In the physical quantity sensor according to this application example,
The wiring may be connected to the fixed electrode portion in the recess.

  According to such a physical quantity sensor, since it is not necessary to form a groove or a recess for arranging the wiring on the substrate, it is easy to manufacture.

[Application Example 7]
In the physical quantity sensor according to this application example,
The distance between the substrate and the movable part may be the same as the depth of the recess.

  According to such a physical quantity sensor, for example, in the manufacturing process, the movable part and the recessed part can be formed in the same etching process. Therefore, the manufacturing process can be simplified.

[Application Example 8]
In the physical quantity sensor according to this application example,
The material of the substrate is glass,
The material of the fixed electrode part may be silicon.

  According to such a physical quantity sensor, for example, the substrate and the fixed electrode portion can be bonded by anodic bonding, so that the substrate and the fixed electrode portion can be firmly bonded.

[Application Example 9]
The electronic device according to this application example is
The physical quantity sensor according to this application example is included.

  According to such an electronic apparatus, since the physical quantity sensor according to this application example is included, it is possible to have high measurement accuracy.

The top view which shows typically the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the manufacturing process of the physical quantity sensor which concerns on 1st Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on the modification of 1st Embodiment. The top view which shows typically the physical quantity sensor which concerns on 2nd Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on 2nd Embodiment. Sectional drawing which shows typically the physical quantity sensor which concerns on 2nd Embodiment. The perspective view which shows typically the electronic device which concerns on 3rd Embodiment. The perspective view which shows typically the electronic device which concerns on 3rd Embodiment. The perspective view which shows typically the electronic device which concerns on 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. 1. First embodiment 1.1. Physical Quantity Sensor First, the physical quantity sensor according to the first embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing a physical quantity sensor 100 according to the present embodiment. FIG. 2 is a cross-sectional view schematically showing the physical quantity sensor 100 according to the present embodiment, and is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a cross-sectional view schematically showing the physical quantity sensor 100 according to this embodiment, and is a cross-sectional view taken along the line III-III in FIG. For convenience, in FIG. 1, the lid 50 is shown through. 1 to 3 show the X axis, the Y axis, and the Z axis as three axes orthogonal to each other.

The physical quantity sensor 100 is, for example, an acceleration sensor (capacitive MEMS acceleration sensor) that detects acceleration in the horizontal direction (X-axis direction). As shown in FIGS. 1 to 3, the physical quantity sensor 100 includes a substrate 10, wirings 20, 22, and 24 provided on the substrate 10,
A movable piece 86, a movable electrode section 87, and an element piece 80 including a fixed electrode section 88 and 89. Further, the physical quantity sensor 100 includes, for example, connection terminals 30, 32, and 34 and a lid body 50.

  The material of the substrate 10 is, for example, glass. The substrate 10 has a flat plate shape, for example. The shape of the substrate 10 is a rectangular parallelepiped in the illustrated example. The substrate 10 has an upper surface 11 and a lower surface 12 opposite to the upper surface 11. The upper surface 11 and the lower surface 12 of the substrate 10 are flat.

  The wiring 20 is provided on the upper surface 11 of the substrate 10. The wiring 20 has a portion extending in a direction (X-axis direction) intersecting with the extending direction (Y-axis direction) of the fixed electrode portions 88 and 89. The wiring 20 is electrically connected to the first fixed electrode portion 88. In the illustrated example, the wiring 20 is electrically connected to the first fixed electrode portion 88 via the contact portion 40 in the recess 8 a of the first fixed electrode portion 88. The wiring 20 electrically connects the connection terminal 30 and the plurality of first fixed electrode portions 88. The wiring 20 passes through the recess 8 b of the second fixed electrode portion 89. Thereby, the wiring 20 can intersect with the second fixed electrode portion 89 in a state of being electrically insulated from the second fixed electrode portion 89.

  The wiring 22 is provided on the upper surface 11 of the substrate 10. The wiring 22 has a portion extending in a direction (X-axis direction) intersecting with the extending direction (Y-axis direction) of the fixed electrode portions 88 and 89. The wiring 22 is electrically connected to the second fixed electrode portion 89. In the illustrated example, the wiring 22 is electrically connected to the second fixed electrode portion 89 via the contact portion 42 in the recess 8 b of the second fixed electrode portion 89. The wiring 22 electrically connects the connection terminal 32 and the plurality of second fixed electrode portions 89. The wiring 22 passes through the recess 8 b of the first fixed electrode portion 88. As a result, the wiring 22 can intersect the first fixed electrode portion 88 in a state of being electrically insulated from the first fixed electrode portion 88.

  The wiring 24 is provided on the upper surface 11 of the substrate 10. The wiring 24 is electrically connected to the first fixing portion 81. In the illustrated example, the wiring 24 is electrically connected to the first fixing portion 81 via the contact portion 44. The wiring 24 electrically connects the connection terminal 34 and the first fixing portion 81.

  The thickness (size in the Z-axis direction) of the wirings 20, 22, and 24 is, for example, 10 nm or more and 1 μm or less. The materials of the wirings 20, 22, and 24 are, for example, ITO (Indium Tin Oxide), FTO (Fluorine-doped Tin Oxide), zinc oxide doped with gallium, aluminum, gold, platinum, titanium, tungsten, chromium, and the like. . When a transparent electrode material such as ITO is used as the wirings 20, 22, 24, when the substrate 10 is transparent, for example, inspection of foreign matter on the wirings 20, 22, 24 is performed from the lower surface 12 side of the substrate 10. By observing, it can carry out simply.

  The connection terminals 30, 32, and 34 are provided on the upper surface 11 of the substrate 10. The connection terminals 30, 32, and 34 are connected to the wirings 20, 22, and 24, respectively. Therefore, the connection terminal 30 is electrically connected to the first fixed electrode portion 88 via the wiring 20, and the connection terminal 32 is electrically connected to the second fixed electrode portion 89 via the wiring 22. 34 is electrically connected to the first fixing portion 81 via the wiring 24. The connection terminals 30, 32, and 34 are provided at positions that do not overlap the lid body 50 in plan view (outside the cavity 52). The material of the connection terminals 30, 32, and 34 is the same as the material of the wirings 20, 22, and 24, for example.

  Although the physical quantity sensor 100 including the three wirings 20, 22, 24 and the three connection terminals 30, 32, 34 has been described here, the number of wirings and connection terminals can be changed as appropriate.

  The contact portion 40 is provided in the recess 8 a of the first fixed electrode portion 88. As shown in FIG. 2, the contact part 40 is provided on the wiring 20 and connects the wiring 20 and the first fixed electrode part 88. The contact part 42 is provided in the recess 8 b of the second fixed electrode part 89. As shown in FIG. 3, the contact portion 42 is provided on the wiring 22 and connects the wiring 22 and the second fixed electrode portion 89. The contact portion 44 is provided on the wiring 24 and connects the wiring 24 and the first fixing portion 81. The material of the contact portions 40, 42, and 44 is not particularly limited as long as it has conductivity. For example, the contact portions 40, 42, and 44 are metals such as Au, Pt, Ag, Cu, and Al, or metals such as alloys containing these metals. .

  The lid 50 is placed (joined) on the upper surface 11 of the substrate 10. The lid 50 has a container shape, and can be formed with the cavity 52 by being joined to the substrate 10. The cavity 52 is sealed, for example, in an inert gas (for example, nitrogen gas) atmosphere or in a reduced pressure state.

  The material of the lid 50 is, for example, silicon or glass. The bonding method of the lid 50 and the substrate 10 is not particularly limited. For example, when the material of the substrate 10 is glass and the material of the lid 50 is silicon, the substrate 10 and the lid 50 are anodic bonded. Can be joined.

  The element piece 80 includes fixed portions 81 and 82, connecting portions 84 and 85, a movable portion 86, a movable electrode portion 87, and fixed electrode portions 88 and 89. The element piece 80 is accommodated in a cavity 52 surrounded by the substrate 10 and the lid 50. The material of the element piece 80 is silicon imparted with conductivity by doping impurities such as phosphorus and boron.

  In the element piece 80, the movable portion 86 and the movable electrode portion 87 are displaced in the X-axis direction while elastically deforming the connecting portions 84 and 85 according to physical quantities such as acceleration and angular velocity. Along with the displacement of the movable portion 86 and the movable electrode portion 87, the size of the gap between the movable electrode portion 87 and the first fixed electrode portion 88, and the distance between the movable electrode portion 87 and the second fixed electrode portion 89. The size of the gap changes. That is, in accordance with the displacement of the movable portion 86 and the movable electrode portion 87, the capacitance between the movable electrode portion 87 and the first fixed electrode portion 88, and between the movable electrode portion 87 and the second fixed electrode portion 89, The capacitance between them changes. Therefore, physical quantities such as acceleration and angular velocity can be detected based on these capacitances.

  The first fixing portion 81 and the second fixing portion 82 are joined to the upper surface 11 of the substrate 10. The planar shape of the fixing portions 81 and 82 is, for example, a rectangle. The first fixing portion 81 is connected to the wiring 24.

  The movable portion 86 is provided between the first fixed portion 81 and the second fixed portion 82. In the example illustrated in FIG. 1, the planar shape of the movable portion 86 is a rectangle having a long side parallel to the X axis. As shown in FIGS. 2 and 3, a gap 2 is provided between the movable portion 86 and the substrate 10. That is, the movable portion 86 is provided on the substrate 10 with the gap 2 interposed therebetween. The distance between the movable portion 86 and the substrate 10 (the size of the gap 2 in the Z-axis direction) is, for example, the same as the depth (the size in the Z-axis direction) of the concave portions 8a and 8b of the fixed electrode portions 88 and 89. It is a size. The gap 2 is also provided between the connecting portions 84 and 85 and the substrate 10 and between the movable electrode portion 87 and the substrate 10. With the gap 2, the movable portion 86, the movable electrode portion 87, and the connecting portions 84 and 85 can be separated from the substrate 10.

The connecting portions 84 and 85 connect the movable portion 86 and the fixed portions 81 and 82. Specifically, the first connecting portion 84 connects the movable portion 86 and the first fixed portion 81, and the second connecting portion 85 connects the movable portion 86 and the second fixed portion 82. The connecting portions 84 and 85 have a desired spring constant and are configured to displace the movable portion 86 in the X-axis direction. In the example shown in FIG. 1, the first connecting portion 84 is configured by two beams 84 a and 84 b having a shape extending in the X-axis direction while reciprocating in the Y-axis direction. Similarly, the 2nd connection part 85 is comprised by two beams 85a and 85b which make the shape extended in a X-axis direction, reciprocating in a Y-axis direction.

  The movable electrode part 87 extends from the movable part 86 in the Y-axis direction. In the illustrated example, a plurality of movable electrode portions 87 are provided. The movable electrode portion 87 protrudes from the movable portion 86 in the + Y axis direction and the −Y axis direction, and is arranged in the X axis direction so as to form a comb shape. The planar shape of the movable electrode portion 87 is a rectangle having a long side parallel to the Y axis in the illustrated example.

  The fixed electrode portions 88 and 89 face the movable electrode portion 87 and extend in the Y-axis direction. The planar shape of the fixed electrode portion 88.89 is a rectangle having a long side parallel to the Y axis in the illustrated example. The fixed electrode portions 88 and 89 are fixed to the substrate 10. In the illustrated example, one surface of the fixed electrode portions 88 and 89 is fixed to the substrate 10. That is, the entire lower surfaces of the fixed electrode portions 88 and 89 are fixed (bonded) to the upper surface 11 of the substrate 10. The lower surfaces (bonding surfaces) of the fixed electrode portions 88 and 89 and the lower surfaces (formation surfaces) of the wirings 20, 22, and 24 are both in contact with the upper surface 11 of the substrate 10 and are on the same plane. A plurality of first fixed electrode portions 88 and second fixed electrode portions 89 are provided. The fixed electrode portions 88 and 89 are alternately arranged in the X-axis direction so as to form a comb shape. The fixed electrode portions 88 and 89 are provided to face the movable electrode portion 87 with a space therebetween. In the example shown in FIG. 1, the first fixed electrode portion 88 is disposed on one side (−X axis direction side) of the movable electrode portion 87, and the second fixed electrode portion 89 is disposed on the other side (+ X axis direction side). Has been placed. For example, the area of the first fixed electrode portion 88 facing the movable electrode portion 87 is the same as the area of the second fixed electrode portion 89 facing the movable electrode portion 87.

  The first fixed electrode portion 88 is provided with a recess 8 a for passing the wiring 20 and a recess 8 b for passing the wiring 22. The recesses 8 a and 8 b are provided on the lower surface of the first fixed electrode portion 88. The concave portion 8a of the first fixed electrode portion 88 is provided at a portion that intersects the wiring 20 in plan view. The wiring 20 is electrically connected to the first fixed electrode portion 88 through the contact portion 40 in the concave portion 8a. The concave portion 8b of the first fixed electrode portion 88 is provided at a portion that intersects the wiring 22 in plan view. The wiring 22 passes through the recess 8b. Thereby, the first fixed electrode portion 88 and the wiring 22 are electrically insulated at the intersecting portion.

  The second fixed electrode portion 89 is provided with a concave portion 8a for allowing the wiring 20 to pass therethrough and a concave portion 8b for allowing the wiring 22 to pass therethrough. The recesses 8 a and 8 b are provided on the lower surface of the second fixed electrode portion 89. The concave portion 8a of the second fixed electrode portion 89 is provided at a portion that intersects the wiring 20 in plan view. The wiring 20 passes through the recess 8a. Thereby, the second fixed electrode portion 89 and the wiring 20 are electrically insulated at the intersecting portion. The concave portion 8b of the second fixed electrode portion 89 is provided at a portion that intersects the wiring 22 in plan view. The wiring 22 is electrically connected to the second fixed electrode portion 89 through the contact portion 42 in the recess 8b.

  The fixed portions 81 and 82, the connecting portions 84 and 85, the movable portion 86, and the movable electrode portion 87 are integrally provided. A method for joining the fixed portions 81 and 82 and the fixed electrode portions 88 and 89 to the substrate 10 is not particularly limited. For example, when the material of the substrate 10 is glass and the material of the fixed portions 81 and 82 and the fixed electrode portions 88 and 89 is silicon, the fixed portions 81 and 82 and the fixed electrode portions 88 and 89 and the substrate 10 are connected to the anode. It can be joined by joining.

In the element piece 80, the thickness of the movable electrode portion 87 (size in the Z-axis direction) is larger than the thickness of the fixed electrode portions 88 and 89 (size in the Z-axis direction), as shown in FIGS. Is also small. Similarly, the thickness of the movable portion 86 (size in the Z-axis direction) and the thickness of the connecting portions 84 and 85 (size in the Z-axis direction) are smaller than the thickness of the fixed electrode portions 88 and 89. Accordingly, the gap 2 can be provided between the movable portion 86, the movable electrode portion 87, the connecting portions 84 and 85, and the substrate 10, and the movable portion 86, the movable electrode portion 87, and the connecting portions 84 and 85 can be provided. Can be separated from the substrate 10. The thickness of the movable portion 86, the thickness of the movable electrode portion 87, and the thickness of the connecting portions 84 and 85 are, for example, the same size. Further, the thickness of the fixed electrode portions 88 and 89 and the thickness of the fixed portions 81 and 82 are, for example, the same size. The upper surface of the movable portion 86, the upper surface of the movable electrode portion 87, the upper surfaces of the connecting portions 84 and 85, the upper surfaces of the fixed electrode portions 88 and 89, and the upper surfaces of the fixed portions 81 and 82 are within the same plane (in the illustrated example, XY Located in a plane parallel to the plane).

  In the physical quantity sensor 100, the capacitance between the movable electrode portion 87 and the first fixed electrode portion 88 can be measured by using the connection terminals 30 and 34. Furthermore, in the physical quantity sensor 100, the capacitance between the movable electrode portion 87 and the second fixed electrode portion 89 can be measured by using the connection terminals 32 and 34. Thus, in the physical quantity sensor 100, the electrostatic capacitance between the movable electrode portion 87 and the first fixed electrode portion 88 and the electrostatic capacitance between the movable electrode portion 87 and the second fixed electrode portion 89 are separately measured. And based on those measurement results, physical quantities (acceleration etc.) can be detected with high accuracy.

  The physical quantity sensor according to the present embodiment has, for example, the following characteristics.

  In the physical quantity sensor 100, the fixed electrode portions 88 and 89 are provided with recesses 8a and 8b through which the wirings 20 and 22 pass at portions intersecting the wirings 20 and 22 in plan view. Therefore, one surface (the entire lower surface) of the fixed electrode portions 88 and 89 can be fixed to the substrate 10.

  In the physical quantity sensor 100, one surface of the fixed electrode portions 88 and 89 is fixed to the substrate 10. In the illustrated example, the entire lower surface of the fixed electrode portions 88 and 89 is fixed to the substrate 10. Thereby, it can suppress that the electrostatic capacitance between the movable electrode part 87 and the fixed electrode parts 88 and 89 fluctuates because the fixed electrode parts 88 and 89 displace. Therefore, the physical quantity sensor 100 can have high measurement accuracy.

  For example, when the fixed electrode portion has a cantilever support structure in which only one end is fixed and most of the fixed electrode portion is separated from the substrate, the portion of the fixed electrode portion separated from the substrate is caused by its own weight or electrostatic attraction. It may bend or be displaced when acceleration is applied. As a result, the capacitance between the movable electrode portion and the fixed electrode portion varies, and the measurement accuracy of the sensor may be reduced. Since the physical quantity sensor 100 does not cause such a problem, it can have high measurement accuracy.

  Furthermore, in the physical quantity sensor 100, since one surface of the fixed electrode portions 88 and 89 is fixed to the substrate 10, for example, the movable electrode portion 87 and the substrate 10 are compared with the case where the fixed electrode portions 88 and 89 have a cantilever support structure. A gas (for example, nitrogen) can be confined in the gap 2 between the two. Thereby, the damping effect by gas viscous resistance can be heightened and it can prevent that the movable electrode part 87 contacts the board | substrate 10. FIG.

  In the physical quantity sensor 100, the thickness of the movable electrode portion 87 is smaller than the thickness of the fixed electrode portions 88 and 89. Therefore, for example, even if the movable electrode portion 87 is displaced in the −Z-axis direction, the capacitance between the movable electrode portion 87 and the fixed electrode portions 88 and 89 cannot be changed. Therefore, erroneous detection due to the displacement of the movable electrode portion 87 in the −Z-axis direction can be prevented, and the detection accuracy can be further improved.

  In the physical quantity sensor 100, since the lower surfaces (bonding surfaces) of the fixed electrode portions 88 and 89 and the lower surfaces (formation surfaces) of the wirings 20, 22, and 24 are on the same plane, for example, a flat substrate 10 can be used. .

  In the physical quantity sensor 100, since the substrate 10 has a flat plate shape, the manufacturing process can be simplified. Such a physical quantity sensor 100 is particularly effective when the material of the substrate 10 is glass that is difficult to process, for example.

  In the physical quantity sensor 100, the wiring 20 is electrically connected to the first fixed electrode portion 88 in the recess 8 a of the first fixed electrode portion 88. The wiring 22 is electrically connected to the second fixed electrode portion 89 in the recess 8 b of the second fixed electrode portion 89. Therefore, for example, when the material of the substrate 10 is glass that is difficult to process and the material of the element piece 80 is silicon that is easy to process, grooves and recesses for arranging the wirings 20 and 22 on the substrate 10. And the like are not required to be formed, so that the manufacturing is easy.

  In the physical quantity sensor 100, the distance between the substrate 10 and the movable portion 86 is the same as the depth of the concave portions 8a and 8b of the fixed electrode portions 88 and 89. For this reason, for example, in the manufacturing process, etching for forming the movable portion 86 and etching for forming the concave portions 8a and 8b of the fixed electrode portions 88 and 89 can be performed in the same step. Therefore, the manufacturing process can be simplified.

  In the physical quantity sensor 100, the material of the substrate 10 is glass, and the material of the fixed electrode portions 88 and 89 is silicon. Accordingly, since the substrate 10 and the fixed electrode portions 88 and 89 can be bonded by anodic bonding, the substrate 10 and the fixed electrode portions 88 and 89 can be firmly bonded.

1.2. Manufacturing Method of Physical Quantity Sensor Next, a manufacturing method of the physical quantity sensor according to the present embodiment will be described with reference to the drawings. 4-7 is sectional drawing which shows typically the manufacturing process of the physical quantity sensor 100 which concerns on this embodiment, Comprising: It respond | corresponds to FIG.

  As shown in FIG. 4, a substrate 10 is prepared. In the illustrated example, the substrate 10 is a flat glass substrate. Next, wirings 20, 22 and 24 are formed on the substrate 10. The wirings 20, 22, and 24 are formed by, for example, film formation by a sputtering method, a CVD (Chemical Vapor Deposition) method, or the like, and patterning by a photolithography technique and an etching technique. Next, connection terminals 30, 32, and 34 are formed on the substrate 10 (see FIG. 1). The connection terminals 30, 32, and 34 are formed by the same method as the wirings 20, 22, and 24. Next, the contact part 40 is formed on the wiring 20, the contact part 42 is formed on the wiring 22, and the contact part 44 is formed on the wiring 24. The contact portions 40, 42, and 44 are formed by, for example, film formation by sputtering or the like, and patterning by photolithography technology and etching technology. Here, the contact portions 40, 42, 44 are formed on the wirings 20, 22, 24 of the substrate 10, but the contact portions 40, 42, 44 may be provided on a semiconductor substrate 80 a described later.

As shown in FIG. 5, a semiconductor substrate 80a is prepared. The semiconductor substrate 80a is, for example, a silicon substrate (silicon substrate). Next, the recesses 8a and 8b and the recess 2a are formed in the semiconductor substrate 80a. The recesses 8a and 8b and the recess 2a are formed on the lower surface of the semiconductor substrate 80a. The recesses 8a and 8b correspond to the recesses 8a and 8b of the fixed electrode portions 88 and 89 shown in FIG. 2, and the recess 2a corresponds to the gap 2 shown in FIG. For example, the recess 2a is formed in the lower surface of the semiconductor substrate 80a in a region excluding the portions to be the fixed portions 81 and 82 and the portions to be the fixed electrode portions 88 and 89. The recess 2a is formed below the semiconductor substrate 80a at least at a portion that becomes the movable portion 86, the movable electrode portion 87, and the connecting portions 84 and 85. The recesses 8a, 8b, 2a are formed by etching such as dry etching or wet etching, for example. At this time, etching can be easily performed by making the depths of the recesses 8a, 8b, and 2a the same.

  As shown in FIG. 6, the semiconductor substrate 80a is placed on the substrate 10 so that the wiring 20 provided on the substrate 10 passes through the recess 8a and the wiring 22 provided on the substrate 10 passes through the recess 8b. . At this time, the contact part 40 and the semiconductor substrate 80a are brought into contact in the recess 8a, the contact part 42 and the semiconductor substrate 80a are brought into contact in the recess 8b, and the contact part 44 and the semiconductor substrate 80a are brought into contact. Next, the semiconductor substrate 80a is ground and thinned by, for example, a grinding machine.

  As shown in FIG. 7, the element piece 80 is formed by patterning the thinned semiconductor substrate 80 a into a desired shape. The patterning is performed by a photolithography technique and an etching technique (dry etching), and a Bosch method can be used as a more specific etching technique. In this step, the fixed portions 81 and 82, the connecting portions 84 and 85, the movable portion 86, and the movable electrode portion 87 can be integrally formed by patterning (etching) the semiconductor substrate 80a.

  As shown in FIG. 2, the lid 50 is bonded to the substrate 10, and the element piece 80 is accommodated in the cavity 52 formed by the substrate 10 and the lid 50. Bonding of the substrate 10 and the lid 50 is performed using, for example, anodic bonding or an adhesive. By performing this step in an inert gas atmosphere, the cavity 52 can be filled with an inert gas.

  Through the above steps, the physical quantity sensor 100 can be manufactured.

  According to the manufacturing method of the physical quantity sensor 100 according to the present embodiment, the wirings 20 and 22 are formed on the semiconductor substrate 80a without forming the recesses and the grooves for arranging the wirings 20, 22, and 24 on the substrate 10 made of glass or the like. , 24 for arranging the recesses 8a, 8b, 2a. Thus, according to this embodiment, since it is not necessary to form the groove part, the recessed part, etc. for arrange | positioning the wiring 20 and 22 in the board | substrate 10 which is difficult to process, the physical quantity sensor 100 can be obtained easily. .

  In the manufacturing method of the physical quantity sensor 100 according to the present embodiment, the recesses 8a, 8b, and 2a formed in the semiconductor substrate 80a have the same depth. Thereby, recessed part 8a, 8b, 2a can be formed in the same process. Therefore, the manufacturing process can be simplified.

1.3. Next, a physical quantity sensor according to a modification of the present embodiment will be described with reference to the drawings. FIG. 8 is a cross-sectional view schematically showing a physical quantity sensor 200 according to a modification of the present embodiment, and corresponds to FIG. Hereinafter, in the physical quantity sensor 200, members having the same functions as the constituent members of the physical quantity sensor 100 described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the example of the physical quantity sensor 100, as shown in FIG. 2, the upper surface of the movable electrode portion 87 is located in the same plane as the upper surfaces of the fixed electrode portions 88 and 89.

On the other hand, in the physical quantity sensor 200, as shown in FIG. 8, the upper surface of the movable electrode portion 87 is not located in the same plane as the upper surfaces of the fixed electrode portions 88 and 89. In the illustrated example, the distance between the upper surface of the movable electrode portion 87 and the substrate 10 is smaller than the distance between the upper surfaces of the fixed electrode portions 88 and 89 and the substrate 10. Therefore, the movable electrode portion 87 is thinner than the fixed electrode portions 88 and 89, and is intermediate between the fixed electrode portions 88 and 89 (thickness of the fixed electrode portions 88 and 89) in the thickness direction (Z-axis direction). Half of the height). Thereby, even if the movable electrode part 87 is displaced in the Z-axis direction, it is possible to prevent the capacitance between the movable electrode part 87 and the fixed electrode parts 88 and 89 from being changed. Therefore, erroneous detection due to displacement of the movable electrode portion 87 in the Z-axis direction can be prevented, and detection accuracy can be further improved.

  Compared with the manufacturing method of the physical quantity sensor 100 described above, the manufacturing method of the physical quantity sensor 200 further includes the step of forming the recesses 8a, 8b, and 2a on the lower surface of the semiconductor substrate 80a shown in FIG. This is the same except that a recess is formed in a region overlapping the recess 2a in plan view, and detailed description thereof is omitted.

2. Second Embodiment Next, a physical quantity sensor according to a second embodiment will be described with reference to the drawings. FIG. 9 is a plan view schematically showing the physical quantity sensor 300 according to this embodiment. FIG. 10 is a cross-sectional view schematically showing the physical quantity sensor 300 according to this embodiment, and is a cross-sectional view taken along the line XX of FIG. FIG. 11 is a cross-sectional view schematically showing the physical quantity sensor 300 according to this embodiment, and is a cross-sectional view taken along the line XI-XI in FIG. For convenience, in FIG. 9, the lid 50 is shown through. 9 to 11 illustrate the X axis, the Y axis, and the Z axis as three axes orthogonal to each other. Hereinafter, in the physical quantity sensor 300, members having the same functions as the constituent members of the physical quantity sensor 100 described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the example of the physical quantity sensor 100, as illustrated in FIGS. 1 to 3, the substrate 10 has a flat plate shape, and the upper surface 11 of the substrate 10 is flat.

  On the other hand, in the physical quantity sensor 300, as shown in FIGS. 9 to 11, a recess 310 is provided on the upper surface 11 of the substrate 10. The recess 310 is formed so as to include the movable portion 86, the movable electrode portion 87, and the connecting portions 84 and 85 of the element piece 80 in plan view. The concave portion 310 can prevent the movable portion 86, the movable electrode portion 87, and the connecting portions 84 and 85 from contacting the substrate 10.

  The fixed electrode portions 88 and 89 face the movable electrode portion 87 and extend in the Y-axis direction. As shown in FIGS. 10 and 11, the fixed electrode portions 88 and 89 have a cantilever support structure in which one side extends onto the recess 310 and is separated from the substrate 10 and the other side is fixed to the substrate 10. In the extending direction (Y-axis direction) of the fixed electrode portions 88 and 89, the length L2 of the portion of the fixed electrode portions 88 and 89 fixed to the substrate 10 is the total length of the fixed electrode portions 88 and 89 ( Total length) 1/2 or more of L1. Thereby, it can suppress that the electrostatic capacitance between the movable electrode part 87 and the fixed electrode parts 88 and 89 fluctuates because the fixed electrode parts 88 and 89 displace. Therefore, the physical quantity sensor 100 can have high measurement accuracy.

  Here, the portion of the fixed electrode portions 88 and 89 fixed to the substrate 10 is a portion overlapping the upper surface 11 of the substrate 10 in plan view of the fixed electrode portions 88 and 89 as shown in FIG. Further, the portions of the fixed electrode portions 88 and 89 that are not fixed to the substrate 10 are portions that overlap the concave portion 310 of the substrate 10 in plan view of the fixed electrode portions 88 and 89.

In the physical quantity sensor 300, the fixed electrode portions 88 and 89 are provided with recesses 8 a and 8 b through which the wirings 20 and 22 pass at portions that intersect the wirings 20 and 22 in plan view. Therefore, in the extending direction of the fixed electrode portions 88 and 89, the length L2 of the portion of the fixed electrode portions 88 and 89 fixed to the substrate 10 is set to ½ or more of the entire length L1 of the fixed electrode portion. can do.

3. Third Embodiment Next, an electronic apparatus according to a third embodiment will be described with reference to the drawings. The electronic device according to the present embodiment includes the physical quantity sensor according to the present invention. Hereinafter, an electronic apparatus including the physical quantity sensor 100 will be described as the physical quantity sensor according to the present invention.

  FIG. 12 is a perspective view schematically showing a mobile (or notebook) personal computer 1100 as the electronic apparatus according to the present embodiment.

  As shown in FIG. 12, the personal computer 1100 includes a main body portion 1104 having a keyboard 1102 and a display unit 1106 having a display portion 1108. The display unit 1106 has a hinge structure portion with respect to the main body portion 1104. It is supported so that rotation is possible.

  Such a personal computer 1100 incorporates a physical quantity sensor 100.

  FIG. 13 is a perspective view schematically showing a mobile phone (including PHS) 1200 as the electronic apparatus according to the present embodiment.

  As shown in FIG. 13, the cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display unit 1208 is disposed between the operation buttons 1202 and the earpiece 1204. .

  Such a cellular phone 1200 incorporates a physical quantity sensor 100.

  FIG. 14 is a perspective view schematically showing a digital still camera 1300 as the electronic apparatus according to the present embodiment. Note that FIG. 14 also shows a simple connection with an external device.

  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 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 1310 displays an object as an electronic image. Functions as a viewfinder.

  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 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 a physical quantity sensor 100.

  The electronic devices 1100, 1200, and 1300 as described above include the physical quantity sensor 100 that can have high measurement accuracy. Therefore, the electronic devices 1100, 1200, and 1300 can have high measurement accuracy.

  The electronic device provided with the physical quantity sensor 100 is, for example, an ink jet type discharge in addition to the personal computer (mobile personal computer) shown in FIG. 12, the mobile phone shown in FIG. 13, and the digital still camera shown in FIG. Devices (for example, inkjet printers), laptop personal computers, televisions, video cameras, video tape recorders, various navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game machines, head-mounted displays , Word processor, workstation, video phone, security TV monitor, electronic binoculars, POS terminal, medical equipment (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder Machine, various measuring instruments, gages (e.g., vehicles, aircraft, rockets, instruments and a ship), attitude control such as a robot or a human body, can be applied to a flight simulator.

  The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

2 ... Gap, 2a ... Recess, 8a, 8b ... Recess, 10 ... Base, 11 ... Upper surface, 12 ... Lower surface, 20, 22, 24 ... Wiring, 30, 32, 34 ... Connection terminal, 40, 42, 44 ... Contact 50, lid, 52 ... cavity, 80 ... element piece, 80a ... semiconductor substrate, 81, 82 ... fixed part, 84 ... connecting part, 84a, 84b ... beam, 85 ... connecting part, 85a, 85b ... beam , 86 ... movable part, 87 ... movable electrode part, 88, 89 ... fixed electrode part, 100 ... physical quantity sensor, 200 ... physical quantity sensor, 300 ... physical quantity sensor, 310 ... concave part, 1100 ... personal computer, 1102 ... keyboard, 1104 ... Main unit, 1106 ... display unit, 1108 ... display unit, 1200 ... mobile phone, 1202 ... operation button, 1204 ... earpiece, 1206 ... mouthpiece, 1208 ... table 1300 ... Digital still 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 ... TV monitor, 1440 …personal computer

Claims (9)

A substrate,
A movable part disposed on the substrate;
A movable electrode portion extending from the movable portion;
A fixed electrode portion that is at least partially fixed to the substrate and extends to face the movable electrode portion;
Wiring provided on the substrate, extending in a direction intersecting with the extending direction of the fixed electrode portion, and electrically connected to the fixed electrode portion;
Including
The physical quantity sensor, wherein the fixed electrode portion is provided with a recess through which the wiring passes at a portion intersecting with the wiring in a plan view. In claim 1,
A physical quantity sensor, wherein a length of a portion of the fixed electrode portion fixed to the substrate in the extending direction of the fixed electrode portion is ½ or more of a total length of the fixed electrode portion. In claim 1 or 2,
A physical quantity sensor in which the thickness of the movable electrode portion is smaller than the thickness of the fixed electrode portion. In any one of Claims 1 thru | or 3,
A physical quantity sensor, wherein one surface of the fixed electrode portion is fixed to the substrate. In any one of Claims 1 thru | or 4,
The physical quantity sensor, wherein a joint surface of the fixed electrode portion and a formation surface of the wiring are on the same plane. In any one of Claims 1 thru | or 5,
The physical quantity sensor, wherein the wiring is connected to the fixed electrode portion in the recess. In any one of Claims 1 thru | or 6,
The physical quantity sensor, wherein the distance between the substrate and the movable part is the same as the depth of the recess. In any one of Claims 1 thru | or 7,
The material of the substrate is glass,
The physical quantity sensor, wherein the material of the fixed electrode portion is silicon.   An electronic device comprising the physical quantity sensor according to claim 1.