Physical quantity sensor, physical quantity sensor device, complex sensor device, inertial measurement unit, and vehicle

A physical quantity sensor includes a substrate, a support portion fixed to the substrate, a movable body which is displaceable in a first direction with respect to the support portion and has a movable electrode provided therein, and a fixed electrode fixed to the substrate. The fixed electrode includes first and second fixed electrode fingers positioned on one side of the support portion, third and fourth fixed electrode fingers positioned on the other side thereof. The movable electrode includes first to fourth movable electrode fingers which face the first to fourth fixed electrode fingers in the first direction, respectively.

CROSS-REFERENCE TO RELATED APPLICATION

This nonprovisional application claims the benefit of Japanese Patent Application No. 2017-228264 filed Nov. 28, 2017, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

1. Technical Field

The present invention relates to a physical quantity sensor, a physical quantity sensor device, a complex sensor device, an inertial measurement unit, a vehicle positioning device, a portable electronic device, an electronic device, and a vehicle.

2. Related Art

For example, an acceleration sensor disclosed in JP-A-2007-139505 includes a fixation portion fixed to a substrate (first silicon substrate), a movable unit which is supported by the fixation portion and is displaceable in an X-axis direction with respect to the fixation portion, a first movable electrode, a second movable electrode, a first fixed electrode, and a second fixed electrode. The first movable electrode and the second movable electrode are connected to the movable unit. The first fixed electrode and the second fixed electrode are fixed to the second silicon substrate.

The first movable electrode includes a first movable electrode finger extending toward a positive side in a Y-axis direction from a portion of the movable unit on a negative side of the Y-axis direction. The second movable electrode includes a second movable electrode finger extending toward the negative side in the Y-axis direction from a portion of the movable unit on the positive side of the Y-axis direction.

The first fixed electrode includes a fixation portion fixed to the substrate, a support portion extending from the fixation portion toward the positive side of the X-axis direction, and a first fixed electrode finger extending from the support portion toward the negative side of the Y-axis direction. The first movable electrode finger and the first fixed electrode finger face each other in the X-axis direction, and electrostatic capacitance is formed between the first movable electrode finger and the first fixed electrode finger.

Similarly, the second fixed electrode includes a fixation portion fixed to the substrate, a support portion extending from the fixation portion toward the positive side of the X-axis direction, and a second fixed electrode finger extending from the support portion toward the negative side of the Y-axis direction. The second movable electrode finger and the second fixed electrode finger face each other in the X-axis direction, and electrostatic capacitance is formed between the second movable electrode finger and the second fixed electrode finger.

In such an acceleration sensor, if the movable unit is displaced by an applied acceleration, the electrostatic capacitance between the first movable electrode finger and the first fixed electrode finger and the electrostatic capacitance between the second movable electrode finger and the second fixed electrode finger change, and thus the received acceleration can be detected based on the change of the electrostatic capacitance.

However, for example, when a large impact is received by falling or the like, the movable unit is largely displaced in the X-axis direction. Thus, the electrode finger may be damaged by the first and second movable electrode fingers colliding with the first and second fixed electrode fingers.

SUMMARY

An advantage of some aspects of the invention is to provide a physical quantity sensor, a physical quantity sensor device, a complex sensor device, an inertial measurement unit, a vehicle positioning device, a portable electronic device, an electronic device, and a vehicle which have excellent impact resistance (mechanical strength).

The invention can be implemented as the following configurations.

A physical quantity sensor includes a substrate, a support portion fixed to the substrate, a movable body which is displaceable in a first direction with respect to the support portion and has a movable electrode provided therein, and a fixed electrode fixed to the substrate. The fixed electrode includes a first fixed electrode, a second fixed electrode, a third fixed electrode, and a fourth fixed electrode. The first fixed electrode is positioned on one side of a second direction orthogonal to the first direction with respect to the support portion and has a first fixed electrode finger provided therein. The second fixed electrode is provided to be separated from the first fixed electrode and has a second fixed electrode finger provided therein. The third fixed electrode is positioned on the other side of the second direction with respect to the support portion and has a third fixed electrode finger provided therein. The fourth fixed electrode is provided to be separated from the third fixed electrode and has a fourth fixed electrode finger provided therein. The movable electrode includes a first movable electrode, a second movable electrode, a third movable electrode, and a fourth movable electrode. The first movable electrode has a first movable electrode finger provided to face the first fixed electrode finger in the first direction. The second movable electrode has a second movable electrode finger provided to face the second fixed electrode finger in the first direction. The third movable electrode has a third movable electrode finger provided to face the third fixed electrode finger in the first direction. The fourth movable electrode has a fourth movable electrode finger provided to face the fourth fixed electrode finger in the first direction.

With this configuration, it is possible to reduce the length of each electrode finger in comparison to that in the related art. Accordingly, the deflection amount of the electrode finger being bent is reduced, and an occurrence in which the electrode finger is damaged by collision between the electrode fingers occurs less frequently. Thus, it is possible to realize a physical quantity sensor having excellent impact resistance (mechanical strength).

It is preferable that the physical quantity sensor further includes a spring that connects the support portion and the movable body.

With this configuration, it is possible to enable the movable body to be displaced in the first direction with respect to the support portion, with a simple configuration.

In the physical quantity sensor, it is preferable that the first movable electrode finger faces the first fixed electrode finger on one side of the first direction, the second movable electrode finger faces the second fixed electrode finger on the other side of the first direction, the third movable electrode finger faces the third fixed electrode finger on the one side of the first direction, and the fourth movable electrode finger faces the fourth fixed electrode finger on the other side of the first direction.

With this configuration, when an acceleration in the first direction is applied, electrostatic capacitance formed between the first movable electrode finger and the first fixed electrode finger and between the third movable electrode finger and the third fixed electrode finger and electrostatic capacitance formed between the second movable electrode finger and the second fixed electrode finger and between the fourth movable electrode finger and the fourth fixed electrode finger change in phases which are opposite to each other. Thus, it is possible to cancel noise and to detect a physical quantity with higher accuracy. Even though the length of the electrode finger is short, detection sensitivity of the physical quantity is not deteriorated.

In the physical quantity sensor, it is preferable that the first fixed electrode and the third fixed electrode are disposed symmetrically with respect to the support portion, and the second fixed electrode and the fourth fixed electrode are disposed symmetrically with respect to the support portion.

With this configuration, for example, it is possible to improve insensitivity to unnecessary vibration (displacement in directions other than the first direction) of the movable body, and to detect the physical quantity with higher accuracy.

In the physical quantity sensor, it is preferable that the first movable electrode and the third movable electrode are disposed symmetrically with respect to the support portion, and the second movable electrode and the fourth movable electrode are disposed symmetrically with respect to the support portion.

With this configuration, for example, it is possible to improve insensitivity to unnecessary vibration (displacement in directions other than the first direction) of the movable body, and to detect the physical quantity with higher accuracy.

In the physical quantity sensor, it is preferable that the first fixed electrode finger and the third fixed electrode finger are electrically connected to each other, and the second fixed electrode finger and the fourth fixed electrode finger are electrically connected to each other.

When the acceleration in the first direction is applied, the electrostatic capacitance formed between the first movable electrode finger and the first fixed electrode finger and between the third movable electrode finger and the third fixed electrode finger, and the electrostatic capacitance formed between the second movable electrode finger and the second fixed electrode finger and between the fourth movable electrode finger and the fourth fixed electrode finger change in phases which are opposite to each other. Thus, it is possible to cancel noise and to detect the acceleration in the first direction with higher accuracy. Even though the length of the electrode finger is short, detection sensitivity of the physical quantity is not deteriorated.

In the physical quantity sensor, it is preferable that the first fixed electrode includes a first fixation portion fixed to the substrate and a first trunk portion provided in the first fixation portion, the first fixed electrode finger is provided in the first trunk portion such that a longitudinal direction thereof is directed along the second direction, and the second fixed electrode includes a second fixation portion fixed to the substrate and a second trunk portion provided in the second fixation portion, the second fixed electrode finger is provided in the second trunk portion such that a longitudinal direction thereof is directed along the second direction, the second trunk portion is positioned closer to the support portion side than the first trunk portion but, the first fixed electrode finger is provided in the first trunk portion on an opposite side of the support portion, and the second fixed electrode finger is provided in the second trunk portion on the support portion side.

With this configuration, it is easy to arrange the first fixation portion and the second fixation portion to be close to each other. Therefore, it is possible to more effectively have an influence of heat deflection or warpage due to residual stress of a substrate on the first and second fixed electrodes equally.

In the physical quantity sensor, it is preferable that the first fixation portion and the second fixation portion are disposed to be adjacent to each other in the second direction.

With this configuration, it is easy to arrange the first and second fixation portions.

In the physical quantity sensor, it is preferable that the third fixed electrode includes a third fixation portion fixed to the substrate and a third trunk portion provided in the third fixation portion, the third fixed electrode finger is provided in the third trunk portion such that a longitudinal direction thereof is directed along the second direction, the fourth fixed electrode includes a fourth fixation portion fixed to the substrate and a fourth trunk portion provided in the fourth fixation portion, and the fourth fixed electrode finger is provided in the fourth trunk portion such that a longitudinal direction thereof is directed along the second direction, the fourth trunk portion is positioned closer to the support portion side than the third trunk portion side, the third fixed electrode finger is provided in the third trunk portion on an opposite side of the support portion, and the fourth fixed electrode finger is provided in the fourth trunk portion on the support portion side.

With this configuration, it is easy to arrange the third fixation portion and the fourth fixation portion to be close to each other. Therefore, it is possible to more effectively have an influence of heat deflection or warpage due to residual stress of a substrate on the third and fourth fixed electrodes equally.

In the physical quantity sensor, it is preferable that the third fixation portion and the fourth fixation portion are disposed to be adjacent to each other in the second direction.

With this configuration, it is easy to arrange the third and fourth fixation portions.

In the physical quantity sensor, it is preferable that the physical quantity sensor is a sensor capable of detecting an acceleration.

With this configuration, a physical quantity sensor having high convenience is obtained.

A physical quantity sensor device includes a physical quantity sensor and a circuit element.

With this configuration, a physical quantity sensor device which is capable of exhibiting the effect of the physical quantity sensor and has high reliability is obtained.

It is preferable that the physical quantity sensor device further includes a base substrate and a lid bonded to the base substrate so as to form a storage space between the lid and the base substrate, and the physical quantity sensor and the circuit element are stored in the storage space.

With this configuration, it is possible to protect the physical quantity sensor and the circuit element.

In the physical quantity sensor device, it is preferable that the physical quantity sensor is mounted on the base substrate, and the circuit element is mounted on the physical quantity sensor.

For example, in a case where the planar size of the circuit element is smaller than the planar size of the physical quantity sensor, if such an arrangement is performed, it is possible to arrange the physical quantity sensor and the circuit element with high balance.

In the physical quantity sensor device, it is preferable that the circuit element is mounted on the base substrate, and the physical quantity sensor is mounted on the circuit element.

For example, in a case where the planar size of the physical quantity sensor is smaller than the planar size of the circuit element, if such an arrangement is performed, it is possible to arrange the physical quantity sensor and the circuit element with high balance.

A complex sensor device includes a first physical quantity sensor being the physical quantity sensor, and a second physical quantity sensor that detects a physical quantity different from that detected by the first physical quantity sensor.

With this configuration, a complex sensor device which is capable of exhibiting the effect of the physical quantity sensor and has high reliability is obtained.

In the complex sensor device, it is preferable that the first physical quantity sensor is a sensor capable of detecting an acceleration, and the second physical quantity sensor is a sensor capable of detecting an angular rate.

With this configuration, a complex sensor device having high convenience is obtained.

An inertial measurement unit includes a physical quantity sensor and a control circuit that controls driving of the physical quantity sensor.

With this configuration, an inertial measurement unit which is capable of exhibiting the effect of the physical quantity sensor and has high reliability is obtained.

A vehicle positioning device includes an inertial measurement unit, a receiving unit (receiver), an acquisition unit, a computation unit, and a calculation unit. The receiving unit (receiver) receives a satellite signal on which position information is superimposed, from a positioning satellite. The acquisition unit acquires the position information in the receiving unit (receiver) based on the received satellite signal. The computation unit computes an attitude of a vehicle based on inertial data output from the inertial measurement unit. The calculation unit calculates the position of the vehicle by correcting the position information based on the computed attitude.

With this configuration, a vehicle positioning device which is capable of exhibiting the effect of the inertial measurement unit and has high reliability is obtained.

A portable electronic device includes a physical quantity sensor, a case in which the physical quantity sensor is accommodated, a processing unit (processor) which is accommodated in the case and processes output data from the physical quantity sensor, a display unit which is accommodated in the case, and a translucent cover that closes an opening portion of the case.

With this configuration, a portable electronic device which is capable of exhibiting the effect of the physical quantity sensor and has high reliability is obtained.

It is preferable that the portable electronic device further includes a satellite positioning system, and measures a distance of a user moving or a movement trajectory.

With this configuration, a portable electronic device having higher convenience is obtained.

An electronic device includes a physical quantity sensor and a control unit (controller) that performs a control based on a detection signal output from the physical quantity sensor.

With this configuration, an electronic device which is capable of exhibiting the effect of the physical quantity sensor and has high reliability is obtained.

A vehicle includes a physical quantity sensor and a control unit (controller) that performs a control based on a detection signal output from the physical quantity sensor.

With this configuration, a vehicle which is capable of exhibiting the effect of the physical quantity sensor and has high reliability is obtained.

It is preferable that the vehicle further includes at least one of an engine system, a brake system, and a keyless entry system, and the control unit (controller) controls the system based on the detection signal.

With this configuration, it is possible to control the system with high precision.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, a physical quantity sensor, a physical quantity sensor device, a complex sensor device, an inertial measurement unit, a vehicle positioning device, a portable electronic device, an electronic device, and a vehicle will be described in detail based on embodiments illustrated in the accompanying drawings.

First Embodiment

Firstly, a physical quantity sensor according to a first embodiment will be described.

FIG. 1is a plan view illustrating the physical quantity sensor according to the first embodiment.FIG. 2is a sectional view taken along line A-A inFIG. 1.FIG. 3is a plan view illustrating a configuration of an element unit in the related art.FIG. 4is a sectional view illustrating an influence of heat deflection on a substrate. For simple descriptions, an X axis, a Y axis, and a Z axis as three axes orthogonal to each other are illustrated in the drawings. A direction parallel to the X axis is referred to as “an X-axis direction. A direction parallel to the Y axis is referred to as “a Y-axis direction. A direction parallel to the Z axis is referred to as “a Z-axis direction”. A tip side of an arrow indicating each axis is referred to as “a positive side”, and an opposite side thereof is referred to as “a negative side”. A positive side of the Z-axis direction is referred to as “being up”, and a negative side of the Z-axis direction is referred to as “being down”.

A physical quantity sensor1illustrated inFIG. 1is an acceleration sensor capable of detecting an acceleration Ax in the X-axis direction. Such a physical quantity sensor1includes a substrate2, an element unit3disposed on the substrate2, and a lid8bonded to the substrate2so as to cover the element unit3.

As illustrated inFIG. 1, the substrate2has a plate shape having a rectangular shape in plan view. The substrate2includes a recess portion21opening to the upper surface side. In plan view in the Z-axis direction, the recess portion21is formed to be larger than the element unit3such that the recess portion21encloses the element unit3. The recess portion21functions as a clearance portion that prevents a contact of the element unit3and the substrate2.

As illustrated inFIG. 2, the substrate2includes a mount22which is provided on the bottom surface of the recess portion21and has a protrusion-like shape. The element unit3is bonded to the upper surface of the mount22. Thus, it is possible to support the element unit3in a state where the element unit3floats from the bottom surface of the recess portion21. As illustrated inFIG. 1, the substrate2includes groove portions25,26, and27opening to the upper surface side.

As the substrate2, a glass substrate made of a glass material (for example, borosilicate glass such as Tempax glass (registered trademark) or Pyrex glass (registered trademark)) containing alkali metal ions (Na+) can be used. The material for forming the substrate2is not particularly limited, and a silicon substrate, a ceramic substrate, and the like can be used.

As illustrated inFIG. 1, wirings75,76, and77are disposed in the groove portions25,26, and27, respectively. Each of the wirings75,76, and77is lead onto the mount22and is electrically connected to the element unit3on the mount22. One end portion of each of the wirings75,76, and77is exposed to the outside of the lid8, and thus functions as an electrode pad P that is electrically connected to an external device.

As illustrated inFIG. 1, the lid8has a plate shape having a rectangular shape in plan view. As illustrated inFIG. 2, the lid8includes a recess portion81opening to the lower surface. The lid8is bonded to the upper surface of the substrate2so as to store the element unit3in the recess portion81. Thus, a storage space S in which the element unit3is stored is formed by the lid8and the substrate2. The storage space S is an airtight space. It is preferable that the storage space is filled with an inert gas such as nitrogen, helium, and argon and is at a use temperature (about −40° C. to 120° C.) at the substantially atmospheric pressure. Thus, viscous resistance increases, and thus a damping effect is exhibited. Accordingly, it is possible to rapidly converge (stop) the vibration of the element unit3. Therefore, it is possible to improve detection accuracy of the acceleration Ax in the physical quantity sensor1.

As the lid8, for example, a silicon substrate can be used. The lid8is not particularly limited. For example, a glass substrate or a ceramic substrate may be used. A method of bonding the substrate2and the lid8to each other is not particularly limited, and may be appropriately selected in accordance with the materials of the substrate2and the lid8. For example, anodic bonding, activated bonding in which bonding surfaces activated by irradiation with plasma are bonded to each other, bonding with a bonding material such as glass frit, and diffusion bonding in which metal films formed on the upper surface of the substrate2and the lower surface of the lid8are bonded to each other are exemplified. In the embodiment, the substrate2and the lid8are bonded to each other with glass frit (low-melting glass)89.

The element unit3is disposed in the storage space S and is bonded to the upper surface of the mount22. The element unit3can be formed in a manner that a conductive silicon substrate in which impurities such as phosphorus (P), boron (B), and arsenic (As) have been doped is patterned by using a dry etching method (silicon deep etching: Bosch method). The element unit3is bonded to the upper surface of the mount22by anodic bonding. A method of bonding the element unit3and the substrate2to each other is not particularly limited. The element unit3will be described below in detail. In the following descriptions, for easy descriptions, in plan view in the Z-axis direction, a straight line which intersects the center O of the element unit3and extends in the X-axis direction is also referred to as “a central axis αx”.

As illustrated inFIG. 1, the element unit3includes a fixed electrode4fixed to the mount22, a support portion51fixed to the mount22, a movable body52which is displaceable in the X-axis direction with respect to the support portion51, springs53and54that connect the support portion51and the movable body52, and a movable electrode6provided in the movable body52. The fixed electrode4includes a first fixed electrode41, a second fixed electrode42, a third fixed electrode43, and a fourth fixed electrode44. The movable electrode6includes a first movable electrode61, a second movable electrode62, a third movable electrode63, and a fourth movable electrode64.

The support portion51has a long shape extending in the X-axis direction. The support portion51is disposed along the central axis αx. As described above, since the support portion51is disposed at the center portion of the element unit3, it is possible to stably support the movable body52. The support portion51is bonded to the upper surface of the mount22at an end portion of the support portion on the negative side of the X-axis direction. The support portion51is electrically connected to the wiring at a portion of the support portion, which has been bonded to the mount22. In this embodiment, the support portion51has a long shape extending in the X-axis direction. However, the shape of the support portion51is not particularly limited so long as the support portion exhibits the function.

As illustrated inFIG. 1, the movable body52has a frame shape in plan view in the Z-axis direction, and surrounds the support portion51, the springs53and54, and the fixed electrode4. As described above, since the movable body52is configured to have a frame shape, it is possible to increase the mass of the movable body52. Therefore, it is possible to improve sensitivity more and to detect the acceleration Ax with higher accuracy. The movable body52includes a first opening portion528and a second opening portion529. The first opening portion528is positioned on one side of the support portion51(on the positive side of the Y-axis direction) and has first and second fixed electrodes41and42disposed therein. The second opening portion529is positioned on the other side of the support portion51(on the negative side of the Y-axis direction) and has third and fourth fixed electrodes43and44disposed therein.

The springs53and54are capable of elastically deforming. The movable body52can be displaced in the X-axis direction with respect to the support portion51, by the springs53and54elastically deforming. As illustrated inFIG. 1, the spring53joins the end portion of the support portion51on the positive side of the X-axis direction to the movable body52. The spring54joins the end portion of the support portion51on the negative side of the X-axis direction to the movable body52. Thus, the movable body52can be supported on both sides of the X-axis direction, and thus the attitude and the movement of the movable body52are stabilized. Therefore, unnecessary vibration is reduced, and it is possible to detect the acceleration Ax with higher accuracy.

The fixed electrode4includes the first and second fixed electrodes41and42positioned in the first opening portion528, and the third and fourth fixed electrodes43and44positioned in the second opening portion529. The first and second fixed electrodes41and42are positioned on the one side of the support portion51(on the positive side of the Y-axis direction). The third and fourth fixed electrodes43and44are positioned on the other side of the support portion51(on the negative side of the Y-axis direction).

The first fixed electrode41includes a fixation portion411fixed to the upper surface of the mount22, a trunk portion412supported on the fixation portion411, and a plurality of fixed electrode fingers413extending from the trunk portion412. The first fixed electrode41is electrically connected to the wiring76at the fixation portion411.

The trunk portion412has a long rod-like shape. One end of the trunk portion412(end thereof on the negative side in the X-axis direction) is connected to the fixation portion411. The trunk portion412extends in a direction inclined from each of the X axis and the Y axis in plan view in the Z-axis direction. Specifically, the trunk portion412is inclined such that a distance from the central axis αx increases toward the tip side of the trunk portion412. The inclination of the trunk portion412from the X axis is not particularly limited. The inclination thereof is preferably from 10° to 45°, and more preferably from 10° to 30°. Thus, it is possible to reduce the expansion of the first fixed electrode41in the Y-axis direction and to reduce the size of the element unit3.

The fixed electrode finger413extends from the trunk portion412toward the positive side (one side) of the Y-axis direction. The plurality of fixed electrode fingers413is provided to be separated from each other at an equal interval in the X-axis direction. The lengths of the plurality of fixed electrode fingers413(length in the Y-axis direction) gradually decrease toward the positive side of the X-axis direction. Tips of the plurality of fixed electrode fingers413are positioned on the same straight line along the X-axis direction.

The second fixed electrode42includes a fixation portion421fixed to the upper surface of the mount22, a trunk portion422supported on the fixation portion421, and a plurality of fixed electrode fingers423extending from the trunk portion422. The second fixed electrode42is electrically connected to the wiring77at the fixation portion421.

The fixation portion421is positioned on a side of the fixation portion411on the negative side of the Y-axis direction, and is disposed side by side with the fixation portion411in the Y-axis direction. In other words, the fixation portion421is positioned between the support portion51and the fixation portion411.

The trunk portion422has a long rod-like shape. One end of the trunk portion422(end thereof on the negative side in the X-axis direction) is connected to the fixation portion421. The trunk portion422extends in a direction inclined from each of the X axis and the Y axis in plan view in the Z-axis direction. The trunk portion422is positioned on a side of the trunk portion412on the negative side of the Y-axis direction and is disposed to be parallel to the trunk portion412.

The fixed electrode finger423extends from the trunk portion422toward the negative side (one side) of the Y-axis direction. The plurality of fixed electrode fingers423is provided to be separated from each other at an equal interval in the X-axis direction. The lengths of the plurality of fixed electrode fingers423(length in the Y-axis direction) gradually increase toward the positive side of the X-axis direction. Tips of the plurality of fixed electrode fingers423are positioned on the same straight line along the X-axis direction.

The third fixed electrode43includes a fixation portion431fixed to the upper surface of the mount22, a trunk portion432supported on the fixation portion431, and a plurality of fixed electrode fingers433extending from the trunk portion432. Such a third fixed electrode is disposed to be symmetrical with the first fixed electrode41with respect to the central axis αx. The third fixed electrode43is electrically connected to the wiring76at the fixation portion431, similar to the first fixed electrode41.

The trunk portion432has a long rod-like shape. One end of the trunk portion432(end thereof on the negative side in the X-axis direction) is connected to the fixation portion431. The trunk portion432extends in a direction inclined from each of the X axis and the Y axis in plan view in the Z-axis direction. Specifically, the trunk portion432is inclined such that a distance from the central axis αx increases toward the tip side of the trunk portion432.

The fixed electrode finger433extends from the trunk portion432toward the negative side (one side) of the Y-axis direction. The plurality of fixed electrode fingers433is provided to be separated from each other at an equal interval in the X-axis direction. The lengths of the plurality of fixed electrode fingers433(length in the Y-axis direction) gradually decrease toward the positive side of the X-axis direction. Tips of the plurality of fixed electrode fingers433are positioned on the same straight line along the X-axis direction.

The fourth fixed electrode44includes a fixation portion441fixed to the upper surface of the mount22, a trunk portion442supported on the fixation portion441, and a plurality of fixed electrode fingers443extending from the trunk portion442. Such a fourth fixed electrode is disposed to be symmetrical with the second fixed electrode42with respect to the central axis αx. The fourth fixed electrode44is electrically connected to the wiring77at the fixation portion441, similar to the second fixed electrode42.

The fixation portion441is positioned on a side of the fixation portion431on the positive side of the Y-axis direction, and is disposed side by side with the fixation portion431in the Y-axis direction. In other words, the fixation portion441is positioned between the support portion51and the fixation portion431.

The trunk portion442has a long rod-like shape. One end of the trunk portion442(end thereof on the negative side in the X-axis direction) is connected to the fixation portion441. The trunk portion442extends in a direction inclined from each of the X axis and the Y axis in plan view in the Z-axis direction. The trunk portion442is positioned on a side of the trunk portion432on the positive side of the Y-axis direction and is disposed to be parallel to the trunk portion432.

The fixed electrode finger443extends from the trunk portion442toward the positive side (one side) of the Y-axis direction. The plurality of fixed electrode fingers443is provided to be separated from each other at an equal interval in the X-axis direction. The lengths of the plurality of fixed electrode fingers443(length in the Y-axis direction) gradually increase toward the positive side of the X-axis direction. Tips of the plurality of fixed electrode fingers443are positioned on the same straight line along the X-axis direction.

The first fixed electrode41(trunk portion412) and the second fixed electrode42(trunk portion422) are disposed to be separated from each other with a gap. The third fixed electrode43(trunk portion432) and the fourth fixed electrode44(trunk portion442) are disposed to be separated from each other with a gap (face each other).

The configurations of the first to fourth fixed electrodes41to44are described above. As described above, the first and second fixed electrodes41and42are disposed on the one side of the central axis αx, and the third and fourth fixed electrodes43and44are disposed on the other side of the central axis αx. Thus, it is possible to reduce the lengths of the fixed electrode fingers413,423,433, and443to about the half without deteriorating detection characteristics of the acceleration Ax, in comparison to, for example, a configuration as illustrated inFIG. 3, in which only the first fixed electrode41is disposed on one side of the central axis αx, and only the fourth fixed electrode44is disposed on the other side of the central axis αx. As described above, according to the physical quantity sensor1, it is possible to reduce the lengths of the fixed electrode fingers413,423,433, and443in comparison to those in the related art. In addition, since the mechanical strength of the fixed electrode fingers413,423,433, and443increases, the fixed electrode finger is damaged less frequently. Each of the fixed electrode fingers413,423,433, and443is an elongated portion, and thus is a portion which is particularly easily damaged in the element unit3. As described above, since each of the fixed electrode fingers413,423,433, and443being portions which are easily damaged is configured to be damaged less frequently, mechanical strength of the entirety of the element unit3is significantly improved.

As described above, each of the trunk portions412,422,432, and442is inclined from the central axis αx. Thus, the fixation portions411,421,431, and441can be arranged to be close to the portion of the support portion51, which is bonded to the mount22. Therefore, it is possible to reduce the shift in, particularly, the Z-axis direction among the X-axis direction, the Y-axis direction, and the Z-axis direction, between the movable body52and the fixed electrode4(the shift occurs by residual stress of the substrate2or heat deflection). In particular, in this embodiment, the fixation portions411,421,431, and441are arranged side by side in the Y-axis direction. Therefore, the fixation portions411,421,431, and441are easily arranged to be close to the portion of the support portion51, which is bonded to the mount22.

As illustrated inFIG. 1, the movable electrode6includes first and second movable electrodes61and62positioned in the first opening portion528and third and fourth movable electrodes63and64positioned in the second opening portion529.

The first movable electrode61is an electrode which forms a pair with the first fixed electrode41, and is provided in the movable body52. Such a first movable electrode61includes a plurality of plurality of movable electrode fingers611which extends in the Y-axis direction to fit with the plurality of fixed electrode fingers413and to form a comb teeth shape. The plurality of movable electrode fingers611is arranged to be separated from each other at an equal interval in the X-axis direction. Each of the movable electrode fingers611is positioned on a side of the corresponding fixed electrode finger413on the positive side of the X-axis direction, and faces the fixed electrode finger413with a gap. The lengths of the plurality of movable electrode fingers611(length in the Y-axis direction) decrease toward the positive side of the X-axis direction, similar to the plurality of fixed electrode fingers413.

The second movable electrode62is an electrode which forms a pair with the second fixed electrode42, and is provided in the movable body52. Such a second movable electrode62includes a plurality of movable electrode fingers621which extends in the Y-axis direction to fit with the plurality of fixed electrode fingers423and to form a comb teeth shape. The plurality of movable electrode fingers621is arranged to be separated from each other at an equal interval in the X-axis direction. Each of the movable electrode fingers621is positioned on a side of the corresponding fixed electrode finger423on the negative side of the X-axis direction, and faces the fixed electrode finger423with a gap. The lengths of the plurality of movable electrode fingers621(length in the Y-axis direction) gradually increase toward the positive side of the X-axis direction, similar to the plurality of fixed electrode fingers423.

The third movable electrode63is an electrode which forms a pair with the third fixed electrode43, and is provided in the movable body52. Such a third movable electrode63includes a plurality of movable electrode fingers631which extends in the Y-axis direction to fit with the plurality of fixed electrode fingers433and to form a comb teeth shape. The plurality of movable electrode fingers631is arranged to be separated from each other at an equal interval in the X-axis direction. Each of the movable electrode fingers631is positioned on a side of the corresponding fixed electrode finger433on the positive side of the X-axis direction, and faces the fixed electrode finger433with a gap. The lengths of the plurality of movable electrode fingers631(length in the Y-axis direction) gradually decrease toward the positive side of the X-axis direction, similar to the plurality of fixed electrode fingers433. Such a third movable electrode63is disposed to be symmetrical with the first movable electrode61with respect to the central axis αx.

The fourth movable electrode64is an electrode which forms a pair with the fourth fixed electrode44, and is provided in the movable body52. Such a fourth movable electrode64includes a plurality of movable electrode fingers641which extends in the Y-axis direction to fit with the plurality of fixed electrode fingers443and to form a comb teeth shape. The plurality of movable electrode fingers641is arranged to be separated from each other at an equal interval in the X-axis direction. Each of the movable electrode fingers641is positioned on a side of the corresponding fixed electrode finger443on the negative side of the X-axis direction, and faces the fixed electrode finger443with a gap. The lengths of the plurality of movable electrode fingers641(length in the Y-axis direction) gradually increase toward the positive side of the X-axis direction, similar to the plurality of fixed electrode fingers443. Such a fourth movable electrode64is disposed to be symmetrical with the second movable electrode62with respect to the central axis αx.

The configurations of the first to fourth movable electrodes61,62,63, and64are described above. As described above, the first and second movable electrodes61and62are disposed on the one side of the central axis αx, and the third and fourth movable electrodes63and64are disposed on the other side of the central axis αx. Thus, it is possible to reduce the lengths of the movable electrode fingers611,621,631, and641to about the half without deteriorating detection characteristics of the acceleration Ax, in comparison to, for example, a configuration as illustrated inFIG. 3, in which only the first movable electrode61is disposed on one side of the central axis αx, and only the fourth movable electrode64disposed on the other side of the central axis αx. As described above, according to the physical quantity sensor1, it is possible to reduce the lengths of the movable electrode fingers611,621,631, and641in comparison to those in the related art. In addition, since the mechanical strength of the movable electrode fingers611,621,631, and641increases, the movable electrode finger is damaged less frequently. Each of the movable electrode fingers611,621,631, and641is an elongated portion, and thus is a portion which is particularly easily damaged in the element unit3. As described above, since each of the movable electrode fingers611,621,631, and641being portions which are easily damaged is configured to be damaged less frequently, mechanical strength of the entirety of the element unit3is significantly improved.

The configuration of the physical quantity sensor1is described above in detail. When the physical quantity sensor1operates, for example, the first and third fixed electrodes41and43are connected to a QV amplifier (charge/voltage conversion circuit) via the wiring76. The second and fourth fixed electrodes42and44are connected to the QV amplifier via the wiring77. Thus, if a driving voltage is applied to the movable electrode6via the wiring75, electrostatic capacitance Ca is formed between the movable electrode finger611and the fixed electrode finger413and between the movable electrode finger631and the fixed electrode finger433. In addition, electrostatic capacitance Cb is formed between the movable electrode finger621and the fixed electrode finger423and between the movable electrode finger641and the fixed electrode finger443.

If the acceleration Ax is applied to the physical quantity sensor1toward the positive side of the X-axis direction, the movable body52is displaced in the X-axis direction with respect to the support portion51, based on the magnitude of the acceleration Ax, while causing the springs53and54to elastically deform. Therefore, each of a gap between the movable electrode finger611and the fixed electrode finger413, a gap between the movable electrode finger621and the fixed electrode finger423, a gap between the movable electrode finger631and the fixed electrode finger433, and a gap between the movable electrode finger641and the fixed electrode finger443changes. With the changes, the electrostatic capacitance Ca and Cb changes with each of the gaps changing. Therefore, the acceleration Ax can be obtained based on the change of the electrostatic capacitance Ca and Cb.

Here, as described above, in the first and third movable electrodes61and63, the movable electrode fingers611and631are positioned on a side of the fixed electrode fingers413and433on the positive side of the X-axis direction. However, in the second and fourth movable electrodes62and64, the movable electrode fingers621and641are positioned on a side of the fixed electrode fingers423and443on the negative side of the X-axis direction. Therefore, if the electrostatic capacitance Ca increases, the electrostatic capacitance Cb decreases. On the contrary, if the electrostatic capacitance Ca decreases, the electrostatic capacitance Cb increases. Thus, if a differential operation (subtraction processing: Ca-Cb) is performed on a detection signal (signal depending on the magnitude of the electrostatic capacitance Ca) output from the wiring76and a detection signal (signal depending on the magnitude of the electrostatic capacitance Cb) output from the wiring77, it is possible to cancel noise and to detect the acceleration Ax with higher accuracy.

In particular, in this embodiment, arrangement is performed in a manner that the first and second fixed electrodes41and42having different polarities are adjacent to one side of the central axis αx (on the positive side of the Y-axis direction), and the third and fourth fixed electrodes43and44having different polarities are adjacent to the other side of the central axis αx (on the negative side of the Y-axis direction). Therefore, the influence of heat deflection or warpage due to residual stress of the substrate2is substantially equal between the first and second fixed electrodes41and42, and is also substantially equal between the third and fourth fixed electrodes43and44. Thus, the shift of the detection signal occurring by the influence is canceled by the first fixed electrode41and the second fixed electrode42, and by the third fixed electrode43and the fourth fixed electrode44. As a result, it is possible to detect the acceleration Ax with higher accuracy.

Examples of the influence of heat deflection or warpage due to residual stress of the substrate2include the shift of the first to fourth fixed electrodes41,42,43, and44from the movable body52in the Z-axis direction, as illustrated inFIG. 4. Since the first and second fixed electrodes41and42are disposed to be adjacent to each other, the shift from the movable body52in the Z-axis direction occurs substantially equally between the first and second fixed electrodes. Similarly, since the third and fourth fixed electrodes43and44are disposed to be adjacent to each other, the shift from the movable body52in the Z-axis direction occurs substantially equally between the third and fourth fixed electrodes. Therefore, the amount of the electrostatic capacitance Ca changing due to displacement of the first fixed electrode41is substantially equal to the amount of the electrostatic capacitance Cb changing due to displacement of the second fixed electrode42. In addition, the amount of the electrostatic capacitance Ca changing due to displacement of the third fixed electrode43is substantially equal to the amount of the electrostatic capacitance Cb changing due to displacement of the fourth fixed electrode44. Accordingly, the amounts of the electrostatic capacitance Ca and Cb changing are substantially equal to each other in total. Thus, it is possible to cancel the amount of the electrostatic capacitance Ca and Cb by performing a differential operation on the electrostatic capacitance Ca and Cb. Accordingly, according to such a configuration, it is possible to detect the acceleration Ax with higher accuracy. In particular, the degree of the heat deflection of the substrate2changes depending on an environmental temperature, and this may cause deterioration of temperature characteristics. On the contrary, as described above, in the physical quantity sensor1, it is possible to reduce the influence of the heat deflection of the substrate2. Thus, it is possible to exhibit excellent temperature characteristics.

That is, regarding the features of the structure of the physical quantity sensor1according to the invention, even in a case, in practice, the amount of warpage changes depending on a place due to not warpage (indicated by a one dot chain line inFIG. 4) of the substrate2, but shape asymmetry of the lid8and the like, for example, like a case of warpage of the substrate2, which is indicated by a solid line inFIG. 4(warpage of the fixation portions411,421,431, and441of the fixed electrode4is not symmetrical with respect to the support portion51of the movable body52), the amount of the electrostatic capacitance Ca and Cb changing of warpage is canceled, and thus it is possible to significantly exhibit the effect.

The physical quantity sensor1is described above in detail. As described above, such a physical quantity sensor1includes the substrate2, the support portion51fixed to the substrate2, the movable body52which is displaceable in the X-axis direction (first direction) with respect to the support portion51and has the movable electrode6provided therein, and the fixed electrode4fixed to the substrate2. The fixed electrode4includes the first fixed electrode41which is positioned on one side of the support portion51in the Y-axis direction (second direction) orthogonal to the X-axis direction and has the fixed electrode finger (first fixed electrode finger)413provided therein, the second fixed electrode42which is provided to be separated from the first fixed electrode41and has the fixed electrode finger (second fixed electrode finger)423provided therein, the third fixed electrode43which is positioned on the other side of the support portion in the Y-axis direction and has the fixed electrode finger (third fixed electrode finger)433provided therein, and the fourth fixed electrode44which is provided to be separated from the third fixed electrode43and has the fixed electrode finger (fourth fixed electrode finger)443provided therein. The movable electrode6includes the first movable electrode61having the movable electrode finger (first movable electrode finger)611provided to face the fixed electrode finger413in the X-axis direction, the second movable electrode62having the movable electrode finger (second movable electrode finger)621provided to face the fixed electrode finger423in the X-axis direction, the third movable electrode63having the movable electrode finger (third movable electrode finger)631provided to face the fixed electrode finger433in the X-axis direction, and the fourth movable electrode64having the movable electrode finger (fourth movable electrode finger)641provided to face the fixed electrode finger443in the X-axis direction. According to such a configuration, for example, it is possible to reduce the length of each of the electrode fingers413,423,433,443,611,621,631, and641to about the half without deteriorating the detection characteristics (magnitude of electrostatic capacitance Ca and Cb) of the acceleration Ax, in comparison to the configuration as illustrated inFIG. 3. Therefore, the mechanical strength of the electrode fingers413,423,433,443,611,621,631, and641increases, and thus the electrode fingers are damaged less frequently. Accordingly, the physical quantity sensor1has excellent impact resistance (mechanical strength).

As described above, the physical quantity sensor1includes the springs53and54that connect the support portion51and the movable body52. Thus, it is possible to enable the movable body52to be displaced in the X-axis direction with respect to the support portion51, with a simple configuration. The configuration of the springs53and54is not particularly limited. For example, any one of the springs53and54may be omitted.

As described above, the movable electrode finger611faces the fixed electrode finger413on the positive side (one side) of the X-axis direction. The movable electrode finger621faces the fixed electrode finger423on the negative side (the other side) of the X-axis direction. The movable electrode finger631faces the fixed electrode finger433on the positive side (one side) of the X-axis direction. The movable electrode finger641faces the fixed electrode finger443on the negative side (the other side) of the X-axis direction. Thus, when the acceleration Ax is applied, the electrostatic capacitance Ca formed between the movable electrode finger611and the fixed electrode finger413and between the movable electrode finger631and the fixed electrode finger433and the electrostatic capacitance Cb formed between the movable electrode finger621and the fixed electrode finger423and between the movable electrode finger641and the fixed electrode finger443change in phases which are opposite to each other. Thus, it is possible to cancel noise and to detect the acceleration Ax with higher accuracy. Detection sensitivity of the physical quantity is not deteriorated even though the length of the electrode finger is reduced. Further, according to such a configuration, the influence of heat deflection or warpage due to residual stress of the substrate2is substantially equal between the first and second fixed electrodes41and42having different polarities, and is substantially equal between the third and fourth fixed electrodes43and44having different polarities. Thus, the shift between the electrostatic capacitance Ca and Cb, which occurs by the influence is canceled. As a result, it is possible to detect the acceleration Ax with higher accuracy.

As described above, in the physical quantity sensor1, the first fixed electrode41and the third fixed electrode43are disposed symmetrically with respect to the support portion51(central axis αx). The second fixed electrode42and the fourth fixed electrode44are disposed symmetrically with respect to the support portion51(central axis αx). The first movable electrode61and the third movable electrode63are disposed symmetrically with respect to the support portion51(central axis αx), and the second movable electrode62and the fourth movable electrode64are disposed symmetrically with respect to the support portion51(central axis αx). According to such a configuration, for example, it is possible to improve insensitivity to unnecessary vibration of the movable body52around the Z axis, and to detect the acceleration Ax with higher accuracy. That is, according to such a configuration, for example, in a case where the movable body52unintentionally rotates about the center O, if the gap between the movable electrode finger611and the fixed electrode finger413decreases, the gap between the movable electrode finger631and the fixed electrode finger433increases. Conversely, if the gap between the movable electrode finger611and the fixed electrode finger413increases, the gap between the movable electrode finger631and the fixed electrode finger433decreases. Therefore, the amount of changing the electrostatic capacitance between the movable electrode finger611and the fixed electrode finger413and the amount of changing the electrostatic capacitance between the movable electrode finger631and the fixed electrode finger433are canceled, and thus it is possible to reduce fluctuation of the electrostatic capacitance Ca. Similarly, if the gap between the movable electrode finger621and the fixed electrode finger423decreases, the gap between the movable electrode finger641and the fixed electrode finger443increases. Conversely, if the gap between the movable electrode finger621and the fixed electrode finger423increases, the gap between the movable electrode finger641and the fixed electrode finger443decreases. Therefore, the amount of changing the electrostatic capacitance between the movable electrode finger621and the fixed electrode finger423and the amount of changing the electrostatic capacitance between the movable electrode finger641and the fixed electrode finger443are canceled, and thus it is possible to reduce the fluctuation of the electrostatic capacitance Cb. Accordingly, the physical quantity sensor1has high insensitivity to unnecessary vibration of the movable body about the Z axis and is capable of detecting the acceleration Ax with higher accuracy.

As described above, the fixed electrode finger413and the fixed electrode finger433are electrically connected to each other, and the fixed electrode finger423and the fixed electrode finger443are electrically connected to each other. Thus, as described above, when the acceleration Ax is applied, the electrostatic capacitance Ca formed between the movable electrode finger611and the fixed electrode finger413and between the movable electrode finger631and the fixed electrode finger433, and the electrostatic capacitance Cb formed between the movable electrode finger621and the fixed electrode finger423and between the movable electrode finger641and the fixed electrode finger443change in phases which are opposite to each other. Thus, it is possible to cancel noise and to detect the acceleration Ax with higher accuracy. The detection sensitivity of the physical quantity is not deteriorated even though the length of the electrode finger is reduced.

As described above, the first fixed electrode41includes the fixation portion (first fixation portion)411fixed to the substrate2and the trunk portion (first trunk portion)412provided in the fixation portion411. The fixed electrode finger413is provided in the trunk portion412such that the longitudinal direction thereof is directed along the Y-axis direction. Similarly, the second fixed electrode42includes the fixation portion (second fixation portion)421fixed to the substrate2and the trunk portion (second trunk portion)422provided in the fixation portion421. The fixed electrode finger423is provided in the trunk portion422such that the longitudinal direction thereof is directed along the Y-axis direction. The trunk portion422is positioned closer to the support portion51(central axis αx) side than the trunk portion412side. The fixed electrode finger413is provided in the trunk portion412on an opposite side of the support portion51(central axis αx). The fixed electrode finger423is provided in the trunk portion422on the support portion51(central axis αx) side. With such a configuration, the fixation portion411and the fixation portion421are easily arranged to be near to each other. Therefore, it is possible to more effectively have an influence of heat deflection or warpage due to residual stress of the substrate2on the first and second fixed electrodes41and42equally.

As described above, the fixation portion411and the fixation portion421are disposed to be adjacent to each other in the Y-axis direction. Thus, it is easy to arrange the fixation portions411and421. The phrase of “being disposed to be adjacent” means, for example, that the fixation portions411and421are arranged side by side without another structural member (for example, a portion of the element unit3) being positioned between the fixation portions411and421.

As described above, the third fixed electrode43includes the fixation portion (third fixation portion)431fixed to the substrate2and the trunk portion (third trunk portion)432provided in the fixation portion431. The fixed electrode finger433is provided in the trunk portion432such that the longitudinal direction thereof is directed along the Y-axis direction. Similarly, the fourth fixed electrode44includes the fixation portion (fourth fixation portion)441fixed to the substrate2and the trunk portion (fourth trunk portion)442provided in the fixation portion441. The fixed electrode finger443is provided in the trunk portion442such that the longitudinal direction thereof is directed along the Y-axis direction. The trunk portion442is positioned closer to the support portion51(central axis αx) side than the trunk portion432side. The fixed electrode finger433is provided in the trunk portion432on an opposite side of the support portion51(central axis αx). The fixed electrode finger443is provided in the trunk portion442on the support portion51(central axis αx) side. With such a configuration, the fixation portion431and the fixation portion441are easily arranged to be near to each other. Therefore, it is possible to more effectively have an influence of heat deflection or warpage due to residual stress of a substrate2on the third and fourth fixed electrodes43and44equally.

As described above, the fixation portion431and the fixation portion441are disposed to be adjacent to each other in the Y-axis direction. Thus, it is easy to arrange the fixation portions431and441. The phrase of “being disposed to be adjacent” means, for example, that the fixation portions431and441are arranged side by side without another structural member (for example, a portion of the element unit3) being positioned between the fixation portions431and441.

Second Embodiment

Next, a physical quantity sensor according to a second embodiment will be described.

FIG. 5is a plan view illustrating the physical quantity sensor according to the second embodiment. For easy descriptions, inFIG. 5, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the first embodiment except that, mainly, a configuration of the element unit3is different from that in the first embodiment. In the following descriptions, the physical quantity sensor1in the second embodiment will be described focusing on a difference from the above-described first embodiment, and descriptions of the similar items will not be repeated. InFIG. 5, the same components as those in the above-described first embodiment are denoted by the same reference signs.

As illustrated inFIG. 5, in the physical quantity sensor1in this embodiment, the arrangement of the third fixed electrode43, the third movable electrode63, the fourth fixed electrode44, and the fourth movable electrode64is reversed in comparison to that in the above-described first embodiment. That is, in comparison to the above-described first embodiment, the first fixed electrode41and the third fixed electrode43are not symmetrical, and the second fixed electrode42and the fourth fixed electrode are not symmetrical. Similarly, the first movable electrode61and the third movable electrode63are not symmetrical, and the second movable electrode62and the fourth movable electrode64are not symmetrical.

With such a second embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Third Embodiment

Next, a physical quantity sensor according to a third embodiment will be described.

FIG. 6is a plan view illustrating the physical quantity sensor according to the third embodiment. For easy descriptions, inFIG. 6, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the first embodiment except that, mainly, a configuration of the element unit3is different from that in the first embodiment. In the following descriptions, the physical quantity sensor1in the third embodiment will be described focusing on a difference from the above-described first embodiment, and descriptions of the similar items will not be repeated. InFIG. 6, the same components as those in the above-described first embodiment are denoted by the same reference signs.

As illustrated inFIG. 6, in the first and second fixed electrodes41and42, the trunk portions412and422are inclined from the X axis in reverse directions, and a distance between the trunk portions412and422gradually increases toward the positive side of the X-axis direction. Each of the plurality of fixed electrode fingers413extends from the trunk portion412toward both sides of the Y-axis direction. That is, the fixed electrode fingers413include a plurality of fixed electrode fingers413′ extending from the trunk portion412toward the positive side of the Y-axis direction and a plurality of fixed electrode fingers413″ extending from the trunk portion412toward the negative side of the Y-axis direction. Similarly, each of the plurality of fixed electrode fingers423extends from the trunk portion422toward both sides of the Y-axis direction. That is, the fixed electrode fingers423include a plurality of fixed electrode fingers423′ extending from the trunk portion422toward the positive side of the Y-axis direction and a plurality of fixed electrode fingers423″ extending from the trunk portion422toward the negative side of the Y-axis direction.

In order to correspond to such fixed electrode fingers413, the movable electrode fingers611include a plurality of movable electrode fingers611′ arranged to fit with the plurality of fixed electrode fingers413′ and a plurality of movable electrode fingers611″ arranged to fit with the plurality of fixed electrode fingers413″. Similarly, in order to correspond to the fixed electrode fingers423, the movable electrode fingers621include a plurality of movable electrode fingers621′ arranged to fit with the plurality of fixed electrode fingers423′ and a plurality of movable electrode fingers621″ arranged to fit with the plurality of fixed electrode fingers423″.

In the third and fourth fixed electrodes43and44, the trunk portions432and442are inclined from the X axis in reverse directions, and a distance between the trunk portions432and442gradually increases toward the positive side of the X-axis direction. Each of the plurality of fixed electrode fingers433extends from the trunk portion432toward both sides of the Y-axis direction. That is, the fixed electrode fingers433include a plurality of fixed electrode fingers433′ extending from the trunk portion432toward the negative side of the Y-axis direction and a plurality of fixed electrode fingers433″ extending from the trunk portion432toward the positive side of the Y-axis direction. Similarly, each of the plurality of fixed electrode fingers443extends from the trunk portion442toward both sides of the Y-axis direction. That is, the fixed electrode fingers443include a plurality of fixed electrode fingers443′ extending from the trunk portion442toward the negative side of the Y-axis direction and a plurality of fixed electrode fingers443″ extending from the trunk portion442toward the positive side of the Y-axis direction.

In order to correspond to such fixed electrode fingers433, the movable electrode fingers631include a plurality of movable electrode fingers631′ arranged to fit with the plurality of fixed electrode fingers433′ and a plurality of movable electrode fingers631″ arranged to fit with the plurality of fixed electrode fingers433″. Similarly, in order to correspond to the fixed electrode fingers443, the movable electrode fingers641include a plurality of movable electrode fingers641′ arranged to fit with the plurality of fixed electrode fingers443′ and a plurality of movable electrode fingers641″ arranged to fit with the plurality of fixed electrode fingers443″.

With such a third embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment. In particular, in this embodiment, it is possible to reduce the length of each of the electrode fingers413,423,433,443,611,621,631, and641to about the half of that in the above-described first embodiment. Thus, the physical quantity sensor1having more excellent impact resistance is obtained.

Fourth Embodiment

Next, a physical quantity sensor according to a fourth embodiment will be described.

FIG. 7is a plan view illustrating the physical quantity sensor according to the fourth embodiment. For easy descriptions, inFIG. 7, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the first embodiment except that, mainly, a configuration of the element unit3is different from that in the first embodiment. In the following descriptions, the physical quantity sensor1in the fourth embodiment will be described focusing on a difference from the above-described first embodiment, and descriptions of the similar items will not be repeated. InFIG. 7, the same components as those in the above-described first embodiment are denoted by the same reference signs.

As illustrated inFIG. 7, in the physical quantity sensor1in this embodiment, each of the trunk portions412,422,432, and442extends in the X-axis direction. The lengths of the plurality of fixed electrode fingers413supported by the trunk portion412are substantially equal to each other. The lengths of the plurality of movable electrode fingers611arranged to fit with the plurality of fixed electrode fingers413are also substantially equal to each other. Similarly, the lengths of the plurality of fixed electrode fingers423supported by the trunk portion422are substantially equal to each other. The lengths of the plurality of movable electrode fingers621arranged to fit with the plurality of fixed electrode fingers423are also substantially equal to each other. The lengths of the plurality of fixed electrode fingers433supported by the trunk portion432are substantially equal to each other. The lengths of the plurality of movable electrode fingers631arranged to fit with the plurality of fixed electrode fingers433are also substantially equal to each other. The lengths of the plurality of fixed electrode fingers443supported by the trunk portion442are substantially equal to each other. The lengths of the plurality of movable electrode fingers641arranged to fit with the plurality of fixed electrode fingers443are also substantially equal to each other.

With such a fourth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Fifth Embodiment

Next, a physical quantity sensor according to a fifth embodiment will be described.

FIG. 8is a plan view illustrating the physical quantity sensor according to the fifth embodiment. For easy descriptions, inFIG. 8, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the fourth embodiment except that, mainly, a configuration of the element unit3is different from that in the fourth embodiment. In the following descriptions, the physical quantity sensor1in the fifth embodiment will be described focusing on a difference from the above-described fourth embodiment, and descriptions of the similar items will not be repeated. InFIG. 8, the same components as those in the above-described fourth embodiment are denoted by the same reference signs.

As illustrated inFIG. 8, the first fixed electrode41further includes a joining portion (first joining portion)414that joins the fixation portion411and the trunk portion412, in addition to the fixation portion411, the trunk portion412, and the fixed electrode finger413. The joining portion414extends from the fixation portion411toward the positive side of the Y-axis direction, and is connected to the end portion of the trunk portion412on the negative side of the X-axis direction. Similarly, the second fixed electrode42further includes a joining portion (second joining portion)424that joins the fixation portion421and the trunk portion422, in addition to the fixation portion421, the trunk portion422, and the fixed electrode finger423. The joining portion424extends from the fixation portion421toward the positive side of the Y-axis direction, and is connected to the end portion of the trunk portion422on the negative side of the X-axis direction. In such first and second fixed electrodes41and42, the fixation portions411and421are arranged side by side so as to be adjacent to each other in the X-axis direction. Further, the fixation portions411and421are disposed to be adjacent to the support portion51in the Y-axis direction.

The third fixed electrode43further includes a joining portion (third joining portion)434that joins the fixation portion431and the trunk portion432, in addition to the fixation portion431, the trunk portion432, and the fixed electrode finger433. The joining portion434extends from the fixation portion431toward the negative side of the Y-axis direction, and is connected to the end portion of the trunk portion432on the negative side of the X-axis direction. Similarly, the fourth fixed electrode44further includes a joining portion (fourth joining portion)444that joins the fixation portion441and the trunk portion442, in addition to the fixation portion441, the trunk portion442, and the fixed electrode finger443. The joining portion444extends from the fixation portion441toward the negative side of the Y-axis direction, and is connected to the end portion of the trunk portion442on the negative side of the X-axis direction. In such third and fourth fixed electrodes43and44, the fixation portions431and441are disposed to be adjacent to each other in the X-axis direction. Further, the fixation portions431and441are disposed to be adjacent to the support portion51in the Y-axis direction.

With such a fifth embodiment, it is also possible to exhibit effects similar to those in the above-described fourth embodiment. In particular, in this embodiment, the joining portions414,424,434, and444are provided. Thus, the fixation portions411,421,431, and441can be arranged to be closer to the portion of the support portion51, which is bonded to the mount22. Therefore, it is possible to effectively reduce the shift in, particularly, the Z-axis direction among the X-axis direction, the Y-axis direction, and the Z-axis direction, between the movable body52and the fixed electrode4(the shift occurs by residual stress of the substrate2or heat deflection). Accordingly, it is possible to detect the acceleration Ax with higher accuracy.

Sixth Embodiment

Next, a physical quantity sensor according to a sixth embodiment will be described.

FIG. 9is a plan view illustrating the physical quantity sensor according to the sixth embodiment. For easy descriptions, inFIG. 9, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the first embodiment except that, mainly, a configuration of the element unit3is different from that in the first embodiment. In the following descriptions, the physical quantity sensor1in the sixth embodiment will be described focusing on a difference from the above-described first embodiment, and descriptions of the similar items will not be repeated. InFIG. 9, the same components as those in the above-described first embodiment are denoted by the same reference signs.

As illustrated inFIG. 9, the first fixed electrode41includes a pair of trunk portions412extending in a direction inclined from each of the X axis and the Y axis. The pair of trunk portions412are positioned on both sides of the fixation portion411in the X-axis direction. That is, one trunk portion412extends from the fixation portion411toward the positive side of the X-axis direction in a direction inclined from the X axis. The other trunk portion412extends from the fixation portion411toward the negative side of the X-axis direction in the direction inclined from the X-axis. The pair of trunk portions412are symmetrically arranged with respect to a central axis αy which intersects the center O of the element unit3and extends in the Y-axis direction. The plurality of fixed electrode fingers413is provided in each of the trunk portions412. The plurality of movable electrode fingers611fit with the plurality of fixed electrode fingers413is provided in the movable body52.

Similarly, the second fixed electrode42includes a pair of trunk portions422extending in a direction inclined from each of the X axis and the Y axis. The pair of trunk portions422are positioned on both sides of the fixation portion421in the X-axis direction and are symmetrically arranged with respect to the central axis αy. The plurality of fixed electrode fingers423is provided in each of the trunk portions422. The plurality of movable electrode fingers621fit with the plurality of fixed electrode fingers423is provided in the movable body52.

Similarly, the third fixed electrode43includes a pair of trunk portions432extending in a direction inclined from each of the X axis and the Y axis. The pair of trunk portions432are positioned on both sides of the fixation portion431in the X-axis direction and are symmetrically arranged with respect to the central axis αy. The plurality of fixed electrode fingers433is provided in each of the trunk portions432. The plurality of movable electrode fingers631fit with the plurality of fixed electrode fingers433is provided in the movable body52.

Similarly, the fourth fixed electrode44includes a pair of trunk portions442extending in a direction inclined from each of the X axis and the Y axis. The pair of trunk portions442are positioned on both sides of the fixation portion441in the X-axis direction and are symmetrically arranged with respect to the central axis αy. The plurality of fixed electrode fingers443is provided in each of the trunk portions442. The plurality of movable electrode fingers641fit with the plurality of fixed electrode fingers443is provided in the movable body52.

According to such a configuration, it is possible to increase the number of fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641to about twice, for example, in comparison to the above-described first embodiment. Therefore, for example, if the length of each of the electrode fingers is equal to that in the above-described first embodiment, it is possible to increase the electrostatic capacitance Ca and Cb. Thus, when the acceleration Ax is applied, the amount of the electrostatic capacitance Ca and Cb changing also increases. Accordingly, the sensitivity is improved, and it is possible to detect the acceleration Ax with higher accuracy. From another viewpoint, for example, if the magnitude of the electrostatic capacitance Ca and Cb is equal to that in the above-described first embodiment, it is possible to shorten the fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641as much as the magnitude thereof is equal. Thus, each of the electrode fingers413,423,433,443,611,621,631, and641is damaged much less frequently.

The support portion51is bonded to the upper surface of the mount22at the center portion of the mount22in the longitudinal direction, corresponding to such a configuration.

With such a sixth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Seventh Embodiment

Next, a physical quantity sensor according to a seventh embodiment will be described.

FIG. 10is a plan view illustrating the physical quantity sensor according to the seventh embodiment. For easy descriptions, inFIG. 10, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the fourth embodiment except that, mainly, a configuration of the element unit3is different from that in the fourth embodiment. In the following descriptions, the physical quantity sensor1in the seventh embodiment will be described focusing on a difference from the above-described fourth embodiment, and descriptions of the similar items will not be repeated. InFIG. 10, the same components as those in the above-described fourth embodiment are denoted by the same reference signs.

As illustrated inFIG. 10, the first fixed electrode41includes a pair of trunk portions412extending in the X-axis direction. The pair of trunk portions412are positioned on both sides of the fixation portion411in the X-axis direction. That is, one trunk portion412extends from the fixation portion411toward the positive side of the X-axis direction. The other trunk portion412extends from the fixation portion411toward the negative side of the X-axis direction. The plurality of fixed electrode fingers413is provided in each of the trunk portions412. The plurality of movable electrode fingers611fit with the plurality of fixed electrode fingers413is provided in the movable body52.

Similarly, the second fixed electrode42includes a pair of trunk portions422extending in the X-axis direction. The pair of trunk portions422are positioned on both sides of the fixation portion421in the X-axis direction. The plurality of fixed electrode fingers423is provided in each of the trunk portions422. The plurality of movable electrode fingers621fit with the plurality of fixed electrode fingers423is provided in the movable body52.

Similarly, the third fixed electrode43includes a pair of trunk portions432extending in the X-axis direction. The pair of trunk portions432are positioned on both sides of the fixation portion431in the X-axis direction. The plurality of fixed electrode fingers433is provided in each of the trunk portions432. The plurality of movable electrode fingers631fit with the plurality of fixed electrode fingers433is provided in the movable body52.

Similarly, the fourth fixed electrode44includes a pair of trunk portions442extending in the X-axis direction. The pair of trunk portions442are positioned on both sides of the fixation portion441in the X-axis direction. The plurality of fixed electrode fingers443is provided in each of the trunk portions442. The plurality of movable electrode fingers641fit with the plurality of fixed electrode fingers443is provided in the movable body52.

According to such a configuration, it is possible to increase the number of fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641, for example, in comparison to the above-described fourth embodiment. Therefore, for example, if the lengths of the electrode fingers are equal to those in the above-described fourth embodiment, it is possible to increase the electrostatic capacitance Ca and Cb. Thus, when the acceleration Ax is applied, the amount of the electrostatic capacitance Ca and Cb changing also increases. Accordingly, the sensitivity is improved, and it is possible to detect the acceleration Ax with higher accuracy. From another viewpoint, for example, if the magnitude of the electrostatic capacitance Ca and Cb is equal to that in the above-described fourth embodiment, it is possible to shorten the fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641as much as the magnitude thereof is equal. Thus, each of the electrode fingers413,423,433,443,611,621,631, and641is damaged much less frequently.

The support portion51is bonded to the upper surface of the mount22at the center portion of the mount22in the longitudinal direction, corresponding to such a configuration.

With such a seventh embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Eighth Embodiment

Next, a physical quantity sensor according to an eighth embodiment will be described.

FIG. 11is a plan view illustrating the physical quantity sensor according to the eighth embodiment.FIG. 12is a plan view illustrating a modification example of an element unit illustrated inFIG. 11. For easy descriptions, inFIGS. 11 and 12, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the fifth embodiment except that, mainly, a configuration of the element unit3is different from that in the fifth embodiment. In the following descriptions, the physical quantity sensor1in the eighth embodiment will be described focusing on a difference from the above-described fifth embodiment, and descriptions of the similar items will not be repeated. InFIG. 11, the same components as those in the above-described fifth embodiment are denoted by the same reference signs.

As illustrated inFIG. 11, in the physical quantity sensor1in this embodiment, a pair of fixed electrodes4are provided side by side in the X-axis direction. The pair of fixed electrodes4are substantially symmetrically arranged with respect to the central axis αy. According to such a configuration, it is possible to increase the number of fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641, in comparison to the above-described fifth embodiment. Therefore, for example, if the lengths of the electrode fingers are equal to those in the above-described fifth embodiment, it is possible to increase the electrostatic capacitance Ca and Cb. Thus, when the acceleration Ax is applied, the amount of the electrostatic capacitance Ca and Cb changing also increases. Accordingly, the sensitivity is improved, and it is possible to detect the acceleration Ax with higher accuracy. From another viewpoint, for example, if the magnitude of the electrostatic capacitance Ca and Cb is equal to that in the above-described fifth embodiment, it is possible to shorten the fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641as much as the magnitude thereof is equal. Thus, each of the electrode fingers413,423,433,443,611,621,631, and641is damaged much less frequently.

The support portion51is bonded to the upper surface of the mount22at the center portion of the mount22in the longitudinal direction, corresponding to such a configuration.

With such an eighth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment. For example, as illustrated inFIG. 12, fixation portions411of the pair of first fixed electrodes41may be integrated, and trunk portions412thereof may be integrated. Similarly, fixation portions431of a pair of third fixed electrodes43may be integrated, and trunk portions432of the pair of third fixed electrodes may be integrated.

Ninth Embodiment

Next, a physical quantity sensor according to a ninth embodiment will be described.

FIG. 13is a plan view illustrating the physical quantity sensor according to the ninth embodiment. For easy descriptions, inFIG. 13, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the first embodiment except that, mainly, a configuration of the element unit3is different from that in the first embodiment. In the following descriptions, the physical quantity sensor1in the ninth embodiment will be described focusing on a difference from the above-described first embodiment, and descriptions of the similar items will not be repeated. InFIG. 13, the same components as those in the above-described first embodiment are denoted by the same reference signs.

As illustrated inFIG. 13, in the physical quantity sensor1in this embodiment, a pair of fixed electrodes4are provided side by side in the X-axis direction. The pair of fixed electrodes4are substantially symmetrically arranged with respect to the central axis αy. According to such a configuration, it is possible to increase the number of fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641, in comparison to the above-described first embodiment. Therefore, for example, if the lengths of the electrode fingers are equal to those in the above-described first embodiment, it is possible to increase the electrostatic capacitance Ca and Cb. Thus, when the acceleration Ax is applied, the amount of the electrostatic capacitance Ca and Cb changing also increases. Accordingly, the sensitivity is improved, and it is possible to detect the acceleration Ax with higher accuracy. From another viewpoint, for example, if the magnitude of the electrostatic capacitance Ca and Cb is equal to that in the above-described first embodiment, it is possible to shorten the fixed electrode fingers413,423,433, and443and the movable electrode fingers611,621,631, and641as much as the magnitude thereof is equal. Thus, each of the electrode fingers413,423,433,443,611,621,631, and641is damaged much less frequently.

The support portion51is positioned between the pair of fixed electrodes4. Specifically, the support portion51is positioned between the fixation portions411,421,431, and441of one fixed electrode4and the fixation portions411,421,431, and441of the other fixed electrode4, and extends in the Y-axis direction. Thus, the end portion of the support portion51on the positive side of the Y-axis direction is connected to the movable body52by a pair of springs53. The end portion of the support portion on the negative side of the Y-axis direction is connected to the movable body52by a pair of springs54. If such an arrangement is performed, the fixation portions411,421,431, and441can be arranged to be close to the portion of the support portion51, which is bonded to the mount22.

With such a ninth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Tenth Embodiment

Next, a physical quantity sensor according to a tenth embodiment will be described.

FIG. 14is a plan view illustrating the physical quantity sensor according to the tenth embodiment. For easy descriptions, inFIG. 14, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the ninth embodiment except that, mainly, a configuration of the element unit3is different from that in the first embodiment. In the following descriptions, the physical quantity sensor1in the eleventh embodiment will be described focusing on a difference from the above-described ninth embodiment, and descriptions of the similar items will not be repeated. InFIG. 14, the same components as those in the above-described ninth embodiment are denoted by the same reference signs.

As illustrated inFIG. 14, the movable body52includes notches521and522formed on both sides of the Y-axis direction. The movable body52includes a beam523which is connected to the notches521and522and is disposed to distinguish the fixed electrode4positioned on the positive side of the X-axis direction from the fixed electrode4positioned on the negative side of the X-axis direction, as a partition.

The support portion51is provided on the outside of the movable body52. The support portion51has a frame shape and is provided to surround the movable body52. The support portion51includes a base portion512having a frame shape and a pair of protruding portions513and514which respectively protrude from the base portion512toward the insides of the notches521and522. Tip portions (end portions on the center O side) of the protruding portions513and514are bonded to the mount22.

Each of the springs53and54is positioned between the movable body52and the support portion51. The spring53joins the end portion of the movable body52on the positive side of the X-axis direction and the end portion of the support portion51on the positive side of the X-axis direction. The spring54joins the end portion of the movable body52on the negative side of the X-axis direction and the end portion of the support portion51on the negative side of the X-axis direction. Thus, the movable body52can be supported on both sides of the X-axis direction, and thus the attitude and the movement of the movable body52are stabilized. Therefore, it is possible to reduce unnecessary vibration and to detect the acceleration Ax with higher accuracy.

With such a tenth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Eleventh Embodiment

Next, a physical quantity sensor according to an eleventh embodiment will be described.

FIG. 15is a plan view illustrating the physical quantity sensor according to the eleventh embodiment. For easy descriptions, inFIG. 15, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the ninth embodiment except that, mainly, a configuration of the element unit3is different from that in the first embodiment. In the following descriptions, the physical quantity sensor1in the eleventh embodiment will be described focusing on a difference from the above-described ninth embodiment, and descriptions of the similar items will not be repeated. InFIG. 15, the same components as those in the above-described ninth embodiment are denoted by the same reference signs.

As illustrated inFIG. 15, a pair of support portions51are provided on the inner side of the movable body52. One support portion51is positioned on the positive side of the central axis αx in the Y-axis direction. The other support portion51is positioned on the negative side of the central axis αx in the Y-axis direction. Each of the support portions51includes a base portion515extending in the X-axis direction and an extension portion516which extends from the center portion of the base portion515toward the center O of the element unit3in the Y-axis direction. Each of the support portions51has a T-like shape. Tip portions (end portions on the center O side) of the extension portions516are bonded to the mount22.

With such an eleventh embodiment, it is also possible to exhibit effects similar to those in the above-described ninth embodiment.

Twelfth Embodiment

Next, a physical quantity sensor according to a twelfth embodiment will be described.

FIG. 16is a plan view illustrating the physical quantity sensor according to the twelfth embodiment. For easy descriptions, inFIG. 16, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the eighth embodiment except that, mainly, a configuration of the element unit3is different from that in the eighth embodiment. In the following descriptions, the physical quantity sensor1in the twelfth embodiment will be described focusing on a difference from the above-described eighth embodiment, and descriptions of the similar items will not be repeated. InFIG. 16, the same components as those in the above-described eighth embodiment are denoted by the same reference signs.

As illustrated inFIG. 16, in the pair of fixed electrodes4, a fixation portion451is formed by integrating the fixation portion411of the first fixed electrode41and the fixation portion431of the third fixed electrode43, and a fixation portion461is formed by integrating the fixation portion421of the second fixed electrode42and the fixation portion441of the fourth fixed electrode44. The fixation portions451and461are disposed along the central axis αx.

The support portion51is positioned between the pair of fixed electrodes4. Specifically, the support portion51is positioned between the fixation portion451of one fixed electrode4and the fixation portion451of the other fixed electrode4, and extends in the Y-axis direction. Thus, the end portion of the support portion51on the positive side of the Y-axis direction is connected to the movable body52by a pair of springs53. The end portion of the support portion on the negative side of the Y-axis direction is connected to the movable body52by a pair of springs54.

With such a twelfth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Thirteenth Embodiment

Next, a physical quantity sensor according to a thirteenth embodiment will be described.

FIG. 17is a plan view illustrating the physical quantity sensor according to the thirteenth embodiment. For easy descriptions, inFIG. 17, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the twelfth embodiment except that, mainly, a configuration of the element unit3is different from that in the twelfth embodiment. In the following descriptions, the physical quantity sensor1in the thirteenth embodiment will be described focusing on a difference from the above-described twelfth embodiment, and descriptions of the similar items will not be repeated. InFIG. 17, the same components as those in the above-described twelfth embodiment are denoted by the same reference signs.

As illustrated inFIG. 17, the movable body52includes notches521and522formed on both sides of the Y-axis direction. The movable body52includes a beam523which is connected to the notches521and522and is disposed to distinguish the fixed electrode4positioned on the positive side of the X-axis direction from the fixed electrode4positioned on the negative side of the X-axis direction, as a partition.

The support portion51is provided on the outside of the movable body52. The support portion51has a frame shape and is provided to surround the movable body52. The support portion51includes a base portion512having a frame shape and a pair of protruding portions513and514which respectively protrude from the base portion512toward the insides of the notches521and522. Tip portions (end portions on the center O side) of the protruding portions513and514are bonded to the mount22.

Each of the springs53and54is positioned between the movable body52and the support portion51. The spring53joins the end portion of the movable body52on the positive side of the X-axis direction and the end portion of the support portion51on the positive side of the X-axis direction. The spring54joins the end portion of the movable body52on the negative side of the X-axis direction and the end portion of the support portion51on the negative side of the X-axis direction.

With such a thirteenth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment.

Fourteenth Embodiment

Next, a physical quantity sensor according to a fourteenth embodiment will be described.

FIG. 18is a plan view illustrating the physical quantity sensor according to the fourteenth embodiment.FIG. 19is a plan view illustrating a modification example of an element unit illustrated inFIG. 18. For easy descriptions, inFIG. 18, illustrations of the substrate2and the lid8are omitted, and only the element unit3is illustrated.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the twelfth embodiment except that, mainly, a configuration of the element unit3is different from that in the twelfth embodiment. In the following descriptions, the physical quantity sensor1in the fourteenth embodiment will be described focusing on a difference from the above-described twelfth embodiment, and descriptions of the similar items will not be repeated. InFIG. 18, the same components as those in the above-described twelfth embodiment are denoted by the same reference signs.

As illustrated inFIG. 18, a pair of support portions51are provided on the inner side of the movable body52. One support portion51is positioned on the positive side of the central axis αx in the Y-axis direction. The other support portion51is positioned on the negative side of the central axis αx in the Y-axis direction. Each of the support portions51includes a base portion515extending in the X-axis direction and an extension portion516which extends from the center portion of the base portion515toward the center O of the element unit3in the Y-axis direction. Each of the support portions51has a T-like shape. Tip portions (end portions on the center O side) of the extension portions516are bonded to the mount22.

With such a fourteenth embodiment, it is also possible to exhibit effects similar to those in the above-described first embodiment. For example, as illustrated inFIG. 19, two fixation portions451may be integrated.

Fifteenth Embodiment

Next, a physical quantity sensor according to a fifteenth embodiment will be described.

FIG. 20is a plan view illustrating the physical quantity sensor according to the fifteenth embodiment.

A physical quantity sensor1in this embodiment is similar to the above-described physical quantity sensor1according to the first embodiment except that, mainly, three element units3X,3Y, and3Z are provided. In the following descriptions, the physical quantity sensor1in the fifteenth embodiment will be described focusing on a difference from the above-described first embodiment, and descriptions of the similar items will not be repeated. InFIG. 20, the same components as those in the above-described first embodiment are denoted by the same reference signs.

As illustrated inFIG. 20, three recess portions21X,21Y, and21Z are provided in the substrate2. The element unit3X is disposed to overlap the recess portion21X. The element unit3Y is disposed to overlap the recess portion21Y. The element unit3Z is disposed to overlap the recess portion21Z. The element unit3X is a sensor element that has the same configuration as that in the above-described first embodiment and is capable of detecting an acceleration Az in the X-axis direction. The element unit3Y is a sensor element that has the same configuration as that in the above-described first embodiment except that the attitude thereof rotates by 90° about the Z axis, and is capable of detecting the acceleration Ay in the Y-axis direction. The element unit3Z is a sensor element capable of detecting the acceleration Az in the Z-axis direction.

Briefly describing the element unit3Z, the element unit3Z includes a movable body91capable of rolling around a rolling axis J, like a seesaw. The movable body91includes a first movable unit911positioned on one side of the rolling axis J and a second movable unit912positioned on the other side thereof. The turning moment of the first movable unit911is different from the turning moment of the second movable unit912. A first fixed electrode92is disposed on the bottom surface of the recess portion21Z, so as to face the first movable unit911. A second fixed electrode93is disposed on the bottom surface of the recess portion21Z, so as to face the second movable unit912. Electrostatic capacitance Cc is formed between the first movable unit911and the first fixed electrode92. Electrostatic capacitance Cd is formed between the second movable unit912and the second fixed electrode93. If the acceleration Az is applied to the physical quantity sensor1, the movable body91rolls around the rolling axis J, like a seesaw. Thus, the electrostatic capacitance Cc and Cd changes, and thus it is possible to detect the acceleration Az based on the change of the electrostatic capacitance Cc and Cd.

According to such a physical quantity sensor1, it is possible to detect accelerations of three axes which are orthogonal to each other.

Sixteenth Embodiment

Next, a physical quantity sensor device according to a sixteenth embodiment will be described.

FIG. 21is a sectional view illustrating the physical quantity sensor device according to the sixteenth embodiment.

As illustrated inFIG. 21, the physical quantity sensor device5000includes a package5100, a physical quantity sensor1, and a semiconductor element (circuit element)5900. The physical quantity sensor and the semiconductor element are stored in the package5100. For example, the physical quantity sensor in any of the above-described embodiments can be used as the physical quantity sensor1.

The package5100includes a cavity-like base (substrate)5200and a lid5300bonded to the upper surface of the base5200. The base5200includes a recess portion5210which opens to the upper surface thereof. The recess portion5210includes a first recess portion5211which opens to the upper surface of the base5200and a second recess portion5212which opens to the bottom surface of the first recess portion5211.

The lid5300has a plate shape and is bonded to the upper surface of the base5200so as to close the opening of the recess portion5210. A storage space S2is formed in the package5100by the lid5300closing the opening of the recess portion5210in this manner, and thus the physical quantity sensor1and the semiconductor element5900are stored in the storage space S2. Therefore, it is possible to properly protect the physical quantity sensor1and the semiconductor element5900from an impact, dust, heat, moisture, and the like, by the package5100. A method of bonding the base5200and the lid5300to each other is not particularly limited. In this embodiment, seam welding using a seam ring5400is used.

The storage space S2is airtightly sealed. The atmosphere of the storage space S2is not particularly limited. For example, the atmosphere of the storage space S2is preferably set to be the same as the atmosphere of the storage space S of the physical quantity sensor1. Thus, it is possible to maintain the atmosphere of the storage space S as it is, even if airtightness of the storage space S collapses, and the storage spaces S and S2communicate with each other. Therefore, it is possible to reduce variation in acceleration detection characteristics of the physical quantity sensor1, which occurs by changing the atmosphere of the storage space S, and to exhibit the stable acceleration detection characteristics.

A material for forming the base5200is not particularly limited. For example, various ceramics such as alumina, zirconia, and titania can be used. A material for forming the lid5300is not particularly limited. For example, a material having a linear expansion coefficient which is approximate to that of the material for forming the base5200may be provided. For example, in a case where the above-described ceramic is provided as the material for forming the base5200, alloys with cobalt and the like are preferably used.

The base5200includes a plurality of internal terminals5230arranged in the storage space S2(on the bottom surface of the first recess portion5211) and a plurality of external terminals5240arranged on the bottom surface of the base. Each of the internal terminals5230is electrically connected to the predetermined external terminal5240via an internal interconnection (not illustrated) disposed in the base5200.

The physical quantity sensor1is fixed to the bottom surface of the recess portion5210via a die-attach material DA. In addition, the semiconductor element5900is disposed on the upper surface of the physical quantity sensor1with a die-attach material DA interposed between the semiconductor element and the upper surface of the physical quantity sensor. Thus, the physical quantity sensor1and the semiconductor element5900are electrically connected to each other via the bonding wiring BW1, and the semiconductor element5900and the internal terminal5230are electrically connected to each other via a bonding wiring BW2.

If necessary, the semiconductor element5900includes, for example, a driving circuit that applies a driving voltage to the element units3X,3Y, and3Z, a detection circuit that detects the accelerations Ax, Ay, and Az based on outputs from the element units3X,3Y, and3Z, or an output circuit that converts a signal from the detection circuit into a predetermined signal and outputs the predetermined signal.

Hitherto, the physical quantity sensor device5000is described. Such a physical quantity sensor device5000includes the physical quantity sensor1and the semiconductor element (circuit element)5900. Therefore, a physical quantity sensor device5000which is capable of exhibiting the effect of the physical quantity sensor1and has high reliability is obtained.

As described above, the physical quantity sensor device5000includes the base (base substrate)5200and the lid5300bonded to the base5200so as to form the storage space S2between the lid5300and the base5200. The physical quantity sensor1and the semiconductor element5900are stored in the storage space S2. Thus, it is possible to properly protect the physical quantity sensor1and the semiconductor element5900from an impact, dust, heat, moisture, and the like.

As described above, the physical quantity sensor1is mounted on the base5200, and the semiconductor element5900is mounted on the physical quantity sensor1. For example, as in this embodiment, in a case where the planar size of the semiconductor element5900is smaller than the planar size of the physical quantity sensor1, if such an arrangement is performed, it is possible to arrange the physical quantity sensor1and the semiconductor element5900with high balance.

Seventeenth Embodiment

Next, a physical quantity sensor device according to a seventeenth embodiment will be described.

FIG. 22is a sectional view illustrating the physical quantity sensor device according to the seventeenth embodiment.

A physical quantity sensor device5000in this embodiment is similar to the above-described physical quantity sensor device5000according to the sixteenth embodiment except that the arrangement of the physical quantity sensor1and the semiconductor element5900is reversed. In the following descriptions, the physical quantity sensor device5000in the seventeenth embodiment will be described focusing on a difference from the above-described sixteenth embodiment, and descriptions of the similar items will not be repeated. InFIG. 22, the same components as those in the above-described sixteenth embodiment are denoted by the same reference signs.

As illustrated inFIG. 22, in the physical quantity sensor device5000in this embodiment, the semiconductor element5900is fixed to the bottom surface of the recess portion5210of the base5200with a die-attach material DA. The physical quantity sensor1is fixed to the upper surface of the semiconductor element5900with a die-attach material DA. That is, the semiconductor element (circuit element)5900is mounted on the base (substrate)5200, and the physical quantity sensor1is mounted on the semiconductor element5900. For example, as in this embodiment, in a case where the planar size of the physical quantity sensor1is smaller than the planar size of the semiconductor element5900, if such an arrangement is performed, it is possible to arrange the physical quantity sensor1and the semiconductor element5900with high balance.

Eighteenth Embodiment

Next, a complex sensor device according to an eighteenth embodiment will be described.

FIG. 23is a plan view illustrating the complex sensor device according to the eighteenth embodiment.FIG. 1is a sectional view illustrating the complex sensor device illustrated inFIG. 23.

As illustrated inFIGS. 23 and 24, a complex sensor device4000includes a base substrate4100, a semiconductor element (circuit element)4200, an acceleration sensor (first physical quantity sensor)4300, an angular rate sensor (second physical quantity sensor)4400, and a resin package4500. The semiconductor element is mounted on the upper surface of the base substrate4100with a die-attach material (resin adhesive) DA. The acceleration sensor and the angular rate sensor are mounted on the upper surface of the semiconductor element4200with a die-attach material. The resin package4500covers the semiconductor element4200, the acceleration sensor4300, and the angular rate sensor4400. The acceleration sensor4300is a three-axis acceleration sensor capable of independently detecting an acceleration of each of three axes (X axis, Y axis, and Z axis) which are orthogonal to each other. For example, the physical quantity sensor1in the above-described fifteenth embodiment can be applied as the acceleration sensor. The angular rate sensor4400is a three-axis angular rate sensor capable of independently detecting an angular rate of each of three axes (X axis, Y axis, and Z axis) which are orthogonal to each other. For example, a vibration gyro sensor using the Coriolis force can be used as the angular rate sensor.

The base substrate4100includes a plurality of connection terminals4110provided on the upper surface of the base substrate and a plurality of external terminals4120provided on the lower surface thereof. Each of the connection terminals4110is electrically connected to the corresponding external terminal4120via an internal interconnection (not illustrated) disposed in the base substrate4100. The semiconductor element4200is disposed on the upper surface of such a base substrate4100.

If necessary, the semiconductor element4200includes a driving circuit, an acceleration detection circuit, an angular-rate detection circuit, an output circuit, and the like. The driving circuit drives the acceleration sensor4300and the angular rate sensor4400. The acceleration detection circuit independently detects each of an acceleration in the X-axis direction, an acceleration in the Y-axis direction, and an acceleration in the Z-axis direction based on an output from the acceleration sensor4300. The angular-rate detection circuit independently detects each of an angular rate about the X axis, an angular rate about the Y axis, and an angular rate about the Z axis based on the output from the angular rate sensor4400. The output circuit converts signals from the acceleration detection circuit and the angular-rate detection circuit into predetermined signals, and outputs the predetermined signals.

Such a semiconductor element4200is electrically connected to the acceleration sensor4300via a bonding wiring BW3, is electrically connected to the angular rate sensor4400via a bonding wiring BW4, and is electrically connected to the connection terminal4110of the base substrate4100via a bonding wiring BW5. The acceleration sensor4300and the angular rate sensor4400are disposed on the upper surface of such a semiconductor element4200, in parallel.

Hitherto, the complex sensor device4000is described. As described above, such a complex sensor device4000includes the acceleration sensor (first physical quantity sensor)4300and the angular rate sensor (second physical quantity sensor)4400that detects a physical quantity different from that in the acceleration sensor4300. Thus, a complex sensor device4000which is capable of detecting physical quantities having different types and has high convenience is obtained. In particular, in this embodiment, the first physical quantity sensor is the acceleration sensor4300capable of detecting an acceleration, and the second physical quantity sensor is the angular rate sensor4400capable of detecting the angular rate. Therefore, a complex sensor device4000which is capable of being suitably used as, for example, a motion sensor and has very high convenience is obtained.

Nineteenth Embodiment

Next, a complex sensor device according to a nineteenth embodiment will be described.

FIG. 25is a sectional view illustrating the complex sensor device according to the nineteenth embodiment.

A complex sensor device4000in this embodiment is similar to the above-described complex sensor device4000according to the eighteenth embodiment except that, mainly, the arrangement of the acceleration sensor4300and the angular rate sensor4400is different from that in the eighteenth embodiment. In the following descriptions, the complex sensor device4000in the nineteenth embodiment will be described focusing on a difference from the above-described eighteenth embodiment, and descriptions of the similar items will not be repeated. InFIG. 25, the same components as those in the above-described eighteenth embodiment are denoted by the same reference signs.

As illustrated inFIG. 25, the acceleration sensor4300and the angular rate sensor4400are mounted on the upper surface of the base substrate4100in a manner that the semiconductor element4200is interposed between the acceleration sensor4300and the angular rate sensor4400. With such a configuration, it is possible to reduce the height of the complex sensor device4000.

Twentieth Embodiment

Next, an inertial measurement unit according to a twentieth embodiment will be described.

FIG. 26is an exploded perspective view illustrating the inertial measurement unit according to the twentieth embodiment.FIG. 27is a perspective view illustrating a substrate provided in the inertial measurement unit illustrated inFIG. 26.

The inertial measurement unit (IMU)2000illustrated inFIG. 26is an inertial measurement unit that detects an attitude or a movement (inertial momentum) of a vehicle (device in which the unit is mounted) such as an automobile or a robot. The inertial measurement unit2000functions as a so-called six-axis motion sensor which includes a three-axis acceleration sensor and a three-axis angular rate sensor.

The inertial measurement unit2000is a rectangular parallelepiped having a planar shape which is roughly square. Screw holes2110as the fixation portions are formed in the vicinity of two vertices positioned in a diagonal direction of the square. The inertial measurement unit2000can be fixed to a mounting target surface of a mounting target object such as an automobile by causing two screws to pass through the two screw holes2110. The size thereof can be reduced to a size as small as can be mounted in, for example, a smartphone or a digital camera, by selecting components or changing a design.

The inertial measurement unit2000includes an outer case2100, a bonding member2200, and a sensor module2300. The inertial measurement unit2000has a configuration in which the sensor module2300is inserted into the outer case2100with the bonding member2200interposed between the outer case2100and the sensor module2300. The sensor module2300includes an inner case2310and a substrate2320.

The appearance of the outer case2100is a rectangular parallelepiped having a planar shape which is roughly square, similar to the entire shape of the above-described inertial measurement unit2000. The screws hole2110are formed in the vicinity of two vertices positioned in a diagonal direction of the square. The outer case2100has a box shape, and the sensor module2300is stored in the outer case2100.

The inner case2310is a member that supports the substrate2320and has a shape that fits in the outer case2100. A recess portion2311for preventing a contact with the substrate2320or an opening2312for exposing a connector2330(which will be described later) is formed in the inner case2310. Such an inner case2310is bonded to the outer case2100with the bonding member2200(for example, packing in which an adhesive has been impregnated). The substrate2320is bonded to the lower surface of the inner case2310with an adhesive.

As illustrated inFIG. 27, the connector2330, an angular rate sensor2340zthat detects an angular rate about the Z axis, an acceleration sensor2350that detects an acceleration in each axis direction of the X axis, the Y axis, and the Z axis, and the like are mounted on the upper surface of the substrate2320. An angular rate sensor2340xthat detects an angular rate about the X axis and an angular rate sensor2340ythat detects an angular rate about the Y axis are mounted on the side surface of the substrate2320. For example, the physical quantity sensor1in the above-described fifteenth embodiment can be used as the acceleration sensor2350. The angular rate sensors2340z,2340x, and2340yare not particularly limited. For example, a vibration gyro sensor using the Coriolis force can be used as the angular rate sensor.

A control IC2360is mounted on the lower surface of the substrate2320. The control IC2360is a micro-controller unit (MCU). The control IC includes a storage unit including a non-volatile memory, an A/D converter, and the like mounted therein, and controls the components of the inertial measurement unit2000. The storage unit stores a program in which the procedure and the details for detecting an acceleration and an angular rate have been specified, a program of digitizing detection data and incorporating the data into packet data, accompanying data, and the like. In addition, a plurality of electronic components is mounted on the substrate2320.

Hitherto, the inertial measurement unit2000is described. Such an inertial measurement unit2000includes the angular rate sensors2340z,2340x, and2340y, and the acceleration sensor2350as the physical quantity sensors and the control IC (control circuit)2360that controls driving of each of the sensors2340z,2340x,2340y, and2350. Thus, an inertial measurement unit2000which is capable of exhibiting the effect of the physical quantity sensor according to the invention and has high reliability is obtained.

Next, a vehicle positioning device according to a twenty-first embodiment will be described.

FIG. 28is a block diagram illustrating the entire system of the vehicle positioning device according to the twenty-first embodiment.FIG. 29is a diagram illustrating an action of the vehicle positioning device illustrated inFIG. 28.

A vehicle positioning device3000illustrated inFIG. 28is a device which is used in a state of being mounted in a vehicle and is used for positioning the vehicle. The vehicle is not particularly limited. Any of bicycles, automobiles (including four-wheeled vehicles and bikes), trains, airplanes, ships, and the like may be provided. In this embodiment, descriptions will be made on the assumption that the vehicle is a four-wheeled vehicle. The vehicle positioning device3000includes an inertial measurement unit (IMU)3100, an arithmetic processing unit (processor)3200, a GPS receiving unit (receiver)3300, a receiving antenna3400, a position information acquisition unit3500, a position synthesis unit (synthesizer)3600, a processing unit (processor)3700, a communication unit3800, and a display unit3900. For example, the above-described inertial measurement unit2000can be used as the inertial measurement unit3100.

The inertial measurement unit3100includes a three-axis acceleration sensor3110and a three-axis angular rate sensor3120. The arithmetic processing unit (processor)3200receives acceleration data from the acceleration sensor3110and angular rate data from the angular rate sensor3120. The arithmetic processing unit (processor)3200performs inertial navigation arithmetic processing on the received data, and thus outputs inertial navigation positioning data (data including an acceleration and an attitude of the vehicle).

The GPS receiving unit (receiver)3300receives a signal (GPS carrier wave, satellite signal on which position information is superimposed) from a GPS satellite through the receiving antenna3400. The position information acquisition unit3500outputs GPS positioning data indicating the position (latitude, longitude, and altitude), the speed, and the azimuth of the vehicle positioning device (vehicle)3000, based on the signal received from the GPS receiving unit3300(receiver). The GPS positioning data also includes status data indicating a reception state, a reception time point, or the like.

The position synthesis unit (synthesizer)3600calculates the position of the vehicle, specifically, the position of the vehicle travelling on a map, based on inertial navigation positioning data output from the arithmetic processing unit (processor)3200and GPS positioning data output from the position information acquisition unit3500. For example, if the attitude of the vehicle is different by an influence of the inclination of a map, as illustrated inFIG. 29, even though the position of the vehicle, which is included in the GPS positioning data is the same, the vehicle seems to travel at a different position on the map. Therefore, calculating the precise position of the vehicle only with GPS positioning data is not possible. The position synthesis unit (synthesizer)3600calculates the position of the vehicle travelling on the map, by using the inertial navigation positioning data (in particular, data regarding the attitude of the vehicle). The determination can be performed relatively easily by calculation using a trigonometric function (inclination θ with respect to the vertical direction).

The processing unit (processor)3700performs predetermined processing on position data output from the position synthesis unit (synthesizer)3600. The resultant is displayed, as a result of the positioning, in the display unit3900. The position data may be transmitted to an external device by the communication unit3800.

Hitherto, the vehicle positioning device3000is described. As described above, such a vehicle positioning device3000includes the inertial measurement unit3100, the GPS receiving unit (receiving unit (receiver))3300that receives a satellite signal on which position information has been superimposed, from a positioning satellite, the position information acquisition unit (acquisition unit)3500that acquires position information of the GPS receiving unit (receiver)3300based on the received satellite signal, the arithmetic processing unit (processor) (computation unit)3200that calculates the attitude of the vehicle based on inertial navigation positioning data (inertial data) output from the inertial measurement unit3100, and the position synthesis unit (synthesizer) (calculation unit)3600that calculates the position of the vehicle by correcting the position information based on the calculated attitude. Thus, a vehicle positioning device3000which is capable of exhibiting the effect of the above-described inertial measurement unit2000and has high reliability is obtained.

Next, an electronic device according to a twenty-second embodiment will be described.

FIG. 30is a perspective view illustrating the electronic device according to the twenty-second embodiment.

The electronic device in this embodiment is applied to a mobile type (or notebook type) personal computer1100illustrated inFIG. 30. The personal computer1100includes a main body1104including a keyboard1102and a display device1106including a display unit1108. The display device1106is supported to be allowed to rotate around the main body1104by a hinge structure portion. A physical quantity sensor1and a control circuit (control unit (controller))1110are mounted in the personal computer1100. The control circuit1110performs control based on a detection signal output from the physical quantity sensor1. For example, the physical quantity sensor in any of the above-described embodiments can be used as the physical quantity sensor1.

Such a personal computer (electronic device)1100includes the physical quantity sensor1and the control circuit (control unit (controller))1110that performs control based on a detection signal output from the physical quantity sensor1. Therefore, it is possible to exhibit the effect of the above-described physical quantity sensor1and to exhibit high reliability.

Next, an electronic device according to a twenty-third embodiment will be described.

FIG. 31is a perspective view illustrating the electronic device according to the twenty-third embodiment.

The electronic device in this embodiment is applied to a portable phone1200(including a PHS) illustrated inFIG. 31. The portable phone1200includes an antenna (not illustrated), a plurality of operation buttons1202, an earpiece1204, and a mouthpiece1206. A display unit1208is disposed between the operation button1202and the earpiece1204. A physical quantity sensor1and a control circuit (control unit (controller))1210are mounted in the portable phone1200. The control circuit1210performs control based on a detection signal output from the physical quantity sensor1.

Such a portable phone (electronic device)1200includes the physical quantity sensor1and the control circuit (control unit (controller))1210that performs control based on a detection signal output from the physical quantity sensor1. Therefore, it is possible to exhibit the effect of the above-described physical quantity sensor1and to exhibit high reliability.

Next, an electronic device according to a twenty-fourth embodiment will be described.

FIG. 32is a perspective view illustrating the electronic device according to the twenty-fourth embodiment.

The electronic device in this embodiment is applied to a digital still camera1300illustrated inFIG. 32. The digital still camera1300includes a case1302. A display unit1310is provided on the back surface of the case1302. The display unit1310has a configuration in which display is performed based on an imaging signal obtained by a CCD. The display unit1310functions as a viewfinder that displays a subject in a form of an electronic image. A light receiving unit (receiver)1304that includes an optical lens (optical imaging system), the CCD, and the like is provided on the front surface side (rear surface side inFIG. 36) of the case1302. If a photographer checks a subject displayed in the display unit1310and pushes the shutter button1306, an imaging signal at this time is transferred from the CCD and stored in the memory1308. A physical quantity sensor1and a control circuit (control unit (controller))1320are mounted in the digital still camera1300. The control circuit1320performs control based on a detection signal output from the physical quantity sensor1. The physical quantity sensor1is used in image stabilization, for example.

Such a digital still camera (electronic device)1300includes the physical quantity sensor1and the control circuit (control unit (controller))1320that performs control based on a detection signal output from the physical quantity sensor1. Therefore, it is possible to exhibit the effect of the above-described physical quantity sensor1and to exhibit high reliability.

The electronic device can be applied to, for example, devices as follows in addition to the personal computer and the portable phone in the above-described embodiments and the digital still camera in this embodiment: a smartphone, a tablet terminal, a clock (including a smart watch), an ink jet ejecting apparatus (for example, ink jet printer), a laptop type personal computer, a television, a wearable terminal such as a head mount display (HMD), a video camera, a video tape recorder, a car navigation system, a pager, an electronic notebook (including a type having a communication function), electronic dictionary, an electronic calculator, an electronic game machine, a word processor, a workstation, a video phone, a security television monitor, electronic binoculars, a POS terminal, medical equipment (for example, a clinical electronic thermometer, a blood pressure monitor, a blood glucose meter, an electrocardiogram measuring device, an ultrasonic diagnostic device, and an electronic endoscope), a fish finder, various measuring instruments, equipment for a vehicle terminal and a base station, instruments (for example, instruments of vehicles, aircrafts, ships), a flight simulator, a network server, and the like.

Next, a portable electronic device according to a twenty-fifth embodiment will be described.

FIG. 33is a plan view illustrating the portable electronic device according to the twenty-fifth embodiment.FIG. 34is a functional block diagram schematically illustrating a configuration of the portable electronic device illustrated inFIG. 33.

A wristwatch type activity meter (active tracker)1400illustrated inFIG. 33is a wrist device to which the portable electronic device in this embodiment has been applied. The activity meter1400is mounted on a part (such as a wrist) (detection target) of a user by a band1401. The activity meter1400includes a display unit1402in a manner of digital display and is capable of wireless communication. The above-described physical quantity sensor1according to the invention is incorporated into the activity meter1400, as a sensor that measures an acceleration and a sensor that measures an angular rate.

The activity meter1400includes a case1403in which the physical quantity sensor1is accommodated, a processing unit (processor)1410which is accommodated in the case1403and processes output data from the physical quantity sensor1, a display unit1402accommodated in the case1403, and a translucent cover1404that closes the opening portion of the case1403. A bezel1405is provided on the outside of the translucent cover1404. A plurality of operation buttons1406and1407is provided on the side surface of the case1403.

As illustrated inFIG. 34, an acceleration sensor1408as the physical quantity sensor1detects an acceleration in each of three axis directions which intersect each other (ideally, orthogonal to each other), and outputs a signal (acceleration signal) depending on the magnitudes and the directions of the detected accelerations in the three axes. An angular rate sensor1409detects an angular rate in each of three axis directions which intersect each other (ideally, orthogonal to each other), and outputs a signal (angular rate signal) depending on the magnitudes and the directions of the detected angular rates in the three axes.

In a liquid crystal display (LCD) constituting the display unit1402, various types of information as follows are displayed in accordance with various detection modes: for example, position information or the movement quantity obtained by using a GPS sensor1411or a terrestrial magnetism sensor1412; motion information such as the momentum, which has been obtained by using the acceleration sensor1408, the angular rate sensor1409, or the like; biometric information regarding a pulse rate obtained by using a pulse sensor1413or the like; and time information on the current time. An environmental temperature obtained by a temperature sensor1414can also be displayed.

A communication unit1415performs various controls for establishing a communication between a user terminal and an information terminal (not illustrated). The communication unit1415includes, for example, a transmitter-receiver compatible with short-range wireless communication standards such as Bluetooth (registered trademark) (including Bluetooth Low Energy (BTLE)), Wi-Fi (Wireless Fidelity) (registered trademark), Zigbee (registered trademark), NFC (Near field communication), and ANT+(registered trademark) and a connector compatible with a communication bus standard such as a universal serial bus (USB).

The processing unit (processor)1410is configured with, for example, a micro-processing unit (MPU), a digital signal processor (DSP), and an application specific integrated circuit (ASIC). The processing unit (processor)1410performs various kinds of processing based on a program stored in a storage unit1416and a signal input from an operation unit1417(For example, operation buttons1406and1407). The processing performed by the processing unit (processor)1410includes data processing on output signals from the GPS sensor1411, the terrestrial magnetism sensor1412, the pressure sensor1418, the acceleration sensor1408, the angular rate sensor1409, the pulse sensor1413, the temperature sensor1414, and a timekeeping unit1419, display processing of displaying an image in the display unit1402, sound output processing of outputting sound to a sound output unit1420, communication processing of performing a communication with an information terminal via the communication unit1415, power control processing of supplying power from a battery1421to the units, and the like.

Such an activity meter1400can have at least functions as follows.

1. Distance: measure the total distance from a point in which measuring starts, by a GPS function having high precision

2. Pace: display the current travel pace through pace distance measurement

3. Average speed: calculate an average speed from a point in which traveling at the average speed start to the current point, and display the calculated average speed

4. Altitude: measure and display the altitude by the GPS function

5. Stride: measure and display the stride even in a tunnel where GPS radio waves do not reach

6. Pitch: measure and display the number of steps per one minute

7. Heart rate: measure and display the heart rate by the pulse sensor

8. Gradient: measure and display the gradient of the ground in training and trail runs in the mountains

9. Auto lap: automatically measure lap time when travelling for a predetermined distance or for a predetermined time

10. Exercise consumed calorie: display calories consumed

11. Number of steps: display the total number of steps from when starting an exercise

Such an activity meter (portable electronic device)1400includes the physical quantity sensor1, the case1403in which the physical quantity sensor1is accommodated, the processing unit (processor)1410which is accommodated in the case1403and processes output data from the physical quantity sensor1, the display unit1402accommodated in the case1403, and the translucent cover1404that closes the opening portion of the case1403. Therefore, it is possible to exhibit the effect of the above-described physical quantity sensor1and to exhibit high reliability.

As described above, the activity meter1400includes the GPS sensor (satellite positioning system)1411, and thus can measure a movement distance or a movement trajectory of a user. Therefore, an activity meter1400having high convenience is obtained.

The activity meter1400can be widely applied to a running watch, a runner's watch, a runner's watch for multisports such as duathlon and triathlon, an outdoor watch, and a GPS watch equipped with a satellite positioning system, for example, a GPS.

The above descriptions are made by using a global positioning system (GPS) as the satellite positioning system. However, other global navigation satellite systems (GNSS) may be used. For example, one, or two or more of satellite positioning systems such as the European geostationary-satellite navigation overlay service (EGNOS), the quasi-zenith satellite system (QZSS), the global navigation satellite system (GLONASS), GALILEO, and the BeiDou navigation satellite system (BeiDou) may be used. A geostationary-satellite type satellite-based augmentation system (SBAS) such as the wide area augmentation system (WAAS) and the European geostationary-satellite navigation overlay service (EGNOS) may be used as at least one satellite positioning system.

Next, a vehicle according to a twenty-sixth embodiment will be described.

FIG. 35is a perspective view illustrating the vehicle according to the twenty-sixth embodiment.

An automobile1500illustrated inFIG. 35is an automobile to which the vehicle in this embodiment has been applied. InFIG. 35, the automobile1500includes a system1510which is at least one of an engine system, a brake system, and a keyless entry system. A physical quantity sensor1is mounted in the automobile1500. A detection signal of the physical quantity sensor1is supplied to a control device1502, and the control device1502can control the system1510based on the detection signal.

Such an automobile (vehicle)1500includes the physical quantity sensor1and the control device (control unit (controller))1502that performs control based on a detection signal output from the physical quantity sensor1. Therefore, it is possible to exhibit the effect of the above-described physical quantity sensor1and to exhibit high reliability. The automobile1500includes the system1510which is at least one of the engine system, the brake system, and the keyless entry system. The control device1502controls the system1510based on the detection signal. Thus, it is possible to control the system1510with high precision.

In addition, the physical quantity sensor1can be widely applied to an electronic control unit (ECU) in a car navigation system, a car air conditioner, an antilocking brake system (ABS), an air bag, a tire pressure monitoring system (TPMS), an engine controller, a battery monitor of a hybrid automobile or an electric automobile, and the like.

The vehicle is not limited to the automobile1500. For example, the vehicle can also be applied to airplanes, rockets, artificial satellites, ships, automated guided vehicles (AGV), bipedal walking robots, and unmanned aircrafts such as drones.

Hitherto, the physical quantity sensor, the physical quantity sensor device, the complex sensor device, the inertial measurement unit, the vehicle positioning device, the portable electronic device, the electronic device, and the vehicle are described based on the embodiments in the drawings. However, the invention is not limited thereto. The components can be substituted with any components having the same functions. Any other constituent may be added to the invention. The above-described embodiments may be appropriately combined.

In the above-described embodiments, the configuration in which the physical quantity sensor detects an acceleration is described. However, the physical quantity detected by the physical quantity sensor is not particularly limited. For example, an angular rate or pressure may be detected. The physical quantity sensor may be capable of detecting a plurality of physical quantities. The plurality of physical quantities may be physical quantities having the same type and different detection axes (for example, an acceleration in the X-axis direction, an acceleration in the Y-axis direction, and an acceleration in the Z-axis direction, or an angular rate about the X axis, an angular rate about the Y axis, and an angular rate about the Z axis), or may be physical quantities different from each other (for example, an angular rate about the X axis and an acceleration in the X-axis direction).