JP2009222524A - Rotation detecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation detecting apparatus miniaturized, improving the degree of freedom for disposing a rotating body, and accurately detecting a rotating state. <P>SOLUTION: The rotation detecting apparatus 100 is disposed adjacent to an outer circumference of the rotating body 1, measures a change in a bias magnetic field due to a rotation of the rotating body 1, detects the rotating state of the rotating body 1. The rotation detecting apparatus 100 includes: a multilayer wiring board 50 disposed adjacent to the outer circumference of the rotating body 1; and multilayer wired coils La, Lb embedded in the multilayer wiring board 50 and formed at an end adjacent to the outer circumference of the rotating body 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotation detection device that is disposed in the vicinity of the outer periphery of a rotating body and detects a rotation state of the rotating body by measuring a change in a bias magnetic field accompanying the rotation of the rotating body.

  For example, Japanese Patent Application Laid-Open No. 11-237256 (Patent Document) discloses a rotation detection device that is arranged in the vicinity of the outer periphery of a rotating body and detects a rotation state of the rotating body by measuring a change in a bias magnetic field accompanying the rotation of the rotating body. Document 1) and Japanese Patent Application Laid-Open No. 2007-101230 (Patent Document 2).

  FIG. 7 is a schematic perspective view of the main part of the rotation detection device 80 disclosed in Patent Document 1. As shown in FIG.

  A rotation detection device 80 shown in FIG. 7 includes a gear 1 having a gear shape (gear tooth 1 a), a bias magnet 2, and an IC chip 3. The gear 1 is arranged such that its outer peripheral surface faces the bias magnet 2, and the bias magnet 2 generates a bias magnetic field toward the outer peripheral surface of the gear 1.

  The bias magnet 2 having a hollow shape is magnetized so that the end face close to the gear 1 is N-pole and the far end face is S-pole, and is generally on the hollow central axis (two-dot chain line in the figure). It arrange | positions so that the rotating shaft (one-dot chain line in a figure) of the gear 1 may be located.

  On the surface of the IC chip 3, two magnetoresistive elements (MRE) 4 and 5 are formed with different directions. Each of the two MREs 4 and 5 has an angle of 45 degrees and −45 degrees with respect to the magnetic center of the bias magnetic field (the central axis of the bias magnet 2), that is, in the shape of a letter C that is orthogonal to each other. It is arranged to be. The IC chip 3 is disposed between the bias magnet 2 and the outer peripheral surface of the gear 1 so as to detect the direction of the bias magnetic field generated by the bias magnet 2. Further, the IC chip 3 is arranged so that the two MREs 4 and 5 are located between the planes formed by the both end faces 1 b of the gear 1.

  The MREs 4 and 5 are subjected to wiring processing so that currents flow in the respective longitudinal directions. These two MREs 4 and 5 are connected in series to form a set of MRE bridges 6. A current flows from the MRE 5 to the MRE 4 with respect to the MRE bridge 6, and the bias magnet 2 is generated with the midpoint potential of the two MREs 4 and 5 connected in series as the output of the MRE bridge 6. A change in the bias magnetic field, that is, rotation of the gear 1 is detected.

  FIG. 8 is a rotation detection device used for detecting rotation of a crank angle sensor or the like of an in-vehicle engine disclosed in Patent Document 2. FIG. 8A is a diagram schematically showing a cross-sectional structure of the rotation detection device 90. FIG. 8B is an exploded perspective view schematically showing the components of the rotation detecting device 90.

  In the rotation detection device 90 shown in FIG. 8 (a), the chip 10 and the magnet (bias magnet) 30 made of a bare chip are sealed in a housing constituted by the case 20 and the cap (member) 40, so that an external atmosphere is maintained. It has a protected structure.

  Of these, the chip 10 includes a sensing chip 11 having a magnetoresistive element pair, and a processing circuit chip 12 which is integrated into an integrated circuit and performs various processing of signals detected by the magnetoresistive element pair. The case 20 is made of a non-magnetic material such as resin, and has a disk-like base portion 25 and a plate-like tongue-shaped holding portion (tongue portion) 21 integrally formed so as to protrude from one surface of the base portion 25. And. A mounting surface for the sensing chip 11 and the processing circuit chip 12 as well as the lead frame 13 is integrally cast in the tongue-shaped holding portion 21. The sensing chip 11 and the processing circuit chip 12 are mounted (mounted) on the tongue-shaped holding portion 21 in such a manner as to be electrically connected to the lead frame.

  On the other hand, the magnet 30 is formed in a cylindrical shape having, for example, a rectangular hollow portion 31 inside the longitudinal direction of a cylinder, and is inserted in a manner covering the tongue-shaped holding portion 21 of the case 20 together with the chip 10. Yes. The magnet 30 applies a bias magnetic field to the magnetoresistive element pair incorporated in the sensing chip 11.

  Further, the cap 40 made of a bottomed cylindrical nonmagnetic material has a tapered surface 41t having an inner surface with an open end 41 opened conically, and the tapered surface 41t is opposed to the case 20. The base portion 25 abuts on the joint surface 25t and is laser welded to the base portion 25. Thereby, the tongue-shaped holding part 21 and the magnet 30 together with the sensor chip 11 are protected from the external atmosphere.

In the rotation detection device 90, as with the rotation detection device 80 shown in FIG. 7, the rotation magnetic field cooperates with the bias magnetic field during rotation of the rotating body arranged facing the tip (the right end in FIG. 8A). The change in the magnetic vector caused by the action is detected as a change in the resistance value of the magnetoresistive element pair.
Japanese Patent Laid-Open No. 11-237256 JP 2007-101230 A

  The rotation detection devices 80 and 90 shown in FIGS. 7 and 8 both change the bias magnetic field generated by the cylindrical magnet with the rotation of the rotating body by a magnetic detection element such as an MRE formed on the semiconductor chip. It is a rotation detection device that measures and detects the rotation state of the rotating body. In order to increase the detection accuracy of the rotation state of the rotating body in the conventional rotation detecting devices 80 and 90, it is necessary to bring the rotation detecting devices 80 and 90 as close to the rotating body (gear 1) as possible. However, the conventional rotation detection devices 80 and 90 both contain the magnetic detection elements 6 and 10 and the magnets 2 and 30 in the case, and the ASSY becomes large, so there are restrictions on the close arrangement. large.

  Therefore, the present invention is a rotation detection device that is arranged close to the outer periphery of the rotating body and measures the change of the bias magnetic field accompanying the rotation of the rotating body to detect the rotating state of the rotating body, and can be miniaturized. Therefore, an object of the present invention is to provide a rotation detection device that has a high degree of freedom in arrangement with respect to a rotating body and can detect a highly accurate rotation state.

  The invention according to claim 1 is a rotation detection device that is disposed in the vicinity of the outer periphery of the rotating body and detects a rotation state of the rotating body by measuring a change in a bias magnetic field accompanying the rotation of the rotating body. And a multilayer wiring board disposed in the vicinity of the outer periphery of the rotating body, and a coil made of the multilayer wiring is embedded in an end portion of the multilayer wiring board close to the outer periphery of the rotating body. It is characterized by.

  The coil in the rotation detection device can be used as an electromagnet, for example, as a fluxgate type magnetic detection element, and used to generate a bias magnetic field instead of a permanent magnet in a conventional rotation detection device, Instead of the magnetoresistive element (MRE), it can be used to measure a change in the bias magnetic field. Further, since the coil is embedded in the multilayer wiring board, the ASSY of the rotation detecting device can be miniaturized. Therefore, the rotation detection device has a higher degree of freedom of arrangement with respect to the rotating body than the conventional rotation detection device, and can be arranged closer to the rotating body. The rotation state can be detected.

  As described above, the rotation detection device is a rotation detection device that is disposed in the vicinity of the outer periphery of the rotating body, and detects a rotation state of the rotating body by measuring a change in the bias magnetic field accompanying the rotation of the rotating body. Thus, it is possible to provide a rotation detection device that can be downsized, has a high degree of freedom in arrangement with respect to the rotating body, and can detect a highly accurate rotation state.

  In the rotation detection device, for example, as described in claim 2, the multilayer wiring board is formed on a silicon substrate, in which a wiring pattern made of a metal thin film is formed in multiple layers via an interlayer insulating film, and the multilayer wiring board is in a different layer. It is a multilayer wiring board in which wiring patterns are connected to each other by connecting conductors embedded in via holes, and the coil is formed by the wiring pattern and the connecting conductor. In manufacturing the coil of the rotation detecting device, since a general semiconductor manufacturing technique can be used, the coil can be manufactured with high dimensional accuracy.

  Further, in the rotation detection device, as described in claim 3, the multilayer wiring board is formed by laminating a plurality of resin films made of a thermoplastic resin having a wiring pattern made of a metal foil on the surface. The wiring patterns are formed in multiple layers, and the wiring patterns in different layers are interlayer-connected with a connection conductor made of a sintered body of a conductive paste, and the coil is connected to the wiring pattern It is also possible to adopt a configuration formed by the connection conductor. When manufacturing the multilayer wiring board of the rotation detecting device, the resin film on which the wiring pattern is formed and the sintering of the conductive paste can be collectively performed by heating and pressing. The substrate can be manufactured at a low cost.

  As described in claim 4, it is preferable that a plurality of the coils in the rotation detection device are formed on the multilayer wiring board.

  A general rotation in which a magnetic detection element such as an MRE is disposed in the vicinity of the outer periphery of the rotating body, and the rotation state of the rotating body is detected by measuring a change in the bias magnetic field accompanying the rotation of the rotating body by the magnetic detection element. In the detection device, by using a plurality of magnetic detection elements, for example, the differential output of the plurality of magnetic detection elements can be determined, and the rotation state can be detected with higher accuracy than in the case of one. is there. Therefore, even when the coil embedded in the multilayer wiring board in the rotation detection device is used as a magnetic detection element, for example, by using a plurality of the coils, it is possible to detect a rotation state with higher accuracy than in the case of a single coil. It becomes. In addition, even when the coil is used as an electromagnet for generating a bias magnetic field instead of a permanent magnet, a more accurate rotation state can be detected by arranging the coil in each of the plurality of magnetic detection elements. It becomes possible.

  As described in claim 5, the rotation detection device may be configured such that a soft magnetic material is inserted into the coil.

  When the coil is formed of a wiring pattern made of a metal thin film and a connection conductor embedded in a via hole via an interlayer insulating film on a silicon substrate as described in claim 2, for example, the soft magnetic material Is also formed of a thin film. According to a third aspect of the present invention, the coil is formed of a connection conductor made of a sintered body of a wiring pattern and a conductive paste in different layers in a multilayer wiring board formed by bonding a plurality of resin films to each other. In the case of forming, for example, the soft magnetic material can be embedded as a chip component in a plurality of resin films bonded to each other. In either case, the soft magnetic material is inserted and arranged in the coil so that the bias magnetic field generated by the coil or the bias magnetic field detected by the coil is converged by the soft magnetic material (flux gate type magnetic detection element) and rotated. It can be effectively used to detect the rotational state of the body.

  As described in claim 6, the coil in the rotation detecting device can be used to generate the bias magnetic field in place of the permanent magnet as described above. Since the rotation detection device can eliminate the permanent magnet for generating the bias magnetic field in the conventional rotation detection device, it can be greatly reduced in size.

  In addition, as described in claim 7, the coil in the rotation detection device can be used to measure a change in the bias magnetic field in place of the MRE as described above. As described above, when the coil is used as a magnetic detection element, the diameter and length of the coil can be appropriately set according to the shape and rotation speed of the rotating body. Compared to this, the degree of freedom in design is high, and it is possible to perform optimal design according to the rotating body to be measured.

  As described above, each of the above rotation detection devices is disposed in the vicinity of the outer periphery of the rotating body, and measures the change in the bias magnetic field accompanying the rotation of the rotating body to detect the rotating state of the rotating body. This is a detection device that can be miniaturized, has a high degree of freedom in arrangement with respect to a rotating body, and can detect a rotation state with high accuracy.

  Therefore, as described in claim 8, the rotation detection device is particularly suitable as a vehicle-mounted rotation detection device that is required to detect a small and highly accurate rotation state.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is an example of the rotation detection device of the present invention, FIG. 1 (a) is a schematic top view of the rotation detection device 100, and FIG. 1 (b) is an alternate long and short dash line A in FIG. 1 (a). It is sectional drawing in -A. In each example shown below, a rotating body (gear) 1 that is an object to be detected is indicated by the same reference numeral as in FIG.

  A rotation detection device 100 shown in FIG. 1 is disposed in the vicinity of the outer periphery of the rotating body 1 and measures a change in the bias magnetic field accompanying the rotation of the rotating body 1 to detect the rotation state of the rotating body 1. It is. The rotation detection device 100 includes a multilayer wiring board 50 that is disposed in the vicinity of the outer periphery of the rotating body 1. Further, at the end of the multilayer wiring board 50 that is close to the outer periphery of the rotating body 1, the central axis indicated by the two-dot chain line in the figure faces the outer periphery of the rotating body 1, so that the coils La, Lb is embedded and formed.

As shown in FIG. 1B, the multi-layer wiring board 50 of the rotation detecting device 100 has a wiring pattern made of a metal thin film on a silicon substrate 51 via an interlayer insulating film 52 such as a silicon oxide (SiO ₂ ) film. 53 is a multilayer wiring board formed in multiple layers. In the multilayer wiring board 50, wiring patterns 53 in different layers are connected to each other by connection conductors 54 embedded in via holes, and coils La and Lb are formed by the wiring patterns 53 and connection conductors 54. . In manufacturing the coils La and Lb of the rotation detecting device 100, since a general semiconductor manufacturing technique can be used, the coils La and Lb can be manufactured with high dimensional accuracy.

  As will be described later, the coils La and Lb in the rotation detection device 100 can be used as an electromagnet, for example, as a fluxgate type magnetic detection element, and the conventional rotation detection shown in FIGS. Used to generate a bias magnetic field in place of the permanent magnets 2 and 30 in the devices 80 and 90, or to measure changes in the bias magnetic field in place of the magnetoresistive elements (MRE) 4 to 6 and 11. Can do. Further, since the coils La and Lb are embedded in the multilayer wiring board 50, the ASSY of the rotation detecting device 100 can be downsized. Therefore, the rotation detecting device 100 has a higher degree of freedom in arrangement with respect to the rotating body 1 and closer to the rotating body 1 than the conventional rotation detecting devices 80 and 90 shown in FIGS. Since it can arrange | position, the rotation state of the rotary body 1 can be detected with higher precision.

  FIG. 2 shows an example in which the coils La and Lb of the rotation detecting device 100 shown in FIG. 1 are used for generating a bias magnetic field. FIG. 2A is a schematic top view of the rotation detection device 101, and FIG. 2B is a cross-sectional view taken along one-dot chain line BB in FIG.

  The rotation detection device 101 shown in FIG. 2 is similar to the rotation detection device 100 shown in FIG. 1, and has a multilayer wiring board 50a arranged close to the outer periphery of the rotating body 1, and the multilayer wiring board 50a. Coils Lc and Ld made of multilayer wiring are embedded in the end portion of the rotating body 1 close to the outer periphery. The coils Lc and Ld in the rotation detector 101 are used as electromagnets and are used to generate bias magnetic fields Bc and Bd indicated by thin line arrows in FIG. In addition, magnetic detection elements Sc and Sd are formed in front of the coils Lc and Ld facing the rotating body 1 on the multilayer wiring board 50a in the rotation detecting device 101 of FIG. The magnetic detection elements Sc and Sd measure changes in the bias magnetic fields Bc and Bd accompanying the rotation of the rotating body 1 to detect the rotating state of the rotating body 1. The strengths of the bias magnetic fields Bc and Bd generated by the coils Lc and Ld are set to about 100 to 200G.

  As described above, the coils Lc and Ld in the rotation detection device 101 of FIG. 2 are used to generate a bias magnetic field in place of the permanent magnets 2 and 30 of the rotation detection devices 80 and 90 shown in FIGS. It was. Therefore, in the rotation detection device 101 of FIG. 2, the permanent magnets 2 and 30 for generating a bias magnetic field that are the same as those of the rotation detection devices 80 and 90 of FIGS. 7 and 8 can be eliminated. Compared to the rotation detectors 80 and 90, the size can be greatly reduced.

  FIG. 3 is an example of the case where the coils La and Lb of the rotation detection device 100 of FIG. 1 are used for detecting a change in the bias magnetic field, and is a schematic top view of the rotation detection device 102.

  The rotation detection device 102 shown in FIG. 3 is similar to the rotation detection device 100 shown in FIG. 1, and has a multilayer wiring board 50 b arranged close to the outer periphery of the rotating body 1. The multilayer wiring board 50 b Coils Le and Lf made of multilayer wiring are embedded in the end portion of the rotating body 1 close to the outer periphery. The coils Le and Lf in the rotation detection device 101 of FIG. 3 are indicated by thin line arrows in the drawing instead of the magnetoresistive elements (MRE) 4 to 6 and 11 of the rotation detection devices 80 and 90 shown in FIGS. It is used to measure the change in the indicated bias magnetic field B0. In other words, in the rotation detection device 101 of FIG. 3, the coils Le and Lf have a rotating magnetic body 1 with a bias magnetic field B0 generated by permanent magnets (not shown) similar to the permanent magnets 2 and 30 shown in FIGS. Measure the change with the rotation of. As described above, the rotation detection device 102 shown in FIG. 3 uses the coils Le and Lf embedded in the multilayer wiring board 50b as magnetic detection elements.

  4 (a) to 4 (c) are diagrams comparing the output characteristics of the coils Lg to Li having different diameters d and lengths x when the coils are used as magnetic detection elements. As can be seen by comparing the output characteristics of FIGS. 4A to 4C, the output time characteristics that are sharp with respect to the rotation are obtained as the coil diameter d decreases, and the coil length x increases as the coil length x increases. Sensitivity is obtained.

  Therefore, in the rotation detection device 102 of FIG. 3, the output characteristics can be appropriately set according to the diameter and length of the coils Le and Lf in accordance with the shape and rotation speed of the rotating body 1. For this reason, the degree of freedom in design is higher than that of other magnetic detection elements such as MRE, and optimum design in accordance with the rotating body 1 to be measured is possible.

  FIG. 5 is an example of another rotation detection device, FIG. 5 (a) is a schematic top view of the rotation detection device 103, and FIG. 5 (b) is an alternate long and short dash line C- in FIG. 5 (a). It is sectional drawing in C.

  In the multilayer wiring board 50 of the rotation detecting device 100 of FIG. 1, a wiring pattern 53 made of a metal thin film is formed on a silicon substrate 51 via an interlayer insulating film 52, and the coils La and Lb are in different layers. The pattern 53 and the connection conductor 54 embedded in the via hole were formed.

  On the other hand, in the multilayer wiring board 50c of the rotation detecting device 103 of FIG. 5, a plurality of resin films 55a to 55f made of a thermoplastic resin having a wiring pattern 56 made of a metal foil formed on the surface are bonded to each other. Thus, the wiring pattern 56 is a multilayer wiring board formed in multiple layers. In the multilayer wiring board 50c, the wiring patterns 56 in different layers are connected to each other by a connection conductor 57 made of a sintered body of conductive paste, and the coils Lj and Lk are formed by the wiring pattern 56 and the connection conductor 57. It has a structure. In manufacturing the multilayer wiring board 50c of the rotation detecting device 103, the resin films 55a to 55f on which the wiring patterns 56 are formed can be bonded together and sintered with the conductive paste by heating and pressurizing. The multilayer wiring board 50c can be manufactured at low cost.

  The rotation detection device 103 shown in FIG. 5 is also similar to the rotation detection device 100 shown in FIG. 1, and has a multilayer wiring board 50c disposed in the vicinity of the outer periphery of the rotating body 1. Coils Lj and Lk made of multilayer wiring are embedded in the end portion of the substrate 50c close to the outer periphery of the rotating body 1. Therefore, similarly to the rotation detection device 100 shown in FIG. 1, the rotation detection device 103 shown in FIG. 5 can be used as an electromagnet or a magnetic detection element, and can be used to generate a bias magnetic field. Needless to say, it can be used to measure changes in the bias magnetic field.

  FIG. 6 is another example of the rotation detection device. FIGS. 6A and 6B are cross-sectional views of the rotation detection devices 104 and 105, respectively. FIG. It is a typical top view. The cross-sectional view of the rotation detection device 104 shown in FIG. 6A corresponds to the cross-sectional view taken along the alternate long and short dash line DD in FIG.

  The rotation detection devices 104 and 105 shown in FIGS. 6A and 6B can be compared with the structures of the rotation detection devices 101 and 103 shown in FIGS. 2 and 4, respectively. The soft magnetic bodies 58 and 59 are inserted and arranged in the coils Ll, Lm, Ln, and Lo embedded in 50e. When the coils Ll and Lm are formed by a wiring pattern made of a metal thin film and a connection conductor embedded in a via hole through an interlayer insulating film on a silicon substrate as in the rotation detection device 104 in FIG. For example, the soft magnetic material 58 is also formed of a thin film. Further, as in the rotation detection device 104 in FIG. 6A, the multilayer wiring board 50e formed by bonding a plurality of resin films to each other is composed of a sintered body of wiring patterns and conductive pastes in different layers. When the coils Ln and Lo are formed with the connection conductor, for example, the soft magnetic material 59 can be embedded as a chip component in a plurality of resin films bonded to each other. In any case, the soft magnetic bodies 58 and 59 are inserted and arranged in the coils Ll, Lm, Ln, and Lo, so that the bias magnetic fields Bl and Bm generated by the coils Ll and Lm in FIG. Furthermore, the bias magnetic field generated by the coils Ll, Lm, Ln, Lo or the bias magnetic field detected by the coils Ll, Lm, Ln, Lo is converged by the soft magnetic bodies 58, 59 (flux gate type magnetic detection element), It can be effectively used to detect the rotational state of the rotating body 1.

  In the rotation detection devices 100 to 105 exemplified above, two coils La to Lo are formed on each of the multilayer wiring boards 50a to 50e. However, the present invention is not limited to this, and only one coil may be formed on the multilayer wiring board, but it is more preferable to form a plurality of coils.

  General rotation detection in which a magnetic detection element such as an MRE is arranged close to the outer periphery of the rotating body, and a change in the bias magnetic field accompanying the rotation of the rotating body is measured by the magnetic detection element to detect the rotating state of the rotating body. In the apparatus, by using a plurality of magnetic detection elements, for example, the differential output of the plurality of magnetic detection elements can be determined, and the rotation state can be detected with higher accuracy than in the case of one. . Therefore, even when a coil embedded in a multilayer wiring board is used as, for example, a magnetic detection element in the rotation detection device of the present invention, by using a plurality of coils, it is possible to detect a rotation state with higher accuracy than a single coil. It becomes. In addition, even when the coil is used as an electromagnet for generating a bias magnetic field instead of a permanent magnet, it is possible to detect the rotational state with higher accuracy by arranging the coil in each of the plurality of magnetic detection elements. Become.

  As described above, each of the rotation detection devices described above is arranged in the vicinity of the outer periphery of the rotating body, and detects the rotation state of the rotating body by measuring the change in the bias magnetic field accompanying the rotation of the rotating body. The rotation detection device is a rotation detection device that can be reduced in size, has a high degree of freedom in arrangement with respect to a rotating body, and can detect a rotation state with high accuracy.

  Therefore, the rotation detection device is particularly suitable as a vehicle-mounted rotation detection device that is required to detect a small and highly accurate rotation state.

In the example of the rotation detection device of the present invention, (a) is a schematic top view of the rotation detection device 100, and (b) is a cross-sectional view taken along a dashed line AA in (a). FIG. 1 is an example in which the coils La and Lb of the rotation detection device 100 of FIG. 1 are used for generating a bias magnetic field, where (a) is a schematic top view of the rotation detection device 101, and (b) is (a). It is sectional drawing in the dashed-dotted line BB in FIG. FIG. 2 is a schematic top view of the rotation detection device 102 in an example in which the coils La and Lb of the rotation detection device 100 of FIG. (A)-(c) is the figure which compared and showed the output characteristic of the coils Lg-Li from which diameter d differs in length x, when using a coil as a magnetic detection element. In another example of the rotation detection device, (a) is a schematic top view of the rotation detection device 103, and (b) is a cross-sectional view taken along one-dot chain line CC in (a). In another example of the rotation detection device, (a) and (b) are cross-sectional views of the rotation detection devices 104 and 105, respectively, and (c) is a schematic top view of the rotation detection device 104. It is a perspective schematic diagram of the principal part of the rotation detection apparatus 80 disclosed by patent document 1. FIG. A rotation detection device used for rotation detection of a crank angle sensor or the like of an in-vehicle engine disclosed in Patent Document 2, (a) schematically shows a cross-sectional structure of the rotation detection device 90, and (b) These are the exploded perspective views which showed typically the component of the rotation detection apparatus 90. FIG.

Explanation of symbols

80, 90, 100 to 105 Rotation detection device 50, 50a to 50e Multi-layer wiring board La to Lo coil 58, 59 Soft magnetic body 1 Rotating body (gear)

Claims (8)

A rotation detection device that is disposed in the vicinity of the outer periphery of the rotating body and measures a change in a bias magnetic field accompanying the rotation of the rotating body to detect the rotating state of the rotating body,
It has a multilayer wiring board arranged close to the outer periphery of the rotating body,
A rotation detecting device, wherein a coil made of a multilayer wiring is embedded in an end portion of the multilayer wiring board close to the outer periphery of the rotating body. The multilayer wiring board is
A wiring pattern made of a metal thin film is formed in multiple layers on the silicon substrate via an interlayer insulating film,
It is a multilayer wiring board in which the wiring patterns in different layers are interlayer-connected with connection conductors embedded in via holes,
The coil is
The rotation detection device according to claim 1, wherein the rotation detection device is formed of the wiring pattern and the connection conductor. The multilayer wiring board is
A plurality of resin films made of a thermoplastic resin having a wiring pattern made of a metal foil formed on the surface are bonded together to form the wiring pattern in multiple layers,
A multilayer wiring board in which the wiring patterns in different layers are interlayer-connected with a connection conductor made of a sintered body of a conductive paste,
The coil is
The rotation detection device according to claim 1, wherein the rotation detection device is formed of the wiring pattern and the connection conductor.   4. The rotation detection device according to claim 1, wherein a plurality of the coils are formed on the multilayer wiring board. 5.   The rotation detecting device according to any one of claims 1 to 4, wherein a soft magnetic material is inserted and arranged in the coil.   The rotation detection apparatus according to claim 1, wherein the coil is used to generate the bias magnetic field.   The rotation detection device according to claim 1, wherein the coil is used to measure a change in the bias magnetic field.   The rotation detection device according to claim 1, wherein the rotation detection device is for vehicle use.

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