JP5240657B2 - Sensing element, sensing device, orientation detection device, and information device - Google Patents

Description

  The present invention relates to a sensing element, a sensing device, an orientation detection device, and an information device, and more particularly to a sensing element having a plurality of magnetic sensors, a sensing device including the sensing element, an orientation detection device, and an information device.

  In recent years, mobile terminals have been improved in functionality and performance, and mobile phones equipped with a so-called navigation function for guiding to a desired position based on map information are also rapidly spreading. In such an application, the convenience is dramatically improved by effectively using geomagnetic information.

  Further, in this case, by combining a triaxial acceleration sensor for posture detection, more accurate information can be utilized and convenience can be dramatically improved.

  Geomagnetism is a vector quantity, and its strength is generally said to be 0.3 to 0.5 Oe (Oersted) and is very weak. Thus, in order to detect the geomagnetism of very weak intensity with high accuracy, the characteristics of the detection element were improved.

  Since geomagnetism is due to magnetic field lines generated from both magnetic poles on the earth, when detecting this geomagnetism on the earth that is not a plane, information only on the horizontal plane (two-dimensional information) is insufficient. Therefore, in order to effectively use information relating to geomagnetism, it is necessary to detect geomagnetism information in three dimensions.

  For example, Patent Document 1 includes a first X-axis GMR element to a fourth X-axis GMR element fixed on a substrate, and a movable coil movably supported on the substrate, and only a magnetic detection element is used as a detection element. A sensor that can be used to measure an external magnetic field, acceleration, and the like is disclosed.

  Patent Document 2 discloses a leaf spring, a detection magnet supported by the leaf spring so as to be displaced in the direction opposite to the acceleration in the detection direction, and a magnetic field detection element that detects a magnetic field generated by the detection magnet. A magnetic acceleration sensor is disclosed.

  Patent Document 3 and Patent Document 4 disclose at least a triaxial magnetic sensor for detecting geomagnetism, a biaxial or higher acceleration sensor for detecting gravitational acceleration, an output signal from the magnetic sensor, and an output signal from the acceleration sensor. An integrated azimuth sensor including a signal processing unit that processes the above is disclosed.

JP 2006-98078 A JP 2006-317184 A Japanese Patent No. 3928775 Japanese Patent No. 3982611

  Recently, not only high performance and high performance of mobile terminals, but also the demand for miniaturization is increasing. Therefore, it is necessary to miniaturize the orientation detection device mounted on the portable terminal.

  However, the sensor disclosed in Patent Document 1 has a disadvantage in that it cannot simultaneously detect both physical quantities of acceleration and geomagnetism. In addition, the sensor disclosed in Patent Document 1 has a disadvantage that it is not possible to save energy because it is necessary to pass a current through the movable coil. In addition, since a control unit for controlling whether or not to allow current to flow through the movable coil is required, the circuit becomes complicated, resulting in an increase in the number of parts and an increase in cost.

  In addition, the magnetic acceleration sensor disclosed in Patent Document 2 is limited in size reduction because all magnetic circuits, magnetic sensors, and the like are assembled using mounting technology.

  In addition, the integrated azimuth sensors disclosed in Patent Documents 3 and 4 require a stress detection element for detecting acceleration and a magnetic sensor for obtaining magnetic information. Eventually, two physical quantities are detected. In addition, two types of detection devices are required. Therefore, a manufacturing process for forming each of them is required, and there is a disadvantage that the manufacturing cost increases.

  The present invention has been made under such circumstances, and a first object of the present invention is to provide a sensing element capable of detecting acceleration and geomagnetism at the same time, having a small size and high reliability without incurring an increase in cost. Is to provide.

  A second object of the present invention is to provide a sensing device that can simultaneously detect the acceleration in the three-axis direction and the geomagnetism in the three-axis direction with high accuracy without causing an increase in cost. .

  A third object of the present invention is to provide an azimuth detecting device that can detect the azimuth with a small size and high accuracy without increasing the cost.

  A fourth object of the present invention is to provide an information device that is small in size and can obtain information optimal for a user's request without incurring an increase in cost.

  From a first aspect, the present invention has a weight portion that is displaced by acceleration and at least one movable portion that is movable by an external force, and at least one magnetism generating member formed on the weight portion, A sensor in which a plurality of magnetic sensors for detecting magnetism from a generating member and a plurality of magnetic sensors for detecting geomagnetism in three axial directions formed at a plurality of positions including the at least one movable part are formed. A sensing element comprising: a substrate; and a cover member that covers the sensor substrate and causes the mechanical force to act to incline the at least one movable part with respect to other than the movable part.

  According to this, it is possible to detect acceleration and geomagnetism at the same time with a small size and high reliability without increasing the cost.

  According to a second aspect, the present invention provides a sensing element according to the present invention; based on output signals of a plurality of magnetic sensors in the sensing element and an inclination angle of the at least one movable part in the sensor element; An arithmetic device that obtains acceleration information related to a direction and geomagnetic information related to a triaxial direction, respectively.

  According to this, since the sensing element of the present invention is provided, it is possible to simultaneously detect the acceleration in the three-axis direction and the geomagnetism in the three-axis direction with a small size and high accuracy without causing an increase in cost. .

  According to a third aspect of the present invention, there is provided a sensing device according to the present invention; an azimuth acquisition device that obtains azimuth information based on acceleration information related to the triaxial direction from the sensing device and geomagnetic information related to the triaxial direction. It is an azimuth detecting device provided.

  According to this, since the sensing device of the present invention is provided, as a result, it is possible to detect the orientation with a small size and high accuracy without causing an increase in cost.

  From a fourth aspect, the present invention is based on a position detection device that acquires position information; an azimuth detection device of the present invention; azimuth information from the azimuth detection device and position information from the position detection device, And an information acquisition device for acquiring information.

  According to this, since the azimuth detecting device of the present invention is provided, as a result, it is possible to obtain information that is small and optimal for the user's request without increasing the cost.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an appearance of a mobile phone 10 as an information device according to an embodiment.

  As shown in FIG. 2 as an example, the cellular phone 10 includes a key input device 11, a display device 12, a memory 13, a wireless circuit 14, an antenna 15, a speaker 16, a microphone 17, a camera module 18, and an interface (IF) 19. , Orientation detection device 20, position detection device 21, power supply device 23, main control device 22, and the like.

  The key input device 11 is used for a user to input data or to select an instruction content for the mobile phone 10, and includes a numeric keypad and various function keys. The key information input here is notified to the main controller 22. The key may be either a hardware key or a software key, or may be used in combination.

  The display device 12 displays various messages to the user and various information input by the user. The display device 12 is also used as various applications and display means in the camera module 18.

  The memory 13 has a plurality of types of storage media and stores various data suitable for each.

  The wireless circuit 14 controls bidirectional wireless communication with the outside via the antenna 15. Note that not only audio data but also character data and image data can be transmitted and received as communication data. Furthermore, a GPS (Global Positioning System) signal can also be received.

  The speaker 16 converts audio data, music data, etc. into sound and outputs the sound.

  The microphone 17 converts input sound into an electric signal.

  The camera module 18 captures an image.

  The interface (IF) 19 has a plurality of types of interface drivers, and controls bidirectional data communication with an external device (for example, a memory chip, a USB device, etc.).

  The azimuth detecting device 20 acquires azimuth information in which the longitudinal direction of the mobile phone 10 is oriented and notifies the main control device 22 of the azimuth information. The configuration of the azimuth detecting device 20 will be described later.

  The position detection device 21 acquires position information of the mobile phone 10 based on the GPS signal.

  The power supply device 23 supplies power to each unit.

  The main control device 22 has a CPU, a ROM, and a RAM, and controls the entire mobile phone 10.

  Here, the azimuth detecting device 20 will be described. As shown in FIG. 3 as an example, the azimuth detecting device 20 includes a sensing device 120 and an azimuth information converting device 130.

  The sensing device 120 includes a sensing element 121 and an arithmetic device 122, and outputs geomagnetic data about the triaxial direction and acceleration data about the triaxial direction.

  As shown in FIG. 4A and FIG. 4B as an example, the sensing element 121 includes a sensor substrate 121A, a cover member 121B that covers the sensor substrate 121A, and a support member 121C that supports the sensor substrate 121A. doing. In this specification, in the XYZ three-dimensional orthogonal coordinate system, the direction perpendicular to the surface of the sensor substrate 121A is described as the Z-axis direction.

  Here, the cover member 121B covers the + Z side surface of the sensor substrate 121A. The support member 121C supports the sensor substrate 121A via the -Z side surface of the sensor substrate 121A.

  Further, the cover member 121B and the sensor substrate 121A, and the support member 121C and the sensor substrate 121A are bonded with an adhesive. Note that they may be joined by so-called anodic bonding.

  As shown in FIG. 5 as an example, the sensor substrate 121A includes a substrate 201, an area for detecting geomagnetism (hereinafter referred to as “geomagnetic detection area”) 201m, and an area for detecting acceleration ( In the following, 201s) (referred to as “acceleration detection region”) is provided.

As shown in FIG. 6, a TMR element 121 _X , a TMR element 121 _Y , a TMR element 121 _Z , a plurality of electrode pads 202, and a plurality of wirings 203 are formed in the geomagnetic detection region 201 m.

The TMR element 121 _X is a magnetic sensor for detecting geomagnetism in the X-axis direction, the TMR element 121 _Y is a magnetic sensor for detecting geomagnetism in the Y-axis direction, and the TMR element 121 _Z is Z-axis It is a magnetic sensor for detecting the geomagnetism in the direction.

Further, in the geomagnetic detection region 201m, as shown in FIG. 7B, which is a cross-sectional view taken along the line AA of FIG. 7A and FIG. 7A, a movable part having a cantilever structure (cantilever structure) 201b is formed. Then, TMR element 121 _Z is formed in the vicinity of the free end of the movable portion 201b.

The TMR element 121 _Y and the TMR element 121 _Y are formed in a non-movable part where one end of the movable part 201b is supported. Here, the TMR element 121 _X and the TMR element 121 _Y are formed so that the detection directions of the magnetic fields are substantially orthogonal to each other.

As shown in FIG. 8, the acceleration detection region 201 s includes a TMR element 121 ₁ , a TMR element 121 ₂ , a TMR element 121 ₃ , a TMR element 121 ₄ , four magnetic generation members (205 _{1 to} 205 ₄ ), a plurality of An electrode pad 202 and a plurality of wirings 203 are formed.

The TMR element 121 ₁ is a magnetic sensor for detecting the magnetism of the magnetic generation member 205 ₁ , and the TMR element 121 ₂ is a magnetic sensor for detecting the magnetism of the magnetic generation member 205 ₂ . Furthermore, TMR element 121 ₃ is a magnetic sensor for detecting magnetism of the magnetic generating member 205 _3, TMR element 121 ₄ is a magnetic sensor for detecting magnetism of the magnetic generating member 205 _4.

  Further, in the acceleration detection region 201s, as shown in FIG. 9A, which is a cross-sectional view taken along line AA in FIG. 9A and FIG. 9A, a weight portion supported by four support portions 201d. 201c is formed.

  As shown in FIG. 10 as an example, the weight portion 201c is displaced according to the magnitude and direction of acceleration, and its position and posture change.

The four magnetism generating members (205 _{1 to} 205 ₄ ) are formed near the four corners on the surface of the weight portion 201c.

The TMR element 121 ₁ , the TMR element 121 ₂ , the TMR element 121 ₃ , and the TMR element 121 ₄ are non-movable parts on which the support part 201d is supported, and are formed at positions close to the corresponding magnetic generation members. ing.

  As an example, as shown in FIGS. 11A to 11C, the cover member 121B is formed with a protrusion 250 for applying a mechanical force to the movable portion 201b of the sensor substrate 121A. . Note that FIG. 11B is a cross-sectional view taken along the line AA in FIG.

Therefore, when the sensor substrate 121A is covered with the cover member 121B, as shown in FIG. 12A and FIG. 12B, which is a cross-sectional view taken along line AA in FIG. 12A, as an example, the cover member 121B. The protrusion 250 causes a pressure in the −Z direction to act on the movable portion 201b. That is, a mechanical force acts on the movable part 201b. The movable portion 201b together with the TMR element 121 _Z is a possible inclined with respect to the XY plane. The inclination angle θ at this time is determined by the position of the protrusion 250 in the XY plane (that is, the pressing position) and the length of the protrusion 250 in the Z-axis direction (that is, the amount of protrusion). In the present embodiment, as an example, the inclination angle θ of the movable portion 201b is set to be 25 degrees.

  FIG. 13 is a cross-sectional view taken along the line BB in FIG.

  By the way, the TMR element is a tunnel magnetoresistive effect element whose resistance value changes in response to a magnetic field. As shown in FIG. 14 as an example, an Fe-Mn thin film 52, a ferromagnetic layer, and an antiferromagnetic layer are used. A Co—Fe thin film 53 (pinned layer), an aluminum oxide film 54 as an insulator layer, and a permalloy thin film 55 as a ferromagnetic layer (free layer) are sequentially laminated. Note that the layer configuration and layer material of the TMR structure film are not limited to these (see, for example, Terunobu Miyazaki, “Spintronics”, Nikkan Kogyo Shimbun, 2004).

  As an example, as shown in FIG. 15, a constant current is supplied from the arithmetic unit 122 to each TMR element, and the voltage of each TMR element is output to the arithmetic unit 122 as a respective signal.

  Next, a method for manufacturing the sensor substrate 121A will be briefly described.

  Here, a single crystal silicon (Si) wafer having a (100) surface and a thermal oxide film with a thickness of 525 nm is used for the substrate 201 (see FIG. 16A).

(1) The TMR structure film is formed on the thermal oxide film of the substrate 201 by using a magnetron sputtering method (see FIG. 16B).

(2) The TMR structure film other than the region corresponding to the TMR element is removed by photolithography and dry etching (see FIGS. 16C and 17A). Here, the region corresponding to the TMR element is rectangular, the short side length Da is set to 70 μm, and the long side length Db is set to 200 μm (see FIG. 17B).

(3) As an example, as shown in FIGS. 18A to 18C, fine processing of the TMR structure film is performed.

(4) Using a sputtering method, a SiO ₂ film having a thickness of 300 nm is formed as an interlayer insulating film.

(5) A contact hole is opened using a known means.

(6) A wiring 203 and an electrode pad 202 are formed by aluminum film formation and patterning (see FIG. 19A). Thereby, a TMR element is completed. As an example, FIG. 19B shows a contact position of the wiring 203 in the TMR structure film. In principle, one TMR element requires four terminals, but here, one terminal is shared and three terminals are provided.

(7) A so-called mask deposition method using a stencil mask (see FIG. 20A) is employed so that the magnetism generating member is formed only in a desired region, and a magnetron sputtering method is applied while applying a magnetic field for magnetization. A magnetic generation member is formed (see FIG. 20B). Here, a cobalt (Co) -iron (Fe) alloy having a thickness of 200 nm was formed as the magnetic generating member.

(8) In order to form the movable portion 201b having a cantilever structure and the weight portion 201c supported by the support portion 201d, an etching mask is formed using a resist film (see FIG. 21A).

(9) An unmasked portion is etched using a silicon dry etching technique.

(10) The etching mask is removed (see FIG. 21B).

  In FIG. 22A, D11 is 1 mm, D12 is 1 mm, D13 is 3 mm, D14 is 3 mm, D15 is 2 mm, and D16 is 5 mm. Further, D17 in FIG. 22B was set to 1.5 mm.

  The cover member 121B was formed by photolithography and dry etching using a Si wafer similarly to the sensor substrate 121A. Here, D21 in FIG. 23 is 1 mm, and D22 is 200 μmφ. In addition, the protrusion part 250 has elasticity.

  The support member 121C was formed by photolithography and dry etching using a Si wafer in the same manner as the sensor substrate 121A. Here, D31 in FIG. 24 is 0.5 mm.

  The cover member 121B and the support member 121C also have a role of protecting the sensor substrate 121A. That is, both the cover member 121 </ b> B and the support member 121 </ b> C also serve as part of the packaging member of the magnetic sensing element 121.

  Therefore, the magnetic sensing element 121 has a thickness (here, the length in the Z-axis direction) of less than 3 mm, and can be made thinner than the conventional magnetic sensing element.

Computing device 122, as shown in FIG. 25, the arithmetic circuit 122 _1, amplifier circuit 122 ₂ for amplifying the output voltage of each TMR element has a constant current circuit 122 ₃ supplies a constant current to each TMR element ing.

Arithmetic circuit 122 ₁ calculates the acceleration data about the three axis directions based on the output voltage of the amplifier circuit 122 TMR elements ₁₂₁ 1, which is amplified by ₂ ～TMR element 121 _4.

The arithmetic circuit 122 _1, is amplified by the amplifier circuit 122 _2, the output voltage of the TMR element 121 _X, the output voltage of the TMR element 121 _Y, and the output voltage of the TMR element 121 _Z, it is amplified by the amplifier circuit 122 ₂ It is corrected based on the output voltage of the TMR element ₁₂₁ 1 ～TMR element 121 _4.

The arithmetic circuit 122 _1, corrected on the basis of the output voltage of the TMR element 121 _X calculates geomagnetic data in the X-axis direction, corrected TMR element 121 _Y geomagnetic data in the Y-axis direction based on the output voltage of the Is calculated. Furthermore, the arithmetic circuit 122 ₁ calculates the geomagnetic data in the Z-axis direction based on the inclination angle of the output voltage and the movable portion 201b of the corrected TMR element 121 _Z. The inclination angle of the movable portion 201b is measured in advance or calculated, it is stored in a memory (not shown) of the arithmetic circuit 122 _1.

When acceleration occurs in the sensing element 121, the position and posture of the weight portion 201c change according to the direction and magnitude of the acceleration, and accordingly, the four magnetism generating members (205 _{1 to} 205 ₄ ) also move to the position and posture. Changes (see FIG. 10). Thereby, the output voltages of the _four TMR elements (121 _{1 to} 121 ₄ ) change respectively. Therefore, acceleration data in the three-axis directions can be calculated from the output voltages of the _four TMR elements (121 _{1 to} 121 ₄ ).

The geomagnetic data related to the triaxial direction and the acceleration data related to the triaxial direction calculated by the arithmetic circuit 122 ₁ are output to the azimuth information converter 130.

  Returning to FIG. 3, the azimuth information conversion device 130 performs a known calculation process based on the geomagnetic data about the triaxial direction from the sensing device 120 and the acceleration data about the triaxial direction, and the longitudinal direction of the mobile phone 10 is oriented. Direction information (for example, azimuth angle) is acquired. The orientation information obtained here is notified to the main controller 22.

  Returning to FIG. 2, the main control device 22 responds to the user's request based on the azimuth information acquired by the azimuth detection device 20 and the position information acquired by the position detection device 21. (For example, navigation information) is displayed on the display device 12 (see, for example, JP-A-2001-289646).

As is clear from the above description, in the sensing element 121 according to the present embodiment, the TMR element 121 _X , the TMR element 121 _Y, and the TMR element 121 _Z are a plurality of magnetic sensors for detecting geomagnetism in three axial directions. Is configured.

Further, by the TMR element 121 ₁ and the TMR element 121 ₂ and the TMR element 121 ₃ and TMR element 121 _4, a plurality of magnetic sensors for detecting magnetism from the magnetism generating member is constituted.

  In the azimuth detection device 20 according to the present embodiment, the azimuth information conversion device 130 constitutes a azimuth acquisition device.

  Further, in the mobile phone 10 according to the present embodiment, the main control device 22 constitutes an information acquisition device.

As described above, according to the sensing element 121 of this embodiment, four magnetic generating member and ₍₂₀₅ 1 to 205 _4), the magnetic generating member ₍₂₀₅ 1 to 205 ₄₎ from for detecting the magnetism of Sensor substrate 121A in which four TMR elements (121 _{1 to} 121 ₄ ) and three TMR elements (121 _X , 121 _Y , 121 _Z ) for detecting geomagnetism in the three-axis directions are formed, and the sensor It has a cover member 121B that covers the substrate 121A.

The sensor substrate 121A includes a weight portion 201c that is displaced by acceleration and a movable portion 201b having a cantilever structure, and four magnetism generating members (205 _{1 to} 205 ₄ ) are formed on the weight portion 201c, and the movable portion 201b. TMR element 121 _Z is formed.

  Further, the cover member 121B is formed with a protrusion 250 that applies a mechanical force to the movable portion 201b when the sensor substrate 121A is covered, and tilts the movable portion 201b with respect to other than the movable portion 201b. ing.

  In this case, since each TMR element is formed on the substrate 201, a magnetic sensor element (magnetic sensor chip) corresponding to each of the X-axis direction, the Y-axis direction, and the Z-axis direction is provided as in the conventional magnetic sensing element. There is no need to bond individually. Therefore, the conventional bonding process becomes unnecessary, and the cost can be reduced. In addition, since there is no adhesive portion, there is no concern about variations in adhesive strength or changes with time (deterioration with time). Furthermore, there is no restriction on the size of the magnetic sensor element.

  Further, since the weight part 201c, the movable part 201b, and each TMR element are manufactured using micromachining technology, the magnetic sensing element 121 is reduced in size, particularly in the height direction (here, the Z-axis direction). Can be achieved.

  Furthermore, since the wiring and the electrode pad can be formed at the time of forming the TMR element, it is not necessary to connect the magnetic sensor and the electrode pad by the wiring member after mounting the magnetic sensor element as in the prior art, and long-term stability. It is possible to fully cope with reliability.

  That is, the acceleration in the triaxial direction and the geomagnetism in the triaxial direction can be detected at the same time without increasing the cost, and the miniaturization can be achieved while maintaining high reliability.

  Further, energy is not required to tilt the movable portion 201b, so that energy saving can be achieved.

  Further, since the TMR element is used as the magnetic sensor, power consumption can be reduced.

  Further, since the cover member 121B and the support member 121C also serve as a part of the package member, it is possible to simultaneously satisfy the simplification of the manufacturing process and the cost reduction.

  Further, since the sensor member 121A, the cover member 121B, and the support member 121C are all made of the same material, the problems that are concerned during packaging such as the generation of stress due to the difference in thermal expansion coefficient and the decrease in mechanical strength are solved. can do.

In addition, since the TMR element 121 _Z for detecting geomagnetism in the Z-axis direction is formed on the (100) plane of the substrate 201, the TMR element 121 _Z is formed on an inclined surface (for example, Japanese Patent Application Laid-Open No. 2004-354182). Compared to Japanese Patent Laid-Open No. 2004-006752 and Japanese Patent Laid-Open No. 2004-006752, a good TMR element can be easily formed. The sensitivity of each TMR element can be made substantially equal to each other.

  According to the sensing device 120 according to the present embodiment, since the sensing element 121 is included, the acceleration in the three-axis direction and the geomagnetism in the three-axis direction are simultaneously detected with high accuracy without incurring a cost increase. Is possible.

  Further, according to the azimuth detecting device 20 according to the present embodiment, since the sensing device 120 is provided, it is possible to detect the azimuth accurately with a small size without increasing the cost.

  Further, according to the mobile phone 10 according to the present embodiment, since the azimuth detecting device 20 is provided, it is possible to obtain information that is small and optimal for the user's request without increasing the cost.

In the above-described embodiment, the case where four magnetic generation members are formed on the sensor substrate 121A has been described. However, the present invention is not limited to this. For example, as shown in FIG. 26, one magnetism generating member 205 may be formed at the center of the surface of the weight portion 201c. Even in this case, when the position and posture of the weight portion 201c change, the position and posture of the magnetism generating member 205 also change accordingly. Therefore, from the output voltages of the _four TMR elements (121 _{1 to} 121 ₄ ) It is possible to calculate acceleration data in the three-axis directions.

  Moreover, although the said embodiment demonstrated the case where the inclination | tilt angle (theta) of the movable part 201b was 25 degree | times, it is not limited to this.

  Moreover, in the said embodiment, as FIG. 27 shows as an example, you may form the piezoresistive element 260 in the movable part 201b as a sensor for detecting the inclination-angle of the movable part 201b.

  The piezoresistive element 260 has a characteristic that its resistance value changes when tensile stress or compressive stress is applied. Therefore, when the movable portion 102b is inclined and deformed, the resistance value changes according to the amount of deformation. The piezoresistive element 260 can also be formed on the substrate 201 using micromachining technology. The piezoresistive element 260 is formed in a region where the protrusion 250 of the cover member 121B in the movable portion 201b does not interfere.

  When a piezoresistive element into which boron is implanted is used as the piezoresistive element 260, a high-temperature process of 900 ° C. is required in the thermal diffusion process after boron is implanted when forming the piezoresistive element. It becomes. By the way, the TMR element loses its characteristics at a high temperature of 350 ° C. or higher. Therefore, the piezoresistive element needs to be formed before the TMR element is formed.

In this case, the amplifier circuit 122 _2, and thus also amplifies the output signal of the piezoresistive element 260. The arithmetic circuit 122 _1, the output signal of the piezoresistive element 260 is amplified by the amplifier circuit 122 ₂ obtains the inclination angle of the movable portion 102b, the inclination angle of the amplification circuit 122 of the amplified TMR element 121 _{Z 2} From the output voltage, geomagnetic data in the Z-axis direction is calculated. Thereby, the detection accuracy of geomagnetism can be further improved.

The relationship between the inclination angle of the output signal and a movable portion 102b of the piezoresistive element 260 is obtained in advance experimentally or the like, are stored in a memory (not shown) of the arithmetic circuit 122 _1.

Moreover, in the said embodiment, as FIG. 28 shows as an example, the movable part 201b may be a flat plate by which both ends are supported by the torsion bar 206. Even in this case, as shown in FIG. 29 as an example, when the sensor substrate 121A is covered by the cover member 121B, the protrusion 250 of the cover member 121B applies a pressure in the −Z direction to the movable portion 201b. The torsion bar 206 is twisted, and the movable portion 201b rotates about the torsion bar 206 as an axis. That is, the movable portion 201b together with the TMR element 121 _Z is a possible inclined with respect to the XY plane. Here, the inclination angle of the movable part 201b is 25 degrees.

  Even such a movable part can be manufactured using a micromachining technique.

As an example, as shown in FIG. 30 and FIG. 31, two movable portions 201b each made of a flat plate each supported by a torsion bar 206 are formed so as to have different inclination directions, and each has a TMR element. 121 _Z may be formed. However, in this case, the protrusions 250 corresponding to the respective movable parts need to be formed on the cover member 131B.

  The positional relationship between the two movable parts is not limited to this. In addition, the inclination angles of the movable parts may be different from each other.

In this case, the arithmetic circuit 122 ₁ calculates the geomagnetic data in the Z-axis direction based on the inclination angle of the output voltage and the movable portion of the amplified two TMR elements 121 _Z by the amplifier circuit 122 _2. Here, the use of the detection results of the two TMR elements 121 _Z inclination directions are different from each other, it is possible to further improve the detection accuracy, it is not necessary to consider the dead region of the TMR element 121 _Z.

  As an example, the piezoresistive element 260 may be formed on each torsion bar 206 as shown in FIG.

As an example, as shown in FIG. 33, the TMR element 121 _X , the TMR element 121 _Y , and the two TMR elements 121 _Z are each a movable part formed of a flat plate whose both ends are supported by a torsion bar 206. 201b may be formed.

  In this case, each TMR element can be on a different plane.

  Moreover, in the said embodiment, it may replace with the said sensing element 121, and may use the sensing element 131 shown by FIGS. 34-38 (B).

  This sensing element 131 has a sensor substrate 131A, a cover member 131B, and a support member 131C, and is characterized in that an inclined surface is formed inside the support member 131C as shown in FIG. .

  As shown in FIG. 36, the cover member 131B is the same cover member as the cover member 121B.

  As shown in FIG. 37B, which is an AA cross-sectional view of FIG. 37A, the sensor substrate 131A has a thickness of a portion supported by the support member 131C (here, the length in the Z-axis direction). ) Is thinner than the sensor substrate 121A.

  In this case, as an example, as shown in FIGS. 38A and 38B, the movable portion 201b can be inclined along the inclined surface of the support member 131C. Thereby, the precision of the inclination angle of the movable part 201b can be ensured.

  For example, when the material of the support member 131C is silicon, anisotropic etching using KOH (potassium hydroxide) or TMAH (tetraethylammonium hydroxide) as an etchant is performed if the surface is a (100) plane. Thus, an inclined surface of {111} plane can be easily formed. The inclination angle of the inclined surface at this time is 54.7 degrees.

  Moreover, although the said embodiment demonstrated the case where the material of the board | substrate 201 was a silicon | silicone, it is not limited to this. It should be elastic enough to incline the movable part, workability enough to use micromachining technology, heat resistance, and surface flatness suitable for the formation of TMR elements (for example, Ra ≦ 1.0 nm). It ’s fine.

  Moreover, although the said embodiment demonstrated the case where a magnetic sensor was a tunnel magnetoresistive effect element, it is not limited to this. For example, a giant magnetoresistive effect (GMR) element may be used.

  In the above embodiment, the magnetism generating member may be a permanent magnet.

  Moreover, although the said embodiment demonstrated the case where the projection part of a cover member was cylindrical shape, this invention is not limited to this. In short, it is sufficient that a mechanical force is applied to the movable part of the sensor member to tilt the movable part.

  Moreover, although the said embodiment demonstrated the case where mechanical force was made to act on the movable part of a sensor member by the projection part of a cover member, mechanical force was made to act on the movable part of a sensor member other than a projection part. Also good.

  Moreover, each dimension in the said embodiment is an example, and is not limited to these.

  Moreover, although the said embodiment demonstrated the case where information equipment was a mobile telephone, it is not limited to this. Any information device that requires geomagnetic information and acceleration information may be used. For example, it may be a PDA (Personal Digital Assistant).

  As described above, the sensing element of the present invention is compact and highly reliable without causing an increase in cost, and is suitable for simultaneously detecting acceleration and geomagnetism. In addition, the sensing device of the present invention is small and suitable for simultaneously detecting the acceleration in the three-axis direction and the geomagnetism in the three-axis direction with high accuracy without incurring an increase in cost. Further, the azimuth detection device of the present invention is suitable for detecting the azimuth with a small size and without causing an increase in cost. In addition, the information device of the present invention is small in size and suitable for obtaining information optimal for the user's request without incurring an increase in cost.

It is a figure for demonstrating the external appearance of the mobile telephone which concerns on one Embodiment of this invention. It is a figure for demonstrating schematic structure of the mobile telephone of FIG. It is a figure for demonstrating the azimuth | direction detection apparatus of FIG. FIG. 4A and FIG. 4B are diagrams for explaining the sensing element, respectively. It is a figure for demonstrating the geomagnetic detection area | region and acceleration detection area | region of a sensor board | substrate. It is a figure for demonstrating a geomagnetic detection area | region. FIG. 7A and FIG. 7B are diagrams for explaining the movable part. It is a figure for demonstrating an acceleration detection area | region. FIG. 9A and FIG. 9B are diagrams for explaining the weight portion. It is a figure for demonstrating the displacement of a weight part. FIGS. 11A to 11C are diagrams for explaining the cover member. FIG. 12A and FIG. 12B are diagrams for explaining the inclination of the movable part. It is BB sectional drawing of FIG. 12 (A). It is a figure for demonstrating a TMR element. It is a figure for demonstrating the input / output of a TMR element. FIGS. 16A to 16C are views (No. 1) for describing a method for manufacturing a sensor substrate, respectively. FIGS. 17A and 17B are views (No. 2) for describing a method for manufacturing a sensor substrate, respectively. 18A to 18C are views (No. 3) for describing a method for manufacturing a sensor substrate, respectively. 19A and 19B are views (No. 4) for describing a method for manufacturing a sensor substrate, respectively. 20A and 20B are views (No. 5) for describing a method for manufacturing a sensor substrate, respectively. 21A and 21B are views (No. 6) for describing a method for manufacturing a sensor substrate, respectively. 22A and 22B are diagrams for explaining the size of the sensor substrate. It is a figure for demonstrating the magnitude | size of a cover member. It is a figure for demonstrating the magnitude | size of a supporting member. It is a figure for demonstrating an arithmetic unit. It is a figure for demonstrating the modification of a magnetic generation member. It is a figure for demonstrating a piezoresistive element. It is a figure for demonstrating the modification 1 of a geomagnetic detection area | region. It is a figure for demonstrating the inclination of the movable part in the modification 1. FIG. It is a figure for demonstrating the modification 2 of a geomagnetic detection area | region. It is a figure for demonstrating the inclination of the movable part in the modification 2. FIG. It is a figure for demonstrating the modification 3 of a geomagnetic detection area | region. It is a figure for demonstrating the modification 4 of a geomagnetic detection area | region. It is a figure for demonstrating the modification of a sensing element. It is a figure for demonstrating the supporting member in the sensing element of FIG. It is a figure for demonstrating the cover member in the sensing element of FIG. FIG. 37A and FIG. 37B are diagrams for explaining a sensor substrate in the sensing element of FIG. 34, respectively. FIG. 38A and FIG. 38B are diagrams for explaining the relationship between the inclined surface and the movable portion in the sensing element of FIG. 34, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mobile phone, 20 ... Direction detection device, 21 ... Position detection device, 22 ... Main control device (information acquisition device), 120 ... Sensing device, 121 ... Sensing element, 121A ... Sensor substrate, 121B ... Cover member, 121C ... Support member, 121 ₁ ... TMR element (magnetic sensor), 121 ₂ ... TMR element (magnetic sensor), 121 ₃ ... TMR element (magnetic sensor), 121 ₄ ... TMR element (magnetic sensor), 121 _X ... TMR element (magnetic) Sensor), 121 _Y ... TMR element (magnetic sensor), 121 _Z ... TMR element (magnetic sensor), 122 ... arithmetic device, 130 ... direction information conversion device (direction acquisition device), 131 ... sensing element, 131A ... sensor substrate, 131B ... Cover member, 131C ... Support member, 201b ... Movable part, 201c ... Weight part, 205 ... Magnetic generating member 205 1 _... magnetism generating member, 205 2 _... magnetism generating member, 205 3 _... magnetism generating member, 205 4 _... magnetism generating member, 206 ... torsion bar, 260 ... piezoresistive element.

Claims (21)

A weight portion that is displaced by acceleration; at least one movable portion that is movable by an external force; at least one magnetism generating member that is formed on the weight portion; and a plurality of magnets for detecting magnetism from the magnetism generation member And a sensor substrate on which a plurality of magnetic sensors for detecting geomagnetism in three axial directions are formed at a plurality of positions including the at least one movable part;
A sensing element comprising: a cover member that covers the sensor substrate and tilts the at least one movable part with respect to other than the movable part by applying a mechanical force.   The sensing element according to claim 1, wherein the at least one movable part has a cantilever structure.   The sensing element according to claim 1, wherein the at least one movable part is a flat plate having both ends supported by a torsion bar.   The sensing element according to any one of claims 1 to 3, wherein the cover member has a protrusion for applying a pressure to the at least one movable part.   The sensing element according to claim 4, wherein the protrusion includes an elastic body.   The sensing element according to claim 1, wherein the cover member also serves as a part of a package member.   The sensing element according to claim 1, wherein the magnetism generating member is a magnetic thin film formed while applying a magnetic field for magnetization.   The sensing element according to claim 1, wherein the magnetism generating member is a permanent magnet.   The sensing element according to claim 1, further comprising a support member that supports the sensor substrate and has an inclined surface with which the inclined at least one movable part comes into contact.   10. The support member is made of single crystal silicon having a (100) surface, and the inclined surface is one of {111} surfaces formed by anisotropic etching. The sensing element according to 1.   The sensing element according to claim 9 or 10, wherein the support member also serves as a part of a package member. The at least one movable part is a plurality of movable parts,
The sensing element according to claim 1, wherein the plurality of movable parts are inclined in different directions.   The sensing element according to any one of claims 1 to 12, wherein the sensor substrate includes a sensor that is formed on the at least one movable portion and measures an inclination angle of the movable portion.   The magnetic sensing element according to claim 13, wherein the sensor for measuring the tilt angle includes a piezoresistive element.   The sensing element according to claim 1, wherein the magnetic sensor includes a magnetoresistive effect element.   The sensing element according to claim 15, wherein the magnetoresistive effect element is a tunnel magnetoresistive effect element.   The sensing element according to claim 15, wherein the magnetoresistive effect element is a giant magnetoresistive effect element. A sensing element according to any one of claims 1 to 17;
A computing device for respectively obtaining acceleration information in the three-axis direction and geomagnetic information in the three-axis direction based on output signals of a plurality of magnetic sensors in the sensing element and an inclination angle of the at least one movable part in the sensing element; A sensing device comprising:   A plurality of magnetic sensors for detecting the geomagnetism according to output signals of the plurality of magnetic sensors for detecting magnetism from the magnetism generating member when obtaining the geomagnetic information in the three-axis directions; 19. The sensing device according to claim 18, wherein the output signal is corrected. A sensing device according to claim 18 or 19;
An azimuth detection device comprising: an azimuth acquisition device that obtains azimuth information based on acceleration information in the three-axis directions and geomagnetic information in the three-axis directions from the sensing device. A position detection device for acquiring position information;
An azimuth detecting device according to claim 20;
An information apparatus comprising: an information acquisition device that acquires information based on azimuth information from the azimuth detection device and position information from the position detection device.

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