JP2019128276A - Magnetic type linear encoder - Google Patents

Abstract

To provide a magnetic type linear encoder that can achieve thinness of a head.SOLUTION: In a magnetic type linear encoder, since a wiring member 12 drawn out externally from a circuit substrate 60 in a head 11 is a flexible wiring substrate 40, thinness of the head 11 can be achieved. Further, since an amplifier circuit 69 is provided in the circuit substrate 60, attenuation of a signal and the like are hardly problems even when a signal external output is conducted by the flexible wiring substrate 40. In the head 11, wiring is made from s sensor substrate 30 to the circuit substrate 60 by the flexible wiring substrate 40. Accordingly, the head 11 is suitable for being further thinned. Further, by folding the flexible wiring substrate 40 at a third part 48, a single-sided substrate, in which a first electrode, a second electrode 44 and a third electrode 45 to be connected to a first terminal 36 of the sensor substrate 30 are provided on a single-sided side, can be used as the flexible wiring substrate 40.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a magnetic linear encoder in which a wiring member is drawn out flexibly from a head provided with a magnetosensitive element.

  In a magnetic linear encoder, a magnetic sensor device provided with a magnetosensitive element is disposed to face a magnetic scale extending in one direction. The magnetic sensor device comprises a head provided with a magnetosensitive element, and a wiring member drawn to the outside from the head, and the wiring member comprises a cable extending from a circuit board disposed in the head (Patent Reference 1).

Unexamined-Japanese-Patent No. 2006-84410

  Although thinning is required for the magnetic sensor device described in Patent Document 1 etc., in the configuration described in Patent Document 1, it is necessary to pull out the cable from the inside to the outside of the holder, so the head is thin Is difficult.

  SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a magnetic linear echo dater capable of reducing the thickness of a head.

  In order to solve the above problems, a magnetic sensor device according to the present invention can output a signal from a head provided with a magnetic scale extending in a first direction, a magnetosensitive element facing the magnetic scale, and the head In a magnetic linear encoder having a magnetic sensor device provided with a flexible wiring member, the head includes a sensor substrate provided with the magnetosensitive element and a first terminal, and an output signal from the magnetosensitive element. A rigid circuit board provided with an amplification circuit to be amplified, a second terminal, and a third terminal, and a first flexible wiring board connected to the third terminal and drawn out to the outside of the head as the wiring member It is characterized by having.

  In the present invention, since the wiring member drawn to the outside from the circuit board in the head is the first flexible wiring board, the head can be thinned. In addition, since the amplifier circuit is provided on the circuit board, even if the signal output to the outside is performed by the first flexible wiring board, the attenuation of the signal and the like are less likely to be a problem. Therefore, even if the head is made thin, position detection and the like can be performed appropriately.

  In the present invention, the head may adopt a mode having a second flexible wiring board which extends from the sensor board to the circuit board and is connected to the first terminal and the second terminal. According to this aspect, it is suitable for further thinning the head.

  In the present invention, the first flexible wiring board and the second flexible wiring board are formed of a single flexible wiring board extending from the sensor board to the outside of the head via the circuit board. Can be adopted. According to this aspect, the cost of the magnetic linear encoder can be reduced.

  In the present invention, the sensor substrate and the circuit substrate are disposed to face each other in the height direction of the head, and the circuit substrate is provided with the second terminal on the surface opposite to the sensor substrate. The third terminal is provided, and the flexible wiring board is a first portion extending in the first direction from one end connected to the sensor board, and a side opposite to the sensor board with respect to the circuit board A second portion extending in the first direction to face the circuit board, and a third portion folded back so as to connect the first portion and the second portion. A mode in which the first electrode to which the first terminal is connected, the second electrode to which the second terminal is connected, and the third electrode to which the third terminal is connected are provided on one side of the flexible wiring substrate Can be adopted. According to this aspect, since the single-sided board in which the first electrode, the second electrode, and the third electrode are provided on one side can be used as the flexible wiring board, the cost of the magnetic linear encoder can be reduced. it can. Further, since the flexible wiring board is folded in the thickness direction, the width of the head can be narrowed.

  In the present invention, the circuit board may be a double-sided board in which a circuit element is mounted on the surface on the side of the sensor board.

  In the present invention, the sensor substrate and the holder for supporting the circuit substrate are provided, and the holder includes a support plate portion disposed between the sensor substrate and the circuit substrate, and the sensor substrate is for supporting It is possible to adopt an aspect in which the circuit board is fixed to the holder in a state of overlapping with one surface of a plate portion, and the circuit board is fixed to the holder in a state of overlapping with the other surface of the support plate portion. According to this aspect, since the sensor substrate and the circuit substrate are overlapped in the thickness direction, the bottom area of the head can be narrowed, and the head can be miniaturized.

  In the present invention, the circuit board can adopt an aspect in which the circuit element is not mounted in a portion overlapping with the support plate portion. According to this aspect, the circuit board can be properly disposed so as to overlap the support plate portion without being affected by the circuit element.

  In the present invention, in the circuit board, the circuit element is mounted on the surface on which the support plate portion is located, and the circuit element is not mounted in a region overlapping 50% or more with the second terminal. It is possible to adopt a mode in which the circuit element is not mounted in a region overlapping with 3 terminals by 50% or more. According to this aspect, it is possible to perform connection with the flexible wiring board using a portion where the circuit elements do not overlap among the terminals (second and third terminals) of the circuit board. Therefore, when connecting the circuit board and the flexible wiring board, heating and pressing can be performed from both sides of the circuit board and the flexible wiring board, so that the circuit board and the flexible wiring board can be connected reliably and efficiently. Can do.

  In the present invention, the holder includes two side walls opposed in the second direction orthogonal to the height direction and the first direction, and the support plate portion is connected to the two side walls. Can be adopted. According to this aspect, since the holder can be reinforced by the support plate portion, the side wall can be thinned. Therefore, the head can be miniaturized.

  In the present invention, the holder is provided with an opening overlapping with the magnetosensitive element on one side in the height direction, the opening is surrounded by a recess on the outer surface side of the holder, and the inside of the recess is A mode in which a plate-like or sheet-like shield member is provided can be employed. According to this aspect, the shield member can reduce the influence of noise. In addition, since the shield member can be prevented from projecting largely in the thickness direction, it is suitable for thinning the head.

In the present invention, the holder is provided in parallel with the first positioning reference plane that defines a position for fixing the head and the first positioning reference plane, and when the sensor substrate is fixed to the holder. A mode in which a second positioning reference surface that defines the position is provided can be employed. According to this aspect, when the holder is fixed to the device, the sensor substrate can be disposed parallel to the magnetic scale.

  In the present invention, an aspect in which the first terminal, the second terminal, and the third terminal are connected to the flexible wiring board by an anisotropic conductive material can be adopted. According to this aspect, even when the terminal pitch is narrowed to miniaturize the head, the electrical connection can be properly made.

  In the present invention, the magnetic scale comprises a rigid substrate, and a magnetic coating film which is a layer in which magnetic powder is mixed in a resin and is formed on one surface of the rigid substrate, and the magnetic coating film is S An aspect in which permanent magnets in which poles and N poles are alternately arranged can be employed. According to this aspect, the flatness of the permanent magnet can be enhanced as compared with the case of using a rubber magnet or the like.

  In the present invention, in the magnetic scale, two tracks in which S poles and N poles are alternately arranged are arranged in parallel in the first direction, and in the magnetosensitive element, the magnetoresistance pattern has a thickness direction The aspect which is the magnetoresistive element laminated | stacked on can be employ | adopted. According to this aspect, the width of the magnetic scale and the head can be reduced. Further, even when the width of the head is narrowed, a space for providing the Z-phase magnetoresistive pattern for detecting the origin position can be secured.

  In the present invention, since the wiring member drawn to the outside from the circuit board in the head is the first flexible wiring board, the head can be thinned. In addition, since the amplifier circuit is provided on the circuit board, even if the signal output to the outside is performed by the first flexible wiring board, the attenuation of the signal and the like are less likely to be a problem. Therefore, even if the head is made thin, position detection and the like can be performed appropriately.

It is the perspective view which saw the magnetic sensor apparatus to which this invention is applied from the other side of the height direction. It is the perspective view which saw the magnetic sensor apparatus shown in FIG. 1 from one side of the height direction. It is sectional drawing of the magnetic sensor apparatus shown in FIG. It is the disassembled perspective view which saw the magnetic sensor apparatus shown in FIG. 1 from the other side of the height direction. It is the disassembled perspective view which saw the magnetic sensor apparatus shown in FIG. 1 from one side of the height direction. It is the disassembled perspective view which isolate | separated the flexible wiring board, the sensor board | substrate, etc. from the state shown in FIG. It is the disassembled perspective view which isolate | separated the flexible wiring board, the sensor board | substrate, etc. from the state shown in FIG. It is the top view which looked at the circuit board shown in FIG. 6 etc. from the other side of the height direction. It is explanatory drawing which shows arrangement | positioning of the adhesive agent in the magnetic sensor apparatus shown in FIG. It is explanatory drawing of the magnetic scale etc. which are shown in FIG. FIG. 11 is an explanatory view of a magnetoresistance pattern of the magnetosensitive element shown in FIG. 10;

  A magnetic sensor device to which the present invention is applied will be described with reference to the drawings. In the drawings referred to below, the length direction of the holder 20 is defined as a first direction X, the width direction orthogonal to the length direction (first direction X) is defined as a second direction Y, and the length direction (first direction) A direction orthogonal to X) and the width direction (second direction Y) is taken as the height direction H.

(Overall Configuration of Magnetic Sensor Device 10)
FIG. 1 is a perspective view of a magnetic sensor device 10 to which the present invention is applied, as viewed from the other side H2 in the height direction H. FIG. FIG. 2 is a perspective view of the magnetic sensor device 10 shown in FIG. 1 from one side H1 in the height direction H. FIG. FIG. 3 is a cross-sectional view of the magnetic sensor device 10 shown in FIG. FIG. 4 is an exploded perspective view of the magnetic sensor device 10 shown in FIG. 1 as viewed from the other side H2 in the height direction H. FIG. FIG. 5 is an exploded perspective view of the magnetic sensor device 10 shown in FIG. 1 as viewed from one side H1 in the height direction H. FIG. FIG. 6 is an exploded perspective view in which the flexible wiring board 40 and the sensor board 30 and the like are separated from the state shown in FIG. FIG. 7 is an exploded perspective view in which the flexible wiring substrate 40 and the sensor substrate 30 and the like are separated from the state shown in FIG.

  The magnetic sensor device 10 shown in FIG. 1 is used together with the magnetic scale 90 as a magnetic linear encoder 1 that detects the table movement distance and position of a machine tool or mounting device. In the magnetic scale 90, N poles and S poles are alternately arranged at a predetermined pitch. In the magnetic linear encoder 1, one of the magnetic sensor device 10 and the magnetic scale 90 is mounted on a fixed body, and the other is mounted on a moving body. The magnetic sensor device 10 includes a head 11 facing the magnetic linear encoder 1 and a flexible wiring member 12 which is drawn from the inside of the head 11 to the outside and extends in the first direction X.

  As shown in FIGS. 2 to 7, the magnetic sensor device 10 is a holder so as to cover the holder 20, the sensor substrate 30 disposed inside the holder 20, and the sensor substrate 30 from the other side H 2 in the height direction H 20, a rigid circuit board 60 disposed between the cover 50 and the sensor substrate 30, and a shield member 70 fixed so as to close the opening 27 of the holder 20. Yes.

  Further, the magnetic sensor device 10 is connected to the circuit board 60 in the head 11 and extends from the sensor board 30 to the circuit board 60 as the first flexible wiring board 40 a drawn to the outside of the holder 20 as the wiring member 12. The second flexible wiring board 40 b connected to the sensor board 30 and the circuit board 60 is provided. In the present embodiment, the first flexible wiring substrate 40 a and the second flexible wiring substrate 40 b are formed of a single flexible wiring substrate 40 extending from the sensor substrate 30 to the outside of the head 11 via the circuit substrate 60.

  The holder 20 is made of a nonmagnetic metal member such as aluminum or stainless steel, the first side wall 21, the second side wall 22 facing the first side wall 21 on one side X1 in the first direction X, and the height direction H And a bottom wall 25 provided between the first side wall 21 and the second side wall 22 on one side H1. The holder 20 has an opening 27 on the other side X2 in the first direction X.

  In addition, the holder 20 has a third side wall 23 connecting the first side wall 21 and the second side wall 22 on one side Y1 in the second direction Y, and a third side wall 23 facing the third side 23 on the other side Y2 in the second direction Y 4 side walls 24, and the fourth side wall 24 connects the first side wall 21 and the second side wall 22. The third side wall 23 and the fourth side wall 24 are shorter in the height direction H than the first side wall 21 and the second side wall 22. A substantially triangular connecting part 230 is formed between the third side wall 23 and the first side wall 21, and a substantially triangular connecting part 240 is formed between the fourth side wall 24 and the first side wall 21. At the end of the other side H 2 in the height direction H of the second side wall 22, a recess 221 is formed in the central portion in the extending direction of the second side wall 22.

A support plate portion 26 connecting the third side wall 23 and the fourth side wall 24 between the cover 50 and the sensor substrate 30 is formed inside the holder 20, and the support plate portion 26 faces the circuit board 60. doing. Accordingly, since the holder 20 can be reinforced by the support plate portion 26, the side wall can be thinned. Therefore, the head 11 is suitable for downsizing.

  The bottom wall 25 is formed only on one side X1 in the first direction X, and ends of one side H1 in the height direction H of the first side wall 21, the third side wall 23, and the fourth side wall 24 are open. It is the opening edge of the part 27. On the outer surface side of the bottom wall 25, a recess 28 recessed around the opening 27 is formed, and the opening 27 is surrounded by the recess 28 all around.

  In this embodiment, a hole 291 for fixing the head 11 to a device with a screw or the like is formed at the end 29 of the other side X2 of the holder 20 in the first direction X. Further, at the end portion 29, the surface on the other side H2 in the height direction H is a first positioning reference surface 290 that defines the position when the head 11 is fixed. The bottom of the recess 28 is provided in parallel to the first positioning reference surface 290 and serves as a second positioning reference surface 280 that defines the position at which the sensor substrate 30 is fixed to the holder 20. Therefore, when the head 11 is fixed to the device via the holder 20, the sensor substrate 30 can be disposed parallel to the magnetic scale 90.

  The sensor substrate 30 is disposed between the opening 27 and the support plate 26 with the one surface 31 facing the opening 27. On the one surface 31 side, the magnetosensitive element 38 and a plurality of first terminals 36 are provided. Are formed in parallel in the second direction Y, and the magnetic sensing element 38 is formed in a region overlapping the opening 27. In the present embodiment, the magnetosensitive element 38 is a magnetoresistance element 380, and as described later with reference to FIG. 10, the magnetoresistance element 380 outputs an A phase magnetoresistance pattern that outputs two signals that are 90 ° out of phase. And a B-phase magnetoresistive pattern.

  The circuit board 60 is disposed between the support plate portion 26 and the cover 50 such that the one surface 61 faces the other surface 32 of the sensor substrate 30. The circuit board 60 is a double-sided board in which a plurality of circuit elements 66 are mounted on one surface 61 and a plurality of second terminals 64 and a plurality of third terminals 65 are formed on the other surface 62. The plurality of second terminals 64 and the plurality of third terminals 65 are respectively formed in parallel in the second direction Y in two regions separated in the first direction X. In the circuit board 60, the circuit element 66 forms an amplifier circuit 69 and the like for amplifying an output signal output from the sensor board 30.

  The cover 50 has an end plate portion 51 facing the other surface 32 of the sensor substrate 30 and the other surface 62 of the circuit substrate 60, and one side H1 in the height direction H from both ends in the second direction Y of the end plate portion 51. And side plates 52 and 53 that protrude to the The end plate portion 51 is fixed to the end of the other side H2 in the height direction H of the first side wall 21, the second side wall 22, the third side wall 23, and the fourth side wall 24. In this state, a gap 222 is formed by the recess 221 between the cover 50 and the second side wall 22.

  One end 41 of the flexible wiring board 40 is connected to the sensor board 30, the middle part is pulled through the circuit board 60, and the other end 42 is pulled out of the holder 20. More specifically, the flexible wiring board 40 includes a first portion 46 extending from one end 41 toward the other side X2 in the first direction X, and between the end plate portion 51 of the cover 50 and the circuit board 60. The second portion 47 extending from the other side X2 of the first direction X to the one side X1 so as to face the other surface 32 of the sensor substrate 30 and the other surface 62 of the circuit substrate 60, and along the first side wall 21 A third portion 48 that is curved in such a manner as to connect the end portion of the first portion 46 on the other side X2 in the first direction X and the end portion of the second portion 47 on the other side X2 in the first direction X. ing. In the present embodiment, the flexible wiring substrate 40 is formed of one substrate from one end 41 to the other end 42.

The flexible wiring substrate 40 is a single-sided substrate, and a first electrode 49 connected to the first terminal 36 of the sensor substrate 30 is formed on the first portion 46 on the surface 43 located inside the third portion 48, A second electrode 44 connected to the second terminal 64 of the circuit board 60 and a third electrode 45 connected to the third terminal 65 of the circuit board 60 are formed on the second portion 47. In the second portion 47 of the flexible wiring board 40, reinforcing flexible sheets 471 and 472 are attached on both sides of the side on which the second electrode 44 and the third electrode 45 are formed in the extending direction. Therefore, the rigidity of the second portion 47 linearly extending in the first direction X in the flexible wiring board 40 can be enhanced.

  The shield member 70 is a nonmagnetic plate member or sheet member such as aluminum or copper, and is disposed in the recess 28 on the outer surface side of the bottom wall 25 to close the opening 27. Therefore, the shield member 70 can reduce the influence of noise. Further, since the shield member 70 can be prevented from largely protruding from the holder 20 in the thickness direction (height direction H), it is suitable for thinning the head 11.

(Connection of sensor board 30 and circuit board 60 to flexible wiring board 40)
FIG. 8 is a plan view of the circuit board 60 shown in FIG. 6 and the like from the other side H2 in the height direction H. As shown in FIG. 6 and 7, when manufacturing the magnetic sensor device 10, the first electrode 49, the second electrode 44, and the third electrode 45 of the flexible wiring substrate 40 are in a state in which the flexible wiring substrate 40 is developed. The first terminal 36 of the sensor substrate 30, the second terminal 64 of the circuit substrate 60, and the third terminal 65 of the circuit substrate 60 are connected. At that time, hot pressing was performed in a state in which an anisotropic conductive material in which conductive particles are dispersed in a thermosetting resin is disposed between the flexible wiring substrate 40 and the circuit substrate 60 to cure the thermosetting resin. Then cool down. In addition, after performing thermosetting pressing in a state where an anisotropic conductive material in which conductive particles are dispersed in a thermosetting resin is disposed between the flexible wiring substrate 40 and the sensor substrate 30, after curing the thermosetting resin ,Cooling. Therefore, even when the terminal pitch is narrowed to miniaturize the head 11, the electrical connection can be properly made.

  In this embodiment, a solder layer is formed on the surfaces of the first electrode 49, the second electrode 44, the third electrode 45, the first terminal 36, the second terminal 64, and the third terminal 65, and the conductive particles are soldered. A plurality of solder particles having a melting point lower than that of the layer. Therefore, at the time of hot pressing, the solder particles are melted without the solder layer melting, and an electrical connection is made. As the resin material, thermosetting resin such as epoxy resin is used. The solder particles contain tin and one of copper, silver, bismuth, antimony and indium, and are made of a low melting point solder material having a melting point of 200 ° C. or less, for example. The solder layer is made of, for example, a tin-copper based solder material and has a melting point of about 230.degree. The solder layer may be a tin-silver-copper-based or tin-bismuth-based solder material in addition to a tin-copper-based solder material.

  As shown in FIG. 8, on one surface 61 of the circuit board 60, the circuit element 66 is not mounted in the area overlapping 50% or more with the second terminal 64, and the circuit element is overlapped 50% or more with the third terminal 65 66 is not implemented. That is, although the circuit element 66 overlaps a part of the second terminal 64 and the third terminal 65 on the one surface 61 of the circuit board 60, the part overlapping the circuit element 66 corresponds to the second terminal 64 and the third terminal. Less than 50%, or even less than 20% of the terminals 65.

  Therefore, among the terminals (the second terminal 64 and the third terminal 65) of the circuit board 60, the portions 64a, 65a where the circuit element 66 is not overlapped (the second terminal 64 and the third terminal 65 shown in FIG. The flexible wiring board 40 and the circuit board 60 can be connected using the gray portion. Therefore, when connecting the circuit board 60 and the flexible wiring board 40 with an anisotropic conductive material, heating and pressing can be performed from both sides of the circuit board 60 and the flexible wiring board 40, so the circuit board 60 and the flexible wiring board 40 are flexible. The wiring substrate 40 can be connected reliably and efficiently.

Further, on the one surface 61 side of the circuit board 60, the circuit element 66 is not mounted in a region overlapping with the support plate portion 26 of the holder 20 in plan view. Therefore, the circuit board 60 can be properly disposed so as to overlap the support plate portion 26 without being affected by the circuit element 66.

(Adhesive structure in magnetic sensor device 10)
FIG. 9 is an explanatory view showing the arrangement of the adhesive in the magnetic sensor device 10 shown in FIG. 1 and shows a state where it is cut inside the third side wall 23.

  In the process of manufacturing the magnetic sensor device 10, after connecting the sensor substrate 30 and the circuit substrate 60 to the flexible wiring substrate 40, as shown in FIG. 9, the flexible wiring substrate 40 is made of the holder 20 while bending the flexible wiring substrate 40. Place inside. Further, the shield member 70 is disposed inside the recess 28 so as to close the opening 27 on the outer surface side of the bottom wall 25.

  In this state, a portion of the flexible wiring board 40 between the first portion 46 and the third portion 48 is fixed to the first side wall 21 of the holder 20 by the first adhesive 91. Therefore, even if vibration is transmitted to the magnetic sensor device 10, the flexible wiring board 40 is moved inside the holder 20 and is less likely to break due to rubbing against the holder 20. Even if the thickness of the magnetic sensor device 10 is reduced using the flexible wiring board 40, high reliability can be secured.

  Further, inside the holder 20, the shield member 70 is fixed at the edge of the opening 27 of the holder 20 by the second adhesive 92 made of the same material as the first adhesive 91. Therefore, even when the empty space in the holder 20 is narrow, it is not necessary to use different adhesives for the first adhesive 91 and the second adhesive 92. In the present embodiment, the shield member is fixed by the second adhesive 92 over the entire circumference. For this reason, since a gap does not easily occur between the shield member 70 and the holder 20, dust and the like hardly enter the inside of the holder 20 from the opening 27.

  Here, the first adhesive 91 and the second adhesive 92 are rubber-based soft adhesives. Therefore, even if the environmental temperature changes and expansion or contraction occurs in the first adhesive 91, the deformation is absorbed by the elasticity of the first adhesive 91. Therefore, it is possible to suppress that the stress of expansion and contraction of the first adhesive 91 is transmitted to the sensor substrate 30 to change the magnetic characteristic of the magnetosensitive element 38. The first adhesive 91 and the second adhesive 92 are thermosetting. Therefore, since the first adhesive 91 and the second adhesive 92 have relatively low viscosity, it is easy to apply the first adhesive 91 and the second adhesive 92 in the narrow gap. For example, the hardness of the first adhesive 91 and the second adhesive 92 is, for example, in the range of Shore D30 to Shore D60 after curing.

  Further, after temporarily fixing the sensor substrate 30 to the holder 20 with the UV curable third adhesive 93, the position of the sensor substrate 30 is adjusted, and then the sensor substrate 30 is held with the thermosetting fourth adhesive 94. Fix at 20. In this embodiment, the sensor substrate 30 is temporarily fixed to the support plate portion 26 of the holder 20 with the third adhesive 93, the position of the sensor substrate 30 is adjusted, and then the sensor substrate 30 is attached to the holder 20 with the fourth adhesive 94. It fixes to the support plate part 26 of this. The fourth adhesive 94 has a hardness after curing, for example, in the range of Shore D60 to Shore D90.

  Further, the circuit board 60 is fixed to the holder 20 with a fast-drying fifth adhesive 95. In this embodiment, the circuit board 60 is fixed to the support plate portion 26 with the fifth adhesive 95. Therefore, the circuit board 60 can be fixed to the holder 20 while keeping the flexible wiring board 40 curved at the third portion 48.

Next, the cover 50 is put on the holder 20. At this time, the second portion 47 of the flexible wiring board 40 is drawn from the gap 222 between the second side wall 22 of the holder 20 and the cover 50. In this embodiment, the cover 50 is fixed to the holder 20 with the sixth adhesive 96. In addition, the second portion 47 of the flexible wiring board 40 is fixed to the second side wall 22 by the soft seventh adhesive 97. Therefore, even if a force is externally applied to the portion of the flexible wiring board 40 pulled out from the holder 20, a situation such as the flexible wiring board 40 being rubbed and broken hardly occurs. The sixth adhesive 96 has a hardness after curing, for example, in the range of Shore D60 to Shore D90. The seventh adhesive 97 is a rubber-based soft adhesive and has lower hardness than the sixth adhesive 96. The seventh adhesive 97 has a hardness after curing, for example, in the range of Shore D30 to Shore D60. As the seventh adhesive 97, for example, a cold-setting adhesive which is cured by moisture in the air is used.

(Configuration of magnetic scale 90 and magnetosensitive element 38)
FIG. 10 is an explanatory view of the magnetic scale 90 etc. shown in FIG. 1. FIG. 10 is an explanatory view (a) schematically showing a cross section of the magnetic scale 90, and the magnetic scale 90 and the magnetosensitive element 38. An explanatory view (b) showing a planar positional relationship is shown. 11 is an explanatory view of a magnetoresistance pattern of the magnetosensitive element 38 shown in FIG. 10, and FIG. 11 is an explanatory view (a) schematically showing a cross section of the magnetosensitive element 38 and FIG. An explanatory view (b) showing a magnetoresistive pattern is shown.

  As shown in FIG. 10A, the magnetic scale 90 has a rigid substrate 903 such as a metal plate and a magnetic coating film 902 formed on one surface of the rigid substrate. The magnetic coating film 902 is a layer in which magnetic powder is blended in a resin, and the magnetic coating film 902 constitutes a permanent magnet 901. The permanent magnet 901 is formed by providing a rigid coating 903 on a rigid substrate 903 and then polishing the surface of the magnetic coating 902 and thereafter magnetizing it. Therefore, the flatness of the permanent magnet can be increased as compared with the case where a rubber magnet or the like is used.

  As shown in FIG. 10B, in the permanent magnet 901, two rows of tracks 901A and 901B in which the S pole and the N pole are alternately arranged in the first direction X are provided in parallel, and the track 901A , 901 </ b> B, the magnetosensitive element 38 formed on the sensor substrate 30 is arranged so as to overlap the boundary.

  As shown in FIG. 11A, in the present embodiment, the magnetosensitive element 38 has a structure in which magnetoresistive patterns 38 are stacked on the sensor substrate 30. More specifically, in the sensor substrate 30, in the magnetosensitive device 38, the SIN + magnetoresistive pattern 38 (+ a) and the COS + magnetoresistive pattern 38 (+ b) are stacked via the insulating film 39, A magnetoresistive pattern 38 (-a) for SIN- and a magnetoresistive pattern 38 (-b) for COS- are laminated with an insulating film 39 interposed therebetween. In this embodiment, the magnetoresistive pattern 38 (+ a) for SIN + and the magnetoresistive pattern 38 (−b) for COS− are formed in the same layer, and the magnetoresistive pattern 38 (+ b) for COS + and SIN− are formed. And the magnetoresistive pattern 38 (-a) are formed in the same layer.

  Here, the A-phase magnetoresistive pattern 38 (+ a) with SIN and the B-phase magnetoresistive pattern 38 (+ b) with COS have a phase difference of 90 ° with each other, and the A with SIN The magnetoresistive pattern 38 (-a) of the phase and the magnetoresistive pattern 38 (-b) of the B phase to which COS has been applied have a phase difference of 90 degrees. The A-phase magnetoresistive pattern 38 (+ a) and the magnetoresistive pattern 38 (-a) have a phase difference of 180 °, and the B-phase magnetoresistive pattern 38 (+ b) and the magnetoresistive pattern 38 (-b) ) Has a phase difference of 180 °.

  According to this aspect, the width dimension (the dimension in the second direction Y) of the magnetic scale 90 and the area of the sensor substrate 30 where the magnetosensitive elements 38 are formed can be narrowed. Therefore, the head 11 can be miniaturized. Further, since the width dimension (dimension in the second direction Y) of the region where the magnetosensitive element 38 is formed in the sensor substrate 30 is narrow, the origin detection is performed in the region adjacent to the magnetosensitive element 38 in the width direction (second direction Y). A Z-phase magnetoresistive pattern can be provided.

(Main effects of this form)
As described above, in the magnetic linear encoder 1 of the present embodiment, since the wiring member 12 drawn to the outside from the circuit board 60 in the head 11 is the flexible wiring board 40, thinning of the head 11 can be achieved. it can. In addition, since the amplifier circuit 69 is provided on the circuit board 60, even if the signal output to the outside is performed by the flexible wiring board 40, signal attenuation or the like hardly occurs. Therefore, even if the thickness of the head 11 is reduced, position detection can be properly performed. The head 11 is wired from the sensor substrate 30 to the circuit substrate 60 by a flexible wiring substrate 40. Therefore, it is suitable for making the head 11 thinner. In addition, since the wiring from the sensor substrate 30 to the circuit substrate 60 and the wiring to the outside are performed by the single flexible wiring substrate 40, the cost of the magnetic linear encoder 1 can be reduced.

  In addition, using the single-sided board in which the first electrode 49, the second electrode 44, and the third electrode 45 are provided on one side as the flexible wiring board 40 by folding the flexible wiring board 40 at the third portion 48. it can. Therefore, the cost of the magnetic linear encoder can be reduced. In addition, since the flexible wiring board 40 is folded in the thickness direction, the width of the head 11 can be reduced.

  Further, the sensor board 30 and the circuit board 60 are respectively overlapped on the opposite side of the support plate portion 26 of the holder 20. Therefore, the bottom area of the head 11 can be reduced, and the head 11 can be reduced in size.

(Other embodiments)
In the above-described embodiment, the circuit element 66 overlaps a part of the second terminal 64 and the third terminal 65 on one surface 61 of the circuit board 60, but the circuit element 66 is disposed on the second terminal 64 and the third terminal 65. If the aspect which does not overlap at all is adopted, the whole of the second terminal 64 and the third terminal 65 can be used for connection with the flexible wiring board 40.

  In the above embodiment, the first flexible wiring board 40a and the second flexible wiring board 40b are formed of one flexible wiring board 40, but the first flexible wiring board 40a and the second flexible wiring board 40b are separate flexible wiring boards. You may be comprised with the board | substrate. In this case, the third electrode 45 to the other end 42 are configured as the first flexible wiring substrate 40 a, and the first electrode 49 to the second electrode 44 are configured as the second flexible wiring substrate 40 b.

DESCRIPTION OF SYMBOLS 1 ... Magnetic type linear encoder, 10 ... Magnetic sensor apparatus, 11 ... Head, 12 ... Wiring member, 20 ... Holder, 21 ... 1st side wall, 22 ... 2nd side wall, 23 ... 3rd side wall, 24 ... 4th side wall, Reference Signs List 25 bottom wall 26 support plate 27 opening 30 sensor board 36 first terminal 38 magnetosensitive element 40 flexible wiring board 41 one end 42 the other end 44 2nd electrode 45 3rd electrode 46 1st portion 47 47 2nd portion 48 48 3rd portion 49 1st electrode 50 cover 51 end plate portion 52, 53 side plate Section 60 Circuit board 64 Second terminal 65 Third terminal 66 Circuit element 70 Shield member 90 Magnetic scale 91 First adhesive 92 Second adhesive 93 Third adhesive 94, fourth adhesive, 95 ... fifth adhesive, 96 ... sixth adhesive, 97 Seventh adhesive, 222: gap, 280: second positioning reference surface, 290: first positioning reference surface, 380: magnetoresistive element, 471, 472: flexible sheet, 901: permanent magnet, 902: magnetic coating, 903 ... rigid substrate, X ... first direction, Y ... second direction, H ... height direction

Claims (14)

A magnetic scale extending in a first direction;
A head provided with a magnetic sensing element facing the magnetic scale, and a magnetic sensor device provided with a flexible wiring member for outputting a signal from the head;
In a magnetic linear encoder having
The head includes a sensor substrate provided with the magnetosensitive element and a first terminal, an amplification circuit for amplifying an output signal from the magnetosensitive element, a rigid circuit board provided with a second terminal, and a third terminal. And a first flexible wiring board connected to the third terminal and drawn out to the outside of the head as the wiring member.   The magnetic linear system according to claim 1, wherein the head includes a second flexible wiring board extending from the sensor substrate to the circuit board and connected to the first terminal and the second terminal. Encoder.   The first flexible wiring board and the second flexible wiring board are formed of a single flexible wiring board extending from the sensor board to the outside of the head via the circuit board. Item 3. A magnetic linear encoder according to Item 2. The sensor substrate and the circuit substrate are disposed to face each other in the height direction of the head,
The circuit board is provided with the second terminal and the third terminal on a surface opposite to the sensor substrate.
The flexible wiring board is opposed to the circuit board on a side opposite to the sensor board with respect to the circuit board and a first part extending in the first direction from one end connected to the sensor board. A second portion that extends in the first direction, and a third portion that is folded back to connect the first portion and the second portion.
A first electrode to which the first terminal is connected, a second electrode to which the second terminal is connected, and a third electrode to which the third terminal is connected are provided on one side of the flexible wiring board. The magnetic linear encoder according to claim 3.   5. The magnetic linear encoder according to claim 4, wherein the circuit board is a double-sided board in which circuit elements are mounted on the surface on the side of the sensor board. A holder for supporting the sensor board and the circuit board;
The holder includes a support plate portion disposed between the sensor substrate and the circuit substrate,
The sensor substrate is fixed to the holder in a state of overlapping with one surface of the support plate portion,
The magnetic linear encoder according to claim 5, wherein the circuit board is fixed to the holder in a state of being overlapped with the other surface of the support plate portion.   7. The magnetic linear encoder according to claim 6, wherein the circuit element is not mounted on a portion of the circuit board overlapping the support plate portion. The circuit board has the circuit element mounted on a surface on which the support plate portion is located,
The circuit element is not mounted in a region that overlaps the second terminal by 50% or more,
The magnetic linear encoder according to claim 6 or 7, wherein the circuit element is not mounted in a region overlapping with the third terminal by 50% or more. The holder includes two side walls opposed in a second direction orthogonal to the height direction and the first direction,
The magnetic linear encoder according to any one of claims 6 to 8, wherein the support plate portion is connected to the two side walls. The holder is provided with an opening overlapping with the magnetic sensing element on one side in the height direction,
On the outer surface side of the holder, the opening is surrounded by a recess,
The magnetic linear encoder according to any one of claims 6 to 9, wherein a plate-like or sheet-like shield member is provided in the concave portion.   The holder is provided with a first positioning reference surface that defines the position when fixing the head, and is provided parallel to the first positioning reference surface, and defines the position when fixing the sensor substrate to the holder The magnetic linear encoder according to any one of claims 6 to 10, wherein a second positioning reference surface is provided.   The said 1st terminal, the said 2nd terminal, and the said 3rd terminal are connected to the said flexible wiring board by anisotropic conductive material, The said 1st terminal is characterized by the above-mentioned. Magnetic linear encoder. The magnetic scale includes a rigid substrate, and a magnetic coating film formed on one surface of the rigid substrate, which is a layer in which magnetic powder is blended in a resin.
The magnetic linear encoder according to any one of claims 1 to 12, wherein a permanent magnet in which an S pole and an N pole are alternately arranged is configured by the magnetic coating film. In the magnetic scale, two rows of tracks in which S poles and N poles are alternately arranged in the first direction are provided in parallel.
14. The magnetic linear encoder according to claim 1, wherein the magnetosensitive element is a magnetoresistive element in which magnetoresistive patterns are laminated in a thickness direction.