magnetic sensor

Abstract

[Problem] To prevent damage to an external magnetic body for collecting magnetic flux to a magnetosensitive element in a magnetic sensor provided with the external magnetic body. [Solution] A magnetic sensor 100 comprises: a sensor chip 20 having an element-forming surface 21 on which magnetosensitive elements R1 to R4 are formed; an external magnetic body 30 having an end surface 33 which is positioned at a distal end in a longitudinal direction and which faces the element-forming surface 21, and side surfaces 34 to 36 configuring an outer peripheral surface of a cross section perpendicular to the longitudinal direction; and a protective resin 4 covering at least a portion of the element-forming surface 21 and the side surfaces 34 to 36 of the external magnetic body 30. It is thus possible to prevent damage to the sensor chip 20 and the external magnetic body 30 even if an impact is imparted from the outside.

Description

[Technical Field]

[0001] The present invention relates to a magnetic sensor, and more particularly to a magnetic sensor having an external magnetic body that concentrates magnetic flux in a magnetic sensing element. [Background technology]

[0002] A known magnetic sensor equipped with an external magnetic body that collects magnetic flux to a magnetic sensing element is the magnetic sensor described in Patent Document 1. The magnetic sensor described in Patent Document 1 includes a sensor chip having an element formation surface on which a magnetic sensing element is provided, and an external magnetic body arranged to face the element formation surface. This makes it possible to efficiently apply the magnetic field collected by the external magnetic body to the magnetic sensing element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 100252 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the external magnetic body is often made of a brittle material such as ferrite, and the sensor chip may also be made of a fragile material such as silicon, which poses a problem of being easily damaged when subjected to external impacts.

[0005] Therefore, an object of the present invention is to prevent damage to the sensor chip and the external magnetic body in a magnetic sensor having an external magnetic body that collects magnetic flux in a magnetic sensing element. [Means for solving the problem]

[0006] The magnetic sensor according to the present invention is characterized by comprising a sensor chip having an element forming surface on which a magnetic sensing element is formed, a first external magnetic body located at the tip in the longitudinal direction and having an end face facing the element forming surface and a plurality of side faces that form the outer peripheral surface of a cross section perpendicular to the longitudinal direction, and a protective resin that covers the element forming surface and at least a portion of the plurality of side faces of the first external magnetic body.

[0007] According to the present invention, the element forming surface of the sensor chip and multiple side surfaces of the first external magnetic body are covered with protective resin, making it possible to protect the sensor chip and the first external magnetic body located in its vicinity, which are prone to damage when subjected to external impacts or the like.

[0008] The magnetic sensor according to the present invention further includes a substrate on which a sensor chip and a first external magnetic body are mounted, the sensor chip being mounted on the substrate so that its element-forming surface is substantially perpendicular to the surface of the substrate, the side surfaces of the first external magnetic body including a first side surface facing the substrate, a second side surface opposite the first side surface, and third and fourth side surfaces opposite each other and connecting the first and second side surfaces, and the protective resin may cover at least a portion of the element-forming surface and the second to fourth side surfaces, thereby making it possible to mitigate impacts applied to the sensor chip and the first external magnetic body via the substrate.

[0009] The magnetic sensor according to the present invention may further include a second external magnetic body having a rod-shaped portion facing the back surface of the sensor chip located on the opposite side of the element formation surface, and a protective resin may be further provided between the back surface of the sensor chip and the rod-shaped portion of the second external magnetic body. This enhances the magnetic collecting effect of the second external magnetic body and makes it possible to prevent damage to the second external magnetic body due to external impact.

[0010] The magnetic sensor according to the present invention may further include an auxiliary chip attached to the back surface of the sensor chip, and the protective resin may be provided between the auxiliary chip and the rod-shaped portion of the second external magnetic body, thereby increasing the mechanical strength of the sensor chip.

[0011] In the present invention, the second external magnetic body may further have an overhanging portion that protrudes from the rod-shaped portion toward the element-forming surface and is bent to cover part of the element-forming surface, and the protective resin may further cover the overhanging portion, thereby making it possible to prevent damage to the overhanging portion due to external impact.

[0012] The magnetic sensor according to the present invention further includes a molded member fixed to the first external magnetic body, a compensation coil, and first and second connection pins, the molded member having a bobbin and a holding portion that houses the first external magnetic body, the holding portion being located between the sensor chip and the bobbin, the compensation coil being wound around the bobbin, the first and second connection pins being fixed to the holding portion, one end and the other end of the compensation coil being connected to the first and second connection pins, respectively, and a protective resin may be embedded between the holding portion and the overhang portion. This more effectively prevents damage to the overhang portion due to external impact and enables the compensation coil to be wound around the first external magnetic body without coming into contact with the first external magnetic body.

[0013] In the present invention, the compensation coil includes a solenoid portion wound around a bobbin, a first lead portion located between one end of the solenoid portion and the first connection pin, and a second lead portion located between the other end of the solenoid portion and the second connection pin, the molded member further has first and second positioning portions that position the first and second lead portions, respectively, and the protective resin may further cover the first positioning portion and the first lead portion, as well as the second positioning portion and the second lead portion. This makes it possible to prevent damage to the first and second positioning portions and breakage of the compensation coil due to external impact.

[0014] In the present invention, the protective resin may be made of a urethane-based material or a silicone-based material, which makes it possible to effectively absorb external impacts. [Effects of the Invention]

[0015] Thus, according to the present invention, in a magnetic sensor having an external magnetic body that collects magnetic flux in a magnetic sensing element, it is possible to prevent damage to the sensor chip and the external magnetic body. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic perspective view showing the appearance of a magnetic sensor 100 according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic exploded perspective view of the magnetic sensor 100. As shown in FIG. [Figure 3] FIG. 3 is a schematic perspective view showing the appearance of the magnetic sensor module 1. As shown in FIG. [Figure 4] FIG. 4 is a schematic exploded perspective view of the magnetic sensor module 1. As shown in FIG. [Figure 5] FIG. 5 is a schematic plan view of the sensor chip 20. As shown in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view taken along line AA in FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view for explaining an example in which the magnetic layer and the magnetic sensing element overlap. [Figure 8] FIG. 8 is a circuit diagram for explaining the connection relationship between the magnetic sensing elements R1 to R4 and the compensation coil C. [Figure 9] FIG. 9 is a schematic perspective view for explaining the structure of the magnetic flux collecting module 60. As shown in FIG. [Figure 10] FIG. 10 is a schematic perspective view for explaining the structure of the magnetic flux collecting module 60. As shown in FIG. [Figure 11] FIG. 11 is a schematic exploded perspective view of the magnetic flux collecting module 60 with the compensation coil C removed. [Figure 12] FIG. 12 is a schematic exploded perspective view for explaining the assembly process of the magnetic sensor 100. As shown in FIG. [Figure 13] FIG. 13 is an enlarged view for explaining the regions where the protective resins 4A to 4D are provided. [Figure 14] FIG. 14 is an enlarged view for explaining the regions where the protective resins 4A to 4D are provided. [Figure 15]FIG. 15 is an enlarged view for explaining the region where the protective resin 4A is provided. [Figure 16] FIG. 16 is an enlarged view for explaining the region where the protective resin 4A is provided. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0018] Fig. 1 is a schematic perspective view showing the appearance of a magnetic sensor 100 according to one embodiment of the present invention, and Fig. 2 is a schematic exploded perspective view of the magnetic sensor 100.

[0019] As shown in FIGS. 1 and 2, the magnetic sensor 100 according to this embodiment includes a magnetic sensor module 1, which is a main body, and a lower case 2 and an upper case 3 that house the magnetic sensor module 1. The lower case 2 and the upper case 3 are made of a non-magnetic insulating material such as resin, and the magnetic sensor module 1 is housed in an internal space formed by fitting them together in the Y direction. The main part of the magnetic sensor module 1 is covered with a protective resin 4 made of a urethane-based material or a silicone-based material. The magnetic sensor 100 is a rod-shaped body with its longitudinal direction in the Z direction, and its end on the +Z direction side forms the sensor head. Wiring (not shown) connected to the magnetic sensor module 1 is drawn out from its end on the -Z direction side.

[0020] Fig. 3 is a schematic perspective view showing the appearance of the magnetic sensor module 1. Fig. 4 is a schematic exploded perspective view of the magnetic sensor module 1.

[0021] As shown in FIGS. 3 and 4 , the magnetic sensor module 1 includes a substrate 10, a sensor chip 20 mounted on a surface 11 constituting the XZ plane of the substrate 10, an external magnetic body 40, an auxiliary chip 50, and a magnetic flux collection module 60 including an external magnetic body 30. The sensor chip 20 has an element formation surface 21 and a back surface 22 constituting the XY plane, side surfaces 23 and 24 constituting the YZ plane, and side surfaces 25 and 26 constituting the XZ plane, and is mounted on the substrate 10 so that the side surface 26 faces the surface 11 of the substrate 10. A magnetic sensing element and magnetic layers M1 to M3, which will be described later, are formed on the element formation surface 21 of the sensor chip 20. As described above, in this embodiment, the surface 11 of the substrate 10 and the element formation surface 21 of the sensor chip 20 are perpendicular to each other. However, in the present invention, it is not essential that the two surfaces be perfectly perpendicular to each other; they may have a predetermined inclination relative to the perpendicular.

[0022] The external magnetic bodies 30 and 40 function to collect magnetic flux toward the sensor chip 20 and are made of a highly permeable material such as ferrite. The external magnetic body 30 is a rod-shaped body with its longitudinal direction in the Z direction and is positioned approximately at the center of the element-forming surface 21 in the X direction so as to cover a portion of the magnetic layer M1. The external magnetic body 40 is located on the opposite side of the sensor chip 20 from the external magnetic body 30. The external magnetic body 40 has its longitudinal direction in the Z direction and includes a rod-shaped portion 41 that covers the back surface 22 of the sensor chip 20, and overhanging portions 42 and 43 that protrude from the rod-shaped portion 41 toward the element-forming surface 21 to cover the side surfaces 23 and 24 of the sensor chip 20, respectively, and are bent to cover a portion of the magnetic layers M2 and M3. This configuration selectively collects magnetic fields in the Z direction, and the collected magnetic fields are applied to the sensor chip 20.

[0023] The auxiliary chip 50 serves to increase the strength of the sensor chip 20, and is attached to the back surface 22 of the sensor chip 20 using an adhesive or the like. The auxiliary chip 50 may be made of the same material as the sensor chip 20. Although not particularly limited, the thickness of the auxiliary chip 50 in the Z direction is greater than the thickness of the sensor chip 20 in the Z direction, thereby sufficiently increasing the mechanical strength of the sensor chip 20.

[0024] The magnetic flux collection module 60 includes a molded member 70 that houses the external magnetic body 30, and a compensation coil C wound around the molded member 70. The number of turns of the wire that makes up the compensation coil C is not particularly limited, and may be any number necessary to generate the desired canceling magnetic field. The molded member 70 is made of a non-magnetic insulating material such as resin. The structure and role of the molded member 70 will be described later.

[0025] FIG. 5 is a schematic plan view of the sensor chip 20, and FIG. 6 is a schematic cross-sectional view taken along line AA in FIG.

[0026] As shown in Figures 5 and 6, four magnetic sensing elements R1 to R4 are formed on the element formation surface 21 of the sensor chip 20. The magnetic sensing elements R1 to R4 are not particularly limited as long as they are elements whose electrical resistance changes depending on the direction of magnetic flux, and for example, MR elements can be used. The fixed magnetization directions of the magnetic sensing elements R1 to R4 are aligned in the same direction (for example, the positive side in the X direction). The magnetic sensing elements R1 to R4 are covered with an insulating layer 27, and magnetic layers M1 to M3 made of permalloy or the like are formed on the surface of the insulating layer 27. The magnetic layers M1 to M3 are covered with an insulating layer 28. Of the magnetic layers M1 to M3, if the portions located on one side in the Y direction (upper side in FIG. 5) are defined as magnetic layers M11, M21, and M31, and the portions located on the other side in the Y direction (lower side in FIG. 5) are defined as magnetic layers M12, M22, and M32, then in a plan view (viewed from the Z direction), the magnetic sensitive element R1 is located between the magnetic layer M11 and the magnetic layer M21, the magnetic sensitive element R2 is located between the magnetic layer M12 and the magnetic layer M22, the magnetic sensitive element R3 is located between the magnetic layer M11 and the magnetic layer M31, and the magnetic sensitive element R4 is located between the magnetic layer M12 and the magnetic layer M32. As a result, a magnetic field passing through the magnetic gaps G1 to G4 is applied to the magnetic sensitive elements R1 to R4.

[0027] However, in the present invention, it is not essential that each magnetic-sensing element R1-R4 be located between two magnetic layers in a planar view. It is sufficient for each magnetic-sensing element R1-R4 to be located near the magnetic gap G1-G4, which is formed by two magnetic layers, i.e., on the magnetic path formed by the magnetic gap G1-G4. Furthermore, the width of the magnetic gap G1-G4 does not need to be wider than the width of the magnetic-sensing elements R1-R4; the width of the magnetic gap G1-G4 may be narrower than the width of the magnetic-sensing elements R1-R4. In the example shown in FIG. 7, the width Gx of the magnetic gap G1 in the X direction is narrower than the width Rx of the magnetic-sensing element R1 in the X direction. As a result, the magnetic layers M1 and M2 and the magnetic-sensing element R1 overlap when viewed from the Z direction, creating an OV. The relationship between the magnetic gaps G1-G4 and the magnetic-sensing elements R1-R4 may be as shown in FIG. 7.

[0028] 5 and 6, the regions indicated by the reference symbols 30a and 40a indicate the regions covered by the external magnetic bodies 30 and 40, respectively. As shown in Fig. 5 and 6, the external magnetic body 30 covers the magnetic layer M1, and the external magnetic body 40 covers the magnetic layers M2 and M3. Here, in order to more efficiently apply the magnetic field collected by the external magnetic body 30 to the magnetic sensing elements R1 to R4, it is preferable that the XY end faces of the external magnetic body 30 facing the element forming surface 21 be in contact with the insulating layer 28 on the magnetic layer M1 directly or via an adhesive.

[0029] FIG. 8 is a circuit diagram for explaining the connection relationship between the magnetic sensing elements R1 to R4 and the compensation coil C.

[0030] As shown in FIG. 8, the magnetic sensing element R1 is connected between the terminal electrodes T11 and T13, the magnetic sensing element R2 is connected between the terminal electrodes T12 and T14, the magnetic sensing element R3 is connected between the terminal electrodes T11 and T12, and the magnetic sensing element R4 is connected between the terminal electrodes T13 and T14. The terminal electrodes T11 to T14 are terminal electrodes that make up the terminal electrode group T10 shown in FIG. 4. The terminal electrode group T10 is provided on the sensor chip 20 and connected to the terminal electrode group T30 shown in FIGS. 3 and 4 via wiring (not shown) formed on the substrate 10. The terminal electrode T11 is supplied with a power supply potential Vcc, and the terminal electrode T14 is supplied with a ground potential GND. Since the magnetic sensing elements R1 to R4 all have the same fixed magnetization direction, a difference occurs between the resistance change amounts of the magnetic sensing elements R1 and R2 located on one side of the external magnetic body 30 and the resistance change amounts of the magnetic sensing elements R3 and R4 located on the other side of the external magnetic body 30. As a result, the magnetic sensing elements R1 to R4 form a differential bridge circuit, and a change in the electrical resistance of the magnetic sensing elements R1 to R4 according to the magnetic flux density appears as a differential signal Va at the terminal electrodes T12 and T13.

[0031] The differential signal Va output from the terminal electrodes T12 and T13 is input to a differential amplifier 81 provided on the substrate 10 or the sensor chip 20. The output signal of the differential amplifier 81 is fed back to the terminal electrode T21. As shown in FIG. 8, a compensation coil C is connected between the terminal electrodes T21 and T22, causing the compensation coil C to generate a canceling magnetic field corresponding to the output signal of the differential amplifier 81. The terminal electrodes T21 and T22 are connected to connection pins P1 and P2, respectively, held by the molded member 70. With this configuration, when a differential signal Va corresponding to changes in the electrical resistance of the magnetic sensing elements R1 to R4 depending on the magnetic flux density of the magnetic field to be detected appears at the terminal electrodes T12 and T13, a corresponding current flows through the compensation coil C, generating a canceling magnetic field in the opposite direction. This cancels out the magnetic field to be detected. The current output from the differential amplifier 81 is then converted into a voltage by a detection circuit 82, making it possible to detect the strength of the magnetic field to be detected. Such closed-loop control makes it possible to detect the magnetic field collected via the external magnetic bodies 30 and 40 with high accuracy.

[0032] 9 and 10 are schematic perspective views for explaining the structure of the magnetic flux collecting module 60, showing states as viewed from different angles. Also, Fig. 11 is a schematic exploded perspective view of the magnetic flux collecting module 60 in a state where the compensation coil C has been removed.

[0033] As shown in FIGS. 9 to 11, the magnetic flux collection module 60 comprises a molded member 70, an external magnetic body 30 fixed to the molded member 70, a compensation coil C, and connection pins P1 and P2. The molded member 70 is a single member including a bobbin 71, a holding portion 72, a tip portion 73, and positioning portions 74 and 75. The bobbin 71 houses the narrow portion 31 of the external magnetic body 30 and has a tip portion 73 at its tip in the +Z direction. The tip portion 73 has a slit 73a extending in the X direction. The slit 73a is used to fix the position of the wire constituting the compensation coil C. The holding portion 72 is located on the -Z direction side of the bobbin 71 and houses the wide portion 32 of the external magnetic body 30 while holding the connection pins P1 and P2 passed through a through-hole 76. The narrow portion 31 of the external magnetic body 30 has a smaller XY cross section than the wide portion 32 of the external magnetic body 30.

[0034] The connection pins P1 and P2 are terminal electrodes made of a substantially U-shaped metal member. The connection pin P1 has protrusions P1a and P1b that protrude in the +Y direction from the surface of the holding portion 72, and the connection pin P2 has protrusions P2a and P2b that protrude in the +Y direction from the surface of the holding portion 72. The protrusion P1a is a portion to which one end of the compensation coil C is connected, and the protrusion P2a is a portion to which the other end of the compensation coil C is connected. The protrusions P1a and P2a are arranged in the X direction and are located on the -Z direction side of the bobbin 71. The protrusions P1b and P2b are connected to terminal electrodes T21 and T22 shown in FIG. 8 via wiring (not shown).

[0035] 10 , portions of the XZ bottom surfaces of the bobbin 71 and the holder 72 are open, and the external magnetic body 30 is exposed from these openings. The XZ bottom surface of the wide portion 32 of the external magnetic body 30 protrudes from the holder 72 in the −Y direction, and when the magnetic flux collection module 60 is mounted on the substrate 10, the wide portion 32 of the external magnetic body 30 is fixed to the surface 11 of the substrate 10. In contrast, the XZ bottom surface of the narrow width portion 31 of the external magnetic body 30 does not protrude from the bobbin 71. Although it is not necessary to provide an opening in the XZ bottom surface of the bobbin 71, providing such an opening makes it possible to attach the external magnetic body 30 to the molded member 70 from the Y direction.

[0036] A compensation coil C is wound around the bobbin 71 with its winding axis aligned in the Z direction. One end of the compensation coil C is connected to the protrusion P1a of the connection pin P1, and the other end of the compensation coil C is connected to the protrusion P2a of the connection pin P2. Positioning portions 84, 85 with locally small diameters are provided on the protrusions P1a, P2a, and one and the other end of the compensation coil C are wound around these positioning portions 84, 85, respectively, and then fixed with solder. This fixes the positions in the Y direction of the one and the other ends of the compensation coil C connected to the protrusions P1a, P2a. The positioning portions 84, 85 are located closer to the tips of the connection pins P1, P2 in the +Y direction than the holding portion 72. This fixes the one and the other ends of the compensation coil C to portions closer to the tips of the connection pins P1, P2 in the +Y direction than the holding portion 72.

[0037] The compensation coil C includes a solenoid portion C0 wound around a bobbin 71, a lead-out portion C1 located between one end of the solenoid portion C0 and the connection pin P1, and a lead-out portion C2 located between the other end of the solenoid portion C0 and the connection pin P2. The solenoid portion C0 functions as a coil and is wound around the bobbin 71 with the Z direction as the winding axis. The solenoid portion C0 is wound around the bobbin 71 so that its position in the Z direction changes with each turn. In other words, if the lead-out portion C1 is the starting point and the lead-out portion C2 is the end point, the position of the wire that makes up the solenoid portion C0 shifts in the +Z direction with each turn.

[0038] In this way, the compensation coil C is not wound directly around the external magnetic body 30, but is wound around the external magnetic body 30 via the bobbin 71, so that the compensation coil C and the external magnetic body 30 do not come into contact with each other, thereby making it possible to prevent damage to the compensation coil C and the external magnetic body 30 due to contact between the two.

[0039] Furthermore, molding member 70 has positioning portions 74 and 75 located between bobbin 71 and holding portion 72. Positioning portion 74 is a protrusion for positioning lead portion C1 of compensation coil C and protrudes in the +X direction. Positioning portion 75 is a protrusion for positioning lead portion C2 of compensation coil C and protrudes in the -X direction. Lead portions C1 and C2, which extend in the Z direction, pass through the -Y direction sides of positioning portions 74 and 75, respectively, and are connected to connection pins P1 and P2. This restricts movement of lead portions C1 and C2 in the +Y direction.

[0040] In this manner, in this embodiment, after the external magnetic body 30 and the connection pins P1 and P2 are fixed to the molded member 70, the magnetic collection module 60 is produced by winding the compensation coil C and connecting the connection pins P1 and P2 to the compensation coil C, and this magnetic collection module 60 is mounted on the substrate 10, thereby enabling the magnetic sensor module 1 to be produced efficiently.

[0041] FIG. 12 is a schematic exploded perspective view for explaining the assembly process of the magnetic sensor 100 according to this embodiment.

[0042] As shown in FIG. 12 , in assembling the magnetic sensor 100, the above-described magnetic sensor module 1 is first fabricated and housed in the lower case 2. After that, a protective resin 4 is applied to the main portion of the magnetic sensor module 1. The protective resin 4 is applied to at least area A shown in FIG. 12 . Area A includes the area where the element formation surface 21 of the sensor chip 20 and the external magnetic body 30 are adjacent to each other. The protective resin 4 serves to prevent damage to the magnetic sensor module 1 by absorbing external impacts, and is made of a highly elastic resin material such as a urethane-based material or a silicone-based material. After the main portion of the magnetic sensor module 1 is covered with the protective resin 4 in this manner, the upper case 3 is fitted into the lower case 2 to complete the magnetic sensor 100 according to this embodiment.

[0043] 13 and 14 are enlarged views for explaining the region where the protective resin 4 is provided, and show states as viewed from different angles.

[0044] 13 and 14, the protective resin 4 includes protective resins 4A to 4D. Of these, protective resin 4A is located around the external magnetic body 30 in the vicinity of the sensor chip 20. As shown in FIGS. 15 and 16, which show a state in which protective resins 4B to 4D are omitted, protective resin 4A is located so as to cover the element forming surface 21 of the sensor chip 20 and the surface of the external magnetic body 30 located in the vicinity of the sensor chip 20. Here, the surface of the external magnetic body 30 located in the vicinity of the sensor chip 20 refers to the side surfaces 34 to 36 of the external magnetic body 30 in the portions adjacent to the overhanging portions 42 and 43 of the external magnetic body 30 in the X direction. The side surfaces 34 to 36 form the outer peripheral surface of a cross section perpendicular to the Z direction, which is the longitudinal direction. Of these, the side surfaces 34 and 35 of the external magnetic body 30 form the YZ plane, and the side surface 36 of the external magnetic body 30 forms the XZ plane. The side surface 37 of the external magnetic body 30, located opposite the side surface 36, is bonded to the surface 11 of the substrate 10 via an adhesive or the like, and since there is almost no gap between them, the side surface 37 of the external magnetic body 30 does not need to be covered with the protective resin 4A. Here, the side surfaces 34 and 35 are surfaces connecting the side surfaces 36 and 37. Furthermore, it is not preferable to cover the end surface 33 (XY plane) of the external magnetic body 30, which is located at the tip in the longitudinal Z direction and faces the element forming surface 21, with the protective resin 4A. As described above, it is preferable for the end surface 33 to be in close contact with the insulating layer 28 located on the element forming surface 21. In this way, the protective resin 4A is provided so as to fill the gap formed by the external magnetic body 30 and the overhanging portions 42 and 43 and to cover a portion of the element forming surface 21.

[0045] The protective resin 4B is embedded in the gap formed between the overhang portions 42, 43 and the holding portion 72 of the molded member 70 so as to cover the surface 11 of the substrate 10 and the side surfaces 34 to 36 of the external magnetic body 30. The protective resin 4B may be integral with the above-mentioned protective resin 4A.

[0046] The protective resin 4C is provided between the XY plane of the rod-shaped portion 41 of the external magnetic body 40 and the auxiliary chip 50. As a result, the gap formed between the rod-shaped portion 41 of the external magnetic body 40 and the auxiliary chip 50 is filled with the protective resin 4C. Furthermore, when the auxiliary chip 50 is not used, the protective resin 4C is filled in the gap formed between the XY plane of the rod-shaped portion 41 of the external magnetic body 40 and the back surface 22 of the sensor chip 20.

[0047] The protective resin 4D is embedded in the recesses of the molded member 70 formed by the protruding positioning portions 74, 75. As a result, not only the positioning portions 74, 75 but also the lead-out portions C1, C2 of the compensation coil C that pass through the positioning portions 74, 75 are covered with the protective resin 4D.

[0048] By providing such protective resins 4A to 4D, the sensor chip 20 and the external magnetic bodies 30 and 40 are less likely to be damaged even when an external impact is applied. In particular, although the area adjacent to the sensor chip 20 and the external magnetic body 30 is most susceptible to damage, the provision of protective resin 4A to cover this area makes it possible to prevent damage to the sensor chip 20 and the external magnetic body 30 in this area. Furthermore, protective resin 4B serves to more firmly protect the external magnetic body 30 and also to protect the tips of the overhanging portions 42 and 43, which are susceptible to damage. Furthermore, protective resin 4C serves to protect the base portions of the overhanging portions 42 and 43, and protective resin 4D serves to prevent breakage of the lead-out portions C1 and C2 of the compensation coil C.

[0049] As described above, in this embodiment, the main part of the magnetic sensor module 1 is covered with the protective resin 4, so that it is possible to prevent the magnetic sensor module 1 from being damaged when an external impact is applied thereto.

[0050] The above describes a preferred embodiment of the present invention, but the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the present invention, and it goes without saying that these modifications are also included within the scope of the present invention. [Explanation of symbols]

[0051] 1 Magnetic Sensor Module 2 Lower case 3 Upper case 4,4A~4D Protective resin 10 Substrate 11 Surface of the board 20 sensor chips 21 Element formation surface 22 Backside of sensor chip 23~26 Side of sensor chip 27,28 Insulating layer 30,40 External magnetic material 30a, 40a: Area covered with external magnetic material 31 Width details 32 Wide section 33 End face of external magnetic body 34-37 Side of external magnetic body 41 Rod-shaped part 42,43 Overhang 50 Auxiliary Chips 60 Magnetic Concentration Module 70 Molded parts 71 Bobbin 72 Holding part 73 Tip 73a Slit 74,75 Positioning part 76 Through Hole 81 Differential Amplifier 82 Detection circuit 84,85 Positioning part 100 Magnetic Sensor C Compensation coil C0 solenoid section C1, C2 drawer section G1~G4 magnetic gap M1~M3,M11,M21,M31,M12,M22,M32 Magnetic layer P1,P2 connection pins P1a,P1b,P2a,P2b protrusion R1~R4 magnetic sensing element T10,T30 terminal electrode group T11~T14, T21, T22 terminal electrodes

Claims

1. a sensor chip having an element forming surface on which a magnetic sensing element is formed; a first external magnetic body located at a tip in a longitudinal direction and having an end surface facing the element forming surface and a plurality of side surfaces constituting an outer circumferential surface in a cross section perpendicular to the longitudinal direction; A magnetic sensor characterized by comprising: a protective resin that covers the portion of the element forming surface that is not covered by the end surface of the first external magnetic body and covers at least a portion of the multiple side surfaces of the first external magnetic body.

2. a substrate on which the sensor chip and the first external magnetic body are mounted, the sensor chip is mounted on the substrate so that the element formation surface is substantially perpendicular to the surface of the substrate; the side surfaces of the first external magnetic body include a first side surface facing the substrate, a second side surface located opposite the first side surface, and third and fourth side surfaces located opposite each other and connecting the first side surface and the second side surface; 2. The magnetic sensor according to claim 1, wherein the protective resin covers the element forming surface and at least a part of the second to fourth side surfaces.

3. a second external magnetic body having a rod-shaped portion facing a back surface of the sensor chip located on the opposite side of the element forming surface, 3. The magnetic sensor according to claim 1, wherein the protective resin is further provided between the rear surface of the sensor chip and the rod-shaped portion of the second external magnetic body.

4. further comprising an auxiliary chip attached to the back surface of the sensor chip; 4. The magnetic sensor according to claim 3, wherein the protective resin is provided between the auxiliary chip and the rod-shaped portion of the second external magnetic body.

5. the second external magnetic body further has an overhang portion that protrudes from the rod-shaped portion toward the element forming surface and is bent so as to cover a part of the element forming surface, 5. The magnetic sensor according to claim 3, wherein the protective resin further covers the overhang portion.

6. a sensor chip having an element forming surface on which a magnetic sensing element is formed; a first external magnetic body located at a tip in a longitudinal direction and having an end surface facing the element forming surface and a plurality of side surfaces constituting an outer circumferential surface in a cross section perpendicular to the longitudinal direction; a protective resin that covers the element formation surface and at least a portion of the plurality of side surfaces of the first external magnetic body; a second external magnetic body having a rod-shaped portion facing a back surface of the sensor chip located on the opposite side of the element forming surface, and an overhang portion protruding from the rod-shaped portion toward the element forming surface and bent so as to cover a part of the element forming surface; a molded member fixed to the first external magnetic body; a compensation coil; first and second connection pins; the protective resin is further provided between the rear surface of the sensor chip and the rod-shaped portion of the second external magnetic body, the protective resin further covers the overhang portion, the molded member has a bobbin that accommodates the first external magnetic body and a holding portion, the holding portion is located between the sensor chip and the bobbin, the compensation coil is wound around the bobbin; the first and second connection pins are fixed to the holding portion; one end and the other end of the compensation coil are connected to the first and second connection pins, respectively; The magnetic sensor is characterized in that the protective resin is embedded between the holding portion and the overhang portion.

7. the compensation coil includes a solenoid portion wound around the bobbin, a first lead portion located between one end of the solenoid portion and the first connection pin, and a second lead portion located between the other end of the solenoid portion and the second connection pin, the molding member further has first and second positioning portions that position the first and second drawer portions, respectively; 7. The magnetic sensor according to claim 6, wherein the protective resin further covers the first positioning portion and the first lead portion, and further covers the second positioning portion and the second lead portion.

8. 8. The magnetic sensor according to claim 1, wherein the protective resin is made of a urethane-based material or a silicone-based material.

Images