Magnetic sensor device

Abstract

The present invention provides a magnetic sensor device that allows for the suitable fixing of a sensor substrate to a support substrate and provides stable output characteristics. [Solution] The magnetic sensor device 1 comprises a support substrate 2 and a sensor substrate 10 fixed to the support substrate 2. The sensor substrate 10 has a first surface 10B facing the support substrate 2 and a second surface 10A located on the opposite side of the first surface 10B, on which a functional film 20 containing a plurality of magnetic detection elements E is provided. The first surface 10B has a hole portion 11 formed therein, which is a bottomed hole recessed from the first surface 10B toward the second surface 10A or a through hole penetrating from the first surface 10B toward the second surface 10A. The contour O11 of the hole portion 11 is circular and does not include corners C1, C2, C3...

Description

Technical Field

[0001] The present disclosure relates to a magnetic sensor device.

Background Art

[0002] There is a magnetic sensor device in which a sensor chip having a magnetic detection element provided on a sensor substrate is adhered to a support substrate by an adhesive. For example, in Patent Document 1, a first chip and a second chip including a magnetic sensor that generates a detection signal, and a support including an application-specific integrated circuit (ASIC) for processing the detection signal are prepared separately, and the first chip and the second chip are joined to the support by an adhesive. A magnetic sensor device is disclosed.

[0003] In such a magnetic sensor device, it is preferable to apply the adhesive so that it slightly protrudes from the adhesion surface of the sensor substrate. If the application amount of the adhesive is insufficient, peeling is likely to occur starting from the portion where the adhesive is not applied, and the adhesion strength may decrease. If the application amount of the adhesive is excessive, the adhesive protruding from the sensor substrate may adhere to the electrodes on the surface of the ASIC or the like, and the connection reliability may decrease.

[0004] If a bottomed hole or a through hole is formed in the adhesion surface of the sensor substrate, even if the application amount changes somewhat, the amount of the adhesive protruding from the sensor chip hardly changes due to surface tension. Since the adhesive layer becomes thicker, the adhesion strength also improves. Patent Document 2 discloses forming a recess on the back surface of a semiconductor element facing a support substrate in a semiconductor device in which the semiconductor element is mounted on the support through an adhesive layer, although it is not a magnetic sensor device.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

[0006] However, unlike the semiconductor device described in Patent Document 2, the magnetic sensor device includes a magnetic detection element made of a magnetic material. When an external force is applied to the magnetic material, the response to the magnetic field changes due to the inverse magnetostrictive effect. In particular, tunnel magnetoresistance elements have excellent output characteristics with a large MR ratio, but on the other hand, their output characteristics are easily affected by external forces. Furthermore, if a bottomed hole or through hole is formed in the sensor substrate, the thickness of the sensor substrate changes locally, which can lead to uneven thermal deformation when the sensor substrate expands or contracts due to temperature changes, potentially causing thermal stress to act on the magnetic detection element.

[0007] This disclosure has been made in view of these circumstances, and aims to provide a magnetic sensor device that can suitably fix a sensor substrate to a support substrate and has stable output characteristics. [Means for solving the problem]

[0008] A magnetic sensor device according to one aspect of the present disclosure comprises a support substrate and a sensor substrate fixed to the support substrate. The sensor substrate has a first surface facing the support substrate and a second surface located on the opposite side of the first surface, the second surface being provided with a functional film containing a plurality of magnetic detection elements. A hole is formed in the first surface, the contour of the hole includes at least one corner, and each of the plurality of magnetic detection elements is arranged such that, in a plan view taken along the direction perpendicular to the surface from the second surface toward the first surface, it does not overlap with at least one corner. The hole may be a bottomed hole recessed from the first surface toward the second surface, or it may be a through hole penetrating from the first surface toward the second surface.

[0009] Another embodiment of the present disclosure of a magnetic sensor device comprises a support substrate and a sensor substrate fixed to the support substrate. The sensor substrate has a first surface facing the support substrate and a second surface located on the opposite side of the first surface, the second surface being provided with a functional film containing a plurality of magnetic detection elements, and a hole is formed in the first surface, the contour of the hole is circular and does not include corners.

[0010] According to these embodiments, since holes are formed in the sensor substrate, the amount of adhesive that protrudes from the bottom surface of the sensor substrate is less likely to change even if the amount of adhesive applied changes, compared to when no holes are formed. The adhesive layer becomes thicker and the adhesive strength is also improved. Therefore, the sensor substrate can be suitably bonded to the support substrate. In a plan view, the position that overlaps with the corner of the hole contour is susceptible to the effects of thermal stress. According to these embodiments, since each of the multiple magnetic detection elements does not overlap with any of the corners, it is possible to provide a magnetic sensor device that is less susceptible to the effects of thermal stress and has stable output characteristics.

[0011] In the above embodiment, the sensor substrate is fixed to the support substrate using an adhesive, and the holes may be filled with adhesive.

[0012] According to this embodiment, the sensor substrate can be suitably fixed to the support substrate with an adhesive.

[0013] In the above embodiment, each of the multiple magnetic detection elements may be arranged so as not to overlap the contour in a plan view.

[0014] While not as susceptible as the positions overlapping the contour of the hole, the positions that overlap the corners are slightly more susceptible to thermal stress than the positions that do not overlap the contour. In this configuration, since each of the multiple magnetic detection elements does not overlap with either the corners or the contour, it becomes even less susceptible to thermal stress, resulting in more stable output characteristics.

[0015] In the above embodiment, some of the multiple magnetic detection elements may be arranged inside the contour in a plan view, and the remaining multiple magnetic detection elements may be arranged outside the contour in a plan view. All of the multiple magnetic detection elements may be arranged inside the contour in a plan view. All of the multiple magnetic detection elements may be arranged outside the contour in a plan view.

[0016] According to these embodiments, magnetic detection elements can be arranged both inside and outside the contour, only inside the contour, or only outside the contour. There are fewer constraints on the arrangement of magnetic detection elements, resulting in excellent design flexibility.

[0017] In the above embodiment, each of the multiple magnetic detection elements may be arranged at a distance of 1 μm or more from the contour in a direction perpendicular to the direction perpendicular to the plane.

[0018] In this embodiment, since each of the multiple magnetic detection elements is located at a distance of at least 1 μm from the contour, it is less susceptible to the effects of thermal stress.

[0019] In the above embodiment, the plurality of magnetic detection elements may include at least one first magnetic detection element arranged to overlap the contour in a plan view taken along the direction perpendicular to the plane from the second surface to the first surface.

[0020] According to this embodiment, the first magnetic detection element can be arranged so as to overlap the contour of the hole. Although the positions that overlap the contour of the hole, other than the corners, are slightly more susceptible to thermal stress than the positions that do not overlap the contour, the influence of thermal stress is sufficiently smaller than that of the positions that overlap the corners, thus providing a magnetic sensor device with stable output characteristics. Compared to the case where the entire contour of the hole must be avoided, there are fewer constraints on the arrangement of the magnetic detection element, resulting in greater design flexibility.

[0021] In the above aspect, the plurality of magnetic detection elements further includes a plurality of second magnetic detection elements arranged so as not to overlap the contour in a plan view. A part of the plurality of second magnetic detection elements may be arranged inside the contour in a plan view, and the remainder of the plurality of second magnetic detection elements may be arranged outside the contour in a plan view. All of at least one second magnetic detection element may be arranged inside the contour in a plan view. All of at least one second magnetic detection element may be arranged outside the contour in a plan view.

[0022] According to these aspects, the first magnetic detection elements overlapping the contour and the second magnetic detection elements not overlapping the contour can be mixed, and the second magnetic detection elements can be arranged straddling inside and outside the contour, or the second magnetic detection elements can be arranged only inside the contour, or the second magnetic detection elements can be arranged only outside the contour. There are few restrictions on the arrangement of the magnetic detection elements, and the design freedom is excellent.

[0023] In the above aspect, the plurality of magnetic detection elements may be arranged at an interval of 1 μm or more from all of at least one corner in a plane direction orthogonal to the plane normal direction.

[0024] According to this aspect, since each of the plurality of magnetic detection elements is at a position at least 1 μm away from the corner, it is hardly affected by thermal stress.

[0025] In the above aspect, the hole portion is a bottomed hole recessed from the first surface toward the second surface, and the depth of the bottomed hole may be half or less of the plate thickness of the sensor substrate in the plane normal direction.

[0026] As the hole portion becomes deeper, the difference in plate thickness between the hole portion and the portion other than the hole portion becomes larger, and when the sensor substrate expands or contracts due to temperature change, the magnetic detection element is likely to be affected by thermal stress. According to this aspect, since the difference between the hole portion and the portion other than the hole portion is half or less of the plate thickness, the influence of thermal stress is unlikely to become excessive, and a magnetic sensor device with stable output characteristics can be provided.

[0027] In the above embodiment, a wiring layer is further provided in a layer distal to the support substrate than the functional film in the direction perpendicular to the plane, and each of the multiple magnetic detection elements may be arranged inside the contour of the wiring layer in a plan view.

[0028] When a magnetic detection element is positioned inside the contour of a wiring layer, it becomes less susceptible to thermal stress compared to when there is no wiring layer.

[0029] In the above embodiment, the hole has an inner surface that is inclined with respect to the direction perpendicular to the surface, and each of the multiple magnetic detection elements may be arranged so as not to overlap the inner surface in a plan view.

[0030] Positions overlapping the inclined inner surface are susceptible to thermal stress. In this embodiment, since each of the multiple magnetic detection elements does not overlap the inclined inner surface, it is possible to provide a magnetic sensor device that is less susceptible to thermal stress and has stable output characteristics.

[0031] In the above embodiment, the angle sensor may be equipped with a magnetic sensor device, the magnetic compass may be equipped with a magnetic sensor device, the current sensor may be equipped with a magnetic sensor device, and the autofocus mechanism and / or optical image stabilization mechanism of the camera module may be equipped with a magnetic sensor device.

[0032] According to these embodiments, magnetic sensor devices can be applied to various purposes. [Effects of the Invention]

[0033] According to this disclosure, it is possible to provide a magnetic sensor device in which a sensor substrate can be suitably fixed to a support substrate and which has stable output characteristics. [Brief explanation of the drawing]

[0034] [Figure 1] Figure 1 is a perspective view showing a magnetic sensor device according to one embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view showing an example of the internal structure of the magnetic sensor device shown in Figure 1. [Figure 3] Figure 3 is a perspective view illustrating the manufacturing process of the magnetic sensor device shown in Figure 1. [Figure 4] Figure 4 shows an example of a magnetic sensor device configured as an angle sensor. [Figure 5] Figure 5 is a plan view showing an example of a magnetic sensor device configured as a magnetic compass. [Figure 6] Figure 6 shows an example of a magnetic sensor device used as part of a current sensor. [Figure 7] Figure 7 shows the circuit configuration of the current sensor shown in Figure 6. [Figure 8] Figure 8 is a perspective view showing an example of a magnetic sensor device used as part of the autofocus mechanism and optical image stabilization mechanism of a camera module. [Figure 9] Figure 9 is a cross-sectional view showing the internal structure of the camera module shown in Figure 8. [Figure 10A] Figure 10A is a plan view of the simulation model with a rectangular hole formed in it, viewed from a direction perpendicular to the surface. [Figure 10B] Figure 10B is a plan view of a simulation model with a rectangular hole with rounded corners, viewed from a direction perpendicular to the surface. [Figure 10C] Figure 10C is a plan view of the simulation model with a circular hole formed in it, viewed from a direction perpendicular to the surface. [Figure 10D] Figure 10D is a plan view of the simulation model, which includes additional wiring layers, as seen from a direction perpendicular to the plane. [Figure 10E] Figure 10E is a plan view of the simulation model with an inclined inner surface, viewed from a direction perpendicular to the surface. [Figure 11] Figure 11 is a cross-sectional view of the simulation model along the XY plane perpendicular to the direction perpendicular to the surface. [Figure 12-13] Figures 12 and 13 show the simulated angular errors at each position shown in Figures 10A and 11. [Figure 14]Figure 14 shows the simulated angular errors at each of the positions shown in Figures 10A, 10B, and 10C. [Figure 15] Figure 15 shows the angular errors simulated at the positions shown in Figures 10A, 10B, and 10C for a model with the wiring layer shown in Figure 10D. [Figure 16] Figure 16 shows the simulated angular error at each position shown in Figure 10E. [Figure 17-20] Figures 17 to 20 are plan views showing the first to fourth examples in which all magnetic detection elements are arranged so as not to overlap the contour of the hole. [Figure 21-23] Figures 21 to 23 are plan views showing the fifth to seventh examples in which the first magnetic detection element is arranged so as to overlap the contour of the hole except at the corners, and the second magnetic detection element is arranged so as not to overlap the contour of the hole. [Figure 24] Figure 24 is a plan view showing an eighth example in which the magnetic detection element is positioned inside the contour of the wiring layer. [Figure 25] Figure 25 is a cross-sectional view showing a ninth example in which magnetic detection elements are arranged so as not to overlap on the inclined inner surface. [Modes for carrying out the invention]

[0035] A preferred embodiment will be described with reference to the attached drawings. In each figure, components with the same reference numerals have the same or similar configuration. A magnetic sensor device 1 according to one embodiment of the present disclosure is characterized in that a hole 11 is formed in the sensor substrate 10, and as shown in Figures 17 to 24, in a plan view along the direction Z perpendicular to the surface, each of the multiple magnetic detection elements E is arranged so as not to overlap the corners C1, C2, C3… of the contour O11 of the hole 11. The contour O11 of the hole 11 may be a polygon such as a quadrilateral that includes multiple corners C1, C2, C3…, or it may be a circle that does not include corners C1, C2, C3…. The corners C1, C2, C3… may be rephrased as, for example, vertices C1, C2, C3… where the curvature takes a maximum value. The contour O11 of the hole 11 may be a combination of vertices C1 and curves, such as a teardrop shape. For example, in a circular arc with constant curvature enclosed by two straight lines, such as angle R, the corners C1, C2, C3, etc., may be the midpoints of the arc (see Figure 10B).

[0036] The magnetic sensor device 1 of the positional embodiment of the present disclosure comprises a support substrate 2 and a sensor substrate 10 fixed to the support substrate 2 with adhesive AD, wherein the sensor substrate 10 has a first surface 10B facing the support substrate 2 and a second surface 10A located on the opposite side of the first surface 10B, the second surface 10A having a functional film 20 containing a plurality of magnetic detection elements E, the adhesive AD is filled into a hole portion 11 formed in a bottomed hole recessed from the first surface 10B toward the second surface 10A or a through hole penetrating from the first surface 10B toward the second surface 10A, the contour O11 of the hole portion 11 includes at least one vertex C1, C2, C3... where the curvature is maximized, and each of the plurality of magnetic detection elements E is arranged such that, in a plan view along the plane-perpendicular direction Z from the second surface 10A toward the first surface 10B, it does not overlap with at least one of the vertices C1, C2, C3... In another embodiment of the magnetic sensor device 1 of the present disclosure, the contour O11 of the hole 11 is circular and does not include the vertices C1, C2, C3… where the curvature is maximized. The magnetic sensor device 1 of the present disclosure has the same or corresponding special technical features in that the magnetic detection elements E are arranged so as not to overlap with the vertices C1, C2, C3… where the curvature is maximized, regardless of whether the contour O11 of the hole 11 is polygonal or circular. Hereinafter, each configuration will be described in detail with reference to Figures 1 to 25.

[0037] Figure 1 is a perspective view showing a magnetic sensor device 1 according to one embodiment. In the illustrated example, the magnetic sensor device 1 includes a support substrate 2, a sensor chip 3, a wiring layer 4, a sealing resin 5, electrodes 6, etc. A single magnetic sensor device 1 may include multiple sensor chips 3.

[0038] As shown in Figure 1, the support substrate 2 is formed in a flat plate shape having an upper surface 2A and a lower surface 2B opposite to the upper surface 2A. In the following description, the thickness direction of the support substrate 2 is referred to as the plane-perpendicular direction Z or the vertical direction Z, the direction from the lower surface 2B to the upper surface 2A is referred to as upward, and the direction from the upper surface 2A to the lower surface 2B is referred to as downward. The upper surface 2A extends parallel to the XY plane which is perpendicular to the plane-perpendicular direction Z.

[0039] Figure 2 is a schematic cross-sectional view showing an example of the internal structure of the magnetic sensor device 1 shown in Figure 1. In the illustrated example, the support substrate 2 is an ASIC (Application Specific Integrated Circuit), and electrodes 2E electrically connected to the wiring layer 4 are provided on the upper surface 2A. The support substrate 2 is not limited to an ASIC and may be a silicon substrate or a sapphire substrate. It may also be an interposer substrate with only wiring formed on it that does not contain an integrated circuit.

[0040] The sensor chip 3 is fixed to the upper surface 2A of the support substrate 2 with adhesive AD. As shown in Figure 2, the sensor chip 3 comprises a sensor substrate 10, at least one magnetic detection element array 30 that generates a detection signal, a functional film 20 surrounding the magnetic detection element array 30, etc. The functional film 20 may be an inorganic film mainly composed of silica (silicon dioxide SiO2), or it may be a laminated film of an inorganic film mainly composed of silica and an inorganic film mainly composed of alumina (aluminum oxide Al2O3).

[0041] The sensor substrate 10 is, for example, a silicon substrate and is positioned between the upper surface 2A of the support substrate 2 and the functional film 20. The sensor substrate 10 has a first surface (lower surface) 10B facing the support substrate 2 and a second surface 10A opposite to the first surface 10B. The second surface 10A is provided with a functional film 20 including a magnetic detection element array 30. The first surface 10B of the sensor substrate 10 has a hole 11 into which adhesive AD can be filled. The hole 11 may be a bottomed hole recessed from the first surface 10B toward the second surface 10A of the sensor substrate 10, or it may be a through hole penetrating from the first surface 10B toward the second surface 10A.

[0042] Each magnetic detection element array 30 is composed of multiple magnetic detection elements E (shown in Figure 17) connected in a daisy-chain fashion and arranged in a matrix. An example of a magnetic detection element E is a TMR (Tunnel magnetoresistance effect) element. The magnetic detection element E is not limited to a TMR element, but may also be a GMR (Giant magnetoresistance effect) element, an AMR (Anisotropic magnetoresistance effect) element, a Hall element, or any other type of magnetic detection element. TMR elements are particularly suitable as magnetic detection elements E because they have a smaller junction area compared to other types of MR elements, allowing for miniaturization of the sensor chip 3, and they have a larger MR ratio, enabling a higher output from the sensor chip 3.

[0043] The magnetic detection element array 30 is located on the upper surface 2A side of the support substrate 2 and is formed in the first layer L1 on the upper surface 2A side of the support substrate 2. The wiring layer 4 is located on the upper surface 2A side of the support substrate 2 and is formed in the second layer L2, which is different from the first layer L1. The second layer L2 is distal to the support substrate 2 than the first layer L1.

[0044] The wiring layer 4 extends parallel to the upper surface 2A of the support substrate 2 and electrically connects the electrode 2E of the support substrate 2 to the electrode 3E provided on the upper surface 3A of the sensor chip 3 via a plurality of vias 40 extending in the direction perpendicular to the plane Z. The wiring layer 4 is arranged so as to partially overlap the sensor substrate 10 in the direction perpendicular to the plane Z.

[0045] The sealing resin 5 is positioned on the upper surface 2A side of the support substrate 2 and covers the sensor chip 3 and the wiring layer 4. The sealing resin 5 is composed of multiple resin layers 51, 52, 53 (shown in Figure 3) that extend parallel to the upper surface 2A of the support substrate 2. The wiring layer 4 is, for example, copper plating provided on the upper surfaces of the resin layers 51 and 52. The electrodes 6 are, for example, solder balls or copper pillars, and are electrically connected to the wiring layer 4 and exposed from the sealing resin 5.

[0046] Figure 3 is a perspective view illustrating the manufacturing process of the magnetic sensor device 1 shown in Figure 1. As shown in Figure 3(A), the sensor chip 3 is fixed to the upper surface 2A of the support substrate 2 with adhesive AD (shown in Figure 2). If the amount of adhesive AD applied is insufficient, it will easily peel off starting from the areas where the adhesive has not been applied, and if the amount of adhesive AD applied is excessive, the adhesive that has squeezed out from the sensor chip 3 will adhere to the electrodes 2E on the upper surface 2A of the support substrate 2. Therefore, it is preferable to apply the adhesive AD so that it slightly squeezes out from the lower surface of the sensor chip 3.

[0047] As shown in Figure 3(B), a resin layer (first resin layer) 51 is formed to cover the sensor chip 3 and the upper surface 2A of the support substrate 2, and through holes 40P for vias 40 (shown in Figure 2) are opened at the positions of electrodes 2E and 3E (shown in Figure 10). As shown in Figure 3(C), a seed layer is formed by sputtering or the like, and the vias 40 and the first wiring layer 41 are formed by plating. The process shown in Figure 3(C) may be a subtractive method or an additive method.

[0048] As shown in Figure 3(D), a resin layer (second resin layer) 52 is formed to cover the via 40, the first wiring layer 41, and the resin layer 51, and a through hole 40P for the via 40 is opened. As shown in Figure 3(E), the via 40 and the second wiring layer 42 are formed by the same process as in Figure 3(C). As shown in Figure 3(F), a resin layer (third resin layer) 53 is formed to cover the via 40, the second wiring layer 42, and the resin layer 52, and a through hole 6P for the electrode 6 is opened. As shown in Figure 3(G), the electrode 6 is formed by filling the through hole 6P with solder or the like. By following the procedure shown in Figures 3(A) to (G), the separately prepared support substrate 2 and sensor chip 3 can be electrically connected to obtain the magnetic sensor device 1 shown in Figure 1.

[0049] Figure 4 shows an example of a magnetic sensor device 1 configured as an angle sensor that generates a detection value corresponding to the angle of the object to be detected. In the illustrated example, the magnetic sensor device 1 is configured as an angle sensor that detects the angle of a magnet 300 that can rotate around the central axis O of a cylinder as its axis of rotation. In the illustrated example, the X, Y, and Z directions are orthogonal to each other, and the central axis O is parallel to the Z direction.

[0050] The magnetic sensor device 1 detects a first component of the magnetic field component MF generated by the magnet 300 that is applied to the magnetic sensor device 1, in a direction parallel to the X direction, and generates a first detection signal representing the intensity of the first component. It also detects a second component of the magnetic field generated by the magnet 300 that is parallel to the Y direction, and generates a second detection signal representing the intensity of the second component. A processor (not shown) calculates the angle θ that the magnetic field generated by the magnet 300 makes with respect to the reference direction DR by calculating the arctangent of the ratio of the first detection signal and the second detection signal.

[0051] Figure 5 shows an example of a magnetic sensor device 1 configured as a magnetic compass that generates detection values ​​corresponding to the angle of the Earth's magnetic field. As shown in Figure 5, the magnetic sensor device 1 is equipped with three sensor chips 3 (first to third sensor chips 3X, 3Y, and 3Z), and is configured so that the first to third sensor chips 3X, 3Y, and 3Z each detect the components of the external magnetic field in three mutually orthogonal directions.

[0052] Figure 6 shows an example of a magnetic sensor device 1 used as part of a current sensor 400 that generates a detection value corresponding to the current value to be detected. In the illustrated example, the current sensor 400 is configured to detect the value of the current Itg flowing through the busbar 410. A magnetic field MF is generated around the busbar 410 by the current Itg. The current sensor 400 is positioned near the busbar 410 at a location where the magnetic field MF is applied.

[0053] Figure 7 shows the circuit configuration of the current sensor 400 shown in Figure 6. In the illustrated example, the current sensor 400 is configured as a magnetic balance type current sensor. The current sensor 400 includes a coil 420 in addition to the magnetic sensor device 1. The coil 420 is for generating a second magnetic field MF2 that cancels out the first magnetic field MF1 of the magnetic field MF. The magnetic sensor device 1 detects the magnetic field of the residual difference between the first magnetic field MF1 and the second magnetic field MF2 and generates a magnetic field detection value S corresponding to the strength of the magnetic field.

[0054] The current sensor 400 further includes a feedback circuit 430, a current detector 440, and the like. The feedback circuit 430 supplies a feedback current to the coil 420 to generate a second magnetic field MF2 based on the detected magnetic field value S. The current detector 440 detects the value of the feedback current flowing through the coil 420. The current detector 440 is, for example, a resistor inserted in the current path of the feedback current. In this case, the potential difference across the resistor corresponds to the detected value of the feedback current. Since the detected value of the feedback current is proportional to the value of the current Itg in the busbar 410, the value of the current Itg can be detected from the detected value of the feedback current.

[0055] The magnetic sensor device 1 of this disclosure may be used as a magnetic compass mounted on electronic equipment such as information equipment to detect the Earth's magnetic field, or as part of the autofocus mechanism or optical image stabilization mechanism of a camera module, or as an angle sensor to detect the angle that the magnetic field generated from a magnet makes with respect to a reference direction, or as part of a current sensor to detect the value of the current flowing through a busbar.

[0056] Figure 8 is a perspective view showing an example of a magnetic sensor device 1 used as part of the autofocus mechanism and optical image stabilization mechanism of the camera module 200. Figure 9 is a cross-sectional view showing the internal structure of the camera module 200 shown in Figure 8. The autofocus mechanism and optical image stabilization mechanism of the camera module 200 include a drive device 230 that moves the lens 220, and the drive device 230 is controlled based on position information of the lens 220 detected by a plurality of magnetic sensor devices 1.

[0057] More specifically, the autofocus mechanism detects when the subject is in focus using an image sensor or autofocus sensor, and moves the lens in the Z direction relative to the image sensor. The optical image stabilization mechanism detects camera shake using a gyro sensor, and moves the lens in the U and / or V directions relative to the image sensor.

[0058] The camera module 200 shown in Figure 8 includes an image sensor 210 such as a CMOS, a lens 220 aligned with the image sensor 210, a first holding member 241 movable in the U and V directions relative to the image sensor 210, a second holding member 242 movable in the Z direction relative to the first holding member 241, a plurality of elastically deformable wires 244 supporting the first and second holding members 241 and 242, a drive device 230 for moving the first and second holding members 241 and 242, and a housing 250 for housing them.

[0059] The autofocus mechanism and optical image stabilization mechanism of the camera module 200 include a drive unit 230, multiple magnetic sensor devices 1, a processor that controls the drive unit 230, an autofocus sensor that detects when the subject is in focus, a gyro sensor that detects camera shake, and the like. The processor, autofocus sensor, gyro sensor, and the like (not shown) are located outside the housing.

[0060] The lens 220 is fixed inside a cylindrical second retaining member 242. The second retaining member 242, along with the lens 220, is housed in a box-shaped first retaining member 241. At least one second magnet 243 is fixed to the second retaining member 242 so that at least one magnetic sensor device 1 can detect the position information of the second retaining member 242.

[0061] The drive unit 230 includes a plurality of first coils 231, a plurality of second coils 232, a plurality of first magnets 233, etc. A plurality of first coils 231 are fixed to the housing 250. A plurality of second coils 232 are fixed to the second holding member 242. A plurality of first magnets 233 are fixed to the first holding member 241. Each of the plurality of first coils 231 faces the corresponding first magnet 233. Each of the plurality of second coils 232 faces the corresponding first magnet 233.

[0062] In the case of an autofocus mechanism, when current flows through any second coil 232 in response to a command from the processor, the interaction between the magnetic field generated by the first magnet 233 and the magnetic field generated by the second coil 232 causes the second retaining member 242, which is fixed to the second coil 232, to move in the Z direction. At least one magnetic sensor device 1 generates a detection signal based on the combined magnetic field obtained by combining the magnetic field generated by at least one second magnet 243 fixed to the second retaining member 242 and the magnetic field generated by the first magnet 233 fixed to the first retaining member 241, and transmits it to the processor. The processor detects the position information of the lens 220 in the Z direction from the detection signal and controls the drive device 230 so that it focuses on the subject.

[0063] In the case of an optical image stabilization mechanism, when current flows through any first coil 231 in response to a command from the processor, the interaction between the magnetic field generated by the first magnet 233 and the magnetic field generated by the first coil 231 causes the first holding member 241, which is fixed to the first magnet 233, to move in the U and / or V directions. Each of the multiple magnetic sensor devices 1 generates a detection signal based on the position of the corresponding first magnet 233 and transmits it to the processor. The processor detects the position information of the lens 220 in the U and V directions from the detection signal and controls the drive device 230 to correct camera shake.

[0064] Next, the magnetic sensor device 1 of this disclosure will be described in detail with reference to Figures 10A to 25. Figure 10A is a plan view of a simulation model in which a rectangular hole 11 with contour O11 is formed on the first surface 10B of the sensor substrate 10, viewed from the direction perpendicular to the surface Z, and shows the positions P and Q plotted on the upper surface 3A of the sensor chip 3.

[0065] As shown in Figure 10A, the position directly above the corner C1 of the 280 μm square hole 11 is defined as P=0 in the X-axis and Y-axis directions, and the points are plotted as P=1, 2, 3, ... 14 by moving 10 μm in the X-axis and Y-axis directions, respectively. For example, P=14 is located 140 μm away from P=0 in both the X-axis and Y-axis directions. Similarly, the position directly above the corner C1 is defined as Q=0, and the points are plotted as Q=1, 2, 3, ... 14 by moving 10 μm in the X-axis direction, respectively.

[0066] Figure 10B is a plan view of a simulation model of a square hole 11 with a contour O11 and rounded corners formed on the first surface 10B of the sensor substrate 10, viewed from the direction perpendicular to the surface Z, and shows the position P plotted on the upper surface 3A of the sensor chip 3. As shown in Figure 10B, the position directly above the corner C1 of the 340 μm square hole 11 with a diameter of 200 μm and rounded corners in both the X and Y directions is set to P=0, and the positions are plotted as P=1, 2, 3, ... 14 by moving 10 μm in both the X and Y directions.

[0067] Figure 10C is a plan view of a simulated model in which a circular hole 11 is formed on the first surface 10B of the sensor substrate 10, viewed from the direction perpendicular to the surface Z, and shows the position P plotted on the upper surface 3A of the sensor chip 3. As shown in Figure 10C, the position directly above the contour O11 of the circular hole 11 with a diameter of 400 μm is set to P=0, and the position is moved by 10 μm in the X-axis direction and the Y-axis direction, respectively, and plotted as P=1, 2, 3, ... 14.

[0068] Figure 10D is a plan view of the simulation model, as seen from the Z direction perpendicular to the plane, of the model shown in Figure 10A, which is further equipped with 100 μm square wiring layers 4 in the X-axis and Y-axis directions, respectively. The wiring layers 4 are positioned so that their centers are at position P=0. In the simulation results shown in Figure 15, which will be described later, similar to Figure 10D, the models shown in Figures 10B and 10C also have 100 μm square wiring layers 4 in the X-axis and Y-axis directions, respectively, with their centers at position P=0.

[0069] Figure 10E is a plan view of the simulation model, which has an inner surface 11C inclined with respect to the direction perpendicular to the surface Z, as seen from the direction perpendicular to the surface Z, and shows the position P plotted on the upper surface 3A of the sensor chip 3. As shown in Figure 10E, the simulation model has a hole 11 of 400 μm square in the X-axis direction and the Y-axis direction, with the deepest central depth D, as shown in Figure 11 later, being 15 μm, and there is no bottom surface 10D; instead, the inner surface 11C is formed inclined or stepped. In this simulation model, a wiring layer 4 shown in Figure 10D is added so as to overlap the hole 11, and the position directly below the center of the wiring layer 4 is set to P=0, and then shifted by 10 μm in the X-axis direction and the Y-axis direction, respectively, and plotted as P=1, 2, 3, ... 14.

[0070] Figure 11 is a cross-sectional view of the simulation model along the XY plane perpendicular to the Z direction perpendicular to the surface. The contour O11 of the hole 11 is the contour of the bottom surface 11D of the hole 11, and is defined by the boundary between the bottom surface 11D and the inner surface 11C. The boundary between the bottom surface 11D and the inner surface 11C may have a radius. In that case, if the bottom surface 11D is flat and the depth D from the first surface 10B to the bottom surface 11D is approximately constant, the boundary between the bottom surface 11D and the inner surface 11C is the position where the gradual decrease in depth D begins.

[0071] In the simulation results shown in Figures 12 to 16, which will be described later, the thickness T of the sensor substrate 10 from the first surface 10B to the second surface 10A is 15 μm, and the thickness of the functional film 20 is also 15 μm. In the simulation results shown in Figure 15, which will be described later, the distance from the top surface 3A of the sensor chip 3 to the bottom surface of the wiring layer 4 is 5 μm.

[0072] Figure 12 shows the simulated angular error for each position P shown in Figure 10A and depth D shown in Figure 11. The simulation results of the angular error when a predetermined stress value is applied to the magnetic sensor device 1 are plotted on the vertical axis, with the position P shown in Figure 10A being varied into 15 patterns from 0 to 14, and the depth D from the first surface 10B of the sensor substrate 10 to the bottom surface 11D of the hole 11 being varied into 4 patterns of 0 μm, 5 μm, 7.5 μm, and 15 μm.

[0073] When the depth D is less than 15 μm, the hole 11 is formed as a bottomed hole that is recessed from the first surface 10B to the second surface 10A of the sensor substrate 10. When the depth D is 15 μm, the hole 11 is formed as a through hole that penetrates from the first surface to the second surface. Even if the hole 11 is a through hole, the magnetic detection element E is fixed by the functional film 20 that surrounds the magnetic detection element E.

[0074] As shown in Figure 12, the angular error increases as P approaches 0. When the magnetic detection element E is located directly above corner C1, it is susceptible to thermal stress from the sensor substrate 10. In the in-plane direction perpendicular to the plane direction Z, it is preferable that each magnetic detection element E is positioned at a distance of 10 μm or more from any of the corners C1 to C4. Furthermore, the greater the depth D of the hole 11, the larger the angular error. Preferably, the depth D of the hole 11 is half or less of the thickness T = 30 μm of the sensor substrate 10.

[0075] Figure 13 shows the simulated angular error for each position Q shown in Figure 10A and depth D shown in Figure 11. The horizontal axis plots the simulation results of the angular error when a predetermined stress value is applied to the magnetic sensor device 1, with position Q shown in Figure 10A being varied in 14 patterns from 1 to 14, and the depth D of the hole 11 shown in Figure 11 being varied in 4 patterns: 0 μm, 5 μm, 7.5 μm, and 15 μm.

[0076] As shown in Figure 13, the angular error increases as Q approaches 0 (equivalent to the plot for P=0 shown in Figure 12). When the magnetic detection element E is located directly above the corner C1, it is susceptible to thermal stress from the sensor substrate 10. Whether P is spaced away from the contour O11 of the hole 11 or Q moves along the contour O11 of the hole 11, the tendency for the angular error to increase as it approaches the corner C1 is common.

[0077] Figure 14 shows the simulated angular error when a predetermined stress value is applied to the magnetic sensor device 1, with the depth D of the hole 11 fixed at 15 μm, and the position P shown in Figures 10A, 10B, and 10C varied to 15 patterns from 0 to 14.

[0078] As shown in Figure 14, the angular error tends to increase in the order of the model with a rectangular shape O11 of the hole 11, followed by the circular model and then the rectangular model. In all models, the angular error increases as P approaches 0. When the magnetic detection element E is located directly above the corner C1, it is susceptible to the influence of thermal stress from the sensor substrate 10.

[0079] Figure 15 shows the simulated angular error when a predetermined stress value is applied to the magnetic sensor device 1, with the depth D of the hole 11 fixed at 15 μm, the wiring layer 4 shown in Figure 10D added, and the position P shown in Figures 10A, 10B, and 10C varied to 15 patterns from 0 to 14.

[0080] Comparing Figures 14 and 15 with the simulation results, regardless of whether the contour O11 of the hole 11 is square, rounded square, or circular, the model with the wiring layer 4 tends to have smaller angular errors than the model without the wiring layer 4 at positions P=0~3, which are inside the contour O4 of the wiring layer 4. In other words, it can be expected that the sensor substrate 10 will be less affected by thermal stress. However, in the square model, the angular error is larger than the model without the wiring layer 4 at positions P=4~6 near the contour O4 of the wiring layer 4.

[0081] Figure 16 shows the simulated angular error when a predetermined stress value is applied to the magnetic sensor device 1, with P, shown in Figure 10E, varied to 15 patterns from 0 to 14. Comparing Figure 15 and Figure 16 with the simulation results, both the model in which the inner surface 11C is inclined with respect to the direction Z perpendicular to the surface and the model in which the inner surface 11C is formed in a stepped shape show a larger angular error than the model in which the inner surface 11C is not inclined. In other words, it tends to be susceptible to the influence of thermal stress from the sensor substrate 10.

[0082] Preferred examples of the present disclosure will be described with reference to Figures 17 to 25. As previously explained with reference to Figures 12 to 15, the angular error increases as you approach the corners C1 to C4. When the magnetic detection element E is located directly above the corners C1 to C4, it is susceptible to thermal stress from the sensor substrate 10. Figures 17 to 20 are plan views showing the first to fourth examples in which all magnetic detection elements are arranged so as not to overlap the contour of the hole. All magnetic detection elements E are arranged so as not to overlap the contour O11 of the hole 11. In the first to fourth examples, in plan view, each of the multiple magnetic detection elements E does not overlap any of the corners C1 to C4 of the contour O11 of the hole 11, so the magnetic detection elements E are less susceptible to thermal stress from the sensor substrate 10.

[0083] In the first example shown in Figure 17, in a plan view, some of the multiple magnetic detection elements E are arranged inside the contour O11 of the hole 11, and the remaining multiple magnetic detection elements E are arranged outside the contour O11 of the hole 11. In other words, in the first example shown in Figure 17, the magnetic detection elements are arranged across the inside and outside of the contour O11.

[0084] As shown in the second example in Figure 18, the hole 11 may be arranged across multiple bridge circuits. In the examples shown in Figures 17 to 24, the magnetic sensor device 1 includes first to fourth magnetic detection element arrays 31, 32, 33, and 34, and the first bridge circuit is formed by two parallel circuits. In the second example shown in Figure 18, the magnetic sensor device 1 further includes fifth to eighth magnetic detection element arrays 35, 36, 37, and 38, and the second bridge circuit is formed by two parallel circuits.

[0085] The first magnetic detection element array 31 and the second magnetic detection element array 32 are connected in series across output port A to form one parallel circuit of the first bridge circuit, and the third magnetic detection element array 33 and the fourth magnetic detection element array 34 are connected in series across output port B to form the other parallel circuit of the first bridge circuit. Similarly, the fifth magnetic detection element array 35 and the sixth magnetic detection element array 36 are connected in series across output port A to form one parallel circuit of the second bridge circuit, and the seventh magnetic detection element array 37 and the eighth magnetic detection element array 38 are connected in series across output port B to form the other parallel circuit of the second bridge circuit. Output ports A and B are connected to a galvanometer, etc. In the second example shown in Figure 18, similar to the first example, the magnetic detection elements are arranged to span both inside and outside the contour O11.

[0086] In the magnetic sensor device 1 of this disclosure, as shown in the third example in Figure 19, all of the multiple magnetic detection elements E may be arranged inside the contour O11 in a plan view, or as shown in the fourth example in Figure 20, all of the multiple magnetic detection elements E may be arranged outside the contour O11 in a plan view. The magnetic sensor device 1 of this disclosure has fewer constraints on the arrangement of the magnetic detection elements E and offers excellent design flexibility.

[0087] Figures 21 to 23 are plan views showing the fifth to seventh examples in which the first magnetic detection element E1 is positioned to overlap the contour O11 of the hole 11 except at corners C1 to C4, and the second magnetic detection element E2 is positioned not to overlap the contour O11 of the hole 11. The positions that overlap the contour O11 of the hole 11 except at corners C1 to C4 are slightly more susceptible to thermal stress than the positions that do not overlap the contour O11, but the influence of thermal stress is sufficiently smaller than that of the positions that overlap the corners C1 to C4. In the fifth to seventh examples, in plan view, each of the multiple magnetic detection elements E does not overlap any of the corners C1 to C4 of the contour O11 of the hole 11. Therefore, the magnetic detection elements E (first magnetic detection element E1 and second magnetic detection element E2) are less susceptible to thermal stress from the sensor substrate 10.

[0088] In the magnetic sensor device 1 of this disclosure, as shown in the fifth example in Figure 21, the second magnetic detection element E2 that does not overlap the contour O11 of the hole 11 may be arranged to straddle the inside and outside of the contour O11 in a plan view, as shown in the sixth example in Figure 22, as the entirety of the second magnetic detection element E2 may be arranged inside the contour O11 in a plan view, as shown in the seventh example in Figure 23, as the entirety of the second magnetic detection element E2 may be arranged outside the contour in a plan view. The magnetic sensor device 1 of this disclosure has fewer constraints on the arrangement of the magnetic detection element E and offers excellent design flexibility.

[0089] Figure 24 is a plan view showing an eighth example in which a wiring layer 4 is added to the first example shown in Figure 17, such that the magnetic detection elements E are positioned inside the contour O4 of the wiring layer 4. In the eighth example, as with the first example, in plan view, each of the multiple magnetic detection elements E does not overlap with any of the corners C1 to C4 of the contour O11 of the hole 11. Therefore, the magnetic detection elements E are less affected by thermal stress from the sensor substrate 10. As explained with reference to Figure 15, adding the wiring layer 4 reduces the angular error inside the contour O4 of the wiring layer 4. In the eighth example, it can be expected that the effect of thermal stress will be even smaller than in the first example.

[0090] Figure 25 is a cross-sectional view showing a ninth example in which the magnetic detection elements are arranged so as not to overlap the inclined inner surface. As explained with reference to Figure 16, when there is an inclined inner surface 11C with respect to the direction perpendicular to the surface Z, the position that overlaps the inner surface 11C in a plan view tends to be susceptible to thermal stress from the sensor substrate 10. In the ninth example, since each of the multiple magnetic detection elements E does not overlap the inclined inner surface 11C, the magnetic detection elements E are less susceptible to thermal stress from the sensor substrate 10.

[0091] As described above, with the magnetic sensor device 1 of this disclosure, since a hole 11 is formed in the sensor substrate 10, the amount of adhesive AD that protrudes from the first surface 10B of the sensor substrate 10 does not change easily even if the amount of adhesive AD applied changes, compared to the case where no hole 11 is formed. The adhesive layer becomes thicker and the adhesive strength is also improved. Therefore, the sensor substrate 10 can be bonded to the support substrate 2 and fixed in a suitable manner. In a plan view, the positions that overlap the corners C1 to C4 of the contour O11 of the hole 11 are susceptible to the effects of thermal stress, but since each of the multiple magnetic detection elements E does not overlap with any of the corners C1 to C4, they are less susceptible to the effects of thermal stress. A magnetic sensor device 1 with stable output characteristics of the magnetic detection element array can be provided.

[0092] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The elements, arrangement, materials, conditions, shapes, and sizes of the embodiments are not limited to those exemplified and can be modified as appropriate. Furthermore, it is possible to partially substitute or combine the configurations shown in different embodiments. [Explanation of symbols]

[0093] 1…Magnetic sensor device, 2…Support substrate, 2A…Top surface, 2B…Bottom surface, 2E…Electrode, 3…Sensor chip, 3A…Top surface, 3E…Electrode, 3X…First sensor chip, 3Y…Second sensor chip, 3Z…Third sensor chip, 4…Wiring layer, 5…Sealing resin, 6…Electrode, 6P…Through hole, 10…Sensor substrate, 10A…Second surface (top surface), 10B…First surface (bottom surface), 11…Hole (bottomed hole or through hole), 11C…Inner surface of hole (Inner wall surface), 11D...Bottom surface of hole, 20...Functional film, 30...Magnetic detection element array, 31~38...1st to 8th magnetic detection element arrays, 40...Via, 40P...Through hole, 41...1st wiring layer, 42...2nd wiring layer, 51~53...Resin layer, 200...Camera module, 210...Image sensor, 220...Lens, 230...Drive unit, 231...1st coil, 232...2nd coil, 233...1st magnet, 241... 1 Holding member, 242... Second holding member, 243... Second magnet, 244... Wire, 250... Housing, 300... Magnet, 400... Current sensor, 410... Busbar, 420... Coil, 430... Feedback circuit, 440... Current detector 440, A... Output port, AD... Adhesive, B... Output port, C1, C2, C3, C4... Corner, D... Hole depth, DR... Reference direction, E... Magnetic detection element, E1... First magnetic detection element Child, E2...Second magnetic detection element, Itg...Current, L1...First layer, L2...Second layer, MF...Magnetic field, MF1...First magnetic field, MF2...Second magnetic field, O...Central axis, O4...Contour of wiring layer, O11...Contour of hole, P,Q...Position, S...Magnetic field detection value, T...Thickness of sensor substrate, U,V...Direction of hand shake, W...Wiring, X...Left-right direction (an example of in-plane direction), Y...Front-back direction (another example of in-plane direction), Z...Direction perpendicular to the plane, θ...Angle.

Claims

1. Support substrate and The system comprises a sensor board fixed to the support board, The sensor substrate has a first surface facing the support substrate and a second surface located on the opposite side of the first surface, the second surface having a functional film containing a plurality of magnetic detection elements. The first surface has a hole formed therein, which is either a bottomed hole recessed from the first surface toward the second surface or a through hole penetrating from the first surface toward the second surface. The outline of the hole is circular and does not include corners. Magnetic sensor device.

2. The sensor substrate is fixed to the support substrate using an adhesive. The aforementioned hole is filled with the aforementioned adhesive. The magnetic sensor device according to claim 1.

3. Each of the plurality of magnetic detection elements is arranged so as not to overlap with the contour in the plan view. The magnetic sensor device according to claim 1.

4. The aforementioned hole is a bottomed hole that is recessed from the first surface toward the second surface. The depth of the bottomed hole is less than or equal to half the thickness of the sensor substrate in the direction perpendicular to the surface. The magnetic sensor device according to claim 1.

5. A magnetic sensor device as described in claim 1, Angle sensor.

6. A magnetic sensor device as described in claim 1, Magnetic compass.

7. A magnetic sensor device as described in claim 1, Current sensor.

8. The autofocus mechanism and / or optical image stabilization mechanism comprising the magnetic sensor device described in claim 1, Camera module.

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