JP5505193B2 - Compound sensor, sensor unit - Google Patents

Description

  The present invention relates to a composite sensor that includes a plurality of sensor units, and is preferably used for vehicles such as railway vehicles and automobiles, and a sensor unit that includes the composite sensor.

  Conventionally, various types of vehicles such as railway vehicles and automobiles have been provided with a vibration sensor unit capable of detecting abnormal vibration, a temperature sensor unit capable of detecting abnormal temperature, or a magnetic sensor in order to improve safety and maintainability. Various sensor units such as a configured speed sensor unit are mounted. And the mode which these various sensor parts are unitized and provided in a common case is known (refer patent documents 1 and 2).

JP 2002-340922 A JP 2003-172347 A

  By the way, the composite sensor described in Patent Document 1 is integrated by arranging each sensor unit in a common case and filling the case with a synthetic resin. Therefore, each sensor has to be individually arranged in a limited narrow space in the case, which is extremely poor in workability and may cause deterioration in reliability.

  Patent Document 2 discloses a sensor unit in which each sensor is mounted on a common circuit board. Although not specified in the document, those skilled in the art will refer to “mounting each sensor on a circuit board” as a circuit for each sensor (completed electronic component) that is individually manufactured and in a finished product state. It is customary to consider that each means mounting on a substrate. If it is such an aspect, since each sensor is naturally manufactured in a separate process, even if there is an overlapping process in the manufacturing process of each sensor, it must be performed separately. High cost can be caused. In particular, if there are inclusions such as an adhesive between the vibration sensor and the temperature sensor, a temperature error is likely to occur, and there is a problem that appropriate temperature measurement cannot be performed.

  Further, in this technical field, further space saving (compacting) of the composite sensor in the case is required.

  In order to solve these problems, the present inventors have devised a composite sensor that can at least perform vibration sensing function, temperature sensing function, and speed sensing function, and realize further miniaturization and reduction of manufacturing cost. It came to do.

  That is, the composite sensor according to the present invention includes a support plate having a cantilever structure with one end fixed or a both-end support structure with both ends fixed, and a multilayered structure on a vibration region of the support plate that can vibrate. A temperature sensor unit formed by a thin film formed of the same material as the lower electrode of the vibration sensor unit on a region other than the vibration region on the support plate. And a speed having a magnetic sensitive thin film formed on a region of the support plate other than a region (vibration / temperature sensor forming region) where the vibration sensor unit and the temperature sensor unit are formed, and an electrode formed on the magnetic sensitive thin film. It is characterized by having a sensor unit integrally.

  Here, the vibration sensor unit has a lower electrode, a piezoelectric thin film and an upper electrode formed on the support plate, and is inseparable from the support plate. Therefore, a vibration sensor that can be handled as an electronic component (can be mounted on a circuit board as an electronic component) is composed of a support plate and a vibration sensor portion. Similarly, the temperature sensor unit has a thin film formed on a support plate, and is inseparable from the support plate. Therefore, a temperature sensor that can be handled as an electronic component (can be mounted on a circuit board as an electronic component) is composed of a support plate and a temperature sensor unit. The speed sensor unit includes a magnetically sensitive thin film and an electrode formed on the support plate, and is inseparable from the support plate. Therefore, a speed sensor that can be handled as an electronic component (can be mounted on a circuit board as an electronic component) includes a support plate and a speed sensor unit. That is, in the present invention, the “sensor unit” alone does not constitute an electronic component, but the “composite sensor” itself can be regarded as one electronic component.

  As described above, the composite sensor of the present invention forms a temperature sensor unit made of a thin film formed of the same material as the lower electrode of the vibration sensor unit on the support plate on which the vibration sensor unit is formed, and further uses a common support plate. A temperature sensor (temperature sensor) utilizing a technical idea of forming a speed sensor unit having a magnetically sensitive thin film formed thereon, that is, a part of a vibration sensor (including a vibration sensor unit and a support plate) And a speed sensor unit on a common support plate on which a vibration sensor unit and a temperature sensor unit are formed. The entire sensor can be made compact and space-saving. In addition, in the composite sensor of the present invention, the temperature sensor unit and the speed on the region (region other than the vibration region, fixed region) that does not directly contribute to the vibration sensing function of the vibration sensor on the support plate constituting the vibration sensor. Since the sensor part is formed, for example, it is possible to efficiently and easily realize the downsizing as compared with the aspect of downsizing by increasing the mounting density of a plurality of electronic components on the circuit board. In particular, a speed sensor unit including a magnetic sensitive thin film (a thin film of a magnetic sensitive substance) and an electrode makes it possible to configure the speed sensor unit with a Hall element mainly composed of the magnetic sensitive thin film and the electrode. The Hall element is advantageous in that it can be downsized and the detection accuracy can be enhanced.

  Furthermore, the composite sensor of the present invention employs a configuration that can fix the relative positions of the vibration sensor unit, the temperature sensor unit, and the speed sensor unit on the support plate at the manufacturing stage. It is possible to eliminate problems that may occur if the electronic components (vibration sensor, temperature sensor, and speed sensor) are individually arranged, that is, workability is extremely poor and reliability may be impaired. In addition, the composite sensor of the present invention that constitutes one electronic component as a whole has a single device (composite sensor of the present invention) as compared to a mode in which individual sensing devices are assembled to predetermined attachment target portions. ) Need only be assembled to a predetermined mounting target portion, and therefore, the ease of assembly can also be realized.

  In the composite sensor according to the present invention, since the lower electrode of the vibration sensor unit and the thin film of the temperature sensor unit are formed on the common support plate using the same material, this film forming process can be performed simultaneously in the same process. Thus, the manufacturing process can be simplified and the manufacturing cost can be reduced. In addition, with the composite sensor of the present invention, there is no need to dispose an inclusion such as an adhesive between the vibration sensor unit and the temperature sensor unit, so the adhesive agent is provided between the vibration sensor unit and the temperature sensor unit. Therefore, it is possible to prevent the occurrence of a malfunction that occurs when there are inclusions such as, that is, a temperature error is likely to occur and an appropriate temperature measurement cannot be performed.

  The sensor unit according to the present invention is characterized in that the composite sensor having the above-described configuration is housed in a common sensor case in a state of being mounted on a circuit board. With such a sensor unit, the handleability of the sensor unit including the composite sensor that exhibits the various functions and effects described above is improved, and the operation of attaching the sensor unit to a predetermined attachment target portion is easy and smooth. It becomes possible to do.

  According to the present invention, the vibration sensor unit, the temperature sensor unit, and the speed sensor unit are formed on a common support plate, and at least a part or all of the vibration sensor unit and the temperature sensor unit are formed using the same material. By forming by processing, it can be expected that the composite sensor that exhibits the vibration sensing function, the temperature sensing function, and the speed sensing function is miniaturized and the manufacturing cost is reduced.

The whole schematic diagram of the sensor unit provided with the compound sensor concerning one embodiment of the present invention. The plane schematic diagram of the composite sensor which concerns on the same embodiment. FIG. 3 is a schematic cross-sectional view taken along line xx of FIG. 2. FIG. 4 is a partially enlarged view of FIG. 3. The flowchart which shows the manufacturing process of the composite sensor and sensor unit which concern on the embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the sensor unit 1 according to the present embodiment accommodates a composite sensor 2 that exhibits a vibration sensing function, a temperature sensing function, and a speed sensing function, a circuit board 3 on which the composite sensor 2 is mounted, and these. And a sensor case 4 that can be attached together with a sensor case 4 to a housing H provided at a predetermined portion of the vehicle, such as a railway vehicle.

  As shown in FIGS. 2 and 3 (FIG. 2 is a schematic plan view of the composite sensor 2, and FIG. 3 is a schematic cross-sectional view taken along the line xx of FIG. 2). A vibration sensor unit 6, a temperature sensor unit 7, and a speed sensor unit 8 are formed on a common support plate 5 (for example, a silicon single crystal substrate). In the present embodiment, the support plate 5 is supported in the form of a cantilever by the support base B and the permanent magnet M. That is, the longitudinal center region and the longitudinal one end side region of the support plate 5 are supported by the support base B and the permanent magnet M, and the other longitudinal end of the support plate 5 is not supported by the support base B and the permanent magnet M. The part side region is a vibration region 51 that can vibrate. In the following description, a region of the support plate 5 that is supported by the support base B and does not vibrate is referred to as a first fixed region 52, and a region that is supported by the permanent magnet M and does not vibrate is referred to as a second fixed region 53.

  In the present embodiment, a support plate 5 (substrate) in which a thermal oxide film is formed on a silicon substrate is used. The thermal oxide film is preferably formed on the entire surface of the silicon substrate opposite to the surface on which the support base B and the permanent magnet M are fixed (the upper surface in FIG. 3). Moreover, although a glass plate is suitable as the support base B, the support base B can be formed of a material other than glass.

  2 and 3, the vibration sensor unit 6 mainly includes a lower electrode 61, a piezoelectric thin film 62, and an upper electrode 63 formed in a multilayer on the vibration region 51 of the support plate 5. The piezoelectric thin film 62 is polarized in response to the vibration 5 and is converted into a voltage by, for example, a charge voltage conversion circuit, a voltage amplification circuit (not shown) through the lower electrode 61 and the upper electrode 63 to electrically detect the vibration. . 2 and 3, different patterns or hatching are given to the lower electrode 61, the piezoelectric thin film 62, and the upper electrode 63 for convenience, and in particular, the thicknesses are exaggerated in FIG.

  In the present embodiment, platinum thin films are applied as the lower electrode 61 and the upper electrode 63 in order to increase the crystallinity of the piezoelectric thin film 62. Although not shown, a titanium thin film is provided between the lower electrode 61 and the support plate 5 in order to improve the adhesion between the lower electrode 61 and the support plate 5, or the adhesion between the upper electrode 63 and the piezoelectric thin film 62 is increased. A chromium thin film or the like can be provided between the upper electrode 63 and the piezoelectric thin film 62 in order to increase the thickness. As the lower electrode 61 and the upper electrode 63, a thin film (for example, gold) made of a material other than platinum can be applied. Moreover, as the piezoelectric thin film 62, a thin film using PZT (lead zirconate titanate) is suitable, but PLZT (lead lanthanum zirconate titanate) can also be used.

  As shown in FIGS. 2 and 3, the temperature sensor unit 7 is formed on the first fixed region 52 of the support plate 5, and is provided between a pair of electrodes 71 provided with a predetermined dimension therebetween, and between these electrodes 71. The temperature measuring resistor 72 is provided. The composite sensor 2 according to the present embodiment includes a pair of electrodes 71 and a temperature measuring resistance unit 72 constituting the temperature sensor unit 7, which are formed by depositing the same material as the lower electrode 61 of the vibration sensor unit 6. Forming. When the lower electrode 61 of the vibration sensor unit 6 is formed of platinum, the electrode 71 of the temperature sensor unit 7 and the temperature measuring resistance unit 72 can be formed of platinum having strong corrosion resistance. In the present embodiment, the resistance temperature measuring section 72 is formed with a meander pattern so as to have a predetermined resistance value, and is set to have a resistance value corresponding to the temperature. In FIG. 2, an example is shown in which the major axis of the meander pattern is laid out so as to be parallel to the direction orthogonal to the longitudinal direction of the support plate 5 as the resistance temperature measuring unit 72, but the major axis of the meander pattern is supported The resistance temperature detector 72 may be laid out so as to be parallel to the longitudinal direction of the plate 5. Such a temperature sensor unit 7 can output a resistance value corresponding to the temperature as an electric signal by a circuit (not shown). 2 and 3, for convenience of explanation, the electrode 71 and the temperature measuring resistance unit 72 of the temperature sensor unit 7 are given the same pattern and hatching as the lower electrode 61 of the vibration sensor unit 6. In FIG. 3, the thicknesses of the electrode 71 and the resistance temperature detector 72 of the temperature sensor unit 7 are exaggerated.

  As shown in FIGS. 2, 3 and 4 (FIG. 4 is a partially enlarged view of FIG. 3), the speed sensor unit 8 forms a vibration sensor unit 6 and a temperature sensor unit 7 in the support plate 5. A magnetic sensitive thin film 81 and an electrode 82 formed on the second fixed region 53 that is not a region, and a permanent magnet M provided so as to face the magnetic sensitive thin film 81 and the electrode 82 through the support plate 5. It is constituted by a Hall element. 2, 3, and 4, for convenience, the magnetic sensitive thin film 81 and the electrode 82 are provided with different patterns or hatching, and particularly in FIGS. 3 and 4, the thicknesses are exaggerated. In this embodiment, an InSb (indium antimonide) thin film is applied as the magnetically sensitive thin film 81, and a titanium base film 82a partially covered with a gold film 82b is applied as the electrode 82. 2, 3, and 4, a predetermined region from the one end (right end) of the support plate 5 is indicated as the second fixed region 53, but the speed sensor unit 8 is attached to the support plate 5 as illustrated in each drawing. When it is formed at a position away from one end (right end) by a predetermined dimension, an area where the speed sensor unit 8 is formed (an area where a permanent magnet M to be described later is fixed) is regarded as a fixed area (second fixed area). Can do.

  As shown in FIG. 1, the sensor unit 1 of the present embodiment has a composite sensor 2 in which a vibration sensor unit 6, a temperature sensor unit 7, and a speed sensor unit 8 are integrally formed mounted on a circuit board 3. In the present embodiment, the composite sensor 2 and the circuit board 3 are accommodated in a common sensor case 4.

  Next, a procedure for manufacturing the composite sensor 2 and a procedure for manufacturing the sensor unit 1 including the composite sensor 2 will be described.

  First, a thin film is formed on the vibration region 51 and the first fixed region 52 of the support plate 5 (see the first film formation step S1, FIG. 5). The thin film formed on the vibration region 51 of the support plate 5 by the first film formation step S1 is the lower electrode 61 of the vibration sensor unit 6, and the thin film formed on the first fixed region 52 of the support plate 5 is the temperature sensor. A pair of electrodes 71 and a resistance temperature measuring unit 72 of the unit 7. When the first film formation step S1 is completed, there is no distinction between the electrode 71 of the temperature sensor section 7 and the temperature measuring resistance section 72, and the first photolithography process performed subsequently to the first film formation process S1. By S2, a meandering resistance temperature measuring portion 72 is formed. A thin film is formed in the vicinity of the boundary between the vibration region 51 and the first fixed region 52 on the support plate 5 in order to insulate the vibration sensor unit 6 (lower electrode 61) from the temperature sensor unit 7. It is necessary to ensure no space (thin film non-formation region 54). In order to secure such a thin film non-formation region 54, a thin film is not formed in the region near the boundary between the vibration region 51 and the first fixed region 52 on the support plate 5 in the film formation process of the first film formation step S1. After forming the film over the entire region of the support plate 5 where the vibration sensor unit 6 and the temperature sensor unit 7 are formed in the first film formation step S1, the vibration region 51 and the first fixed region 52 What is necessary is just to remove the thin film formed in the boundary vicinity area | region. This thin film removal process can also be performed by the photolithography process in the first photolithography step S2.

  Next, a piezoelectric thin film 62 is formed on the lower electrode 61 of the vibration sensor unit 6 which is a thin film formed on the vibration region 51 (secondary film forming step S3, see FIG. 5), and then the upper portion on the piezoelectric thin film 62 is formed. A thin film functioning as the electrode 63 is formed (third film formation step S4, see FIG. 5). As shown in FIG. 2, the plane area of the piezoelectric thin film 62 is set smaller than the plane area of the lower electrode 61, and the plane area of the upper electrode 63 is set smaller than the plane area of the piezoelectric thin film 62.

  Subsequently, the electrode 71 of the temperature sensor unit 7, the piezoelectric thin film 62 and the upper electrode 63 of the vibration sensor unit 6 are subjected to a photolithography process (second photolithography step S5, see FIG. 5). The vibration sensor unit 6 and the temperature sensor unit 7 can be formed on the support plate 5 by the above procedure.

  Next, a magnetic sensitive thin film 81 is formed in the second fixed region 53 in the support plate 5 where the vibration sensor unit 6 and the temperature sensor unit 7 are not formed (fourth film forming step S6 (“magnetic sensitive thin film” Formation process ”), see FIG. The magnetic sensitive thin film 81 can be formed by, for example, a vacuum evaporation method. In the present embodiment, the secondary resistance heating method is adopted as the vacuum vapor deposition method, but vapor deposition methods other than this method can also be adopted. Moreover, the situation which forms the magnetic sensitive thin film 81 in the area | region (The vibration area | region 51 and the 1st fixed area | region 52) in which the vibration sensor part 6 and the temperature sensor part 7 were formed among the support plates 5 is avoided, and the 1st fixed area | region 52 is avoided. In order to secure a space in which no thin film is formed (thin film non-formation region 55) between the first fixed region 53 and the second fixed region 53, for example, the film formation area of the magnetic sensitive thin film 81 (the flat area of the second fixed region 53) Film formation may be performed using a metal mask having a corresponding opening window, or the thin film formed in the vicinity of the first fixed region 52 after the fourth film formation step S6 may be removed.

  After the fourth film formation step S6, a desired magnetic sensitive thin film pattern (InSb pattern in this embodiment) is formed by photolithography and etching (third photolithography step S7 ("magnetic sensitive thin film pattern forming step"). See FIG. 5). As an etchant, a ferric chloride solution, a hydrogen fluoride (hydrofluoric acid) solution, or the like can be used. Moreover, in this embodiment, in order to improve the magnetoelectric conversion performance of the magnetic sensitive thin film 81 formed in the desired magnetic sensitive thin film pattern, it is crystallized by heat treatment. Specifically, heat treatment is performed at a temperature near the melting point of the magnetoresistive material (InSb in this embodiment) by infrared heating. Furthermore, by performing this heat treatment in an inert gas (nitrogen gas) atmosphere, it is possible to prevent oxidative degradation of the magnetic sensitive thin film 81.

  Subsequently, a thin film constituting the electrode 82 of the speed sensor unit 8 is formed (fifth film forming step S8 (can be regarded as “electrode thin film forming step”), see FIG. 5). In the present embodiment, as shown in FIG. 4, an electrode 82 is formed by forming a base film 82a from titanium and forming a gold film 82b on the base film 82a. The film formation process of the base film 82a and the gold film 82b is preferably performed by a vapor deposition method, a sputtering method, or the like using a metal mask having an opening window corresponding to the film formation region of the base film 82a and the gold film 82b. Next, a desired electrode pattern is formed by a photolithography process and an etching process (fourth photolithography process S9 (can be regarded as a “speed sensor part electrode pattern formation process”, see FIG. 5). In addition, it is also possible to employ | adopt patterns other than the magnetic sensitive thin film pattern and electrode pattern shown in FIG. 3, and a bridge | bridging structure. After forming a desired electrode pattern, the permanent magnet M is fixed to the back surface of the support plate 5 (refer to permanent magnet fixing step S10, FIG. 5). The permanent magnet M only needs to have a size corresponding to the region where the magnetic sensitive thin film 81 and the electrode 82 are formed. In the present embodiment, the permanent magnet M is attached to the back surface of the support plate 5 with an adhesive or the like, for example. It is fixed. By attaching the permanent magnet M to the back surface of the support plate 5 in this manner, the speed sensor unit 8 that functions as a Hall element for magnetoelectric conversion can be formed. That is, the magnetic sensitive thin film 81 functions as a Hall element thin film. In addition, the process (process S1-S5 mentioned above) which forms the vibration sensor part 6 and the temperature sensor part 7 in the support plate 5 is the process (process S6-S10 mentioned above) which forms the speed sensor part 8 in the support plate 5. It can also be done later.

  By the above procedure, the composite sensor 2 in which the vibration sensor unit 6, the temperature sensor unit 7, and the speed sensor unit 8 are formed on the common support plate 5 can be manufactured.

  In order to manufacture the sensor unit 1 using the composite sensor 2, first, the composite sensor 2 is cut into a predetermined size by dicing processing (see the dicing step S11, FIG. 5), and the cut-out composite sensor 2 is cut into a circuit board. 3 and mounted (circuit board bonding step S12, see FIG. 5), and the lower electrode 61 and the upper electrode 63 of the vibration sensor unit 6, the electrode 71 of the temperature sensor unit 7, and the magnetism of the speed sensor unit 8 by wire bonding processing. The sensitive thin film 81 and the electrode 82 are each connected to the circuit board 3 (wire bonding process S13, refer FIG. 5).

  Further, in the present embodiment, the composite sensor 2 mounted on the circuit board 3 in a state where the support base B and the permanent magnet M are in contact with the circuit board 3 is covered with the can C. The can C has a bottomed cylindrical shape, and the opening C1 of the can C is covered with a circuit board 3 on which the composite sensor 2 is mounted, so that the internal space CS of the can C in which the composite sensor 2 is sealed is sealed. Can be arranged. By the above procedure, the composite sensor 2 is accommodated in the hollow can C, and in this state, the composite sensor 2 is accommodated in the sensor case 4 together with the circuit board 3 and the can C, and the inside of the sensor case 4 is sealed (case) Sealing step S14, see FIG. In the present embodiment, the circuit board 3 is fixed in contact with a plate-like fixing portion F provided in the sensor case 4, and the sensor case 4 is filled with an appropriate resin. At this time, since the can C is sealed, the internal space CS of the can C is not filled with the synthetic resin.

  The sensor unit 1 according to the present embodiment can be manufactured by the above procedure. When the sensor unit 1 is fixed to a housing H provided at an appropriate position of the vehicle, for example, as shown in FIG. Of the composite sensor 2 arranged at the position to be moved, the speed sensor unit 8 can detect the speed based on the rotation of the gear G, and the vibration sensor unit 6 and the temperature sensor 7 can detect vibration and temperature. Also, a cable L is connected to the sensor unit 1, and various information detected by the vibration sensor unit 6, the temperature sensor unit 7 and the speed sensor unit 83 is output to a control unit (not shown) through the cable L to control an ABS device or the like. It is configured so that it can be used.

  As described above, the sensor unit 1 according to the present embodiment includes the composite sensor 2 in which the vibration sensor unit 6, the temperature sensor unit 7, and the speed sensor unit 8 are integrally formed, and includes the support plate 5 constituting the vibration sensor unit 6. Among them, the temperature sensor unit 7 and the speed sensor unit 8 are provided on a region that does not directly contribute to the vibration sensing function of the vibration sensor unit 6 (the first fixed region 52 and the second fixed region 53 other than the vibration region 51). Therefore, for example, it is possible to efficiently and easily achieve compactness as compared with an aspect in which compactness is achieved by increasing the mounting density of a plurality of electronic components on the circuit board 3.

  In particular, the composite sensor 2 of the present embodiment includes the magnetic sensitive thin film 81 and the electrode 82 in which the speed sensor unit 8 is formed on one surface (upward surface in FIG. 3) of the second fixed region 53 of the support plate 5, 2 The permanent magnet M provided on the other surface (downward surface in FIG. 3) of the fixed region 53 is used, so that the magnetic sensitive thin film 81, the electrode 82, and the permanent magnet M are mainly used to reduce the size. A hall element that can be realized can be configured, and can greatly contribute to downsizing of the composite sensor 2. In addition, unlike the electromagnetic induction type sensor method, the detection by the Hall element can accurately measure the rotational position or angle without depending on the rotational speed and acceleration of the gear, realizing higher detection accuracy. can do.

  Furthermore, the composite sensor 2 according to the present embodiment is formed by a thin film in which the lower electrode 61 of the vibration sensor unit 6, the electrode 71 of the temperature sensor unit 7, and the resistance temperature measuring unit 72 are formed using the same material. Therefore, conventionally, the same process can be performed separately in the same process, and the manufacturing cost can be reduced and the manufacturing process can be simplified. In addition, waste of materials can be prevented. Moreover, the composite sensor 2 of the present embodiment does not individually mount electronic component vibration sensors, temperature sensors, and speed sensors on the circuit board 3 but supports the support plate 5 that functions as a beam structure of the vibration sensor unit 6. Since the temperature sensor section 7 and the speed sensor section 8 are formed on the top by film formation processing or photolithography processing, for example, high mounting processing for increasing the mounting density of each sensor on the circuit board 3 is not required, and the composite sensor 2 can be made compact as a whole, contributing to space saving. And the operation | work which arrange | positions the composite sensor 2 integrated in this way in the sensor case 4 can also be performed easily, and the improvement of work efficiency can be aimed at, without impairing reliability.

  In addition, by adopting the sensor unit 1 in which the composite sensor 2 is accommodated in the sensor case 4 and unitized, the speed, vibration and temperature of the vehicle can be suitably detected while being small and low cost. Can do.

  In addition, this invention is not limited to embodiment mentioned above. For example, in the above-described embodiment, the support plate having the cantilever structure is exemplified, but the support plate having the both-end support structure can be applied. In this case, one end side region in the longitudinal direction of the support plate is supported by the support base, the other end portion in the longitudinal direction is supported by the permanent magnet, and the center region in the longitudinal direction not supported by the support base or permanent magnet can be vibrated. The vibration sensor unit is formed on the vibration region, the temperature sensor unit is formed on the fixed region of the support plate supported by the support base, and the fixed region supported by the permanent magnet is formed. What is necessary is just to form a speed sensor part.

  Moreover, it is also possible to form the support base which supports a support plate with the permanent magnet which comprises a part of speed sensor part. In particular, when a cantilever structure support plate is applied, a single permanent magnet having a size corresponding to a region where the temperature sensor portion and the speed sensor portion of the support plate are formed is applied. It is not necessary to use a dedicated support stand that is separate from the magnet, and the manufacturing process can be simplified and the cost can be reduced by sharing the parts.

  Furthermore, a part of the can that accommodates the composite sensor (for example, a bottom part and a part of a side wall extending from the bottom part toward the circuit board side) may function as a part of the sensor case. Specifically, there is an aspect in which a portion of the can is fitted into the can fitting opening formed in the sensor case, and a portion of the sensor case exposed to the outside of the sensor case functions as a part of the sensor case. be able to.

  In addition to silicon, aluminum, stainless steel, or the like may be applied as the support plate that functions as the base of the vibration sensor unit, temperature sensor unit, and speed sensor unit.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Sensor unit 2 ... Composite sensor 3 ... Circuit board 4 ... Sensor case 5 ... Support plate 51 ... Vibration area 52, 53 ... Area | regions other than a vibration area (1st fixed area, 2nd fixed area)
DESCRIPTION OF SYMBOLS 6 ... Vibration sensor part 61 ... Lower electrode 62 ... Piezoelectric thin film 63 ... Upper electrode 7 ... Temperature sensor part 71 ... Electrode 72 ... Resistance temperature detector 8 ... Speed sensor part 81 ... Magnetic sensitive thin film 82 ... Electrode

Claims (2)

A support plate having a cantilever structure with one end fixed or a doubly supported beam structure with both ends fixed;
A vibration sensor unit having a lower electrode, a piezoelectric thin film, and an upper electrode formed in a multilayer shape on a vibration region that can vibrate in the support plate;
A temperature sensor unit formed of a thin film formed of the same material as the lower electrode of the vibration sensor unit on a region other than the vibration region of the support plate;
Of the support plate, a magnetic sensitive thin film formed on a region other than the region where the vibration sensor unit and the temperature sensor unit are formed, and a speed sensor unit having an electrode formed on the magnetic sensitive thin film are integrally provided. A composite sensor characterized by A sensor unit comprising: the composite sensor according to claim 1; a circuit board on which the composite sensor is mounted; and a sensor case that houses the composite sensor and the circuit board.

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