WO2003100449A1

WO2003100449A1 - Magnetic sensor and direction sensor

Info

Publication number: WO2003100449A1
Application number: PCT/JP2002/005170
Authority: WO
Inventors: Yasuhiro Tamura
Original assignee: Vitec Co., Ltd.
Priority date: 2002-05-28
Filing date: 2002-05-28
Publication date: 2003-12-04
Also published as: TW200405023A; JPWO2003100449A1; TWI287101B; AU2002256927A1

Abstract

A direction sensor (500) in which a magnetic sensor (600) for measuring the three axis components of the terrestrial magnetism vector and an inclination sensor (700) for measuring the inclinations in the three axis directions are integrally provided on one substrate. The magnetic sensor (600) has magnetic sensing elements some of which are secured to a thermally-shrinkable polyimide film. When the polyimide film is heated, the magnetic sensing elements are erected from the surface of the substrate.

Description

Description Magnetic sensor and direction sensor Technical field

The present invention relates to a mobile terminal device, and more particularly to a position information display system in which map information for displaying a current position on a display unit of a mobile phone rotates in response to a change in direction due to movement of the mobile phone. The present invention relates to a technology for detecting geomagnetism used to realize an information display system. Background art

A navigation system that displays the current position on a terminal device, for example, mounted on a vehicle, uses a GPS (Global Positioning System). GPS measures the current position by transmitting the difference in the arrival times of radio waves from four or more satellites to the user via a ground-based control station. The direction of travel can be obtained, for example, by calculating the amount of movement based on the signals from the gyro and GPS using the integration method. The current position and traveling direction measured by GPS and gyro are displayed on the monitor along with map data.

However, in the navigation system described above, the gyro and GPS travel at a speed of about 40 km / h or more are used for azimuth detection, so there is a time difference between the start point (display point) and the measurement point. In addition, errors are accumulated because the received signal is calculated by the integration method. To correct this, the signal from the gyro is corrected, but the signal processing of the gyro itself is also calculated by the integration method.If there is an error in the original information itself, the error is maintained or expanded as it is. Will be displayed.

In addition, the map data displayed on the monitor as the vehicle moves simply scrolls forward, backward, left and right to display the current position. For this reason, the direction of the vehicle may not match the direction of movement on the map data, which may cause discomfort. Further, it is difficult to reduce the size of the azimuth detecting device, and the integration method as described above causes unevenness or error in azimuth detection. For this reason, the conventional position display system includes a mobile terminal device, This is particularly difficult to apply to mobile phones.

Although the use of a magnetic sensor to realize the position display function of a mobile terminal device is an effective method, it is important to reduce the size of a high-accuracy magnetic sensor due to the demand for miniaturization of the mobile terminal device. Is an important issue. Disclosure of the invention

Therefore, an object of the present invention is to provide a technology for displaying a map by recognizing a current position in a portable terminal device and a technology for a magnetic sensor and a direction sensor incorporated in the portable terminal device.

One embodiment of the present invention is a geomagnetic sensor that is built in a portable terminal device and has a magnetic detection element that detects each of the three-axis components of the geomagnetic vector formed on a substrate, wherein at least one magnetic detection element is an MR sensor. (MagnetoEesistance) Provided is a geomagnetic sensor characterized by being an element or a Hall element. By making the MR element or hall element on the substrate, a small geomagnetic sensor can be realized.

Another aspect of the present invention is a magnetic sensor having a substrate with a magnetic detection element for detecting an axial component of a magnetic vector, wherein the magnetic detection element is an MR element or a Hall element, A magnetic sensor fixed to a film having By utilizing the heat shrinkage of the film, it is possible to form small-scale MR elements or Hall elements on a substrate.

The magnetic detecting element is preferably fixed to a polyimide film at least partially fixed to the substrate, and is preferably formed at a predetermined angle to the surface of the substrate. The predetermined angle may be, for example, perpendicular to the surface of the substrate. For example, in a three-axis magnetic sensor, two magnetic detection elements are configured to stand upright on the surface of the substrate in order to detect magnetic components in the X-axis direction and the Y-axis direction. They may be arranged at an angle of 90 ° to each other. The magnetic detection element for detecting the magnetic component in the Z-axis direction is formed on the surface of the substrate, and the Z-axis magnetic detection element does not necessarily need to be fixed to the polyimide film. Another example of a three-axis sensor is when one magnetic sensing element is configured upright on the surface of a substrate. Then, a magnetic component in one axial direction may be detected, and two magnetic detecting elements may be formed on the surface of the substrate to detect two axial components of a vertical magnetic field and a horizontal magnetic field, respectively.

It is preferable that the magnetic detection element is configured so that the polyimide film is heated and thermally contracted so as to form an angle with respect to the surface of the substrate. By utilizing the heat shrinkage of polyimide, it is possible to lift the magnetic sensing element from the surface of the substrate and erect it.

The surface of the polyimide film opposite to the side to which the magnetic detection element is fixed may be fixed to the pressing member. Polyimide has the property of being very strongly thermally bonded to silicon when heated to high temperatures. Therefore, it is preferable that the pressing member is formed of silicon from the viewpoint of adhesion to the polyimide. Similarly, the substrate may be formed of silicon.

Still another embodiment of the present invention provides a geomagnetic sensor having a magnetic detection element that detects each of the three-axis components of the geomagnetic vector, and a tilt sensor that detects a tilt in the three-axis direction are integrally formed on one substrate. A directional sensor provided. By forming a plurality of sensors integrally on one substrate, it is possible to form a very compact azimuth sensor. Preferably, the magnetic sensor and the tilt sensor are fabricated on a substrate. Some of the plurality of magnetic detection elements, for example, a magnetic detection element for detecting a magnetic component in a direction parallel to the substrate surface may be fixed to the polyimide film.

Yet another aspect of the present invention is a magnetic sensor including a substrate with a magnetic detection element that detects an axial component of a magnetic vector, wherein the magnetic detection element is an MR element or a Hall element, and the surface of the substrate is To provide a magnetic sensor formed on a slope having a predetermined angle with respect to the magnetic sensor. For example, the slope may be a side wall of a scribe line formed for cutting a silicon wafer. Further, when the substrate is etched, a sidewall having a predetermined angle is formed at the etching location due to the characteristics of the material, but the magnetic sensing element may be formed on such a sidewall.

It is to be noted that any combination of the above-described elements and any change of the expression between methods, devices, and the like are also included in the scope of the present invention. BRIEF DESCRIPTION OF THE FIGURES

The above and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings. FIG. 1 is a block diagram schematically showing a system according to the first embodiment of the present invention.

FIG. 2 is an exploded explanatory view showing an example of a magnetic detection unit included in the magnetic sensor. FIG. 3 is an explanatory diagram of a magnetic vector for determining a rotation angle of map information. FIG. 4 is an explanatory diagram showing map information of the current position specified by the GPS. FIG. 5 is a diagram illustrating a process of processing map information by the map information display processing unit, and is an explanatory diagram illustrating a map that is classified and selected from the map information of FIG. FIG. 6 is an explanatory diagram showing a map in a state where the selected map of FIG. 5 is rotated based on the azimuth.

FIG. 7 is a configuration diagram of a fluxgate magnetic sensor according to the second embodiment of the present invention.

FIG. 8 is a configuration diagram of the azimuth sensor according to the third embodiment of the present invention.

FIG. 9 is a diagram illustrating an example of the tilt sensor.

FIG. 10 is a diagram illustrating an example of the magnetic sensor.

Fig. 11 (a) is a diagram showing a state where the first magnetic sensing element is formed on the first silicon substrate, and Fig. 11 (b) is a state where a polyimide film is adhered above the first magnetic sensing element. Fig. 11 (c) is a top view of the polyimide film, and Fig. 11 (d) is a diagram showing a state in which the polyimide film is bent upward to make the first magnetic sensing element stand upright. FIG. 11 (e) is a view showing a state where the polyimide is fixed to the side of the second silicon substrate.

Fig. 12 (a) is a diagram showing the silicon wafer before dicing, Fig. 12 (b) is a partial cross-sectional view of the silicon wafer, and Fig. 12 (c) is the magnetic detection on the side wall of the scribe line. It is a figure showing the state where the element was formed. BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment> Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. The purpose of the first embodiment is to make it possible to display the current position of the holder together with the map information on a small portable terminal device, mainly a mobile phone, and to rotate the map information as the portable terminal device moves in the direction. The mobile terminal device is always displayed so that the traveling direction of the mobile terminal device is directed to a specific direction set in the plane of the display unit, and the position information of the GPS receiving unit is corrected by the azimuth information from the geomagnetic sensor. It is an object of the present invention to provide a position information display system which makes accumulation of error information as small as possible. FIG. 1 is a block diagram of a system according to a first embodiment of the present invention mounted on a mobile phone. In the figure, reference numeral 1 denotes a GPS receiver as a position detecting means, and the current longitude and latitude are calculated by the GPS satellite radio wave received from the antenna.

Numeral 2 denotes a terrestrial magnetism sensor serving as an azimuth detecting means, which comprises a sensor board in which a magnetic field detecting coil board 4 and an exciting coil board 5 are stacked above and below a sensor core 3. Here, a fluxgate magnetic sensor is illustrated as the azimuth detecting means 2, but other geomagnetic sensors may be used. Examples of the flux gate type magnetic sensor include the magnetic sensors disclosed by the present inventors in, for example, JP-A-9-43332 and JP-A-11-118892. It does not matter whether the sensor core is a plate-shaped amorphous core or a ring-shaped amorphous core. Other geomagnetic sensors using Hall elements or magnetoresistive elements are conceivable. Both are preferably small enough to be mounted on a portable terminal device and have high sensitivity.

FIG. 2 is an exploded view of a specific example of the magnetic detection unit 100 included in the magnetic sensor. The sensor core 3 is formed by cutting amorphous thin plates in a ring shape, and etching them as if wound with a toroidal core. The magnetic field detection coil substrate 4 includes a first detection coil substrate 41 having a coil pattern 41 a for forming an X-axis direction component magnetic field detection coil, and a coil pattern 42 a for forming a Y-axis direction component magnetic field detection coil. And a second detection coil substrate 42. The first detection coil board 41 has two X coil boards 411 that are stacked so as to be mutually conductive so as to sandwich the sensor core 3 from above and below. Each X-coil board 4 1 1 forms an X-coil pattern 4 1 a for the X-axis component magnetic field detection coil on the surface of the epoxy board, and a terminal for connecting each X-coil pattern 4 1 a on the periphery. Through hole for 4 1 b. Similarly, the second detection coil substrate 42 has two Y coil substrates 421, which are stacked so as to be conductive with each other so as to sandwich the sensor core 3 from above and below. Each Y-coil substrate 4 21 forms a Y-coil pattern 4 2a for the Y-axis component magnetic field detection coil on the surface of the epoxy substrate, while a terminal for connecting each Y-coil pattern 4 2a on the periphery. Formed through holes 4 2 b.

Further, the excitation coil substrate 5 has two excitation coil substrates 51 and 52 that are stacked so as to be mutually conductive so as to sandwich the sensor core 3 from above and below. Each of the excitation coil substrates 51 and 52 has excitation coil patterns 51a and 52a formed on the surface of the epoxy substrate, and through holes 51b and 136b for terminals for connecting the excitation coil patterns on the peripheral edge. 5 2b is formed. The magnetic detection unit 100 is formed by laminating the sensor core 3, the magnetic field detection coil substrate 4, and the excitation coil substrate 5 sequentially around the sensor core 3 and pressing the sensor core 3 to form a layer.

In the magnetic detection unit 100, the sensor core 3 is saturated by passing an alternating current around the sensor core 3. In the state where there is no influence of the external magnetic field, the timing at which the sensor core 3 saturates appears evenly when going in the positive direction and when going in the negative direction of the alternating current. However, when a magnetic flux from a certain direction passes through the sensor core 3, the magnetic field is superimposed on the magnetic field generated in the sensor core 3 by either the above-mentioned positive or negative current, and the saturation of the sensor core 3 in that direction occurs. Hasten. A sense coil is wound around the sensor core 3, and the imbalance of the saturated state is externally detected as a voltage. By arranging two pairs of sense coils (X coil and Y coil) orthogonally, it is possible to detect the output voltage corresponding to the magnetic field component in the X-axis direction and the magnetic field component in the Y-axis direction.

Reference numeral 6 denotes a CPU, which performs predetermined arithmetic processing based on the input position signal from the GPS receiver 1 and the azimuth signal from the magnetic sensor 2 to measure the current position (longitude, latitude, and azimuth). Is read out from the map information recording section 7 and displayed on the display 91 of the position information display section 9 together with the current location index. At the same time, the position information display section 9 sounds and displays the current position, direction, and the like with synthesized speech.

The position information from the GPS receiver 1 and the azimuth information from the magnetic sensor 2 complement each other. Calculates from changes in the location information of GPS receiver 1 due to movement of the mobile terminal device Thus, the azimuth information can be obtained. By comparing this azimuth information with the azimuth information from the magnetic sensor 2 and determining that the azimuth information from the magnetic sensor 2 is positive, the start point can be determined. This makes it possible to return the position information of the GPS receiver 1 to the start time, and to return the integrated and accumulated error information to zero.

The map information display processing unit 8 rotates the map information of the current position displayed on the display 91 by a required angle, if necessary, and moves the current position index on the map information of the current position (the direction in which the magnetic sensor is facing). Is displayed so that always faces the top of the display. This will be described with reference to FIG. The azimuth signal from the magnetic sensor 2 is input to the CPU 6 as an analog value obtained by decomposing the detected geomagnetism into a magnetic field vector value in the X-axis direction (east-west direction) and a magnetic field vector in the Y-axis direction (north-south direction). The CPU 6 converts this input signal into a digital signal by AZD. The resolution of the magnetic field vector values in the X-axis direction and the Y-axis direction can be increased by using a predetermined correction parameter stored in EEP-ROM. Assuming that the magnetic north direction is 0 degrees, the clockwise rotation angle to the composite vector T (representing the direction of the magnetic sensor) of the X-axis magnetic field vector value XI and the Y-axis magnetic field vector value Y1 (Azimuth) Θ is obtained by the following equation.

Θ = tan— ¹ X 1 / Y 1

The azimuth angle can be calculated by calculation logic that does not use a correction parameter for the magnetic field vector value in each direction.

The processing steps of the map information display processing unit 8 will be described with reference to FIGS. For example, suppose that the user of the mobile terminal device is currently located at the corner of Gakuin University on Shinjuku Station Chuo-dori and is facing northeast (with an azimuth angle of 45 degrees). The corresponding longitude and latitude map information (see Fig. 4) is called from the map information recording unit 7 by the position signal from the GPS receiving unit 1. Then, map information in a range matching the size of the display screen (for example, 200 dots X 200 dots) centering on the current position P is selected. At this time, the selected map information A is map information in a range rotated clockwise by the azimuth angle Θ obtained by the azimuth signal from the magnetic sensor 2 (see FIG. 5). Then, when displayed on the display 91, the display processing unit 8 selects Map information A is rotated counterclockwise by the azimuth and displayed as corrected (see Fig. 6). As a result, the map information B is a map in which the direction in which the magnetic sensor 2 faces (the traveling direction) is always set to the upper side of the display 91. Whenever the direction of the traveling direction is changed due to the movement of the mobile terminal, the map information display processing unit 8 performs the same processing as above each time, and always displays the map information in which the traveling direction is directed to the upper side of the display. These series of processes are performed quickly and in real time.

Further, the map information display processing section 8 converts the characters and symbols included in the map information displayed on the display 91 without rotating the map information when the map information is rotated based on the azimuth. The original positional relationship is maintained in the upper side direction. In FIG. 6, characters and the like are also rotated by the azimuth and displayed without performing such processing. The characters and symbols written in the horizontal direction also maintain the mode written in the horizontal direction when the map information is rotated and displayed. This makes it easier to visually recognize information such as characters.

The destination may be input by using a key of the mobile terminal device. In that case, the shortest route to the destination and the required time are calculated based on the map information, and these are displayed on the display of the position information display unit or by the audio output unit. Also, if the received or measured position information of the GPS receiving unit and the azimuth information of the magnetic sensor are temporarily recorded, the trajectory of the mobile terminal device can be confirmed later based on the information.

According to the first embodiment of the present invention, the following effects can be obtained. A fluxgate magnetic sensor consisting of a sensor board with a magnetic field detection coil board and excitation coil board laminated above and below the sensor core, or a Hall element or a magnetoresistive element, etc. is used for the direction detection means used in conjunction with the GPS position detection means. Since the geomagnetic sensor is used, it is possible to display the accurate current position of the holder together with the map information on the display of a small-sized mobile terminal device, especially a mobile phone.

Since the map information is rotated and scrolled by the map information processing means based on the azimuth angle obtained from the magnetic field vector value of the magnetic sensor, the moving direction of the mobile terminal device is always set in advance in the plane of the display unit. The direction of the map information matches the direction of travel, giving a sense of discomfort to the user. Not only will you not be able to obtain it, but you will also be able to dynamically understand the correct orientation and position.

Further, since the position information by the GPS is supplemented by the azimuth information by the geomagnetic sensor, the error information accumulated by the integration method can be eliminated as much as possible, and an accurate 髙ぃ position display system can be provided.

The features of the first embodiment are defined in the following items.

(Item 111) A fluxgate type consisting of a mobile terminal device with position detection means for detecting the position based on GPS signals, and a sensor board in which a magnetic field detection coil board and an excitation coil board are stacked above and below a sensor core. Azimuth detecting means for detecting an azimuth by a geomagnetic sensor using a magnetic sensor or a Hall element or a magnetoresistive element, calculating means for correcting the position information by the position detecting means by the azimuth detecting means, and map information are stored. Map information storage means, position information display means for displaying the current position determined based on the calculation means together with the map information, and a map displayed by the position information display means with a change in the direction of the current position Display processing means for rotating and scrolling information by a change angle based on an output signal from the direction detection means, When the azimuth is changed by the movement of the band terminal device, the map information is rotated by the display processing means, the current position of the portable terminal device is displayed on the display section of the position information display means, and the traveling direction of the mobile terminal device is displayed. A position information display system, characterized in that the display is always performed so as to face a predetermined direction in a plane of the display unit.

(Item 1-2) The magnetic field detecting coil substrate of the flux gate type magnetic sensor includes a first detecting coil substrate having a coil pattern for forming an X-axis direction component magnetic field detecting coil, and a Y-axis direction component magnetic field detecting coil forming coil. A second detection coil substrate having a coil pattern, the excitation coil substrate has an annular coil pattern for forming an excitation coil, and an edge of the sensor substrate is connected to each coil pattern. The position information display system according to (1) wherein a through hole is formed.

(Item 1-13) The position information display system according to (Item 1-11), wherein the current position of the mobile terminal device is always displayed with the upper side direction in the plane of the display unit of the position information display means as the traveling direction.

(Item 114) The position information display means includes visual display means of images and characters, and sound. The position information display system according to (11-1), further comprising: an auditory display means comprising a voice, wherein the current position and / or the movement progress status are displayed by voice together with the visual sense.

(Item 115) When the map information displayed by the position information display means is rotated by the display processing means, the characters included in the map information are rotated in the specific direction. The position information display system described in (1) to maintain the previous positional relationship.

(Item 1-6) The magnetic sensor decomposes geomagnetism into an X-axis direction magnetic field component and a Y-axis direction magnetic field component, and outputs this as an analog value signal.The arithmetic unit converts the analog signal into a digital signal. The display processing means rotates the map information in a required direction by using an angle up to the current position azimuth when the direction of the north magnetic pole is 0 degrees as a rotation angle (item 11-1). Location information display system.

(Item 11) The position information display means displays a shortest route to the destination or a required time; a position information table according to (Item 11);

Geomagnetic sensors have conventionally been used to measure the magnetic orientation at an observation point. The geomagnetic sensor is installed on the horizontal plane at the observation point and detects the biaxial components of the geomagnetic vector on the horizontal plane. The magnetic azimuth is calculated from the two-axis components detected by the geomagnetic sensor.

Applications for displaying map information on mobile devices such as mobile phones and mobile terminal devices are expanding. To this end, it is assumed that geomagnetic sensors will be incorporated into portable devices, and small, high-performance geomagnetic sensors are required. The present inventor has made the present invention based on the above recognition, and has an object to provide a small-sized and high-performance geomagnetic sensor.

An aspect of the second embodiment relates to a fluxgate magnetic sensor. It has a magnetic detection unit including a sensor coil (X coil, Y coil) and a toroidal coil that generates an AC magnetic field that excites them, and a signal processing circuit that processes the output signal of the magnetic detection unit.

The magnetic detection section may be formed by integrating a plurality of substrate layers. In these substrate layers, the coil portions of the sensor coil (X coil, γ coil) and toroidal coil may be constituted by a substrate pattern.

The signal processing circuit includes a direction dependency circuit provided independently for each of the X coil and the Y coil. Each direction-dependent circuit includes a first and a second analog switch configured such that one is turned on and the other is turned off according to the frequency of the alternating magnetic field, and an active first integration that integrates an output of the first analog switch. Circuit, an active second integrating circuit for integrating the output of the second analog switch, a differential amplifier for amplifying a difference between the first integrating circuit and the second integrating circuit, and an output of the differential amplifier It is composed of an A / D converter that converts digital signals into digital signals.

The fluxgate magnetic sensor according to the second embodiment will be described with reference to FIG.

FIG. 7 is a configuration diagram of the flux gate type magnetic sensor 300, and shows the X coil pattern 41 a of the magnetic detection unit 100 shown in FIG. 2 and the corresponding signal processing circuit 200. Things. One end of the X coil pattern 41 a is grounded, but may be connected to the plus side of the operational amplifier in the first integration circuit 24 and the second integration circuit 26.

The signal processing circuit 200 includes an active first integration circuit 24, an integration circuit for integrating the outputs of the first analog switch 20, the second analog switch 22, and the first analog switch 20. An active second integration circuit 26 for integrating the output of the analog switch 22, a differential amplifier 28 for amplifying the difference between the first integration circuit 24 and the second integration circuit 26, and its differential An A / D converter 30 for converting the output of the amplifier 28 into a digital signal is arranged as shown in FIG. The integration constant and the differential amplifier 28 in the first integration circuit 24 and the second integration circuit 26 are determined according to the capability of the A / D converter 30.

In the signal processing circuit 200, the frequency f corresponding to the cycle of the AC magnetic field. Accordingly, the first analog switch 20 and the second analog switch 22 are alternately turned on and off. The respective output voltages are integrated by the first integration circuit 24 and the second integration circuit 26, and the difference between them is amplified by the differential amplifier 28, so that the output corresponding to the magnetic field component in the X-axis direction is obtained. Voltage can be obtained. A / D converter 30 outputs the output voltage. The data is converted from analog to digital, and the data of the magnetic component in the X-axis direction is transferred to the CPU. The signal processing circuit 200 is provided independently for each of the X coil and the Y coil (not shown), but the same processing is performed on the signal detected from the Y coil.

By performing the above-described signal processing on the output voltage detected from the X coil and the Y coil, digital data corresponding to the magnetic components in the X-axis direction and the Y-axis direction can be obtained, and the magnetic direction can be known. .

According to the second embodiment of the present invention, signal processing for specifying a magnetic azimuth in a fluxgate magnetic sensor is realized.

The features of the second embodiment are defined in the following items.

(Item 2-1) A fluxgate magnetic sensor including a magnetic detection unit including an XY coil and a toroidal coil for generating an AC magnetic field for exciting the XY coil and a signal processing circuit for processing an output signal of the magnetic detection unit. hand,

The signal processing circuit includes two directionality dependent circuits independently provided corresponding to the XY coils, respectively.

Each direction-dependent circuit is

According to the frequency of the AC magnetic field, the signals output from the corresponding coils are integrated with the first and second analog switches configured so that one is on and the other is off, and the output of the first analog switch. An active first integration circuit, an active second integration circuit for integrating the output of the second analog switch, and a differential amplifier for amplifying a difference between the first integration circuit and the second integration circuit. ,

An A / D converter that converts the output of the differential amplifier to a digital signal,

A geomagnetic sensor comprising:

(Item 2-1) A flux gate type magnetic sensor including a magnetic detection unit including an XY coil and a toroidal coil for generating an AC magnetic field for exciting them and a signal processing circuit for processing an output signal of the magnetic detection unit. So,

The magnetic detection unit is formed by integrating a plurality of substrate layers, and each of the substrate layers constitutes an XY coil and a toroidal coil by a substrate pattern. The signal processing circuit includes two direction-dependent circuits independently provided corresponding to the XY coils, respectively.

Each direction-dependent circuit is

A first and a second analog switch configured so that one is turned on and the other is turned off according to the frequency of the AC magnetic field according to the frequency of the AC magnetic field, and an output that integrates the output of the first analog switch. A first integrating circuit, an active second integrating circuit that integrates the output of the second analog switch, a differential amplifier that amplifies the difference between the first integrating circuit and the second integrating circuit,

A geomagnetic sensor comprising:

The third embodiment aims at realizing a smaller magnetic sensor. In the following, a technology for fabricating a magnetic sensor and a direction sensor incorporating the magnetic sensor in a small size will be described.

FIG. 8 is a diagram showing a configuration of the direction sensor 500 according to the third embodiment of the present invention. The direction sensor 500 includes a magnetic sensor 600, an inclination sensor 700, a pressure sensor 800, and a temperature sensor 900, and has a function of detecting a position, a direction, a height, and the like. In the direction sensor 500, the magnetic sensor 600, the tilt sensor 700, the barometric pressure sensor 800, and the temperature sensor 900 may be formed separately, but are mounted on a portable terminal device or the like. In addition, it is preferable to be constructed on a single substrate and formed in a small size. The magnetic sensor 600 has at least three magnetic detecting elements for detecting each of the three axis components of XYZ of the magnetic vector. It is preferable that the tilt sensor 700 has a function of detecting the tilt angle of the substrate, and can detect the tilt angles of the XYZ three-axis directions. The tilt angle in the X-axis direction may be called a pitch angle, and the tilt angle in the Y-axis direction may be called a roll angle. The atmospheric pressure sensor 800 detects the pressure of the outside air. The temperature sensor 900 detects the temperature. The detected temperature is used to correct the deviation of the output of the magnetic sensor 600 due to the temperature drift.

FIG. 9 is a diagram illustrating an example of the tilt sensor 700. The tilt sensor 700 is a weight 70 2. When an acceleration component is applied to the weight body 702, a distortion occurs in the support member 704 that supports the weight body 702, and the distortion is detected by a resistor to measure the inclination. Although only one support member 704 is shown in the figure, it is preferable that the weight body 702 be supported by a plurality of support members 704 from three axial directions of XYZ. Preferably, these support members 704 include a piezo element. The tilt sensor 700 detects tilt angles in the XYZ three-axis directions. Since the tilt of the magnetic sensor 600 is detected as the tilt angle in the Z-axis direction, the tilt angles detected in the X-axis and Y-axis directions can be corrected.

FIG. 10 is a diagram illustrating an example of the magnetic sensor 600. The magnetic sensor 600 functions as a three-axis magnetic sensor, and includes a first magnetic detecting element 602 for detecting a magnetic component in the X-axis direction and a second magnetic detecting element 604 for detecting a magnetic component in the Y-axis direction. And a third magnetic detecting element 606 for detecting a magnetic component in the Z-axis direction.

In the first and second embodiments, an example in which magnetic components in the X-axis direction and the Y-axis direction are detected by a flux gut type magnetic sensor has been mainly described. The flux gate magnetic sensor requires a ring core, which is a coil, and therefore has a slightly larger configuration. For this reason, there is no problem when the fluxgate magnetic sensor is mounted on a vehicle that can provide a sufficient space, but when the fluxgate magnetic sensor is mounted on a small terminal device such as a mobile phone, the case is not considered due to the relationship with other built-in elements. It was necessary to devise a layout design in the body.

On the other hand, it is known that a magnetoresistive element such as an MR element and a magnetically sensitive element such as a Hall element can be formed in a small size using a fluxgate magnetic sensor. It has not been easy to successfully manufacture MR elements or Hall elements. Therefore, the third embodiment provides a technology for forming the magnetic sensor 600 in a small size. In particular, this magnetic sensor 600 is formed on a single substrate together with another sensor such as a tilt sensor. Provide technology to do.

In the magnetic sensor 600, at least the first magnetic detecting element 602 and the second magnetic detecting element 604 are preferably an MR element or a Hall element, and the third magnetic detecting element 606 is also the same. It is preferably an MR element or a Hall element. By forming all magnetic sensing elements as MR elements or Hall elements, The magnetic sensor 600 can be formed using a series of semiconductor manufacturing processes.

The first magnetic sensing element 602 and the second magnetic sensing element 604 are formed at a predetermined angle with respect to the surface of the substrate 610, and are arranged in a direction parallel to the substrate surface (X-axis direction and the like). (Y axis direction). Here, it is preferable that the first magnetic detecting element 602 and the second magnetic detecting element 604 are formed so as to be substantially upright on the surface of the substrate 610. Further, on the surface of the substrate 61, the first magnetic detecting element 602 and the second magnetic detecting element 604 are arranged so that the direction parallel to each surface is 90 °. Is preferred. The third magnetic detecting element 606 is formed on the surface of the substrate 610 and detects a magnetic component in a direction perpendicular to the substrate surface (Z-axis direction).

Each magnetic sensing element has a magnetoresistive film having a thin film structure represented by the general formula (Col-aFea))-y-zLxMyOz. The magnetic film may have a magnetic permeability of 1,000, 0001e or more, and may be made of a rare-earth element capable of detecting a magnetic field of {μ} or more and a nano-order magnetic metal powder.

In the manufacturing process of the magnetic sensing element, it is preferable that a magnetic sensing element, which is an MR element or a Hall element, is first formed on a substrate, and then the formed magnetic sensing element is fixed to a polyimide film. In this example, the first magnetic detection element 602 and the second magnetic detection element 604 are fixed to a polyimide film. At least a part of the polyimide film is fixed to the substrate.

The polyimide film has a property of shrinking by applying a predetermined heat. In the third embodiment, by utilizing the heat shrinkage characteristic of the polyimide film, a magnetic detection element is fixed to one surface of the polyimide film, and then the area between the area where the magnetic detection element is fixed and the area fixed to the substrate is determined. A part of the intervening region is linearly heated and contracted, and the region where the magnetic sensing element is fixed is bent in a desired direction. In this way, it is possible to produce a magnetic sensing element that stands substantially upright on the surface of the substrate 610. Hereinafter, a description will be given of a method of configuring the first magnetic sensing element 622 upright on the substrate. The second magnetic sensing element 604 can be set upright by the same method. In the magnetic sensor 600 shown in FIG. 10, two magnetic detecting elements 602 and 604 are configured to be upright. In another example, two magnetic detecting elements are provided. May be formed on the plane of the substrate 6 10, and one magnetic sensing element may be configured to stand upright on the substrate 6 10. At this time, the two magnetic detecting elements formed on the plane of the substrate 6 10 detect the vertical magnetic field and the horizontal magnetic field of the magnetic vector, and the upright magnetic detecting element detects these magnetic fields. What is necessary is just to detect a perpendicular component.

Hereinafter, a process of manufacturing the magnetic sensor 600 shown in FIG. 10 will be described. FIG. 11A is a diagram showing a state where the first magnetic sensing element 602 is formed on the first silicon substrate 620. Although not shown, in this step, the second magnetic detecting element 604 and the third magnetic detecting element 606 are also formed on the first silicon substrate 62 at the same time. Each magnetic sensing element is formed using a semiconductor manufacturing process.

FIG. 11B is a diagram showing a state in which a polyimide film 62 2 is adhered above the first magnetic detection element 62 2. For example, when using polyimide mixed with silica, the polyimide film 622 can be thermally bonded to the first silicon substrate 620 by heating to approximately 365 ° C. Then, the polyimide film 62 2 above the first magnetic detection element 62 is cut by etching according to the shape of the first magnetic detection element 62. Further, silicon present below the first magnetic sensing element 602 is removed by etching. At this time, it is preferable that the polyimide film 622 located above the third magnetic sensing element 606 which does not need to be erected is removed by etching. Wiring and circuit elements required for each magnetic detection element are formed on the first silicon substrate 62 or on the polyimide film 62.

FIG. 11C is a top view of the polyimide film 62. FIG. The polyimide film 622 has a rectangular bendable area 626 formed with cuts on three sides. The bent region 626 is formed by making a cut so as to cover at least the lower first magnetic sensing element 602. The bent region 626 may be formed after the polyimide film 622 is bonded to the first silicon substrate 620 as described above, but may be formed before bonding. FIG. 11D is a diagram showing a state in which the polyimide film 622 is bent upward and the first magnetic detection element 622 is erected. The polyimide film 622 has a property of contracting when heated to a high temperature. In the present embodiment, by utilizing the characteristics, a part of the polyimide finolem 622 is heated, the polyimide film 622 is bent, and the first magnetic sensing element 602 is connected to the first silicon. It stands upright in the direction perpendicular to the surface of the substrate 62. As a matter of course, the polyimide film 622 may be bent downward.

FIG. 11E is a diagram showing a state where the polyimide film 62 2 is fixed to the side of the second silicon substrate 62 4. The second silicon substrate 624 has an opening 628 corresponding to the shape of the bending area 626 of the polyimide film 622, and the portion in contact with the polyimide film 622 is It functions as a holding member for fixing the polyimide film 62. Specifically, the surface of the polyimide film 622 opposite to the side to which the first magnetic detection element 62 is fixed is fixed to the pressing member. Preferably, the second silicon substrate 624 on the third magnetic sensing element 606 has an opening formed by etching. The second silicon substrate 624 may be fixed to the polyimide film 622 before the first magnetic sensing element 62 is erected, or may be fixed after the first magnetic sensing element 602 is erected. It is preferable that the side portions (pressing members) of the polyimide film 622 and the second silicon substrate 624 are heated and thermally bonded.

By the above process, the first magnetic sensing element 622 standing upright on the surface of the substrate is formed. In order to manufacture the magnetic sensor 600 shown in FIG. 10, it is preferable to simultaneously form the second magnetic detecting element 604. The second silicon substrate 624 may be provided with other parts, if necessary, so as to leave only a holding member for fixing the first magnetic detection element 602 and the second magnetic detection element 604. This region may be removed by etching. Further, in the third embodiment, the use of the silicon substrate and the polyimide film allows the magnetic sensor to be formed as an integral structure, thereby contributing to downsizing of the magnetic sensor. Further, since other sensors, that is, a tilt sensor and a barometric pressure sensor, can be formed on the silicon substrate, a very compact azimuth sensor can be manufactured as a whole. FIG. 12A is a diagram showing the silicon wafer 6550 before dicing. A scribe line, which is a cutting margin for cutting into chips, is formed on the silicon wafer 65 by etching. FIG. 12B is a partial cross-sectional view of the silicon wafer 65. Due to the etching characteristics of silicon, the side wall 656 of the scribe line 652 is formed with an inclination of about 67 degrees with respect to a plane parallel to the surface of the wafer. In the figure, the dotted line is the cut line at the time of dicing.

FIG. 12C is a diagram showing a state in which the magnetic sensing element 654 is formed on the side wall 656 of the scribe line 652. As described above, by forming the magnetic detection element 654 on a surface having a predetermined angle with respect to the surface of the silicon wafer 650, a three-axis magnetic sensor can be easily manufactured. Since the magnetic sensing element 654 is not configured perpendicular to the surface of the silicon substrate, the detected magnetic component is corrected based on the angle of the slope (67 degrees).

Magnetic sensors mounted on mobile terminals, etc., can detect not only natural magnetic fields, but also dynamic magnetic fields generated inside mobile terminals, in urban areas and in areas with developed transportation networks. There is. Therefore, in order to extract only the natural magnetic field component, it is necessary to remove the dynamic magnetic component from the detected magnetic component. When a conventional two-axis magnetic sensor is used, the dynamic magnetic component cannot be efficiently removed because the magnetic field strength cannot be obtained.

On the other hand, the magnetic sensor 600 according to the present embodiment can detect magnetic components in three axial directions, and thus can measure the magnetic field strength. For example, in the magnetic sensor 600, a predetermined magnetic field strength is set and recorded in a recording unit in advance, and when a magnetic component exceeding the set strength is detected, the magnetic component is determined to be noise and canceled. It is possible to do. As described above, since the magnetic sensor 600 can detect the magnetic field strength, it is possible to realize automatic calibration by arithmetic processing of the CPU 6.

When detecting the geomagnetic component, if the magnetic sensor 600 is tilted, it is necessary to correct the tilt by the output value of the tilt sensor. When a conventional two-axis tilt sensor (acceleration sensor) is used, only correction data in the X-axis and Y-axis directions can be obtained, and the tilt of the tilt sensor itself cannot be detected. Was. So Therefore, when using a 2-axis tilt sensor, calibration is performed with the Z-axis component of the tilt sensor set to 0, that is, with the tilt sensor horizontal, and the detection value of the magnetic sensor is corrected. I needed to.

Since the tilt sensor 700 according to the third embodiment can detect the tilt angles in the three axial directions, calibration that is performed by setting the tilt sensor horizontally is unnecessary. In addition, since the weight body 700 is used, the tilt sensor 700 can be formed compactly on one substrate together with the magnetic sensor 600 and the like. According to the tilt sensor 700, the calibration of the tilt angle can be automatically performed by the arithmetic processing of the CPU 6 without being conscious of the user, and the extremely accurate magnetic sensor 600 can be realized. Output can be obtained.

When the map information is distributed on the mobile terminal device, the direction sensor 500 can measure the position and direction with extremely high accuracy. It is possible to process and display map information. For example, map information cutout and display processing may be performed by installing application software such as JAVA (registered trademark) in advance on the portable terminal device. Needless to say, as described in the first embodiment, the orientation sensor 500 built in the portable terminal device and the GPS cooperate to measure the position and orientation of the portable terminal device. Is also good. In any case, it is preferable that the mobile terminal device can display the distributed map information in an enlarged or reduced size according to its own screen size.

In addition, by mounting the atmospheric pressure sensor 800 on the portable terminal device, it is possible to measure the height at which the portable terminal device is located. Since the measured value of air pressure changes depending on the climate, the relationship between the air pressure at the ground surface (absolute air pressure) and the rise in air pressure at a position higher than the ground surface (relative air pressure) is recorded in the recording unit in advance as a table It is preferable to keep it. The relationship between the absolute pressure and the relative pressure may be stored in the recording unit in the form of an arithmetic expression. The CPU 6 calculates the absolute pressure and the relative pressure based on the output value of the atmospheric pressure sensor 800 to specify the height, and based on the output value of the magnetic sensor 600, determines the current position of the portable terminal device ( Latitude and longitude) to determine the floor of the building as a result. For example, being located on the third floor of a building When it is determined, it is possible to display the information of the store on the third floor of the building on the display screen of the mobile terminal device, and it is possible to realize a mobile terminal device that is highly convenient for the user. Become.

By manufacturing a three-axis magnetic sensor 600, a three-axis tilt sensor 700, and the like on one substrate, it is possible to form a highly accurate azimuth sensor 500 in a very compact manner. The direction sensor 500 has been mainly described as being incorporated in a portable terminal device. However, it is easily understood by those skilled in the art that the direction sensor 500 may be incorporated in a vehicle or other large-sized mobile device. It is understood. Industrial applicability

INDUSTRIAL APPLICABILITY As described above, the present invention can be used for a device for displaying position information and a magnetic sensor or a direction sensor incorporated in the display device.

Claims

The scope of the claims

1. A geomagnetic sensor built in a mobile terminal device and formed on a substrate with a magnetic detecting element for detecting each of the three axial components of the geomagnetic vector,

A geomagnetic sensor characterized in that at least one magnetic detection element is an MR element or a Hall element.

2. A magnetic sensor provided on a substrate with a magnetic detecting element for detecting an axial component of a magnetic vector, wherein the magnetic detecting element is an MR element or a Hall element and is formed on a film having heat shrinkage. A magnetic sensor, which is fixed.

3. The magnetic sensing element is fixed to a polyimide film at least partially fixed to the substrate, and is formed at a predetermined angle with respect to the surface of the substrate. The magnetic sensor according to range 2.

4. The magnetic sensor according to claim 3, wherein the magnetic detection element is configured to be inclined with respect to the surface of the substrate by heating and contracting a polyimide film. .

5. The magnetic sensor according to claim 3, wherein a surface of the polyimide film on a side opposite to a side to which the magnetic detection element is fixed is fixed to a pressing member.

6. The magnetic sensor according to claim 5, wherein the pressing member is formed of silicon.

7. The magnetic sensor according to claim 2, wherein the substrate is formed of silicon.

8. An azimuth sensor in which a geomagnetic sensor having a magnetic detection element that detects each of the three axial components of the geomagnetic vector and a tilt sensor that detects the tilt in the three axial directions are integrally formed on a single substrate. .

9. The direction sensor according to claim 8, wherein some of the magnetic detection elements are fixed to a polyimide film.

10. A magnetic sensor provided with a magnetic detection element for detecting an axial component of a magnetic vector on a substrate, wherein the magnetic detection element is an MR element or a Hall element, and A magnetic sensor characterized by being formed on a slope having a predetermined angle with respect to the surface of a plate.