JP5651040B2 - Sensor unit and composite substrate - Google Patents

Description

  The present invention relates to a sensor unit in which a flexible board is electrically connected to a rigid circuit board, and a composite board.

  In general, a rotary encoder that detects the rotation of a rotating body with respect to a fixed body has a magnetosensitive element such as a magnetoresistive element opposed to a magnetic scale having a magnetic track in which N and S poles are arranged in the circumferential direction. It has a configuration (see, for example, Patent Documents 1 to 3).

JP 2007-271608 A JP 2000-121384 A Japanese Patent No. 3200361

  In such a detection device such as a rotary encoder, a sensor element such as a magnetosensitive element is connected to a flexible substrate due to restrictions on the position to be arranged. An amplifier circuit for an output signal from such a sensor element is acceptable. It is difficult to construct on a flexible substrate. Therefore, the inventors of the present application are considering using a composite substrate in which an amplifier circuit or the like is configured on a rigid circuit substrate and the circuit substrate and the flexible substrate are electrically connected. However, in the flexible substrate, a plurality of conductive patterns and an insulating protective layer are formed in this order on one side of the insulating base film, and insulation is provided at one end of the flexible substrate. Since the end portion of the conductive pattern exposed from the protective layer is used as a flexible substrate side terminal electrically connected to the circuit substrate, when stress is applied to the flexible substrate, the insulating protective layer The stress is concentrated along the edge, and the problem that the conductive pattern is cut at the edge of the insulating protective layer is likely to occur. Such a problem occurs similarly in a composite substrate used in a sensor unit using a sensor element other than a magnetosensitive element as a sensor element, and also occurs in a composite substrate used in an apparatus other than the sensor unit.

  In view of the above problems, the object of the present invention is to prevent the conductive pattern from being cut at the edge of the insulating protective layer in the flexible substrate even when the flexible substrate and the rigid circuit substrate are connected. An object of the present invention is to provide a sensor unit and a composite substrate that can be used.

In order to solve the above problems, the present invention provides a sensor element, a flexible board to which the sensor element is electrically connected, a rigid circuit board to be electrically connected to the flexible board, The flexible substrate includes an insulating base film, a plurality of conductive patterns formed on one surface of the base film, and the plurality of conductive patterns. An insulating protection layer laminated on the conductive pattern so as to avoid one substrate end arranged in the width direction as a flexible substrate side terminal, and an end electrically connected to the circuit board, Stress relaxation that relaxes the concentration of bending stress on the edge on the extension line of the edge on the side where the one substrate edge is located in the insulating protective layer at both ends in the width direction of the flexible substrate part is provided et al is, the stress absorbing portions, the leaving the base film It characterized that it is cut out portion to remove an edge protective layer.

Further, the present invention is a composite substrate having a flexible substrate and a rigid circuit substrate electrically connected to the flexible substrate, wherein the flexible substrate is an insulating substrate. A film, a plurality of conductive patterns formed on one surface of the base film, and an end portion of the plurality of conductive patterns electrically connected to the circuit board is a flexible substrate side terminal An insulating protective layer that is laminated on the conductive pattern so as to avoid one end of the substrate aligned in the width direction, and the one end of the insulating protective layer is disposed at both ends in the width direction of the flexible substrate. on the extension of the edge on the side where the substrate ends of the are located, stress absorbing portion to alleviate the concentration of a bending stress in the edge is provided et al is, the stress absorbing portions, leaving the base film wherein It is characterized by a cutout portion from which the insulating protective layer has been removed .

  In the present invention, a flexible substrate and a circuit board are electrically connected to form a composite substrate, and in such a composite substrate, the flexible substrate is placed on one side of the insulating base film. A plurality of conductive patterns and an insulating protective layer are formed in this order, and at one end of the flexible substrate, the end of the conductive pattern exposed from the insulating protective layer is electrically connected to the circuit board. Used as a flexible substrate side terminal to be connected. Here, when stress is applied to the flexible substrate, bending stress tends to concentrate along the edge of the insulating protective layer, but the edge of the insulating protective layer is formed at both ends in the width direction of the flexible substrate. Since the stress relaxation portion is provided on the extended line, it is possible to avoid bending stress from being concentrated on the edge of the insulating protective layer. Therefore, it is possible to prevent the conductive pattern from being cut at the edge of the insulating protective layer.

In the present invention, since the stress relaxation portion is a cutout portion of the insulating protective layer, when stress is applied to the flexible substrate, the stress is provided at both ends in the width direction. Absorption at the notch portion of the insulating protective layer and the strong transmission linearly along the edge of the insulating protective layer can be mitigated. Therefore, it is possible to prevent the conductive pattern from being cut at the edge of the insulating protective layer.

  In this case, in the stress relaxation part, it is preferable that the notch portion of the insulating protective layer is notched so as to be recessed with a curved shape. According to such a configuration, it is possible to more reliably relieve stress from being transmitted linearly and strongly along the edge of the insulating protective layer, so that the conductive pattern is more reliably cut at the edge of the insulating protective layer. Can be prevented.

  In this invention, it is preferable that the stress relaxation part is provided with a dummy terminal that does not contribute to electrical connection with the circuit board. According to this configuration, when stress is applied to the flexible substrate, the stress is absorbed by the dummy terminal and can be mitigated from being strongly transmitted linearly along the edge of the insulating protective layer. Therefore, it is possible to prevent the conductive pattern from being cut at the edge of the insulating protective layer.

  In the present invention, the one substrate end of the flexible substrate is overlaid on the circuit board with the surface side where the terminals are exposed facing away from the side on which the circuit board is located. The circuit board side terminal exposed from the one board end of the flexible board and the terminal in the board are electrically connected by solder provided so as to straddle the circuit board side terminal and the terminal. Can be adopted. According to such a configuration, the flexible substrate and the circuit board can be electrically connected even if the orientation of the flexible substrate is restricted because the flexible substrate is a single-sided substrate or the like.

  In the present invention, when the flexible substrate is bent in a U shape between the one substrate end and the other substrate end located on the opposite side of the one substrate end. It is effective when applied. When the flexible substrate is bent in a U-shape, a large stress is applied to the flexible substrate, and the bending stress tends to concentrate along the edge of the insulating protective layer. Since the stress relaxation portion is provided on the extended line of the edge, it is possible to avoid the bending stress from being concentrated on the edge of the insulating protective layer. Therefore, it is possible to prevent the conductive pattern from being cut at the edge of the insulating protective layer. Therefore, even when the flexible substrate is bent in a U shape, high reliability can be obtained.

  In the present invention, the flexible substrate has a plurality of conductive patterns and an insulating protective layer formed in this order on one side of the insulating base film, and at one end of the flexible substrate. The end portion of the conductive pattern exposed from the insulating protective layer is used as a flexible substrate side terminal electrically connected to the circuit board. Here, when stress is applied to the flexible substrate, bending stress tends to concentrate along the edge of the insulating protective layer, but the edge of the insulating protective layer is formed at both ends in the width direction of the flexible substrate. Since the stress relaxation portion is provided on the extension line, it is possible to avoid bending stress from being concentrated on the edge of the insulating protective layer. Therefore, it is possible to prevent the conductive pattern from being cut at the edge of the insulating protective layer.

It is explanatory drawing which shows the basic composition etc. of the rotary encoder which concerns on this invention. It is explanatory drawing which shows the specific structural example of the rotary encoder which concerns on this invention. It is explanatory drawing of the sensor unit of the rotary encoder which concerns on this invention. It is a disassembled perspective view of the sensor unit of the rotary encoder which concerns on this invention. It is explanatory drawing of the magnetic sensitive element of the rotary encoder which concerns on this invention. It is explanatory drawing of the holder used for the sensor unit of the rotary encoder which concerns on this invention. It is explanatory drawing of the flexible board | substrate etc. which were used for the sensor unit of the rotary encoder which concerns on this invention. It is explanatory drawing which shows a mode that the magnetosensitive element was fixed to the holder in the sensor unit of the rotary encoder which concerns on this invention. It is explanatory drawing of the magnetic scale of the rotary encoder which concerns on this invention.

  Embodiments of a rotary encoder to which the present invention is applied will be described below with reference to the drawings. In the rotary encoder, when detecting the rotation of the rotating body relative to the fixed body, the fixed body is provided with a magnetic scale, the rotating body is provided with a magnetosensitive element (sensor unit), and the fixed body has a magnetosensitive element ( Any of the configurations in which the sensor unit is provided and the rotating body is provided with a magnetic scale may be employed. However, in the following description, a magnetic sensitive element (sensor unit) is provided in the fixed body and the rotating body is provided with a magnetic scale. A description will be given centering on the configuration provided with. Further, in the drawings referred to below, configurations of a magnet, a magnetosensitive element, and the like are schematically shown.

(Basic configuration of rotary encoder)
FIG. 1 is an explanatory diagram showing a basic configuration and the like of a rotary encoder 1 according to the present invention. FIGS. 1A, 1B, and 1C schematically illustrate a positional relationship between a magnetic scale and a magnetosensitive element. FIG. 3 is an explanatory diagram showing an output signal from the magnetosensitive element, and an explanatory diagram showing a relationship between the output signal from the magnetosensitive element and the angular position θ (electrical angle) of the rotating body.

  As shown in FIG. 1, in the rotary encoder 1 of this embodiment, a magnetic scale 2 is provided on the rotating body side, and a sensor unit 5 is provided on the fixed body side. The magnetic scale 2 directs the magnetic track 31 in which the N pole and the S pole are alternately magnetized in the circumferential direction toward one side L1 in the rotation axis direction L, and the sensor unit 5 rotates with respect to the magnetic track 31. A magnetosensitive element 6 (sensor element) is provided opposite to one side L1 in the axial direction L. In this embodiment, the magnetic track 31 has two rows of tracks 311 and 312 concentrically arranged in parallel. In the magnetic track 31, the positions of the N pole and the S pole are shifted in the circumferential direction between the two tracks 311 and 312. In this embodiment, the N pole and the S pole are rotated between the two tracks 311 and 312. It is shifted by one pole in the direction.

  In this embodiment, the magnetosensitive element 6 is a magnetoresistive element, and has an A phase (SIN) magnetoresistive pattern and a B phase (COS) magnetism having a phase difference of 90 ° with respect to the phase of the magnetic track 31. And a resistance pattern. In such a magnetosensitive element (magnetoresistance element), the A phase magnetoresistive pattern is a + a phase (SIN +) magnetoresistive pattern 64 and −a phase (SIN−) that detects the movement of the rotating body with a phase difference of 180 °. The B phase magnetoresistive pattern includes a + b phase (COS +) magnetoresistive pattern 63 and a −b phase (COS−) magnetoresistive pattern 63 for detecting the movement of the rotating body with a phase difference of 180 °. A magnetoresistive pattern 61 is provided. The + a-phase magnetoresistive pattern 64 and the -a-phase magnetoresistive pattern 62 constitute a bridge circuit, with one end connected to the power supply terminal (Vcc) and the other end connected to the ground terminal (GND). Yes. Further, a terminal (+ a) from which the + a phase is output is provided at the midpoint position of the + a phase magnetoresistive pattern 64, and the −a phase is output at the midpoint position of the −a phase magnetoresistive pattern 62. The terminal (-a) to be used is provided. Similarly to the + a-phase magnetoresistive pattern 64 and the -a-phase magnetoresistive pattern 62, the + b-phase magnetoresistive pattern 63 and the -b-phase magnetoresistive pattern 61 also constitute a bridge circuit. The other end is connected to the power terminal (Vcc) and the ground terminal (GND). Further, a terminal (+ b) from which a + b phase is output is provided at the midpoint position of the + b phase magnetoresistive pattern 63, and a −b phase is output at the midpoint position of the −b phase magnetoresistive pattern 61. Terminal (-b) is provided.

The magnetic sensing element 6 having such a configuration is arranged at a position overlapping with the boundary portion 313 of the adjacent tracks 311 and 312 in the magnetic track 31 in the rotation axis direction L. Therefore, the magnetoresistive patterns 61 to 64 of the magnetosensitive element 6 have a rotating magnetic field whose direction changes in the in-plane direction of the magnetic track 31 with a magnetic field strength equal to or higher than the saturation sensitivity region of the resistance value of each of the magnetoresistive patterns 61 to 64. Can be detected. That is, in the boundary portion 313 between the adjacent tracks 311 and 312, the in-plane direction of the tracks 311 and 312 gradually increases in the circumferential direction with a magnetic field intensity equal to or higher than the saturation sensitivity region of the resistance value of each of the magnetoresistive patterns 61 to 64. A rotating rotating magnetic field is generated. The saturation sensitivity region generally refers to a region other than the region in which the resistance value change amount k can be approximately expressed by the magnetic field strength H and the expression “k∝H2”. The principle of detecting the direction of the rotating magnetic field (rotation of the magnetic vector) with a magnetic field strength equal to or greater than the saturation sensitivity region is that the resistance value saturates when the magnetoresistive patterns 61 to 64 made of ferromagnetic metal are energized. Between the angle θ formed by the magnetic field and the current direction when the magnetic field strength is applied and the resistance value R of the magnetoresistive patterns 61 to 64, the following equation is given: R = R0−k × sin2θ
R0: resistance value in a non-magnetic field k: resistance value change (a constant when the saturation sensitivity region is exceeded)
The fact that there is a relationship indicated by is used. If the rotating magnetic field is detected based on such a principle, the resistance value R changes along the sine wave when the angle θ changes, so that the A phase and the B phase with high waveform quality can be obtained.

In the rotary encoder 1 having such a configuration, the magnetosensitive element 6 includes an amplifier circuit 13, 14 and a CPU 10 (interpolation process and various arithmetic processes performed on the sine wave signals sin, cos output from the amplifier circuits 13, 14). An arithmetic circuit) is provided, and based on the output from the magnetosensitive element 6, the rotational speed, rotational direction, and angular position of the rotating body relative to the fixed body are detected. More specifically, in the rotary encoder 1, when the rotating body rotates by one period of the magnetic pole, the sine wave signals sin and cos shown in FIG. . Therefore, after the sine wave signals sin and cos are amplified by the amplifier circuits 13 and 14, the CPU 10 generates θ = tan ⁻¹ (sin / cos) from the sine wave signals sin and cos as shown in FIG. If it calculates | requires, angular position (theta) of a rotary body will be known.

(Specific configuration of the rotary encoder 1)
FIG. 2 is an explanatory diagram showing a specific configuration example of the rotary encoder 1 according to the present invention. FIGS. 2A, 2B, 2C, and 2D are side views of the rotary encoder 1, and magnetic FIG. 3 is a perspective view of the scale 2 as viewed from the sensor unit 5 side, an explanatory view of the magnetic track 31 of the magnetic scale 2, and a perspective view of the sensor unit 5. FIG. 2D shows a state where the shield tape is peeled off from the surface of the magnetosensitive element 6. FIG. 3 is an explanatory diagram of the sensor unit 5 of the rotary encoder 1 according to the present invention. FIGS. 3 (a), (b), (c), and (d) show the sensor unit 5 as a sensor of the magnetosensitive element 6. FIG. 3 is a plan view seen from the surface side, a side view of the sensor unit 5, a bottom view of the sensor unit 5 seen from the side opposite to the sensor surface, and an explanatory view showing the shield tape peeled off from the surface of the magnetosensitive element 6. 4 is an exploded perspective view of the sensor unit 5 of the rotary encoder 1 according to the present invention. FIGS. 4 (a), 4 (b), 4 (c), and 4 (d) show a circuit board and the like from the holder in the sensor unit 5. FIG. The perspective view of the state which removed the flexible substrate etc. from the circuit board, the perspective view of the state which unfolded the flexible substrate, and the circuit board back side (the side opposite to the sensor surface) It is a perspective view which shows a mode that it saw.

  As shown in FIGS. 2A, 2B, and 2D, in the rotary encoder 1 of the present embodiment, the magnetic scale 2 and the sensor unit 5 are both annular and face each other in the rotation axis direction L of the rotating body. In addition, the center O2 of the magnetic scale 2 and the center O5 of the sensor unit 5 are arranged on the rotation axis direction L of the rotating body.

  As shown in FIG. 2B, the magnetic scale 2 includes an annular yoke plate 20 made of metal such as SPPC (cold rolled steel plate) and the surface of the yoke plate 20 (the side on which the sensor unit 5 is located). The annular sensor magnet 30 is fixed to the surface of the sensor magnet 30. As shown in FIG. 2C, the annular surface of the sensor magnet 30 (the magnetized surface 33) extends in the circumferential direction. A track 31 is provided. The magnetic track 31 includes an inner track 311 and an outer track 312 that extend in the circumferential direction in parallel with the radial direction. These tracks 311 and 312 are provided by magnetizing the sensor magnet 30 with a magnetizing head.

  As shown by a dotted line in FIG. 2B, an annular protective sheet 40 made of a nonmagnetic material such as stainless steel is attached to the magnetized surface of the sensor magnet 30. In this example, the magnetic track 31 is divided into 90 parts in the circumferential direction, and N poles and S poles are alternately magnetized, and the angle range in which each magnetic pole is magnetized is 4 °. Moreover, the planar shape of each S pole and each N pole is a fan shape whose width becomes narrower from the outer periphery toward the inner periphery. The protective cover 4 can be omitted from the magnetic scale 2.

  As shown in FIGS. 2A, 2D, 3 and 4, the sensor unit 5 includes an annular holder 8 made of a zinc die-cast product or an aluminum die-cast product, and a back surface side (magnetic scale) of the holder 8 2, a rigid circuit board 7 attached to the side opposite to the side where 2 is located, a flexible board 9 electrically connected to the circuit board 7, and an electrical connection to the flexible board 9. The surface of the magnetosensitive element 6 on which the magnetic scale 2 is located is a sensor surface 6a. A connector 15 that outputs the output from the circuit board 7 to the CPU 10 shown in FIG. 1A is mounted on the circuit board 7. A metal shield tape 66 (see FIG. 3A) is attached to the sensor surface 6a of the magnetosensitive element 6 as a countermeasure against electric noise, and the sensor surface 6a is covered with the shield tape 66.

(Specific configuration example of magnetosensitive element 8)
FIG. 5 is an explanatory diagram of the magnetosensitive element 6 of the rotary encoder 1 according to the present invention. FIGS. 5A and 5B are a plan view of the magnetosensitive element 6 and a magnetoresistive pattern in the magnetosensitive element 6. It is explanatory drawing which shows typically the lamination | stacking state. In FIG. 5 (a), tracks 311 and 312 are shown which are arranged to face each magnetoresistive pattern so as to overlap each magnetoresistive pattern.

  In FIG. 5, the magnetosensitive element 6 used in this embodiment includes a first magnetoresistive pattern 64 (SIN +) of + a phase and a magnetoresistive pattern 63 (COS +) of + b phase, which are stacked via an interlayer insulating film. The laminated magnetoresistive pattern 601 is formed on the main surface 60a of the element substrate 60, and the main surface 60a side of the element substrate 60 is the sensor surface 6a. The + a-phase magnetoresistive pattern 64 (SIN +) and the + b-phase magnetoresistive pattern 63 (COS +) are arranged so that their centers are opposed to the boundary portions 313 of the tracks 311 and 312 in the radial direction of the magnetic track 31. In the circumferential direction of the magnetic track 31, the + b phase detected by the + a phase and the + b phase magnetoresistive pattern 63 (COS +) detected by the + a phase magnetoresistive pattern 64 (SIN +) is the minimum phase difference. Arranged at the minimum machine angle offset position. That is, the + a phase magnetoresistive pattern 64 (SIN +) and the + b phase magnetoresistive pattern 63 (COS +) are arranged at angular positions where the same wavelength obtained from the magnetic scale 2 can be detected with a phase difference of 90 °. ing. In this example, the + a-phase magnetoresistive pattern 64 (SIN +) and the + b-phase magnetoresistive pattern 63 (COS +) are arranged at positions shifted by 1 ° in the circumferential direction. In this embodiment, as shown in FIG. 5B, a + b phase magnetoresistive pattern 63 (COS +) is formed on the main surface 60a of the element substrate 60, and a + a phase magnetoresistive pattern 64 (SIN +) is formed. It is laminated on it. The minimum phase difference is a phase difference of 90 °, and the vertical relationship between the + a phase magnetoresistance pattern 64 (SIN +) and the + b phase magnetoresistance pattern 63 (COS +) may be reversed.

  The −a phase magnetoresistance pattern 62 (SIN−) and the −b phase magnetoresistance pattern 61 (COS−) are also the + a phase magnetoresistance pattern 64 (SIN +) and the + b phase magnetoresistance pattern 63 (COS +). Similarly to the above, the second laminated magnetoresistive pattern 602 is formed on the main surface 60a of the element substrate 60 through the interlayer insulating film. The −a phase magnetoresistive pattern 62 (SIN−) and the −b phase magnetoresistive pattern 61 (COS−) are each centered at the boundary portion 313 of the tracks 311 and 312 in the radial direction of the magnetic track 31. In the circumferential direction of the magnetic track 31, the -a phase and -b phase magnetoresistance patterns 61 (COS-) are detected in the circumferential direction of the magnetic track 31. The -b phase is arranged at a position shifted by the minimum mechanical angle at which the minimum phase difference is obtained. That is, the −a phase magnetoresistive pattern 62 (SIN−) and the −b phase magnetoresistive pattern 61 (COS−) are angles at which the same wavelength obtained from the magnetic scale 2 can be detected with a phase difference of 90 °. Placed in position. In this example, the -a phase magnetoresistive pattern 62 (SIN-) and the -b phase magnetoresistive pattern 61 (COS-) are arranged at positions shifted by 1 ° in the circumferential direction. In this embodiment, as shown in FIG. 5B, the -a phase magnetoresistive pattern 62 (SIN-) is formed on the main surface 60a of the element substrate 60, and the -b phase magnetoresistive pattern 61 ( COS-) is stacked on top of it. The minimum phase difference is a phase difference of 90 °, and the stacking relationship between the −a phase magnetoresistive pattern 62 (SIN−) and the −b phase magnetoresistive pattern 61 (COS−) may be reversed.

  Next, the first laminated magnetoresistive pattern 601 and the second laminated magnetoresistive pattern 602 are arranged at positions that do not overlap in the circumferential direction. More specifically, the first laminated magnetoresistive pattern 601 and the second laminated magnetoresistive pattern 602 include the + a phase detected from the + a phase magnetoresistive pattern 64 (SIN +) of the first laminated magnetoresistive pattern 601, and the second The -a phase detected from the -a phase magnetoresistive pattern 62 (SIN-) of the laminated magnetoresistive pattern 602 is a position where the phase difference is 180 °, and the + b phase magnetoresistance of the first laminated magnetoresistive pattern 601 The position where the + b phase detected from the pattern 63 (COS +) and the −b phase detected from the −b phase magnetoresistive pattern 61 (COS−) of the second laminated magnetoresistive pattern 602 have a phase difference of 180 °. Is arranged. Further, the first laminated magnetoresistive pattern 601 and the second laminated magnetoresistive pattern 602 are arranged at an angular position separated by a minimum distance that does not interfere electrically or magnetically. In this example, the + a phase magnetoresistive pattern 64 (SIN +) of the first laminated magnetoresistive pattern 601 and the −a phase magnetoresistive pattern 62 (SIN−) of the second laminated magnetoresistive pattern 602 are 22 ° in the circumferential direction. It is arranged at a shifted position. Similarly, the + b phase magnetoresistive pattern 63 (COS +) of the first laminated magnetoresistive pattern 601 and the −b phase magnetoresistive pattern 61 (COS−) of the second laminated magnetoresistive pattern 602 are also 22 ° in the circumferential direction. It is arranged at a shifted position.

  Here, the magnetoresistive patterns 61 to 64 are not parallel to each other but are positioned on a plurality of imaginary lines extending in the radial direction from the center O8 of the holder 8 (center O5 of the sensor unit 5) shown in FIG. The holder 8 and the sensor unit 5 extend in the radial direction. The magnetoresistive patterns 61 to 64 are formed by laminating a magnetic film such as a ferromagnetic NiFe on the element substrate 60 made of glass or silicon by a semiconductor process. The element substrate 60 has a rectangular shape, and the magnetoresistive patterns 61 to 64 are formed in the central region of the element substrate 60. A plurality of terminals 68 are formed at one end of the element substrate 60 along one long side, and the terminals 68 are used for electrical connection with the flexible substrate 9 shown in FIG. ing. Further, each of the magnetoresistive patterns 61 to 64 is covered with a protective layer (not shown) such as an epoxy resin formed so as to avoid the terminal 68, and the protective layer is formed by, for example, screen printing. Yes.

(Detailed configuration of circuit board 7)
As shown in FIG. 4, the circuit board 7 has an annular shape having a shape substantially along the outer peripheral shape of the holder 8, and a round hole 78 is formed at the center. The circuit board 7 is a rigid board such as a glass-epoxy board, and is placed on the back side of the holder 8 and fixed to the holder 8 with screws. For this reason, a plurality of holes 77 for fastening screws are formed on the outer peripheral side of the circuit board 7.

  In the circuit board 7, electronic components 79 and connectors 15 constituting the amplifier circuits 13 and 14 shown in FIG. 1A are mounted on the first board surface 71 located on the holder 8 side. A plurality of terminals 73 used for electrical connection with the flexible substrate 9 are formed on the first substrate surface 71 of the circuit substrate 7 in the vicinity of the round hole 78. The connection with the flexible substrate 9 using the terminal 73 will be described later with reference to FIG. In this embodiment, a total of eight terminals 73 are formed, and among these terminals 73, a total of six terminals 731 excluding the terminals 732 on both sides are used for electrical connection with the flexible substrate 9. On the other hand, the terminals 732 on both sides are dummy terminals that are connected to the flexible substrate 9 by solder but are not used for electrical connection. The dummy terminal 732 has a larger width than the other terminal 731 and is disposed slightly outside in the radial direction with respect to the other terminal 731.

  The circuit board 7 is a double-sided board, and various wiring patterns are formed on the second board surface 72 opposite to the side on which the holder 8 is located, but a wide area including the area where the wiring pattern is formed. Further, an insulating printed layer 76 (region shown in gray in FIGS. 3C and 4D) is further formed on the surface of the resist layer covering the wiring pattern.

(Detailed configuration of holder 8)
FIG. 6 is an explanatory diagram of the holder 8 used in the sensor unit 5 of the rotary encoder 1 according to the present invention. FIGS. 6 (a), (b), (c), (d), and (e) 8 is a plan view of the sensor surface 6a as viewed from the side, a side view of the holder 8, a bottom view of the holder 8 as viewed from the side opposite to the sensor surface 6a, and a plan view showing an enlarged periphery of the opening where the magnetosensitive element 6 is disposed; And EE ′ cross-sectional view.

  As shown in FIGS. 2, 3, 4, and 6, the holder 8 has a tray shape having an annular shape as a whole, and a main body portion thereof includes an annular plate-like portion 80. A circular center hole 82 is formed in the plate-like portion 80, and an outer peripheral portion 81 of the plate-like portion 80 is a concentric circle with the center hole 82. Accordingly, the holder 8 includes an arc-shaped outer peripheral portion 81 (circumferential portion) centered on the center O8 of the holder 8 and a circular inner peripheral portion 82a (circumferential portion) centered on the center O8 of the holder 8. It has.

  The holder 8 also includes a substrate support step portion 85 that partially receives the first substrate surface 71 of the circuit board 7 on the back surface side of the plate-shaped portion 80. FIG. A portion corresponding to the step portion 85 is represented as a gray region. The substrate support step 85 is located slightly higher than the other region on the back side of the plate-like portion 80, and the region where the substrate support step 85 is not formed on the back side of the plate-like portion 80. When viewed from the substrate supporting step 85, it is a shallow recess. For this reason, when the circuit board 7 is overlapped and fixed on the back surface side of the holder 8, a narrow gap is secured between the back surface side of the plate-like portion 80 and the first substrate surface 71 of the circuit board 7.

  In the holder 8, a substantially rectangular opening 86 in which the magnetosensitive element 6 is disposed inside is formed in the plate-like portion 80, and an outer peripheral portion 81 at a position opposite to the opening 86 across the center O 8. Is formed with a notch 87 in which the connector 15 is disposed inside.

  In the holder 8, the side portion on the side where the center O 8 is located in the inner peripheral portion of the opening 86 is a contact portion 89 for positioning the magnetic sensing element 6 in the radial direction. Further, the holder 8 is formed with two protrusions 881 and 882 that protrude toward the inside of the opening 86 so as to face each other. The protrusions 881 and 882 are formed at a position midway in the thickness direction of the plate-like portion 80 with a dimension thinner than that of the plate-like portion 80, and the upper surfaces of the protrusions 881 and 882 are lower positions when viewed from the surface side of the holder 8. It is in. The protrusions 881 and 882 are portions for positioning the magnetic sensing element 6 in the thickness direction and fixing the magnetic sensing element 6 with an adhesive, as will be described later with reference to FIG.

(Detailed configuration of flexible substrate 9)
FIG. 7 is an explanatory diagram of the flexible substrate 9 and the like used in the sensor unit 5 of the rotary encoder 1 according to the present invention. FIGS. 7 (a), (b), (c), and (d) are acceptable. A plan view of the flexible substrate 9, a plan view showing the mutual positional relationship when the magnetosensitive element 6 and the circuit board 7 are connected to the flexible substrate 9, a cross-sectional view after soldering, and the flexible substrate 9 It is sectional drawing which shows a mode that it bent in U shape.

  As shown in FIG. 7, the flexible substrate 9 has a rectangular planar shape, and a plurality of conductive patterns 96 extending linearly in the longitudinal direction are formed. In the flexible substrate 9, a plurality of terminals 98 connected to the circuit substrate 7 are provided along the width direction of the flexible substrate 9 at the substrate end portion 9 s on one side in the longitudinal direction. A plurality of terminals 99 to which the magnetosensitive element 6 is connected are provided along the width direction of the flexible substrate 9 at the other end 9t of the substrate.

  In this embodiment, a total of six conductive patterns 96 are formed, whereas a total of eight terminals 99 are formed. That is, out of the eight terminals 99, a total of six terminals 991 excluding the terminals 992 on both sides are used for electrical connection with the magnetosensitive element 6, whereas the terminals 992 on both sides are magnetized by solder. A dummy terminal connected to the element 6 but not used for electrical connection. Accordingly, the terminal 991 is formed as an end portion of the conductive pattern 96, but the terminal 992 is not connected to the conductive pattern 96.

  Similarly to the terminal 99, a total of eight terminals 98 are formed, and among the eight terminals 98, a total of six terminals 981 excluding the terminals 982 on both sides are connected to the terminals 731 of the circuit board 7 to form a circuit. The terminals 982 on both sides are dummy terminals that are connected to the dummy terminals 732 of the circuit board 7 by soldering while being used for electrical connection with the board 7. Accordingly, the terminal 981 is formed as an end portion of the conductive pattern 96, but the terminal 982 is not connected to the conductive pattern 96.

  The flexible substrate 9 having such a configuration includes an insulating base film 95, a plurality of conductive patterns 96 formed on one surface of the base film 95, and an insulating protection that covers the surfaces of the plurality of conductive patterns 96. A single-sided substrate having a layer 97, and a conductive pattern 96 and terminals 98 and 99 are formed only on the first substrate surface 91 side of the first substrate surface 91 and the second substrate surface 92. Here, the insulating protective layer 97 is formed so as to avoid both substrate end portions 9 s and 9 t in the longitudinal direction of the flexible substrate 9. That is, the insulating protective layer 97 is formed at a position separated from the side portion of the flexible substrate 9 by a predetermined dimension at the substrate end 9s on one side, and the edge 970 of the insulating protective layer 97 is It extends linearly parallel to the part. Therefore, the terminal 981 is formed of a portion of the conductive pattern 96 exposed from the insulating protective layer 97. The insulating protective layer 97 is also formed at a position separated from the side portion of the flexible substrate 9 by a predetermined dimension even at the other end 9 t of the substrate, and the terminal 982 is insulated from the conductive pattern 96. It consists of a portion exposed from the protective layer 97. The conductive pattern 96 is made of a copper foil pattern, and the portions corresponding to the terminals 98 and 99 are plated with tin-copper or the like on the surface of the copper foil pattern.

  In electrically connecting the magnetosensitive element 6 to the flexible substrate 9 having such a configuration, the element used for the first substrate surface 91 and the magnetosensitive element 6 at the substrate end 9 t of the flexible substrate 9. With the main surface 60a side (sensor surface 6a side) of the substrate 60 facing each other, the terminals 99 of the flexible substrate 9 and the terminals 68 of the magnetosensitive element 6 are connected by solder 67.

  When electrically connecting the flexible board 9 and the circuit board 7, the terminal 98 of the flexible board 9 and the terminal 73 of the circuit board 7 are connected to each other at the board end 9 s of the flexible board 9. Connection is made by solder 90. At that time, the flexible substrate 9 is a single-sided substrate, and it is necessary to bend the flexible substrate 9 in a U shape so that the sensor surface 6 a of the magnetic sensitive element 6 faces the surface side of the holder 8.

  Therefore, in this embodiment, when the flexible substrate 9 and the circuit substrate 7 are electrically connected, first, the first end portion 9s of the flexible substrate 9 has the terminal 98 exposed. The substrate surface 91 is overlaid on the circuit board 7 with the side opposite to the side where the circuit board 7 is located. In this state, the terminal 73 of the circuit board 7 is exposed from the board end 9s of the flexible board 9, and the terminal 99 of the flexible board 9 and the terminal 73 of the circuit board 7 are in a one-to-one relationship. Line up linearly with relationships. In this state, the solder 90 is provided so as to straddle the terminals 73 and 99, and the terminal 73 and the terminal 99 are connected by the solder 90.

  In this way, the composite substrate 50 is configured by connecting the flexible substrate 9 and the circuit substrate 7. Therefore, the signal output from the magnetosensitive element 6 is output to the circuit board 7 via the flexible substrate 9, amplified by the amplifier circuits 12 and 13 formed on the circuit board 7, and then via the connector 15. Are output to the CPU 10. Therefore, since it is not necessary to output the weak analog signal output from the magnetosensitive element 6 via the connector 15, signal degradation does not occur. Further, since the magnetosensitive element 6 is connected to the flexible substrate 9, there is an advantage that the flexible substrate 9 can be directed to the surface side of the holder 8 by bending the flexible substrate 9.

(Reinforcement for flexible substrate 9)
In the sensor unit 5 and the composite substrate 50 described with reference to FIG. 7 and the like, the insulating protective layer 97 has a predetermined dimension from the side portion of the flexible substrate 9 at the substrate end 9 s on one side of the flexible substrate 9. The end edge 970 of the insulating protective layer 97 extends linearly in parallel to the side portion. The flexible substrate 9 is bent in a U shape between the substrate end portions 9s and 9t. For this reason, the stress applied to the flexible substrate 9 is concentrated along the edge 970 of the insulating protective layer 97, and the conductive pattern 96 is disconnected at the edge 970. There is a possibility that the problem of disconnection will occur.

  Therefore, in this embodiment, as will be described below with reference to FIG. 7, at both ends in the width direction of the flexible substrate 9, on the extension line of the edge 970 of the insulating protective layer 97, to the edge 970. A stress relieving portion is provided to alleviate the concentration of bending stress and prevent occurrence of defects at the edge 970.

  First, in the present embodiment, the edge 970 of the insulating protective layer 97 is provided at both end portions in the width direction of the flexible substrate 9 as stress relaxing portions that relieve the concentration of bending stress on the edge 970 of the insulating protective layer 97. A cutout portion 971 (non-formed portion of the insulating protective layer 97 / stress relaxation portion) of the insulating protective layer 97 is provided on the extended line. Here, the cutout portion 971 of the insulating protective layer 97 is cut out so as to be recessed with a curved shape. For this reason, when a stress is applied to the flexible substrate 9, the stress is absorbed by the cutout portions 971 of the insulating protective layer 97 provided at both ends in the width direction and is applied to the edge 970 of the insulating protective layer 97. It is possible to ease the strong transmission along the straight line. In addition, since the notched portion 971 of the insulating protective layer 97 is notched so as to be recessed with a curved shape, when the stress is applied to the flexible substrate 9, the stress is curved at the notched portion 971. Absorption along the shape and strong transmission linearly along the edge 970 of the insulating protective layer 97 can be effectively mitigated. Therefore, it is possible to prevent the conductive pattern 96 from being cut at the edge 970 of the insulating protective layer 97.

  In this embodiment, the edge 970 of the insulating protective layer 97 is provided at both end portions in the width direction of the flexible substrate 9 as stress relaxing portions for relaxing the concentration of bending stress on the edge 970 of the insulating protective layer 97. A dummy terminal 982 (stress relieving part) that does not contribute to electrical connection with the circuit board 7 is provided on the extension line. Moreover, the dummy terminals 982 of the flexible substrate 9 are fixed to the dummy terminals 732 of the circuit substrate 7 by solder 90. For this reason, when a stress is applied to the flexible substrate 9, the stress is dispersed by the dummy terminals 982 and the dummy terminals 732 of the circuit substrate 7, so that the stress is along the edge 970 of the insulating protective layer 97. Can be effectively relieved from being transmitted strongly in a straight line. Therefore, it is possible to prevent the conductive pattern 96 from being cut at the edge 970 of the insulating protective layer 97.

(Magnetic sensing element 6 positioning structure)
FIGS. 8A and 8B are explanatory views showing a state in which the magnetosensitive element 6 is fixed to the holder 8 in the sensor unit 5 of the rotary encoder 1 according to the present invention. FIGS. 8A and 8B show the magnetosensitive element 6. It is the top view which looked at the fixed state from the surface side, and explanatory drawing seen from the back surface side.

  In this embodiment, the flexible substrate 9 described with reference to FIG. 7 is bent into a U shape so that the sensor surface 6a of the magnetosensitive element 6 faces the surface of the holder 8, and the magnetosensitive element 6 is placed in the holder 8 in this state. Secure to. Specifically, the flexible substrate 9 is bent into a U-shape as shown in FIG. 7D, and the magnetosensitive element 6 is disposed in the opening 86 of the holder 8 as shown in FIG. At that time, the magnetosensitive element 6 is overlaid on the upper surfaces of the protrusions 881 and 882 of the holder 8. In this state, the elastic force of the flexible substrate 9 acts on the magnetic sensing element 6, and the magnetic sensing element 6 is biased toward the center O 8 of the holder 8. As a result, the magnetic sensing element 6 abuts against the contact portion 89 of the holder 8 and the magnetic sensing element 6 is positioned. Accordingly, when the magnetic sensitive element 6 is positioned in contact with the contact portion 89 of the holder 8 and is positioned so as to straddle the protrusions 881 and 882 and the magnetic sensitive element 6, The magnetosensitive element 6 is fixed at a predetermined radial position on the holder 8. Accordingly, the magnetoresistive patterns 61 to 64 described with reference to FIG. 5 are located on a plurality of imaginary lines extending in the radial direction from the center O8 of the holder 8 (center O5 of the sensor unit 5).

(Detailed configuration of magnetic scale 2)
FIG. 9 is an explanatory diagram of a magnetic scale of the rotary encoder 1 according to the present invention. FIGS. 9A, 9B, 9C, 9D, 9E are a plan view and a cross-section of the magnetic scale. It is a figure, the top view of a sensor magnet, the top view of a yoke board, and explanatory drawing of the sensor magnet immediately after shaping | molding (before grinding | polishing). As described with reference to FIG. 2B, in the rotary encoder 1 of the present embodiment, the magnetic scale 2 includes the annular yoke plate 20 and the surface of the yoke plate 20 (the side on which the sensor unit 5 is located). And an annular sensor magnet 30 fixed to the head. As shown in FIG. 9, the yoke plate 20 is larger in width than the sensor magnet 30, and the inner peripheral portion 21 of the yoke plate 20 is located on the inner side of the inner peripheral edge 35 of the sensor magnet 30. The outer peripheral portion 22 is located outside the outer peripheral edge 32 of the sensor magnet 30. Accordingly, the circular outer peripheral edge and the circular inner peripheral edge of the magnetic scale 2 correspond to the inner peripheral portion 21 and the outer peripheral portion 22 of the yoke plate 20.

  In the magnetic scale 2 having such a configuration, the sensor magnet 30 is magnetized based on the circular shape of the yoke plate 20. More specifically, the sensor magnet 30 fixes the magnetic track 31 by fixing the annular magnetic body to the yoke plate 20 with an adhesive, polishing the surface of the magnetic body, and then magnetizing it. It is formed by forming. At the time of such magnetization, in this embodiment, the sensor magnet 30 (magnetic body) is not circular, but is magnetized based on the circular shape of the yoke plate 20 such as the inner peripheral portion 21 and the outer peripheral portion 22 of the yoke plate 20. Yes. Therefore, in the magnetic scale 2, the magnetic track 31 and the inner peripheral portion 21 and the outer peripheral portion 22 of the yoke plate 20 are concentric.

  Here, the sensor magnet 30 is a plastic magnet formed by mixing magnetic powder (magnet raw material) such as ferrite and a thermoplastic resin material (plastic material) such as PPS (polyphenylene sulfide). In this embodiment, the sensor magnet 30 is a plastic magnet formed by a film gate (flash gate) among various plastic magnets. In forming with such a film gate, a film-like (film-like) gate is used, and this film-like gate is provided on the entire circumference of the portion that becomes the inner peripheral surface of the annular sensor magnet 30. Accordingly, there is no parting line in the sensor magnet 30 of this embodiment. Further, when a film gate is used, the position of the gate is indicated by an arrow G in FIG. 9E, and the edge of the inner peripheral surface of the sensor magnet 30 immediately after the molding is formed over the entire circumference where the gate was located. A gate mark 39 is generated. Therefore, in this embodiment, after the sensor magnet 30 is formed by a film gate, the entire surface side where the gate is located is polished to remove the gate trace. For this reason, although the sensor magnet 30 is a plastic magnet, there is no gate mark. The sensor magnet 30 has a higher degree of flatness than the opposite surface 34 of the magnetized surface 33 of both surfaces. However, as for the sensor magnet 30, it is sufficient that at least the magnetized surface 33 is polished, and both surfaces of the sensor magnet 30 may be polished.

  In removing the gate mark, there is also a method of removing by inserting a jig or the like on the inner peripheral surface of the sensor magnet 30. However, in this case, the end surface of the sensor magnet 30 may be chipped (damaged) simultaneously with the removal of the gate trace. In this respect, the entire surface side where the gate is located in the sensor magnet 30 is polished. Is preferred. Further, if the entire surface of the sensor magnet 30 on which the gate is located is polished, a smooth surface with high flatness can be obtained, so that there is an advantage that such a smooth surface can be used as a magnetized surface.

  Here, the sensor magnet 30 is polished on the side where the gate is located, and the polished surface is magnetized. For this reason, even when bubbles are mixed when formed by the film gate, the residual bubble density is low on the side where the gate is located, and the residual bubble density is high on the side opposite to the side where the gate is located. The sensor magnet 30 is a plastic magnet in which the surface of the sensor magnet 30 on which the residual bubble density is low is magnetized. Further, since the sensor magnet 30 is polished on the side where the gate is located and the polished surface is magnetized, the inner surface and the outer surface of the sensor magnet 30 are magnetized out of both surfaces of the sensor magnet 30. A draft taper is formed so that the formed surface 33 is wider than the opposite surface 34. The film gate may be provided on the outer peripheral edge of the sensor magnet 30.

(Main effects of this form)
As described above, in the rotary encoder 1 of the present embodiment, the composite substrate 50 in which the flexible substrate 9 and the circuit substrate 7 are connected is used, and the width of the flexible substrate 9 in the composite substrate 50 is used. At both ends in the direction, stress relaxation portions such as a cutout portion 971 of the insulating protective layer 97 and dummy terminals 982 are provided on an extension line of the edge 970 of the insulating protective layer 97. For this reason, when stress is applied to the flexible substrate 9, bending stress tends to concentrate along the edge 970 of the insulating protective layer 97, and this stress is applied to the cutout portion 971 and the dummy of the insulating protective layer 97. It is possible to avoid the bending stress from being concentrated on the end edge 970 of the insulating protective layer 97 by being relaxed by the stress relaxation portion such as the terminal 982. Accordingly, it is possible to prevent the conductive pattern 96 from being cut at the edge 970 of the insulating protective layer 97.

  In particular, in this embodiment, the cutout portion 971 of the insulating protective layer 97 is cut out so as to be recessed with a curved shape, so that the stress is strongly transmitted linearly along the edge 970 of the insulating protective layer 97. Can be more reliably mitigated. Therefore, it is possible to more reliably prevent the conductive pattern 96 from being cut at the edge 970 of the insulating protective layer 97.

  Further, in this embodiment, since the flexible substrate 9 is bent in a U-shape, a large stress is easily applied to the flexible substrate 9 due to twisting or the like at that time. Since the stress relaxation portions such as the notch portion 971 and the dummy terminal 982 of the layer 97 are provided, the conductive pattern 96 can be prevented from being cut at the edge 970 of the insulating protective layer 97, and high reliability is achieved. Sex can be obtained.

  Further, in the sensor unit 5 and the composite substrate 50 of the present embodiment, when the flexible substrate 9 and the circuit substrate 7 are electrically connected, one terminal end 9s of the flexible substrate 9 is connected to the terminal 98. The exposed first substrate surface 91 side is overlaid on the circuit board 7 facing the side opposite to the side on which the circuit board 7 is located. In this state, the solder 90 is provided so as to straddle the terminals 73 and 99. The terminal 99 is connected by solder. For this reason, even if the direction of the flexible substrate 9 is restricted because the flexible substrate 9 is a single-sided substrate, the flexible substrate 9 and the circuit board 7 can be electrically connected. .

  In the rotary encoder 1 of the present embodiment, the holder 8 of the sensor unit 5 includes circumferential portions (inner peripheral portion 82a and outer peripheral portion 81) centered on the center O5 of the sensor unit 5 and the center O8 of the holder 8. The magnetic scale 2 includes a circumferential portion (the inner peripheral portion 21 and the outer peripheral portion 22 of the yoke plate 20) that is concentric with the magnetic track 31. For this reason, when the magnetic scale 2 is attached to the rotating body and the sensor unit 5 is attached to the fixed body, the holder 8 can be obtained by aligning the circumferential portion of the holder 8 and the circumferential portion of the magnetic scale 2 using a jig. The sensor unit 5 and the magnetic track 31 can be arranged concentrically. It is also easy to place the center O8 of the holder 8 and the center of the magnetic track 31 on the rotation center axis L of the rotating body with the rotary encoder 1 mounted on various devices. Here, since the magnetosensitive element 6 is held by the holder 8, the positional accuracy of the magnetosensitive element 6 with respect to the center O8 of the holder 8 is high. Therefore, if the circumferential portion of the holder 8 and the circumferential portion of the magnetic scale 2 are aligned, the radial positions of the magnetic scale 2 and the magnetic sensitive element 6 can be reliably and easily aligned.

  Further, the holder 8 includes a contact portion 89 that defines the radial position of the magnetic sensing element 6, and the flexible substrate 9 generates a biasing force that makes the magnetic sensing element 6 contact the contact portion 89. Curved in shape. For this reason, when assembling the sensor unit 5, the magnetosensitive element 6 can be reliably arranged at a predetermined radial position on the holder 8. Therefore, if the holder 8 and the magnetic scale 2 are accurately aligned, the radial positions of the magnetic scale 2 and the magnetosensitive element 6 can be reliably and easily aligned. In particular, in the present embodiment, the magnetosensitive element 6 is a magnetoresistive element provided with magnetoresistive patterns 61 to 64 on each of a plurality of virtual lines extending in the radial direction from the center O8 of the holder 8. For this reason, since the magnetoresistive patterns 61 to 64 are in a direction that suitably corresponds to the magnetization pattern of the magnetic track 31, the radial direction between the magnetic scale 2 and the magnetosensitive element 6 can be used instead of improving the sensitivity. If the position of is shifted, the sensitivity is significantly lowered. However, according to the present embodiment, the radial positions of the magnetic scale 2 and the magnetosensitive element 6 can be reliably aligned, so that the magnetoresistive patterns 61 to 64 extend from the center O8 of the holder 8 in the radial direction. The effect when arranged on each of the plurality of virtual lines can be sufficiently exhibited.

  In the sensor unit 5, the holder 8 partially receives the first board surface 71 of the circuit board 7 and secures a gap between the plate-like portion 80 of the holder 8 and the first board surface 71. The step part 85 and the opening part 86 by which the magnetosensitive element 6 is arrange | positioned inside are provided. For this reason, even if the circuit board 7 is stacked on the back side of the holder 8, the interference between the electronic component 79 and the holder 8 does not occur and the magnetosensitive element 6 and the holder 8 do not overlap. Therefore, the sensor unit 5 can be thinned.

  The circuit board 7 is a double-sided board, but the second board surface 72 is further provided with an insulating printed layer 76 on the surface of the resist layer. Even when the metal fixed body and the second substrate surface 72 of the circuit board 7 are opposed to each other, a high withstand voltage can be secured between the circuit board 7 and the fixed body.

  Further, in the rotary encoder 1 of the present embodiment, the magnetic scale 2 has an annular sensor magnet 30 constituting the magnetic track 31 and an annular yoke plate 20 fixed to one surface side of the sensor magnet 30. ing. For this reason, the magnetic field change when the sensor magnet 30 rotates can be detected by the magnetosensitive element 6 with high sensitivity. Further, since the yoke plate 20 has an annular shape, the sensor magnet 30 is magnetized with reference to the outer peripheral portion 22 and the inner peripheral portion 21 of the yoke plate 20, and then the outer peripheral portion 22 and the inner peripheral portion of the yoke plate 20 are magnetized. If the attachment to the rotating body or the alignment with the sensor unit 5 is performed based on the portion 21, the magnetic track 31 and the magnetosensitive element 6 can be connected even if the shape accuracy and dimensional accuracy of the sensor magnet 30 are low. Alignment can be performed with high accuracy. Therefore, even when a plastic magnet or the like is used for the sensor magnet 30 constituting the magnetic track 31, detection sensitivity and detection accuracy are high. Moreover, the yoke plate 20 is larger in width than the sensor magnet 30, the inner peripheral portion 21 of the yoke plate 20 is located inside the inner peripheral edge 35 of the sensor magnet 30, and the outer peripheral portion 22 of the yoke plate 20 is The sensor magnet 30 is located outside the outer peripheral edge 32. Accordingly, the circular outer peripheral edge and the circular inner peripheral edge of the magnetic scale 2 correspond to the inner peripheral portion 21 and the outer peripheral portion 22 of the yoke plate 20, so that the handling of the magnetic scale 2, the outer peripheral portion 22 and the inner peripheral portion of the yoke plate 20 are performed. The operation | work etc. which attach the magnetic scale 2 to a rotary body on the basis of the surrounding part 21 are easy.

  Further, since the sensor magnet 30 is a plastic magnet formed by a film gate, the sensor magnet 30 has no parting line. Therefore, a decrease in magnetization accuracy due to the parting line does not occur. Further, the sensor magnet 30 is polished on the side where the gate is located, and the polished surface is magnetized. For this reason, in the sensor magnet 30, a decrease in magnetization accuracy due to gate traces and residual bubbles is unlikely to occur.

[Other embodiments]
In the above embodiment, an example in which a magnetoresistive element is mounted as a magnetosensitive element has been described. However, the present invention is applied to a case where a Hall element or both a magnetoresistive element and a Hall element are mounted as a magnetosensitive element. May be.

  In the above embodiment, a plastic magnet is used as the sensor magnet 30, but the sensor magnet 30 may be a sintered magnet or a rubber magnet instead of the plastic magnet. The sintered magnet is formed by baking and solidifying magnetic powder, and the rubber magnet is formed by mixing a rubber material and magnetic powder. In the above embodiment, ferrite is used as the magnetic powder, but neodymium, samarium, or the like may be used.

  In the above embodiment, the case where solder is used for electrical connection has been illustrated, but an anisotropic conductive film, metal junction, or the like may be used.

  In the above embodiment, the gate mark is removed from the sensor magnet 30, but the gate mark is left, while the side opposite to the side where the gate mark is generated may be a magnetized surface.

DESCRIPTION OF SYMBOLS 1 Rotary encoder 2 Magnetic scale 5 Sensor unit 6 Magnetoresistive element 7 Circuit board 8 Holder 9 Flexible board 20 Yoke board 30 Sensor magnet 31 Magnetic track 50 Composite board 76 Printing layer 85 Board | substrate support step part 86 Opening part per 89 degree | times Portion 96 Conductive pattern 97 Insulating protective layer 970 Insulating protective layer edge 971 Notched portion of insulating protective layer (stress relaxation portion)
982 Dummy terminal (stress relief)

Claims (10)

A sensor unit comprising: a sensor element; a flexible substrate to which the sensor element is electrically connected; and a rigid circuit board electrically connected to the flexible substrate,
The flexible substrate is electrically connected to the circuit substrate among the plurality of conductive patterns and an insulating base film, a plurality of conductive patterns formed on one surface of the base film. And an insulating protective layer laminated on the conductive pattern while avoiding one substrate end lined in the width direction as a flexible substrate side terminal,
Stress that relaxes the concentration of bending stress on the edge on the extension line of the edge on the side where the one substrate edge is located in the insulating protective layer at both ends in the width direction of the flexible substrate relaxation portion is formed, et al. are,
The sensor unit, wherein the stress relaxation part is a cutout part from which the insulating protective layer is removed leaving the base film . 2. The sensor unit according to claim 1 , wherein the notch portion of the insulating protective layer is notched so as to be recessed with a curved shape in the stress relaxation portion . The sensor unit according to claim 1, wherein the stress relaxation portion is provided with a dummy terminal that does not contribute to electrical connection with the circuit board . The one substrate end of the flexible substrate is overlaid on the circuit board with the surface side where the terminals are exposed facing away from the side where the circuit board is located,
In the circuit board, the circuit board side terminal exposed from the one end of the flexible board and the terminal are electrically connected by solder provided so as to straddle the circuit board side terminal and the terminal. sensor unit according to any one of claims 1 to 3, characterized in that there. The flexible substrate is bent in a U-shape between the one substrate end and the other substrate end located on the opposite side of the one substrate end. Item 5. The sensor unit according to any one of Items 1 to 4. A composite substrate having a flexible substrate and a rigid circuit substrate electrically connected to the flexible substrate,
The flexible substrate is electrically connected to the circuit substrate among the plurality of conductive patterns and an insulating base film, a plurality of conductive patterns formed on one surface of the base film. And an insulating protective layer laminated on the conductive pattern while avoiding one substrate end lined in the width direction as a flexible substrate side terminal,
Stress that relaxes the concentration of bending stress on the edge on the extension line of the edge on the side where the one substrate edge is located in the insulating protective layer at both ends in the width direction of the flexible substrate A mitigation part is provided,
The composite substrate according to claim 1, wherein the stress relaxation portion is a cutout portion in which the insulating protective layer is removed while leaving the base film . 7. The composite substrate according to claim 6, wherein, in the stress relaxation portion, a cutout portion of the insulating protective layer is cut out so as to be recessed with a curved shape . The composite substrate according to claim 6 or 7 , wherein the stress relaxation portion is provided with a dummy terminal that does not contribute to electrical connection with the circuit substrate. The one substrate end of the flexible substrate is overlaid on the circuit board with the surface side where the terminals are exposed facing away from the side where the circuit board is located,
In the circuit board, the circuit board side terminal exposed from the one end of the flexible board and the terminal are electrically connected by solder provided so as to straddle the circuit board side terminal and the terminal. the composite substrate according to any one of claims 6 to 8, characterized in that there. The flexible substrate, claims, characterized in that the bent in a U shape between said one substrate end, and the other substrate edge portion located on the opposite side of the one substrate edge the Item 10. The composite substrate according to any one of Items 6 to 9 .