JP2022052997A - Physical quantity sensor and inertial measurement device - Google Patents

Abstract

To provide a physical quantity sensor that can effectively suppress generation of problems caused by regulation of rotation of a mobile body by a first stopper.SOLUTION: A physical quantity sensor 1 includes: a substrate 2; a movable body 3 swingable with respect to the substrate 2 around an axis AY of rotation; a first stopper 11 for regulating the rotation of the movable body 3 around the axis AY of rotation; and a second stopper 12 for regulating the rotation of the movable body 3 around an axis corresponding to the first stopper 11 after the first stopper 11 regulates the rotation of the movable body 3 around the axis AY of rotation.SELECTED DRAWING: Figure 3

Description

The present invention relates to a physical quantity sensor, an inertial measurement unit, and the like.

Conventionally, physical quantity sensors that detect physical quantities such as acceleration have been known. For example, in Patent Document 1, a substrate, a movable body displaceably provided facing the substrate and provided with a through hole, and a protrusion formed integrally with the substrate on the movable body side of the substrate. The physical quantity sensor having the above is disclosed. In the physical quantity sensor of Patent Document 1, the protrusion is provided at a position overlapping the through hole and the movable body in a plan view to secure the toughness of the protrusion and suppress the sticking between the movable body and the substrate.

Japanese Unexamined Patent Publication No. 2020-24098

However, when such a protrusion is provided, when the physical quantity sensor receives a strong impact or vibration from the outside, for example, there is a possibility that a problem may occur due to the regulation of rotation of the movable body by the protrusion. There was found. For example, various problems may occur due to the rotational movement around the axis corresponding to the top of the protrusion.

One aspect of the present disclosure includes a substrate, a movable body that is swingably provided with respect to the substrate about the rotation axis, and a first stopper that regulates the rotation of the movable body about the rotation axis. After the rotation of the movable body around the rotation axis is restricted by the first stopper, a second stopper that regulates the rotation of the movable body around the axis corresponding to the first stopper is used. Related to physical quantity sensors including.

Further, one aspect of the present disclosure relates to an inertial measurement unit including the physical quantity sensor described above and a control unit that controls based on a detection signal output from the physical quantity sensor.

The plan view of the physical quantity sensor of 1st Embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. The schematic block diagram of the physical quantity sensor of 1st Embodiment. An explanatory diagram of the operation of the physical quantity sensor when a downward acceleration is applied. An explanatory diagram of the operation of the physical quantity sensor when a downward acceleration is applied. Explanatory drawing about the relationship of distance t1, t2, L1, L2. An explanatory diagram of the operation of the physical quantity sensor when an upward acceleration is applied. An explanatory diagram of the operation of the physical quantity sensor when an upward acceleration is applied. An explanatory diagram of the operation of the physical quantity sensor when an upward acceleration is applied. The operation explanatory drawing of the physical quantity sensor when the height of the 2nd stopper is higher. The operation explanatory drawing of the physical quantity sensor when the height of the 2nd stopper is higher. Explanatory drawing about displacement of a rotating shaft. Explanatory drawing of stress applied to support beam which is a spring body. The schematic block diagram of the physical quantity sensor of the 2nd Embodiment. The schematic block diagram of the physical quantity sensor of the 3rd Embodiment. The schematic block diagram of the physical quantity sensor of 4th Embodiment. The schematic block diagram of the physical quantity sensor of 5th Embodiment. The schematic block diagram of the physical quantity sensor of the 6th Embodiment. The figure which shows the specific example of the elastic part. The figure which shows the specific example of the elastic part. An exploded perspective view showing a schematic configuration of an inertial measurement unit having a physical quantity sensor. A perspective view of the circuit board of the physical quantity sensor.

Hereinafter, this embodiment will be described. It should be noted that the present embodiment described below does not unreasonably limit the description of the scope of claims. Moreover, not all of the configurations described in this embodiment are essential configuration requirements. Further, in each of the following drawings, some components may be omitted for convenience of explanation. Further, in each drawing, the dimensional ratio of each component is different from the actual one for the sake of clarity.

1. 1. First Embodiment First, the physical quantity sensor 1 of the first embodiment will be described with reference to FIGS. 1 and 2 by taking an acceleration sensor that detects acceleration in the vertical direction as an example. FIG. 1 is a plan view of the physical quantity sensor 1 of the first embodiment, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. The physical quantity sensor 1 is a MEMS (Micro Electro Mechanical Systems) device, for example, an inertial sensor.

Note that FIG. 1 illustrates a state in which the lid portion 5 of FIG. 2 is removed for convenience of explaining the internal configuration of the physical quantity sensor 1. Further, in FIG. 1, the wiring of the substrate 2 is omitted. In the following, the case where the physical quantity detected by the physical quantity sensor 1 is an acceleration will be mainly described, but the physical quantity is not limited to the acceleration and may be another physical quantity such as angular velocity, velocity, pressure or gravity. , The physical quantity sensor 1 may be used as a gyro sensor, a pressure sensor, a MEMS switch, or the like. Further, for convenience of explanation, the X-axis, the Y-axis, and the Z-axis are shown in each figure as three axes orthogonal to each other. The direction along the X axis is referred to as "X direction", the direction along the Y axis is referred to as "Y direction", and the direction along the Z axis is referred to as "Z direction". Here, for example, the X direction is the first direction, the Y direction is the second direction, and the Z direction is the third direction. Further, the tip side of the arrow in each axial direction is also referred to as "plus side", the base end side is also referred to as "minus side", the plus side in the Z direction is referred to as "up", and the minus side in the Z direction is also referred to as "down". The Z direction is along the vertical direction, and the XY plane is along the horizontal plane.

The physical quantity sensor 1 shown in FIGS. 1 and 2 can detect acceleration in the Z direction, which is the vertical direction. Such a physical quantity sensor 1 has a substrate 2, a movable body 3 provided facing the substrate 2, and a lid portion 5 joined to the substrate 2 and covering the movable body 3. The movable body 3 can also be called a swing structure or a sensor element.

As shown in FIG. 1, the substrate 2 has a spread in the X direction and the Y direction, and the thickness is in the Z direction. Further, as shown in FIG. 2, the substrate 2 is formed with a recess 21 and a recess 21a that are recessed on the lower surface side and have different depths. The depth of the recess 21a from the upper surface is deeper than that of the recess 21. The recess 21 and the recess 21a include the movable body 3 inside in a plan view from the Z direction, and are formed larger than the movable body 3. The recess 21 and the recess 21a function as a relief portion for suppressing contact between the movable body 3 and the substrate 2. Further, the substrate 2 has a fixing portion 22 protruding from the surface 8 which is the bottom surface of the recess 21 toward the movable body 3, a first stopper 11, and a second stopper 12. Further, on the substrate 2, the first detection electrode 24 and the second detection electrode 25 are arranged on the bottom surface of the recess 21, and the dummy electrode 26 is arranged on the bottom surface of the recess 21a. The first detection electrode 24 and the second detection electrode 25 are respectively connected to a QV amplifier (not shown), and the capacitance difference thereof is detected as an electric signal by a differential detection method. Therefore, it is desirable that the first detection electrode 24 and the second detection electrode 25 have the same area. The movable body 3 is joined to the upper surface of the fixed portion 22 of the substrate 2.

The first stopper 11, which is the first protrusion, causes the movable body 3 to swing further when the top of the movable body 3 comes into contact with the movable body 3 when the movable body 3 swings excessively. regulate. By providing such a first stopper 11, it is possible to prevent the movable body 3 having different potentials from being excessively close to the first detection electrode 24 and the second detection electrode 25. Generally, an electrostatic attraction is generated between electrodes having different potentials. Therefore, when excessive proximity occurs, the movable body is caused by the electrostatic attraction generated between the movable body 3 and the first detection electrode 24 and the second detection electrode 25. 3 causes the generation of "pull-in" that is attracted to the first detection electrode 24 and the second detection electrode 25 and cannot return. In such a state, the physical quantity sensor 1 does not operate normally. Therefore, it is important to provide the first stopper 11 to prevent excessive proximity. The second stopper 12 can also have the same function as the first stopper 11. Then, as will be described later, the second stopper 12 is a movable body centered on the axis corresponding to the first stopper 11 after the rotation of the movable body 3 centered on the rotation axis AY is restricted by the first stopper 11. Regulate the rotation of 3. As described above, since the movable body 3 has different potentials from the first detection electrode 24 and the second detection electrode 25, as shown in FIG. 2, the tops of the first stopper 11 and the second stopper 12 have different potentials. Is provided with insulating layers 13 and 14 as a protective film for preventing a short circuit. Silicon oxide, silicon nitride, or the like is used as the material of the insulating layers 13 and 14. Instead of the insulating layers 13 and 14, an electrode electrically separated from the first detection electrode 24 and the second detection electrode 25 is formed so as to cover the tops of the first stopper 11 and the second stopper 12, for example. You may.

As the substrate 2, for example, a glass substrate containing alkali metal ions, for example, a glass substrate made of borosilicate glass such as Pyrex (registered trademark) glass or Tempax (registered trademark) glass can be used. However, the constituent material of the substrate 2 is not particularly limited, and for example, a silicon substrate, a quartz substrate, an SOI (Silicon On Insulator) substrate, or the like may be used.

As shown in FIG. 2, the lid portion 5 is formed with a recess 51 recessed on the upper surface side. The lid portion 5 accommodates the movable body 3 in the recess 51 and is joined to the upper surface of the substrate 2. A storage space S for accommodating the movable body 3 is formed inside the lid portion 5 and the substrate 2. The storage space S is an airtight space, and is preferably filled with an inert gas such as nitrogen, helium, or argon, and has an operating temperature of about −40 ° C. to 125 ° C., which is substantially atmospheric pressure. However, the atmosphere of the storage space S is not particularly limited, and may be in a reduced pressure state or a pressurized state, for example.

As the lid portion 5, for example, a silicon substrate can be used. However, the present invention is not particularly limited, and for example, a glass substrate or a quartz substrate may be used as the lid portion 5. The method of joining the substrate 2 and the lid 5 is not particularly limited, and may be appropriately selected depending on the material of the substrate 2 and the lid 5. For example, the bonding surfaces activated by anode bonding or plasma irradiation are bonded to each other. It is possible to use activated bonding, bonding with a bonding material such as glass frit, metal eutectic bonding for bonding metal films formed on the upper surface of the substrate 2 and the lower surface of the lid 5, and the like.

The movable body 3 is to vertically process a conductive silicon substrate doped with impurities such as phosphorus (P), boron (B) or arsenic (As) by etching, especially by the Bosch process, which is a deep etching technique. Can be formed by.

The movable body 3 can swing around the rotation axis AY along the Y direction. The movable body 3 has a holding portion 32, a support beam 33, a first mass portion 34, a second mass portion 35, and a third mass portion 36. The holding portion 32 is joined to the upper surface of the fixing portion 22 of the substrate 2. The support beam 33 supports the movable body 3 as the axis of rotation AY. For example, the fixing portion 22 of the substrate 2 and the holding portion 32 of the movable body 3 are joined to each other by an anode, and the support beam 33 connects the movable body 3 and the fixing portion 22 of the substrate 2 via the holding portion 32. Will be there.

The movable body 3 has a rectangular shape with the X direction as the longitudinal direction in a plan view from the Z direction. The first mass portion 34 and the second mass portion 35 of the movable body 3 are arranged so as to sandwich the rotation axis AY along the Y direction in a plan view from the Z direction. Specifically, in the movable body 3, the first mass portion 34 and the second mass portion 35 are connected by the first connecting portion 41, and the first opening portion is formed between the first mass portion 34 and the second mass portion 35. Has 45. A holding portion 32 and a support beam 33 are arranged in the first opening 45. By arranging the holding portion 32 and the support beam 33 inside the movable body 3 in this way, the size of the movable body 3 can be reduced. Further, the third mass portion 36 is connected by the second connecting portion 42 at both ends of the second mass portion 35 in the Y direction. A second opening 46 is provided between the second mass portion 35 and the third mass portion 36 in order to make the area of the first mass portion 34 equal to the area of the second mass portion 35. The first mass part 34 is located on the plus side in the X direction with respect to the rotation axis AY, and the second mass part 35 and the third mass part 36 are located on the minus side in the X direction with respect to the rotation axis AY. Further, the second mass part 35 and the third mass part 36 are longer in the X direction than the first mass part 34, and the rotational moment around the rotation axis AY when the acceleration az in the Z direction is applied is the first mass part 34. Greater than.

Due to this difference in rotational moment, the movable body 3 swings around the rotation axis AY with a seesaw when an acceleration az in the Z direction is applied. In the seesaw swing, when the first mass part 34 is displaced to the plus side in the Z direction, the second mass part 35 is displaced to the minus side in the Z direction, and conversely, the first mass part 34 is displaced to the minus side in the Z direction. When displaced, it means that the second mass portion 35 is displaced to the plus side in the Z direction.

Further, the movable body 3 has a plurality of through holes uniformly formed in the entire area thereof. This makes it possible to optimize damping due to viscosity. That is, when acceleration is applied in normal operation, the seesaw swing can be easily converged by the damping effect. The effect of damping is adversely affected by the detection operation if it is too high or too low. The through holes may be omitted or the arrangement may not be uniform as long as the necessary and sufficient damping effect is obtained.

Further, in the movable body 3, the first connecting portion 41 and the holding portion 32 arranged in the Y direction are connected by a support beam 33 extending in the Y direction. Therefore, the support beam 33 can be used as the rotation axis AY, and the movable body 3 can be displaced around the rotation axis AY by swinging the seesaw.

Next, the first detection electrode 24 and the second detection electrode 25 arranged on the bottom surface of the recess 21 of the substrate 2 and the dummy electrode 26 arranged on the bottom surface of the recess 21a will be described.

As shown in FIGS. 1 and 2, in a plan view from the Z direction, the first detection electrode 24 is arranged so as to overlap the first mass portion 34, and the second detection electrode 25 overlaps the second mass portion 35. Are arranged. The first detection electrode 24 and the second detection electrode 25 are viewed in a plan view from the Z direction so that the capacitances Ca and Cb shown in FIG. 1 are equal in a natural state in which the acceleration az in the Z direction is not applied. , Is provided substantially symmetrically with respect to the rotation axis AY. Insulating layers 13 and 14 are provided at the portions where the first detection electrode 24 and the second detection electrode 25 overlap with the first stopper 11 and the second stopper 12, respectively. The insulating layers 13 and 14 prevent a short circuit between the movable body 3 and the first detection electrode 24 and the second detection electrode 25. The second stopper 12 may not be provided with the insulating layer 14. Further, an electrode electrically non-connected to the first detection electrode 24 and the second detection electrode 25 may be formed as a protective film so as to cover the top of the first stopper 11 or the like.

Further, the dummy electrode 26 is located on the minus side in the X direction with respect to the second detection electrode 25, and is provided so as to overlap with the third mass portion 36. By covering the bottom surface of the recess 21a with the dummy electrode 26 in this way, it is possible to suppress the charging of the bottom surface of the recess 21a due to the movement of the alkali metal ions in the substrate 2. Therefore, it is possible to effectively suppress the generation of an unintended electrostatic attraction that leads to a malfunction of the movable body 3 between the bottom surface of the recess 21 and the second mass portion 35. Thereby, the physical quantity sensor 1 capable of detecting the acceleration az with higher accuracy can be realized.

The first detection electrode 24 and the second detection electrode 25 are electrically connected to a differential QV amplifier (not shown). When the physical quantity sensor 1 is driven, a drive signal is applied to the movable body 3, so that a capacitance Ca is formed between the first mass portion 34 and the first detection electrode 24. Similarly, the capacitance Cb is formed between the second mass portion 35 and the second detection electrode 25. In the natural state where the acceleration az in the Z direction is not applied, the capacitances Ca and Cb are almost equal to each other.

When the acceleration az is applied to the physical quantity sensor 1, the movable body 3 swings around the rotation axis AY. Due to the seesaw swing of the movable body 3, the gap between the first mass portion 34 and the first detection electrode 24 and the gap between the second mass portion 35 and the second detection electrode 25 change in opposite phases. The capacitances Ca and Cb change in opposite phases to each other. As a result, the physical quantity sensor 1 can detect the acceleration az based on the difference between the capacitance values of the capacitances Ca and Cb.

Next, the features of this embodiment will be described. FIG. 3 is a schematic configuration diagram of the physical quantity sensor 1, and FIGS. 4 and 5 are explanatory views of the operation of the physical quantity sensor when a downward acceleration is applied.

The physical quantity sensor 1 has a substrate 2, a movable body 3, a first stopper 11, and a second stopper 12. The movable body 3 is provided so as to be swingable with respect to the substrate 2 about the rotation axis AY. For example, as described above, the movable body 3 swings around the rotation axis AY with a seesaw. The first stopper 11 regulates the rotation of the movable body 3 about the rotation axis AY. Then, after the rotation of the movable body 3 around the rotation axis AY is restricted by the first stopper 11, the second stopper 12 regulates the rotation of the movable body 3 around the axis corresponding to the first stopper 11. do.

For example, as shown in FIG. 4, when a downward acceleration in the vertical direction acts, the movable body 3 rotates clockwise around the rotation axis AY on the paper surface of the figure. When the surface 6 of the movable body 3 on the substrate 2 side comes into contact with the top of the first stopper 11, the first stopper 11 regulates the rotation of the movable body 3 about the rotation axis AY. For example, the rotation of the movable body 3 is restricted by the first stopper 11 and stops. Then, as shown in FIG. 5, the movable body 3 rotates about the axis corresponding to the first stopper 11. For example, when the top of the first stopper 11 comes into contact with the surface 6 of the movable body 3 on the substrate 2 side, the movable body 3 rotates with the top of the first stopper 11 as a fulcrum FC. That is, the movable body 3 rotates about the axis passing through the fulcrum FC, which is the axis corresponding to the first stopper 11. The axis passing through the fulcrum FC is, for example, an axis along the Y direction. Then, in this way, the movable body 3 rotates clockwise around the axis passing through the fulcrum FC, and when the top of the second stopper 12 comes into contact with the surface 6 of the movable body 3 on the substrate 2 side, it is shown in FIG. As described above, the second stopper 12 regulates the rotation of the movable body 3 about the axis passing through the fulcrum FC. For example, when the surface 6 on the substrate 2 side of the movable body 3 comes into contact with the top of the second stopper 12, the clockwise rotation of the movable body 3 on the axis passing through the fulcrum FC is restricted by the second stopper 12. And stop.

For example, in the configuration in which only the first stopper 11 is provided without providing the second stopper 12 as in the above-mentioned Patent Document 1, when a strong impact force or the like is applied to the physical quantity sensor 1, the movable body 3 is attached to the first stopper 11. After the collision, a rotational motion is generated around the axis corresponding to the first stopper 11. Then, due to this rotational movement, stress may be concentrated on the support beams 33 of FIGS. 1 and 2 which are spring bodies, resulting in damage or the like. When the physical quantity sensor 1 is required to have high sensitivity, it is necessary to narrow the width of the support beam 33 that functions as a torsion spring, so that there is a high possibility that damage or the like will occur due to the concentration of stress.

In this respect, in the physical quantity sensor 1 of the present embodiment, a second stopper 12 is further provided in addition to the first stopper 11. Therefore, after the rotation of the movable body 3 around the rotation axis AY is restricted by the first stopper 11, when the rotation of the movable body 3 around the axis corresponding to the first stopper 11 occurs, this The rotation is restricted by the second stopper 12 and stops. Therefore, it is possible to effectively suppress the concentration of stress on the support beam 33, which is a spring body, and the occurrence of breakage or the like.

Further, in the physical quantity sensor 1 of the first embodiment, as shown in FIG. 3, the first stopper 11 and the second stopper 12 are provided on the movable body 3 side of the substrate 2. For example, the first stopper 11 and the second stopper 12 are provided on the surface 8 of the substrate 2 on the movable body 3 side. The second stopper 12 is provided at a position farther from the rotation axis AY than the first stopper 11 in the side view seen from the direction parallel to the rotation axis AY. For example, as shown in FIG. 3, in the side view seen from the Y direction, which is the direction along the rotation axis AY, the distance from the rotation axis AY to the first stopper 11 is L1, and the distance from the rotation axis AY to the second stopper 12 is set. Let L2 be the distance. In this case, the distance L1 and the distance L2 are different, for example, L2> L1. Further, the distance from the surface 6 on the substrate 2 side of the movable body 3 to the top of the first stopper 11 is t1, and the distance from the surface 6 to the top of the second stopper 12 is t2. In this case, in the physical quantity sensor 1 of the present embodiment, the distance t2 from the surface 6 on the substrate 2 side of the movable body 3 to the top of the second stopper 12 is larger than the distance t1 from the surface 6 to the top of the first stopper 11. big. That is, the distance t1 and the distance t2 are different, for example, t2> t1. In other words, the height of the second stopper 12 protruding from the surface 8 on the movable body 3 side of the substrate 2 is lower than the height of the first stopper 11 protruding from the surface 8. By providing the first stopper 11 and the second stopper 12 so that the relationship of L2> L1 and t2> t1 is established in this way, as shown in FIG. 4, a strong impact or the like is applied to the first stopper 11. Even when the movable body 3 rotates around the corresponding axis, as shown in FIG. 5, the rotation can be regulated by the second stopper 12 having the top at a distance t2 far from the surface 6 of the movable body 3. Become. Therefore, by restricting the rotation by the second stopper 12 and stopping the rotation, it is possible to suppress the occurrence of problems such as damage to the support beam 33 of the physical quantity sensor 1 when a strong impact or the like is applied.

Further, in the physical quantity sensor 1 of the first embodiment, as shown in FIG. 3, the first stopper 11 is a first protrusion protruding from the substrate 2 toward the movable body 3, and the second stopper 12 is from the substrate 2. It is a second protrusion protruding toward the movable body 3. That is, the first stopper 11 and the second stopper 12 are first protrusions and second protrusions formed so as to project from the surface 8 on the movable body 3 side of the substrate 2, respectively. The distance t2 from the top of the second protrusion, which is the second stopper 12, to the surface 6 on the substrate 2 side of the movable body 3 is from the distance t1 from the top of the first protrusion, which is the first stopper 11, to the surface 6. Is also big. By doing so, after the rotation of the movable body 3 about the rotation axis AY is restricted by the first protrusion portion which is the first stopper 11, the second protrusion portion which is the second stopper 12 causes the second protrusion. It becomes possible to regulate the rotation of the movable body 3 about the axis corresponding to one protrusion. That is, it becomes possible to regulate the rotation of the movable body 3 about the axis passing through the fulcrum FC, which is the top of the first protrusion, and stop the rotation, and the physical quantity sensor 1 malfunctions due to a strong impact or the like. Can be suppressed.

Further, as described above, the distances from the surface 6 of the movable body 3 to the tops of the first stopper 11 and the second stopper 12 are t1 and t2, respectively, and from the rotation axis AY to the first stopper 11 and the second stopper 12. Let the distances be L1 and L2, respectively. In this case, in this embodiment, the relationship of t1 / L1 ≦ t2 / L2 is established. For example, FIG. 6 schematically shows the relationship between the distances L1, L2, t1, and t2. Since the thickness of the movable body 3 is actually very thin, in FIG. 6, the cross section of the movable body 3 in the side view is represented by a line segment. Further, P1 and P2 are the tops of the first stopper 11 and the second stopper 12, respectively.

The condition that the movable body 3 rotates about the rotation axis AY and the movable body 3 and the top P1 of the first stopper 11 and the top P2 of the second stopper 12 come into contact with each other at the same time as shown in FIG. 6 is t1 / L1 = t2. / L2. Therefore, the condition that the movable body 3 comes into contact with the top P2 of the second stopper 12 after the movable body 3 comes into contact with the top P1 of the first stopper 11 is a condition of t1 / L1 ≦ t2 / L2. That is, if t2 ≧ (L2 / L1) × t1 is established, the movable body 3 comes into contact with the top P2 of the second stopper 12 after the movable body 3 comes into contact with the top P1 of the first stopper 11. .. In this way, after the rotation of the movable body 3 centered on the rotation axis AY is restricted by the first stopper 11, the movable body centered on the axis corresponding to the first stopper 11 is controlled by the second stopper 12. It becomes possible to regulate the rotation of 3. Therefore, it is possible to suppress the occurrence of malfunction of the physical quantity sensor 1 due to the application of a strong impact or the like.

FIGS. 7, 8 and 9 are explanatory views of the operation of the physical quantity sensor when an upward acceleration is applied. In this case, since the rotation moment of the second mass part 35 and the third mass part 36 side is larger than that of the first mass part 34 side, the movable body 3 is counterclockwise with respect to the rotation axis AY on the paper surface of the figure. Rotate clockwise. Then, as shown in FIG. 8, when the first stopper 11 on the second mass portion 35 side comes into contact with the movable body 3, the movable body 3 rotates clockwise around the fulcrum FC at the top of the first stopper 11, and FIG. As shown in 9, the first stopper 11 on the first mass portion 34 side comes into contact with the movable body 3. Therefore, compared to the case where the downward acceleration acts as shown in FIGS. 4 and 5, the possibility that the stress is concentrated on the support beam 33 and the beam is damaged is low. That is, in the physical quantity sensor 1, defects such as breakage are likely to occur when a downward acceleration is applied as shown in FIGS. 4 and 5.

10 and 11 are examples in which the height of the second stopper 12 is higher than the height of the first stopper 11. In this case, for example, when an acceleration acts upward, the second stopper 12 on the second mass portion 35 side first comes into contact with the movable body 3. Then, the movable body 3 rotates clockwise around the fulcrum FC2 at the top of the second stopper 12. At this time, when a strong upward acceleration acts due to a strong impact, a large downward force F1 acts on the vicinity of the rotation axis AY of the movable body 3 as shown in FIG. For example, since the fulcrum FC2 of the second stopper 12 restrains the movable body 3 in the out-of-plane axial direction and the distance between the two fulcrums FC2 of the two second stoppers 12 on both sides is long, the movable body 3 is centered around the rotation axis AY. Bend. Therefore, damage is likely to occur at the portion connecting the support beam 33, which is a spring body, and the portion at the base of the support beam 33. Further, since the second stopper 12 far from the rotation axis AY comes into contact first, there is an advantage that the movable range is narrowed. Therefore, it is desirable that the height of the second stopper 12 is lower than that of the first stopper 11. That is, as described with reference to FIGS. 3, 4, and 5, the distance t2 from the surface 6 of the movable body 3 to the top of the second stopper 12 is larger than the distance t1 from the surface 6 to the top of the first stopper 11. Larger is desirable.

As described above, in the physical quantity sensor 1 of the present embodiment, the first stopper 11 near the rotation axis AY and the second stopper 12 far from the rotation axis AY function step by step, and the first stopper 11 and the second stopper 11 and the second stopper 11 function in stages. By appropriately managing the position and height of the stopper 12, it is possible to realize the physical quantity sensor 1 that is not easily damaged even by a strong impact or the like.

Further, the first stopper 11 and the second stopper 12 are provided between the rotation axis AY and the end portion of the movable body 3 in a plan view viewed from a direction orthogonal to the substrate 2. For example, in FIG. 1, the first stopper 11 and the second stopper 12 on the side of the first mass portion 34 are on the right side of the rotation axis AY and the movable body 3 in a plan view seen from the Z direction which is a direction orthogonal to the substrate 2. It is provided between the end and the end. That is, the second stopper 12 is not a stopper located at the right end of the movable body 3, but a stopper located between the right end of the movable body 3 and the rotation axis AY. Here, the right side is the plus side in the X direction. Further, the first stopper 11 and the second stopper 12 on the second mass portion 35 side are provided between the rotation axis AY and the left end portion of the movable body 3 in a plan view. That is, the second stopper 12 is not a stopper located at the left end of the movable body 3, but a stopper located between the left end of the movable body 3 and the rotation axis AY. Here, the left side is the minus side in the X direction. By providing the second stopper 12 at such a position, even when the movable body rotates around the axis corresponding to the first stopper, the rotation can be appropriately regulated.

Further, as shown in FIGS. 1 and 2, the movable body 3 has a support beam 33 which is a spring body provided along the direction of the rotation axis AY and having one end fixed to the substrate 2. For example, the longitudinal direction of the support beam 33 is along the direction of the axis of rotation AY. One end of the support beam 33 is fixed to the fixing portion 22 of the substrate 2 via the holding portion 32. Then, the length of the support beam 33 in the direction along the rotation axis AY is defined as LS. Further, the displacement of the rotation axis AY caused by the rotation of the movable body 3 about the axis corresponding to the first stopper 11 is defined as X1. Specifically, after the rotation of the movable body 3 about the rotation axis AY is restricted by the first stopper 11 as shown in FIG. 4, the axis corresponding to the first stopper 11 is centered as shown in FIG. The displacement of the rotating shaft AY caused by the rotation of the movable body 3 about the axis corresponding to the first stopper 11 until the rotation of the movable body 3 is regulated by the second stopper 12 is defined as X1. .. For example, in FIG. 5, the rotation axis AY of the movable body 3 is displaced upward by X1 due to the rotation with the top of the first stopper 11 as the fulcrum FC. Here, the upward direction is, for example, a positive direction in the Z direction. At this time, it is desirable that the displacement X1 of the rotation axis AY is less than 10% of the length LS of the support beam 33 which is a spring body. That is, it is desirable that X1 <LS × 0.1. In this way, by suppressing the displacement X1 of the rotation axis AY to less than 10% of the length LS of the support beam 33, the support which is a spring body is caused by the rotation around the fulcrum FC as shown in FIG. It is possible to effectively prevent the beam 33 from being damaged. More preferably, the displacement X1 of the rotating shaft AY is less than 2% of the length LS. That is, it is desirable that X1 <LS × 0.02.

FIG. 12 is a diagram schematically showing the relationship between the distances L1, L2, t1, t2 and the displacement X1 in the same manner as in FIG. In FIG. 12, the rotation axis AY is displaced upward by X1 due to the rotation about the axis of the top P1 of the first stopper 11. As is clear from FIG. 12, this displacement X1 can be expressed as X1 = (t2-t1) / (L2-L1) × L1-t1. Therefore, in order to prevent the support beam 33 from being damaged by the displacement X1 of the rotation axis AY, the relationship of X1 = (t2-t1) / (L2-L1) × L1-t1 <LS × 0.1. Is desirable, and more preferably, the relationship of X1 = (t2-t1) / (L2-L1) × L1-t1 <LS × 0.02 is established.

FIG. 13 is a diagram schematically showing the vicinity of the rotation axis AY. The left side of FIG. 13 is a schematic plan view seen from the Z direction, and the right side of FIG. 13 is a schematic side view seen from the X direction. One end of the support beam 33 is fixed to the fixing portion 22 of the substrate 2 via the holding portion 32. Then, as shown in FIG. 12, when the rotation axis AY is displaced to the plus side in the Z direction, which is the upward direction, due to the rotation around the axis of the top P1 of the first stopper 11, the other end of the support beam 33 is also upward. And the support beam 33 is deformed as shown in FIG. Due to such deformation of the support beam 33 which is a spring body, stress is applied to a stress concentration point such as a portion at the base of the support beam 33, and the support beam 33 may be damaged or the like. In particular, since the support beam 33 has a shape having a narrow width in the X direction in order to increase the sensitivity of the physical quantity sensor 1, the support beam 33 is damaged due to the concentration of stress at the stress concentration point in this way. Cheap. Assuming that the displacement X1 which is the amount that the rotation axis AY is lifted up is the same, the longer the length LS of the support beam 33, which is the length of the spring body, the smaller the stress applied to the stress concentration point. .. Therefore, in the present embodiment, a threshold value such as 10% is set for X1 / LS, which is the ratio of the displacement X1 of the rotation axis AY to the length LS of the spring body. That is, by suppressing X1 / LS to less than 10% and setting X1 <LS × 0.10, it is possible to suppress the occurrence of damage to the support beam 33 due to stress concentration.

The physical quantity sensor 1 of the present embodiment can be manufactured by a manufacturing method including a substrate forming step, a fixed electrode forming step, a substrate bonding step, a movable body forming step, and a sealing step. In the substrate forming step, for example, by patterning a glass substrate using a photolithography technique and an etching technique, the first stopper 11, the first stopper 12, the second protrusion, and the movable body 3 are supported. The substrate 2 on which the fixing portion 22 and the like are formed is formed. In the fixed electrode forming step, a conductive film is formed on the substrate 2, and the conductive film is patterned by a photolithography technique and an etching technique to form fixed electrodes such as the first detection electrode 24 and the second detection electrode 25. In the substrate bonding step, the substrate 2 and the silicon substrate are bonded by anode bonding or the like. In the movable body forming step, the silicon substrate is thinned to a predetermined thickness, and the silicon substrate is patterned by using a photolithography technique and an etching technique to form the movable body 3. In this case, the Bosch process, which is a deep-drill etching technique, is used. In the sealing step, the lid portion 5 is joined to the substrate 2, and the movable body 3 is accommodated in the space formed by the substrate 2 and the lid portion 5. The manufacturing method of the physical quantity sensor 1 in the present embodiment is not limited to the manufacturing method as described above, and various manufacturing methods such as a manufacturing method using a sacrificial layer as described later can be adopted.

2. 2. 2nd Embodiment FIG. 14 shows a schematic configuration example of the physical quantity sensor 1 of the 2nd embodiment. In the physical quantity sensor 1 of the second embodiment, the second stopper 12 is realized by the corner portion of the step. For example, as shown in FIG. 14, the substrate 2 has a first upper surface 8a and a second upper surface 8b on the movable body 3 side. That is, the substrate 2 has a first upper surface 8a and a second upper surface 8b, 8c as a surface 8 on the movable body 3 side. The heights of the second upper surfaces 8b and 8c in the direction orthogonal to the substrate 2 are lower than those of the first upper surface 8a. That is, the boundary between the first upper surface 8a and the second upper surface 8b is a step, and the boundary between the first upper surface 8a and the second upper surface 8c is a step. Specifically, these steps are formed by the counterbore of the substrate 2.

As shown in FIG. 14, the first stopper 11 is a first protrusion protruding from the first upper surface 8a toward the movable body 3. That is, the first stopper 11 is a first protrusion formed so as to protrude from the first upper surface 8a on the movable body 3 side of the substrate 2. On the other hand, the second stopper 12 is a corner portion at the end of the first upper surface 8a on the second upper surface 8b side. That is, the second stopper 12 provided on the side of the first mass portion 34 of the movable body 3 is a corner portion that becomes a step at the boundary between the first upper surface 8a and the second upper surface 8b. The second stopper 12 is a corner portion at the end of the first upper surface 8a on the second upper surface 8c side. That is, the second stopper 12 on the second mass portion 35 side is a corner portion that becomes a step at the boundary between the first upper surface 8a and the second upper surface 8c. As described above, in FIG. 14, the corner portion of the step formed by the counterbore of the substrate 2 is used as the second stopper 12.

By doing so, after the rotation of the movable body 3 about the rotation axis AY is restricted by the first protrusion portion which is the first stopper 11, the first protrusion is formed by the corner portion which is the second stopper 12. It becomes possible to regulate the rotation of the movable body 3 about the axis corresponding to the portion. That is, it is possible to restrict the rotation of the movable body 3 about the axis passing through the top of the first protrusion and stop it, and it is possible to suppress the occurrence of malfunction of the physical quantity sensor 1 due to the application of a strong impact or the like. Further, according to the method of using the corner portion as the second stopper 12 as shown in FIG. 14, the step of forming the second protrusion portion as the second stopper 12 becomes unnecessary, and only a step is provided on the surface 8 of the substrate 2. There is an advantage that the second stopper 12 can be realized. That is, the formation of the protrusion is difficult because it is a small area machining, but the method of using the corner of the step formed by the counterbore as the second stopper 12 is easy because it is a large area machining. There is an advantage that there is.

Further, in the present embodiment, the movable body 3 has a first mass portion 34 provided on the first direction side of the rotation axis AY in a plan view viewed from a direction orthogonal to the substrate 2, and a first mass portion 34 of the rotation axis AY in a plan view. It has a second mass portion 35 and a third mass portion 36 provided on the opposite side of the direction. The first direction is a direction orthogonal to the rotation axis AY, an X direction, and specifically, a positive direction in the X direction. On the other hand, the opposite direction of the first direction is the direction on the minus side of the X direction. Further, FIG. 14 is characterized in that the corner portion on the first mass portion 34 side is provided as the second stopper 12 in a plan view viewed from a direction orthogonal to the substrate 2. For example, as described with reference to FIGS. 3 to 5 described above, the physical quantity sensor is more likely to have a downward acceleration than when an upward acceleration is applied as shown in FIGS. 7 to 9. There is a high possibility that problems such as damage to 1 will occur. As shown in FIG. 14, by providing the second stopper 12 at the corner due to the step on the side of the first mass portion 34, even when a downward acceleration due to a strong impact or the like acts, the physical quantity sensor 1 is damaged or the like. It becomes possible to effectively suppress the occurrence of defects.

3. 3. Third Embodiment FIG. 15 shows a schematic configuration example of the physical quantity sensor 1 of the third embodiment. In the physical quantity sensor 1 of the third embodiment, the first stopper 11 and the second stopper 12 are provided on the movable body 3. Specifically, the first stopper 11 and the second stopper 12 are provided on the substrate 2 side of the movable body 3. That is, the first stopper 11 and the second stopper 12 are provided on the surface 6 of the movable body 3 on the substrate 2 side. Further, the second stopper 12 is provided at a position farther from the rotation axis AY than the first stopper 11 in the side view seen from the direction parallel to the rotation axis AY. For example, as shown in FIG. 15, in the side view seen from the direction along the rotation axis AY, the distance from the rotation axis AY to the first stopper 11 is L1, and the distance from the rotation axis AY to the second stopper 12 is L2. Then, L2> L1. Further, the distance from the surface 8 on the movable body 3 side of the substrate 2 to the top of the first stopper 11 is t1, and the distance from the surface 8 to the top of the second stopper 12 is t2. In this case, in FIG. 15, the distance t2 from the surface 8 on the movable body 3 side of the substrate 2 to the top of the second stopper 12 is larger than the distance t1 from the surface 8 to the top of the first stopper 11. That is, the distance t1 and the distance t2 are different, for example, t2> t1. In other words, the height of the second stopper 12 projecting from the surface 6 of the movable body 3 on the substrate 2 side is lower than the height of the first stopper 11 projecting from the surface 6. By providing the first stopper 11 and the second stopper 12 so that the relationship of L2> L1 and t2> t1 is established in this way, it is possible to move around the axis corresponding to the first stopper 11 by applying a strong impact or the like. Even when the body 3 rotates, the rotation can be regulated by the second stopper 12 having the top at a distance t2 far from the surface 8 of the substrate 2. Therefore, when the second stopper 12 comes into contact with the surface 8, the rotation is restricted and stopped, so that it is possible to suppress the occurrence of problems such as damage to the physical quantity sensor 1 when a strong impact or the like is applied.

Further, in the physical quantity sensor 1 of the third embodiment, as shown in FIG. 15, the first stopper 11 is a first protrusion protruding from the movable body 3 toward the substrate 2, and the second stopper 12 is the movable body 3. It is a second protrusion protruding from the substrate 2 side. That is, the first stopper 11 and the second stopper 12 are first protrusions and second protrusions formed so as to project from the surface 6 of the movable body 3 on the substrate 2 side, respectively. The distance t2 from the top of the second protrusion, which is the second stopper 12, to the surface 8 on the movable body 3 side of the substrate 2 is from the distance t1 from the top of the first protrusion, which is the first stopper 11, to the surface 8. Is also big. By doing so, after the rotation of the movable body 3 about the rotation axis AY is restricted by the first protrusion portion which is the first stopper 11, the second protrusion portion which is the second stopper 12 causes the second protrusion. It becomes possible to regulate the rotation of the movable body 3 about the axis corresponding to one protrusion.

Further, as shown in FIG. 15, the distances from the surface 8 of the substrate 2 to the tops of the first stopper 11 and the second stopper 12 are t1 and t2, respectively, and the rotation shaft AY to the first stopper 11 and the second stopper 12 are set, respectively. The distances to are L1 and L2, respectively. In this case, the relationship of t1 / L1 ≦ t2 / L2 is established. That is, the condition that the substrate 2 and the top of the first stopper 11 and the top of the second stopper 12 are in contact at the same time is t1 / L1 = t2 / L2. Therefore, the condition that the substrate 2 comes into contact with the top of the second stopper 12 after the substrate 2 comes into contact with the top of the first stopper 11 is a condition of t1 / L1 ≦ t2 / L2. That is, if t2 ≧ (L2 / L1) × t1 is established, the substrate 2 comes into contact with the top of the second stopper 12 after the substrate 2 comes into contact with the top of the first stopper 11. In this way, after the rotation of the movable body 3 centered on the rotation axis AY is restricted by the first stopper 11, the movable body centered on the axis corresponding to the first stopper 11 is controlled by the second stopper 12. It becomes possible to regulate the rotation of 3. Therefore, it is possible to suppress the occurrence of malfunction of the physical quantity sensor 1 due to the application of a strong impact or the like.

4. Fourth Embodiment FIG. 16 shows a schematic configuration example of the physical quantity sensor 1 of the fourth embodiment. In the physical quantity sensor 1 of the fourth embodiment, the first stopper 11 and the second stopper 12 are provided on the lid portion 5. For example, the physical quantity sensor 1 is provided facing the substrate 2 and includes a lid portion 5 that covers the movable body 3. The first stopper 11 and the second stopper 12 are provided on the movable body 3 side of the lid portion 5. That is, the first stopper 11 and the second stopper 12 are provided on the surface 9 of the lid portion 5 on the movable body 3 side. Further, the second stopper 12 is provided at a position farther from the rotation axis AY than the first stopper 11 in the side view seen from the direction parallel to the rotation axis AY. For example, as shown in FIG. 16, when viewed from the side along the rotation axis AY, the distance from the rotation axis AY to the first stopper 11 is L1, and the distance from the rotation axis AY to the second stopper 12 is L2. Then, L2> L1. Further, the distance from the surface 7 on the lid 5 side of the movable body 3 to the top of the first stopper 11 is t1, and the distance from the surface 7 to the top of the second stopper 12 is t2. In this case, in FIG. 16, the distance t2 from the surface 7 on the lid 5 side of the movable body 3 to the top of the second stopper 12 is larger than the distance t1 from the surface 7 to the top of the first stopper 11. That is, the distance t1 and the distance t2 are different, for example, t2> t1. In other words, the height of the second stopper 12 protruding from the surface 9 of the lid 5 on the movable body 3 side is lower than the height of the first stopper 11 protruding from the surface 9. By providing the first stopper 11 and the second stopper 12 so that the relationship of L2> L1 and t2> t1 is established in this way, it is possible to move around the axis corresponding to the first stopper 11 by applying a strong impact or the like. Even when the body 3 rotates, the rotation can be regulated by the second stopper 12 having the top at a distance t2 far from the surface 7 of the movable body 3. Therefore, when the second stopper 12 comes into contact with the surface 7, the rotation is restricted and stopped, so that it is possible to suppress the occurrence of problems such as damage to the physical quantity sensor 1 when a strong impact or the like is applied.

Further, in the physical quantity sensor 1 of the fourth embodiment, as shown in FIG. 16, the first stopper 11 is the first protrusion portion protruding from the lid portion 5 toward the movable body 3, and the second stopper 12 is the lid portion. It is a second protrusion protruding from 5 toward the movable body 3. That is, the first stopper 11 and the second stopper 12 are the first protrusion portion and the second protrusion portion formed so as to project from the surface 9 on the movable body 3 side of the lid portion 5, respectively. The distance t2 from the top of the second protrusion, which is the second stopper 12, to the surface 7 on the lid 5 side of the movable body 3 is the distance t1 from the top of the first protrusion, which is the first stopper 11, to the surface 7. Greater than. By doing so, after the rotation of the movable body 3 about the rotation axis AY is restricted by the first protrusion portion which is the first stopper 11, the second protrusion portion which is the second stopper 12 causes the second protrusion. It becomes possible to regulate the rotation of the movable body 3 about the axis corresponding to one protrusion.

Further, as shown in FIG. 16, the distances from the surface 7 of the movable body 3 to the tops of the first stopper 11 and the second stopper 12 are t1 and t2, respectively, and the rotation shaft AY to the first stopper 11 and the second stopper are set as t2, respectively. Let the distances to 12 be L1 and L2, respectively. In this case, the relationship of t1 / L1 ≦ t2 / L2 is established. That is, the condition that the movable body 3 and the top of the first stopper 11 and the top of the second stopper 12 come into contact with each other at the same time is t1 / L1 = t2 / L2. Therefore, the condition that the movable body 3 comes into contact with the top of the second stopper 12 after the movable body 3 comes into contact with the top of the first stopper 11 is t1 / L1 ≦ t2 / L2. That is, if t2 ≧ (L2 / L1) × t1 is established, the movable body 3 comes into contact with the top of the second stopper 12 after the movable body 3 comes into contact with the top of the first stopper 11. In this way, after the rotation of the movable body 3 centered on the rotation axis AY is restricted by the first stopper 11, the movable body centered on the axis corresponding to the first stopper 11 is controlled by the second stopper 12. It becomes possible to regulate the rotation of 3. Therefore, it is possible to suppress the occurrence of malfunction of the physical quantity sensor 1 due to the application of a strong impact or the like.

In FIG. 16, the physical quantity sensor 1 is formed by a manufacturing method using the sacrificial layer 28. In this manufacturing method, the silicon substrate on which the sacrificial layer 28 is formed and the substrate 2 which is the support substrate are joined via the sacrificial layer 28, and a cavity in which the movable body 3 can swing is formed in the sacrificial layer 28. do. Specifically, after forming the movable body 3 on the silicon substrate, a cavity is formed by etching and removing the sacrificial layer 28 sandwiched between the silicon substrate and the substrate 2, and the movable body is formed from the substrate 2. Release 3 In the present embodiment, the physical quantity sensor 1 having the substrate 2 and the movable body 3 may be formed by such a manufacturing method.

5. Fifth Embodiment FIG. 17 shows a schematic configuration example of the physical quantity sensor 1 of the fifth embodiment. In FIG. 17, the upper surface of the substrate 2 and the detection electrodes are formed in a stepped shape. By forming the upper surface of the substrate 2 and the detection electrodes in a stepped shape in this way, the movable range of the movable body 3 can be expanded, and the sensitivity of the physical quantity sensor 1 can be improved.

Specifically, in FIG. 17, the surfaces 10a, 10b, 10c, and 10d are formed as the upper surface of the substrate 2. In the direction orthogonal to the substrate 2, the heights of the surfaces 10b and 10c are lower than the surfaces 10a, and the height of the surfaces 10d is lower than the surfaces 10b and 10c. A first detection electrode 24a and a second detection electrode 25a are formed on the surface 10a. The first detection electrode 24b is formed on the surface 10b, and the second detection electrode 25b is formed on the surface 10c. A dummy electrode 26 is formed on the surface 10d. On the surfaces 10b and 10c, an electrode 29 as a protective film for preventing a short circuit is formed so as to cover the top of the first stopper 11. The electrode 29 is not connected to the first detection electrodes 24a and 24b and the second detection electrodes 25a and 25b, and the first stopper 11 is in contact with the surface 6 of the movable body 3 as shown in FIG. In the state, the potential of the electrode 29 becomes the same potential as that of the movable body 3. Therefore, the electrode 29 can protect the top of the first stopper 11 and prevent a short circuit at the time of contact with the first stopper 11. For example, when the insulating layer 13 is provided as the protective film of the first stopper 11 as shown in FIG. 2, the movable body 3 has the first detection electrode 24 and the second detection electrode due to the electrostatic attraction caused by the charging of the insulating layer 13. There is a possibility that a situation may occur in which the person is attracted to the 25 and cannot return. In this regard, if the electrode 29 is formed so as to cover the top of the first stopper 11 as shown in FIG. 17, the occurrence of such a situation can be suppressed.

In FIG. 17, the first detection electrode 24b and the second detection electrode 25b are formed so as to cover the top of the second stopper 12. Regarding the first stopper 11, during the actual operation of the physical quantity sensor 1, the surface 6 of the movable body 3 may approach the top of the first stopper 11 and the above-mentioned problem caused by the electrostatic attraction may occur. There is. However, the situation where the surface 6 of the movable body 3 comes into contact with the top of the second stopper 12 is a situation in which a strong impact is applied to the physical quantity sensor 1, and is not a situation at the time of actual operation. Therefore, in FIG. 17, the first detection electrode 24b and the second detection electrode 25b are provided as a protective film on the top of the second stopper 12.

6. 6th Embodiment FIG. 18 shows a schematic configuration example of the physical quantity sensor 1 of the 6th embodiment. In FIG. 18, the movable body 3 has an elastic portion 38 at a position corresponding to the first stopper 11. For example, the elastic portion 38 is provided at a position corresponding to the position of the first stopper 11 in a plan view viewed from a direction orthogonal to the substrate 2. Specifically, the elastic portion 38 is provided at a position where the movable body 3 comes into contact with the first stopper 11 due to the swing of the movable body 3. As shown in A1 of FIG. 18, the elastic portion 38 is, for example, a spring body that moves in a direction intersecting the main surface of the movable body 3.

For example, when the movable body 3 and the first stopper 11 collide with each other due to the seesaw swing of the movable body 3, the rigidity of the movable body 3 and the first stopper 11 cannot absorb the impact, and the movable body 3 and the first stopper 11 cannot be absorbed. 1 There is a possibility that the stopper 11 may be damaged. In this regard, in FIG. 18, the elastic portion 38 is provided at a position corresponding to the first stopper 11. Therefore, even when the movable body 3 and the first stopper 11 collide with each other, the elastic portion 38 moves in the direction intersecting the movable body 3 as shown in A1, so that the impact of the collision is absorbed. Therefore, it becomes possible to suppress damage to the movable body 3 and the first stopper 11.

FIG. 19 shows a specific example of the elastic portion 38. In FIG. 19, the elastic portion 38 is realized by a torsion spring that moves around the rotation axis AX along the X direction. Specifically, the elastic portion 38 has a movable portion 62 having the Y direction as the long side direction and a support beam 64 having the X direction as the long side direction and supporting one end of the movable portion 62. The first stopper 11 is located at a position on the other end side of the movable portion 62 in a plan view. Then, for example, it is assumed that an acceleration acts on the physical quantity sensor 1 and the movable body 3 swings around the rotation axis AY with a seesaw, so that the elastic portion 38 of the movable body 3 comes into contact with the top of the first stopper 11. At this time, the support beam 64 of the elastic portion 38 is deformed, and the elastic portion 38 is displaced upward, which is the positive side in the Z direction, so that the impact energy at the time of contact is absorbed. Here, the elastic portion 38 displaces the support beam 64, which is a torsion spring, as the rotation axis AX. As a result, the impact between the movable body 3 and the first stopper 11 can be reduced, and damage to the movable body 3 and the first stopper 11 can be suppressed.

FIG. 20 shows another specific example of the elastic portion 38. In FIG. 20, the elastic portion 38 is realized by a spiral spring. Specifically, the elastic portion 38 has a spiral shape in which the movable portion 66 located at the position of the first stopper 11 in a plan view and the movable portion 66 are supported at one end thereof and the other end is fixed to the movable body 3. It has a support beam 68. Then, for example, it is assumed that an acceleration acts on the physical quantity sensor 1 and the movable body 3 swings around the rotation axis AY with a seesaw, so that the elastic portion 38 of the movable body 3 comes into contact with the top of the first stopper 11. At this time, the support beam 68 of the elastic portion 38, which is a spiral spring, is deformed, and the movable portion 66 is displaced upward, which is the positive side in the Z direction, so that the impact energy at the time of contact is absorbed. As a result, the impact between the movable body 3 and the first stopper 11 can be reduced, and damage to the movable body 3 and the first stopper 11 can be suppressed.

As described above, the physical quantity sensor 1 of the first to sixth embodiments has been described as the physical quantity sensor 1 of the present embodiment, but the physical quantity sensor 1 of the present embodiment is not limited to this. For example, the physical quantity sensor 1 of the present embodiment may be a physical quantity sensor 1 having a configuration in which at least two embodiments of the first to sixth embodiments are combined. Further, in the above, the case where the physical quantity sensor 1 is an acceleration sensor has been mainly described, but the present embodiment is not limited to this. For example, the physical quantity sensor 1 may be a gyro sensor which is an angular velocity sensor. In this case, the oscillator of the gyro sensor is realized by the movable body 3. Then, the movable body 3 which is an oscillator is vibrated by a given drive signal to realize a vibration gyro sensor utilizing the Coriolis force. Then, the first stopper 11 and the second stopper 12 are provided in order to prevent the movable body 3 which is the vibrator from being damaged. Alternatively, the physical quantity sensor 1 of this embodiment may be used as a MEMS switch. In this case, the first stopper 11 functions as a switch contact of the MEMS switch. Then, by providing the second stopper 12 or the like, damage to the movable body 3 of the MEMS switch or the like is prevented.

7. Inertial measurement unit Next, the inertial measurement unit 2000 of the present embodiment will be described with reference to FIGS. 21 and 22. The inertial measurement unit 2000 (IMU: Inertial Measurement Unit) shown in FIG. 21 is a device that detects the amount of inertial momentum such as the posture and behavior of a moving body such as an automobile or a robot. The inertial measurement unit 2000 includes a so-called 6-axis accelerometer that detects accelerations ax, ay, and az in directions along the three axes, and an angular velocity sensor that detects angular velocities ωx, ωy, and ωz around the three axes. It is a motion sensor.

The inertial measurement unit 2000 is a rectangular parallelepiped having a substantially square plane shape. Further, screw holes 2110 as fixing portions are formed in the vicinity of two vertices located in the diagonal direction of the square. The inertial measurement unit 2000 can be fixed to the mounted surface of a mounted body such as an automobile by passing two screws through the two screw holes 2110. By selecting parts and changing the design, it is possible to reduce the size to a size that can be mounted on a smartphone or a digital camera, for example.

The inertial measurement unit 2000 has an outer case 2100, a joining member 2200, and a sensor module 2300, and has a configuration in which the sensor module 2300 is inserted by interposing the joining member 2200 inside the outer case 2100. Further, the sensor module 2300 has an inner case 2310 and a circuit board 2320.

The outer shape of the outer case 2100 is a rectangular parallelepiped whose plane shape is substantially square, similar to the overall shape of the inertial measurement unit 2000, and screw holes 2110 are formed in the vicinity of two vertices located in the diagonal direction of the square. There is. Further, the outer case 2100 has a box shape, and the sensor module 2300 is housed inside the outer case 2100.

The inner case 2310 is a member that supports the circuit board 2320, and has a shape that fits inside the outer case 2100. Further, the inner case 2310 is formed with a recess 2311 for preventing contact with the circuit board 2320 and an opening 2312 for exposing the connector 2330 described later. Such an inner case 2310 is joined to the outer case 2100 via a joining member 2200. Further, a circuit board 2320 is bonded to the lower surface of the inner case 2310 via an adhesive.

As shown in FIG. 22, on the upper surface of the circuit board 2320, there is a connector 2330, an angular velocity sensor 2340z that detects an angular velocity around the Z axis, and an acceleration sensor unit that detects acceleration in each axis of the X axis, the Y axis, and the Z axis. 2350 and the like are implemented. Further, on the side surface of the circuit board 2320, an angular velocity sensor 2340x for detecting the angular velocity around the X axis and an angular velocity sensor 2340y for detecting the angular velocity around the Y axis are mounted.

The acceleration sensor unit 2350 includes at least the physical quantity sensor 1 for measuring the acceleration in the Z direction described above, and detects acceleration in the uniaxial direction or detects acceleration in the biaxial direction or triaxial direction as needed. Can be done. The angular velocity sensors 2340x, 2340y, and 2340z are not particularly limited, but for example, a vibration gyro sensor using the Coriolis force can be used.

A control IC 2360 is mounted on the lower surface of the circuit board 2320. The control IC 2360 as a control unit that controls based on the detection signal output from the physical quantity sensor 1 is, for example, an MCU (Micro Controller Unit), and has a built-in storage unit including a non-volatile memory, an A / D converter, and the like. It controls each part of the inertial measurement unit 2000. The storage unit stores a program that defines the order and contents for detecting acceleration and angular velocity, a program that digitizes detection data and incorporates it into packet data, and accompanying data. In addition, a plurality of other electronic components are mounted on the circuit board 2320.

As described above, the inertial measurement unit 2000 of the present embodiment includes the physical quantity sensor 1 and the control IC 2360 as a control unit that controls based on the detection signal output from the physical quantity sensor 1. According to this inertial measurement unit 2000, since the acceleration sensor unit 2350 including the physical quantity sensor 1 is used, the inertial measurement unit 2000 having excellent impact resistance and high reliability can be obtained.

As described above, the physical quantity sensor of the present embodiment regulates the rotation of the substrate, the movable body provided so as to be swingable with respect to the substrate about the rotation axis, and the rotation of the movable body around the rotation axis. It includes a first stopper and a second stopper that regulates the rotation of the movable body around the axis corresponding to the first stopper after the rotation of the movable body around the rotation axis is restricted by the first stopper. ..

According to the present embodiment, when the movable body swings with respect to the substrate about the rotation axis, the rotation of the movable body around the rotation axis is restricted by the first stopper. Then, after the rotation of the movable body around the rotation axis is regulated by the first stopper, when the rotation of the movable body around the axis corresponding to the first stopper occurs, this rotation is regulated by the second stopper. Become so. By doing so, it becomes possible to effectively suppress the occurrence of a defect caused by the regulation of the rotation of the movable body by the first stopper by using the second stopper.

Further, in the present embodiment, the first stopper and the second stopper are provided on the movable body side of the substrate, and the second stopper is farther from the rotation axis than the first stopper in the side view seen from the direction parallel to the rotation axis. It may be provided at a position. The distance from the surface of the movable body on the substrate side to the top of the second stopper may be larger than the distance from the surface of the movable body on the substrate side to the top of the first stopper.

By doing so, even when the movable body rotates around the axis corresponding to the first stopper, the rotation can be regulated by the second stopper having the top at a distance far from the surface of the movable body on the substrate side. Therefore, it becomes possible to effectively suppress the occurrence of problems caused by the regulation of the rotation of the movable body by the first stopper.

Further, in the present embodiment, the first stopper may be a first protrusion protruding from the substrate toward the movable body, and the second stopper may be a second protrusion protruding from the substrate toward the movable body.

By doing so, after the rotation of the movable body about the rotation axis is restricted by the first protrusion, which is the first stopper, the second protrusion, which is the second stopper, makes the first protrusion. It will be possible to regulate the rotation of the movable body around the corresponding axis.

Further, in the present embodiment, the substrate has a first upper surface and a second upper surface having a height lower than the first upper surface in the direction orthogonal to the substrate on the movable body side, and the first stopper is the first upper surface. It is a first protrusion protruding from the movable body side, and the second stopper may be a corner portion at the end of the first upper surface on the second upper surface side.

By doing so, after the rotation of the movable body about the rotation axis is restricted by the first protrusion, which is the first stopper, the corner at the end on the second upper surface side of the first upper surface of the substrate. The second stopper, which is a portion, makes it possible to regulate the rotation of the movable body around the axis corresponding to the first protrusion.

Further, in the present embodiment, the distance from the surface of the movable body on the substrate side to the top of the first stopper is t1, and the distance from the surface of the movable body on the substrate side to the top of the second stopper is t2. When the distance from the shaft to the first stopper is L1 and the distance from the rotation shaft to the second stopper in the side view is L2, t1 / L1 ≦ t2 / L2 may be satisfied.

If t2 ≧ (L2 / L1) × t1 is established in this way, after the movable body comes into contact with the top of the first stopper provided on the substrate, the movable body is attached to the second stopper provided on the substrate. It comes into contact with the top. Therefore, after the rotation of the movable body around the rotation axis is restricted by the first stopper, the rotation of the movable body around the axis corresponding to the first stopper can be regulated by the second stopper.

Further, in the present embodiment, the first stopper and the second stopper are provided on the substrate side of the movable body, and the second stopper is from the rotation axis rather than the first stopper in the side view seen from the direction parallel to the rotation axis. The distance from the movable body side surface of the substrate to the top of the second stopper may be larger than the distance from the movable body side surface of the substrate to the top of the first stopper.

By doing so, even when the movable body rotates around the axis corresponding to the first stopper, the rotation can be regulated by the second stopper having the top at a distance far from the surface of the substrate on the movable body side. Therefore, it becomes possible to effectively suppress the occurrence of defects due to the restriction on the rotation of the movable body by the first stopper.

Further, in the present embodiment, the distance from the movable body side surface of the substrate to the top of the first stopper is t1, and the distance from the movable body side surface of the substrate to the top of the second stopper is t2, from the rotation axis in the side view. When the distance to the first stopper is L1 and the distance from the rotation axis in the side view to the second stopper is L2, t1 / L1 ≦ t2 / L2 may be satisfied.

If t2 ≧ (L2 / L1) × t1 is established in this way, after the substrate comes into contact with the top of the first stopper provided on the movable body, the substrate is attached to the second stopper provided on the movable body. It comes into contact with the top. Therefore, after the rotation of the movable body around the rotation axis is restricted by the first stopper, the rotation of the movable body around the axis corresponding to the first stopper can be regulated by the second stopper.

Further, in the present embodiment, a lid portion provided facing the substrate and covering the movable body may be included. The first stopper and the second stopper are provided on the movable body side of the lid portion, and the second stopper is provided at a position farther from the rotation axis than the first stopper in the side view seen from the direction parallel to the rotation axis. The distance from the surface of the movable body on the lid side to the top of the second stopper may be larger than the distance from the surface of the movable body on the lid side to the top of the first stopper.

By doing so, even when the movable body rotates around the axis corresponding to the first stopper, the rotation can be regulated by the second stopper having the top at a distance far from the surface of the movable body on the lid side. Therefore, it becomes possible to effectively suppress the occurrence of defects due to the restriction on the rotation of the movable body by the first stopper.

Further, in the present embodiment, the distance from the surface of the movable body on the lid side to the top of the first stopper is t1, and the distance from the surface of the movable body on the lid side to the top of the second stopper is t2. When the distance from the rotation axis to the first stopper is L1 and the distance from the rotation axis to the second stopper in the side view is L2, t1 / L1 ≦ t2 / L2 may be satisfied.

If t2 ≧ (L2 / L1) × t1 is established in this way, the movable body is provided on the lid portion after the movable body comes into contact with the top of the first stopper provided on the lid portion. It comes into contact with the top of the stopper. Therefore, after the rotation of the movable body around the rotation axis is restricted by the first stopper, the rotation of the movable body around the axis corresponding to the first stopper can be regulated by the second stopper.

Further, in the present embodiment, the movable body has a spring body provided along the direction of the rotation axis and one end thereof is fixed to the substrate, and the length of the spring body in the direction along the rotation axis is LS. When the displacement of the rotating shaft due to the rotation of the movable body about the axis corresponding to the first stopper is X1, X1 <LS × 0.1 may be used.

In this way, by suppressing the displacement X1 of the rotating shaft to less than 10% of the length LS of the spring body, the spring body is damaged due to the rotation around the shaft corresponding to the first stopper. The situation can be effectively suppressed.

Further, in the present embodiment, the movable body may have an elastic portion at a position corresponding to the first stopper.

By doing so, the elastic portion provided at the position corresponding to the first stopper can absorb the impact of the collision and suppress the damage to the movable body and the first stopper.

Further, in the present embodiment, the first stopper and the second stopper may be provided between the rotation axis and the end portion of the movable body in a plan view viewed from a direction orthogonal to the substrate.

By providing the second stopper at such a position, even when the movable body rotates around the axis corresponding to the first stopper, the rotation can be appropriately regulated.

Further, the present embodiment relates to an inertial measurement unit including the above-mentioned physical quantity sensor and a control unit that controls based on a detection signal output from the physical quantity sensor.

Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications that do not substantially deviate from the novel matters and effects of the present disclosure are possible. Therefore, all such variations are included in the scope of the present disclosure. For example, a term described at least once in a specification or drawing with a different term in a broader or synonymous manner may be replaced by that different term anywhere in the specification or drawing. All combinations of the present embodiment and modifications are also included in the scope of the present disclosure. Further, the configuration and operation of the physical quantity sensor and the inertial measurement unit are not limited to those described in this embodiment, and various modifications can be carried out.

1 ... Physical quantity sensor, 2 ... Board, 3 ... Movable body, 5 ... Cover, 6, 7, 8 ... Surface,
8a ... 1st upper surface, 8b, 8c ... 2nd upper surface, 9, 10a, 10b, 10c, 10d ... surface,
11 ... 1st stopper, 12 ... 2nd stopper, 13, 14 ... Insulating layer,
21, 21a ... Recessed portion, 22 ... Fixed portion, 24, 24a, 24b ... First detection electrode,
25, 25a, 25b ... second detection electrode, 26 ... dummy electrode, 28 ... sacrificial layer,
29 ... Electrode, 32 ... Holding part, 33 ... Support beam, 38 ... Elastic part, 41 ... First connecting part,
42 ... 2nd connecting portion, 45 ... 1st opening, 46 ... 2nd opening, 51 ... concave,
62 ... Movable part, 64 ... Support beam, 66 ... Movable part, 68 ... Support beam 2000 ... Inertial measurement unit, 2100 ... Outer case, 2110 ... Screw hole,
2200 ... Joining member, 2300 ... Sensor module, 2310 ... Inner case,
2311 ... concave, 2312 ... opening, 2320 ... circuit board, 2330 ... connector,
2340x, 2340y, 2340z ... Angular velocity sensor, 2360 ... Control IC,
2350 ... Accelerometer unit,
AX, AY ... rotation axis, Ca, Cb ... capacitance, FC, FC2 ... fulcrum,
L1, L2 ... distance, P1, P2 ... top, S ... storage space, X1 ... displacement, t1, t2 ... distance

Claims (13)

With the board
A movable body that is swingably provided with respect to the substrate about the axis of rotation, and
A first stopper that regulates the rotation of the movable body about the axis of rotation,
After the rotation of the movable body around the rotation axis is restricted by the first stopper, a second stopper that regulates the rotation of the movable body around the axis corresponding to the first stopper, and
A physical quantity sensor characterized by containing. In the physical quantity sensor according to claim 1,
The first stopper and the second stopper are provided on the movable body side of the substrate.
The second stopper is provided at a position farther from the rotation axis than the first stopper in a side view seen from a direction parallel to the rotation axis.
A physical quantity sensor characterized in that the distance from the surface of the movable body on the substrate side to the top of the second stopper is larger than the distance from the surface of the movable body on the substrate side to the top of the first stopper. .. In the physical quantity sensor according to claim 2,
The first stopper is a first protrusion protruding from the substrate toward the movable body.
The second stopper is a physical quantity sensor characterized by being a second protrusion protruding from the substrate toward the movable body. In the physical quantity sensor according to claim 2,
The substrate has a first upper surface and a second upper surface having a height in a direction orthogonal to the substrate lower than the first upper surface on the movable body side.
The first stopper is a first protrusion protruding from the first upper surface toward the movable body.
The second stopper is a physical quantity sensor characterized by being a corner portion at an end portion of the first upper surface on the second upper surface side. In the physical quantity sensor according to any one of claims 2 to 4.
The distance from the surface of the movable body on the substrate side to the top of the first stopper is t1, and the distance from the surface of the movable body on the substrate side to the top of the second stopper is t2. When the distance from the rotating shaft to the first stopper is L1 and the distance from the rotating shaft to the second stopper in the side view is L2, t1 / L1 ≦ t2 / L2. Physical quantity sensor. In the physical quantity sensor according to claim 1,
The first stopper and the second stopper are provided on the substrate side of the movable body.
The second stopper is provided at a position farther from the rotation axis than the first stopper in a side view seen from a direction parallel to the rotation axis.
A physical quantity sensor characterized in that the distance from the surface of the substrate on the movable body side to the top of the second stopper is larger than the distance from the surface of the substrate on the movable body side to the top of the first stopper. In the physical quantity sensor according to claim 6,
The distance from the movable body side surface of the substrate to the top of the first stopper is t1, the distance from the movable body side surface of the substrate to the top of the second stopper is t2, and the rotation in the side view. When the distance from the shaft to the first stopper is L1 and the distance from the rotation shaft to the second stopper in the side view is L2, the physical quantity sensor is t1 / L1 ≦ t2 / L2. .. In the physical quantity sensor according to claim 1,
A lid portion provided facing the substrate and covering the movable body is included.
The first stopper and the second stopper are provided on the movable body side of the lid portion.
The second stopper is provided at a position farther from the rotation axis than the first stopper in a side view seen from a direction parallel to the rotation axis.
The distance from the surface of the movable body on the lid side to the top of the second stopper is larger than the distance from the surface of the movable body on the lid side to the top of the first stopper. Physical quantity sensor. In the physical quantity sensor according to claim 8,
The distance from the surface of the movable body on the lid side to the top of the first stopper is t1, and the distance from the surface of the movable body on the lid side to the top of the second stopper is t2. When the distance from the rotation axis to the first stopper in the visual view is L1, and the distance from the rotation axis to the second stopper in the side view is L2.
A physical quantity sensor characterized in that t1 / L1 ≦ t2 / L2. In the physical quantity sensor according to any one of claims 1 to 9.
The movable body has a spring body provided along the direction of the rotation axis and one end thereof is fixed to the substrate.
When the length of the spring body in the direction along the rotation axis is LS, and the displacement of the rotation axis due to the rotation of the movable body around the axis corresponding to the first stopper is X1. , X1 <LS × 0.1 Physical quantity sensor. In the physical quantity sensor according to any one of claims 1 to 10.
The movable body is a physical quantity sensor characterized by having an elastic portion at a position corresponding to the first stopper. In the physical quantity sensor according to any one of claims 1 to 11.
The first stopper and the second stopper are physical quantity sensors provided between the rotation axis and the end portion of the movable body in a plan view viewed from a direction orthogonal to the substrate. The physical quantity sensor according to any one of claims 1 to 12.
A control unit that controls based on the detection signal output from the physical quantity sensor, and
An inertial measurement unit characterized by including.

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