Current sensor

Abstract

An electric current sensor (100) comprises an electric current line (8), a magnetic core (1), and a main substrate (5). A gap (2) is provided in the magnetic core (1). The main substrate (5) is disposed in the gap (2). The magnetic core (1) has a first surface (11) and a second surface (21). The second surface (21) faces the first surface (11). The gap (2) is formed between the first surface (11) and the second surface (21). The magnetic core (1) and the gap (2) surround the electric current line (8). A first element (3) is provided on the main substrate (5). The first element (3) detects magnetic flux generated by electric current flowing through the electric current line (8). When viewed in a direction from the first surface (11) to the second surface (21), the first element (3) overlaps each of the first and second surfaces (11) and (21). The main substrate (5) is composed of a translucent material.

Description

Technical Field

[0001] The present disclosure relates to a current sensor.

Background Art

[0002] As an inexpensive current sensor for measuring a large current flowing through a current line, there is a current sensor using a current transformer (CT) method. According to the current sensor using the CT method, a detection coil (secondary current line) is wound around a magnetic core. The magnetic core surrounds the current line (primary current line). Due to the current flowing through the current line, a magnetic flux change occurs in the magnetic core. As a result, an induced voltage is generated in the detection coil. By measuring the induced voltage, the current sensor measures the current value of the current flowing through the current line. However, when the detection coil is directly wound around the magnetic core, when a large current flows through the current line, the current sensor is directly susceptible to the influence of magnetic saturation in the magnetic core. For this reason, the measurement error of the current value in the current sensor becomes large. Therefore, a current sensor has been devised that provides a gap in a part of the magnetic core and measures an induced voltage caused by leakage magnetic flux in the gap using an element such as a coil pattern disposed in the gap. As an example of such a current sensor, Japanese Unexamined Patent Application Publication No. 2010-48755 (Patent Document 1) discloses a current sensor having a main substrate and a coil pattern.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described current sensor, alignment is performed between the surface of the magnetic core that forms the gap, specifically the surface of the magnetic core facing the coil pattern, and the coil pattern itself. However, it is difficult to align the surface of the magnetic core on the opposite side of the coil pattern relative to the main substrate with the coil pattern. As a result, misalignment may occur between the surface forming the gap and the coil pattern. If misalignment occurs, the detection sensitivity of the current sensor may decrease.

[0005] This disclosure has been made in view of the above, and its purpose is to provide a current sensor with high detection sensitivity. [Means for solving the problem]

[0006] The current sensor according to this disclosure comprises a current line, a magnetic core, and a main substrate. A gap is provided in the magnetic core. The main substrate is placed in the gap. The magnetic core has a first surface and a second surface. The second surface faces the first surface. The gap is formed between the first surface and the second surface. The magnetic core and the gap surround the current line. A first element is provided in the main substrate. The first element detects the magnetic flux generated by the current flowing through the current line. Viewed in the direction from the first surface to the second surface, the first element overlaps with the first surface and the second surface, respectively. The main substrate is made of a translucent material. [Effects of the Invention]

[0007] According to the current sensor disclosed herein, the main substrate is made of a light-transmitting material. Therefore, alignment can be performed between the magnetic core surface on the opposite side of the first element from the main substrate and the first element. This makes it possible to provide a current sensor with high detection sensitivity. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view showing the configuration of the current sensor according to Embodiment 1. [Figure 2]This is a schematic front view showing the configuration of the magnetic core and current lines according to Embodiment 1. [Figure 3] This is a schematic cross-sectional view illustrating the configuration of the current sensor according to Embodiment 1. [Figure 4] This is a first schematic plan view illustrating the configuration of the current sensor according to Embodiment 1. [Figure 5] This is a second schematic plan view illustrating the configuration of the current sensor according to Embodiment 1. [Figure 6] This is an enlarged schematic plan view illustrating the configuration of the substrate structure according to Embodiment 1. [Figure 7] This is an enlarged schematic cross-sectional view along the line VII-VII in Figure 6. [Figure 8] This is a schematic flowchart showing the manufacturing method of the current sensor according to Embodiment 1. [Figure 9] This is an enlarged cross-sectional schematic diagram illustrating the substrate structure fabrication process according to Embodiment 1. [Figure 10] This is a schematic cross-sectional view illustrating the assembly process according to Embodiment 1. [Figure 11] This is a schematic cross-sectional view illustrating the state in which current is flowing through the current line of the current sensor according to Embodiment 1. [Figure 12] This is a schematic cross-sectional view illustrating the configuration of a current sensor according to a modified example of Embodiment 1. [Figure 13] This is an enlarged schematic plan view illustrating the configuration of the current sensor according to Embodiment 2. [Figure 14] This is a schematic perspective view showing the configuration of the current sensor according to Embodiment 3. [Figure 15] This is a schematic plan view illustrating the configuration of the current sensor according to Embodiment 3. [Figure 16] This is a schematic cross-sectional view along the line XVI-XVI in Figure 15. [Figure 17] This is a schematic cross-sectional view illustrating the configuration of the current sensor according to Embodiment 4. [Figure 18] This is a schematic cross-sectional view illustrating the configuration of the current sensor according to Embodiment 5. [Figure 19] It is an enlarged plan schematic view schematically showing the configuration of the substrate structure according to Embodiment 5. [Figure 20] It is an enlarged plan schematic view schematically showing the positional relationship between the first element and the second element in the substrate structure according to Embodiment 5. [Figure 21] It is an enlarged cross-sectional schematic view taken along line XXI-XXI of FIG. 19. [Figure 22] It is an enlarged cross-sectional schematic view taken along line XXII-XXII of FIG. 19. [Figure 23] It is an enlarged cross-sectional schematic view schematically showing the configuration of the current sensor according to Embodiment 6. [[ID=**16]] [Figure 24] It is an enlarged cross-sectional schematic view schematically showing a state where current is flowing through the current line in the current sensor according to Embodiment 4. [Figure 25] It is an enlarged cross-sectional schematic view schematically showing a state where current is flowing through the current line in the current sensor according to Embodiment 6. [Figure 26] It is an enlarged cross-sectional schematic view schematically showing the configuration of the current sensor according to the first modification of Embodiment 6. [Figure 27] It is an enlarged cross-sectional schematic view schematically showing the configuration of the current sensor according to the second modification of Embodiment 6. [Figure 28] It is an enlarged cross-sectional schematic view schematically showing the configuration of the current sensor according to the third modification of Embodiment 6. [Figure 29] It is an enlarged cross-sectional schematic view schematically showing the configuration of the current sensor according to the fourth modification of Embodiment 6. [Figure 30] It is a perspective schematic view schematically showing the configuration of the current sensor according to Embodiment 7. [Figure 31] It is a front schematic view schematically showing the configuration of each of the magnetic core and the current line according to Embodiment 7. [Figure 32] It is a cross-sectional schematic view schematically showing the configuration of the current sensor according to Embodiment 7. [Figure 33] It is a first plan schematic view schematically showing the configuration of the current sensor according to Embodiment 7. [Figure 34]This is a second schematic plan view illustrating the configuration of the current sensor according to Embodiment 7. [Figure 35] This is an enlarged schematic plan view illustrating the configuration of the substrate structure according to Embodiment 7. [Figure 36] This is an enlarged schematic cross-sectional view along the line XXXVI-XXXVI in Figure 35. [Figure 37] This is an enlarged schematic cross-sectional view along the line XXXVII-XXXVII in Figure 35. [Figure 38] This is an enlarged schematic plan view illustrating the state of the substrate structure when current is flowing through the current line of the current sensor according to Embodiment 7. [Figure 39] This is an enlarged schematic plan view illustrating the configuration of the substrate structure according to Embodiment 8. [Figure 40] This is a schematic plan view illustrating the positional relationship between the first coil pattern portion and the second coil pattern portion in the substrate structure according to Embodiment 8. [Figure 41] This is an enlarged schematic cross-sectional view along the line XXXXI-XXXXI in Figure 39. [Figure 42] This is an enlarged schematic cross-sectional view along the line XXXXII-XXXXII in Figure 39. [Figure 43] This is an enlarged cross-sectional schematic diagram illustrating the configuration of the current sensor according to Embodiment 8. [Figure 44] This is an enlarged cross-sectional schematic diagram illustrating the configuration of the current sensor according to Embodiment 9. [Figure 45] This is a schematic plan view illustrating the configuration of the second element according to Embodiment 9. [Modes for carrying out the invention]

[0009] Embodiments of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to the following description, and the shape of the magnetic core, the shape of the first element and connecting wiring, the arrangement of the first element, connecting wiring and measurement circuit on the main board, etc. are examples and are not limited thereto. In addition, the size (aspect ratio), number (number of turns of windings), positional relationship (up, down, left, right) and range of each component shown in the drawings may not accurately represent the actual size, number, positional relationship and range for the sake of clarity. Therefore, the present disclosure is not necessarily limited to the size, number, positional relationship and range of each component shown in the drawings.

[0010] In all drawings of this disclosure, components of the same part or part having substantially the same function are, in principle, denoted by the same reference numeral. Furthermore, the drawings of this disclosure show the current detection unit, which is the main component of the current sensor, and in all drawings of this disclosure, components and package housings that are implemented according to the actual application are omitted.

[0011] Embodiment 1. (Current sensor configuration) The configuration of the current sensor 100 according to Embodiment 1 will be described with reference to Figures 1 to 5.

[0012] As shown in Figure 1, the current sensor 100 mainly consists of a magnetic core 1, a substrate structure 200, a current line 8, and a substrate fixing part 80. The current line 8 functions as a current channel. Hereinafter, the current flowing through the current line 8 will also be referred to as the current under test. The magnetic core 1 amplifies the magnetic flux generated by the current under test. The substrate structure 200 measures the current value or the energy of the current under test based on the magnetic flux generated by the current under test. The substrate fixing part 80 fixes the substrate structure 200.

[0013] The magnetic core 1 is composed of, for example, a first core portion 10 and a second core portion 20. The first core portion 10 is located on the second core portion 20. The first core portion 10 and the second core portion 20 are sandwiched between the substrate fixing portion 80 and the substrate structure 200.

[0014] The current line 8 is located between the first core section 10 and the second core section 20. The current line 8 is spaced apart from both the first core section 10 and the second core section 20. The direction in which the current line 8 extends is the front-to-back direction Y.

[0015] The substrate structure 200 includes a main substrate 5, a first insulating film 41, a third insulating film 43, a first element 3, a measurement circuit 50, and connection wiring 7. The first insulating film 41 is provided on the main substrate 5. The third insulating film 43 is provided on the first insulating film 41. The first element 3, connection wiring 7, and measurement circuit 50 are provided inside the substrate structure 200.

[0016] The first element 3 detects the magnetic flux generated by the current flowing through the current line 8. Specifically, the time change in magnetic flux density in the space surrounded by the first element 3 induces an electromotive force, which is generated in the first element 3 as a voltage signal. The connecting wiring 7 is connected to the first element 3. The measurement circuit 50 is connected to the connecting wiring 7. The measurement circuit 50 is connected to the first element 3 via the connecting wiring 7. The measurement circuit 50 processes the signal sent from the first element 3. Specifically, a voltage signal is sent from the first element 3 to the measurement circuit 50 via the connecting wiring 7. Based on the voltage signal, the measurement circuit 50 measures the current value or the energy of the current being measured.

[0017] The connecting wiring 7 has a first wiring section 71 and a second wiring section 72. The second wiring section 72 is spaced apart from the first wiring section 71. Each of the first wiring section 71 and the second wiring section 72 electrically connects the first element 3 and the measurement circuit 50.

[0018] As shown in Figure 2, a gap 2 is provided in the magnetic core 1. The gap 2 is formed between the first core portion 10 and the second core portion 20. The magnetic core 1 and the gap 2 surround the current line 8. From another perspective, the annular region formed by the magnetic core 1 and the gap 2 surrounds the current line 8. The direction parallel to the direction from the first core portion 10 toward the second core portion 20 is defined as the vertical direction Z. The vertical direction Z is perpendicular to the front-rear direction Y. The direction from the first core portion 10 toward the second core portion 20 is defined as the first direction 101. The direction from the second core portion 20 toward the first core portion 10 is defined as the second direction 102.

[0019] The first core portion 10 is composed of a first core member 12, a first protrusion 13, and a second protrusion 14. The shape of the first core member 12 is, for example, a rectangular parallelepiped. The direction in which the first core member 12 extends is the left-right direction X. The left-right direction X is perpendicular to the up-down direction Z and the front-back direction Y.

[0020] The first protrusion 13 is connected to the first core member 12. The first protrusion 13 extends from the first core member 12 in the first direction 101. The second protrusion 14 is connected to the first core member 12. The second protrusion 14 is spaced apart from the first protrusion 13. The second protrusion 14 extends from the first core member 12 in the first direction 101.

[0021] The second core portion 20 includes a second core member 22, a third protrusion 23, and a fourth protrusion 24. The shape of the second core member 22 is, for example, a rectangular parallelepiped. The direction in which the second core member 22 extends may be substantially parallel to the direction in which the first core member 12 extends.

[0022] The third protrusion 23 is connected to the second core member 22. The third protrusion 23 extends from the second core member 22 in the second direction 102. The third protrusion 23 faces the first protrusion 13. The third protrusion 23 is spaced apart from the first protrusion 13. The fourth protrusion 24 is connected to the second core member 22. The fourth protrusion 24 is spaced apart from the third protrusion 23. The fourth protrusion 24 extends from the second core member 22 in the second direction 102. The fourth protrusion 24 is in contact with the second protrusion 14.

[0023] The first core portion 10 has a first surface 11, a first outer peripheral surface 91, a first bonding surface 15, and a second outer peripheral surface 92. Each of the first surface 11 and the first outer peripheral surface 91 is formed by a first protrusion 13. The first surface 11 faces the second core portion 20. The first surface 11 extends, for example, along a direction perpendicular to the vertical direction Z. The first outer peripheral surface 91 is connected to the first surface 11. The first outer peripheral surface 91 extends, for example, along the vertical direction Z.

[0024] Each of the first adhesive surface 15 and the second outer peripheral surface 92 is formed by the second protrusion 14. At the first adhesive surface 15, the first core portion 10 and the second core portion 20 are in contact. The first adhesive surface 15 extends, for example, along a direction perpendicular to the vertical direction Z. In the vertical direction Z, the first adhesive surface 15 is on the first direction 101 side with respect to the first surface 11. The second outer peripheral surface 92 is connected to the first adhesive surface 15. The second outer peripheral surface 92 extends, for example, along the vertical direction Z.

[0025] The second core portion 20 has a second surface 21, a third outer peripheral surface 93, a second bonding surface 25, and a fourth outer peripheral surface 94. Each of the second surface 21 and the third outer peripheral surface 93 is formed by a third protrusion 23. The second surface 21 faces the first surface 11. The direction from the first surface 11 toward the second surface 21 is the first direction 101. The direction from the second surface 21 toward the first surface 11 is the second direction 102. The second surface 21 extends, for example, along a direction perpendicular to the vertical direction Z. A gap 2 is formed between the first surface 11 and the second surface 21. The third outer peripheral surface 93 is connected to the second surface 21. The third outer peripheral surface 93 extends, for example, along the vertical direction Z.

[0026] Each of the second bonding surface 25 and the fourth outer peripheral surface 94 is formed by the fourth protrusion 24. The first core portion 10 and the second core portion 20 are in contact at the second bonding surface 25. The second bonding surface 25 extends, for example, in a direction perpendicular to the vertical direction Z. In the vertical direction Z, the second bonding surface 25 is on the second direction 102 side with respect to the second surface 21. The fourth outer peripheral surface 94 is connected to the second bonding surface 25. The fourth outer peripheral surface 94 extends, for example, along the vertical direction Z.

[0027] Between the first bonding surface 15 and the second bonding surface 25, the first core portion 10 and the second core portion 20 may be bonded together by an adhesive (not shown). Specifically, the first core portion 10 and the second core portion 20 may be bonded together by the adhesive seeping into the minute gap between the first bonding surface 15 and the second bonding surface 25 while the two bonding surfaces 15 and 25 are in contact with each other. In other words, an adhesive may be provided between the first bonding surface 15 and the second bonding surface 25. The adhesive is, for example, a resin-based adhesive.

[0028] Each of the first core portion 10 and the second core portion 20 is made of a soft magnetic material such as an iron oxide (Fe2O3)-based material. Specifically, each of the first core portion 10 and the second core portion 20 is made of, for example, spinel-type manganese zinc (MnZn) ferrite. It is preferable that each of the first core portion 10 and the second core portion 20 is made of the same material. The relative permeability (μr) of the magnetic core 1 is, for example, 10 or more and 5000 or less. The relative permeability of the magnetic core 1 is preferably 100 or more. The saturation magnetic flux density (Bs) of the magnetic core 1 is, for example, 0.4T or more and 0.6T or less.

[0029] Figure 3 is a schematic cross-sectional view showing a cross-section parallel to the vertical Z direction and the horizontal X direction, respectively, and intersecting the first element 3. As shown in Figure 3, the substrate fixing portion 80 has a first substrate fixing member 81 and a second substrate fixing member 82. The first substrate fixing member 81 is located between the first surface 11 and the second surface 21. In other words, the first substrate fixing member 81 is positioned in the gap 2 (see Figure 2). The first substrate fixing member 81 may be in contact with the first surface 11. In the direction perpendicular to the vertical Z direction, the first substrate fixing member 81 is along the outer edge of the first surface 11. In other words, in the direction perpendicular to the vertical Z direction, the first substrate fixing member 81 is along the first outer peripheral surface 91. In the direction perpendicular to the vertical Z direction, the first substrate fixing member 81 may be inside the outer edge of the first surface 11. In other words, in a direction perpendicular to the vertical direction Z, the first substrate fixing member 81 may be located inside the first outer peripheral surface 91.

[0030] The second substrate fixing member 82 is located between the first substrate fixing member 81 and the second surface 21. In other words, the second substrate fixing member 82 is positioned in the gap 2 (see Figure 2). The second substrate fixing member 82 may be in contact with the second surface 21. The second substrate fixing member 82 faces the first substrate fixing member 81. In a direction perpendicular to the vertical direction Z, the second substrate fixing member 82 is along the outer edge of the second surface 21. In other words, in a direction perpendicular to the vertical direction Z, the second substrate fixing member 82 is along the third outer surface 93. In a direction perpendicular to the vertical direction Z, the second substrate fixing member 82 may be inside the outer edge of the second surface 21. In other words, in a direction perpendicular to the vertical direction Z, the second substrate fixing member 82 may be inside the third outer surface 93.

[0031] Each of the first substrate fixing member 81 and the second substrate fixing member 82 is made of a non-magnetic material. Each of the first substrate fixing member 81 and the second substrate fixing member 82 may be translucent. Specifically, each of the first substrate fixing member 81 and the second substrate fixing member 82 may be made of a translucent material such as glass or plastic. Each of the first substrate fixing member 81 and the second substrate fixing member 82 may be transparent.

[0032] As shown in Figure 3, in the vertical direction Z, the substrate structure 200 is located between the first substrate fixing member 81 and the second substrate fixing member 82. In other words, the substrate structure 200 is located in the gap 2 (see Figure 2). From another perspective, the main substrate 5 is located in the gap 2. The main substrate 5 is in contact with the second substrate fixing member 82. The main substrate 5 has a first main surface 51 and a second main surface 52. The first main surface 51 is the front surface of the main substrate 5. The second main surface 52 is on the opposite side of the first main surface 51. The second main surface 52 is the back surface of the main substrate 5. On the second main surface 52, the main substrate 5 is in contact with the second substrate fixing member 82. The main substrate 5 extends in a direction perpendicular to the vertical direction Z.

[0033] The main substrate 5 is made of a light-transmitting material. The main substrate 5 is made of, for example, glass. Specifically, the main substrate 5 is made of glass that does not contain alkali metal elements. More specifically, the main substrate 5 is made of, for example, amorphous alkali-free glass or borosilicate glass. The main substrate 5 may also be transparent.

[0034] A first element 3 is provided on the main substrate 5. Specifically, the first element 3 is provided on the first main surface 51 of the main substrate 5. The first element 3 is in contact with the first main surface 51. The first element 3 is located between the first substrate fixing member 81 and the second substrate fixing member 82. The first element 3 is located between the first surface 11 and the second surface 21. The first element 3 is located in the gap 2 (see Figure 2).

[0035] A measurement circuit 50 is provided on the main board 5. Specifically, the measurement circuit 50 is provided on the first main surface 51 of the main board 5. The measurement circuit 50 is in contact with the first main surface 51. The first wiring section 71 is in contact with the first element 3. In the vertical direction Z, the first wiring section 71 is located between the first element 3 and the first board fixing member 81.

[0036] The first insulating film 41 is in contact with the first main surface 51, the first element 3, the measurement circuit 50, and the first wiring section 71. The first element 3 is located between the main substrate 5 and the first insulating film 41. The measurement circuit 50 is located between the main substrate 5 and the first insulating film 41. In the vertical direction Z, the first insulating film 41 is located between the main substrate 5 and the first substrate fixing member 81. The first insulating film 41 is made of a light-transmitting material. The first insulating film 41 may be transparent.

[0037] The third insulating film 43 is located on the opposite side of the main substrate 5 from the first insulating film 41. From another perspective, the first insulating film 41 is located between the main substrate 5 and the third insulating film 43. The third insulating film 43 is in contact with each of the first insulating film 41, the first wiring section 71, and the first substrate fixing member 81. In the vertical direction Z, the third insulating film 43 is located between the first insulating film 41 and the first substrate fixing member 81. The third insulating film 43 is made of a translucent material. The third insulating film 43 may be transparent. The third insulating film 43 is made of the same material as, for example, the first insulating film 41.

[0038] Figure 4 is a first schematic plan view showing the configuration of the current sensor 100 as seen in the first direction 101. For the sake of explanation, the first insulating film 41, the third insulating film 43, and the substrate fixing portion 80 are not shown in Figure 4. Figure 5 is a second schematic plan view showing the configuration of the current sensor 100 as seen in the first direction 101. For the sake of explanation, the first core portion 10, the substrate fixing portion 80, the first insulating film 41, and the third insulating film 43 are not shown in Figure 5.

[0039] As shown in Figures 4 and 5, the first element 3 is, for example, a coil pattern. Viewed in the first direction 101, the first element 3 is arranged in a spiral shape. Specifically, viewed in the first direction 101, the shape of the first element 3 is a spiral shape formed on the same plane. In each of Figures 4 and 5, the shaded area represents the first element 3. Viewed in the first direction 101, the first element 3 overlaps the first surface 11 of the first core portion 10 and the second surface 21 of the second core portion 20. Viewed in the first direction 101, it is preferable that the first element 3 is inside the outer edges of the first surface 11 and the second surface 21. From another point of view, it is preferable that the first element 3 is inside the first outer surface 91 and the third outer surface 93. When viewed in the first direction 101, it is preferable that the center of the first element 3 substantially coincides with the centers of the first surface 11 and the second surface 21, respectively.

[0040] As shown in Figures 4 and 5, when viewed in the first direction 101, the measurement circuit 50 is outside the first surface 11 and the second surface 21, respectively. From another perspective, when viewed in the first direction 101, the measurement circuit 50 is outside the gap 2 (see Figure 2). When viewed in the first direction 101, the measurement circuit 50 is outside the first outer surface 91 and the third outer surface 93, respectively.

[0041] As shown in Figures 4 and 5, the main substrate 5 has a detection region 85 and an outer peripheral region 86. The detection region 85 is the region of the main substrate 5 located inside the outer edge of the second surface 21 when viewed in the first direction 101. The outer peripheral region 86 is connected to the detection region 85. The outer peripheral region 86 is the region of the main substrate 5 located outside the second surface 21 when viewed in the first direction 101. When viewed in the first direction 101, the first element 3 is located within the detection region 85. When viewed in the first direction 101, the measurement circuit 50 is located within the outer peripheral region 86.

[0042] In the left-right direction X, the end of the main substrate 5 may be located on the second outer surface 92 side of the first outer surface 91. In the left-right direction X, the end of the main substrate 5 may be located on the fourth outer surface 94 side of the third outer surface 93.

[0043] (Configuration of the substrate structure) Next, the configuration of the substrate structure 200 according to Embodiment 1 will be described with reference to Figures 6 and 7. For the sake of clarity, the first insulating film 41 and the third insulating film 43 are not shown in Figure 6.

[0044] As shown in Figure 6, the first element 3 has a first coil pattern portion 17, a first outer peripheral end portion 19, and a first inner peripheral end portion 18. Viewed in the first direction 101, the first coil pattern portion 17 is arranged in a spiral shape. Specifically, viewed in the first direction 101, the shape of the first coil pattern portion 17 is a spiral shape formed on the same plane. The first outer peripheral end portion 19 is connected to the first coil pattern portion 17. The first inner peripheral end portion 18 is connected to the first coil pattern portion 17. The first inner peripheral end portion 18 is surrounded by the first coil pattern portion 17.

[0045] The first element 3 is composed of, for example, copper (Cu), aluminum (Al), an alloy mainly composed of Cu, or an alloy mainly composed of Al. In this specification, "main component" refers to the element with the largest weight among the elements contained in the alloy. The first element 3 is preferably composed of a paramagnetic or nonmagnetic material so as not to absorb magnetic flux. The first element 3 is preferably composed of a conductive material with low electrical resistance. The resistivity of the first element 3 is, for example, 5 μΩ·cm or less.

[0046] As shown in Figure 6, when viewed in the first direction 101, a portion of the first wiring section 71 overlaps with the first element 3. The first wiring section 71 is connected to the first inner circumference end 18 of the first element 3. When viewed in the first direction 101, the first wiring section 71 intersects with the first element 3. Specifically, the first wiring section 71 extends above the first element 3 from the first inner circumference end 18 toward the outer peripheral region 86 of the main substrate 5.

[0047] The first wiring section 71 is made of a material that is both conductive and translucent. Specifically, the first wiring section 71 is made of, for example, polycrystalline indium tin oxide (ITO). In other words, the first wiring section 71 is made of, for example, indium oxide (In2O3) and tin oxide (SnO2). In the first wiring section 71, the ratio of the weight of In2O3 to the total weight of the first wiring section 71 is, for example, 90%. In the first wiring section 71, the ratio of the weight of SnO2 to the total weight of the first wiring section 71 is, for example, 10%. The resistivity of the first wiring section 71 is, for example, 200 μΩ·cm. The translucency of the first wiring section 71 to visible light is, for example, 80% or more.

[0048] The second wiring section 72 is connected to the first outer peripheral end 19 of the first element 3. The second wiring section 72 is made of the same material as the first element 3, for example.

[0049] Figure 7 is an enlarged schematic cross-sectional view showing a cross-section parallel to the vertical Z direction and the left-right X direction and intersecting with the first element 3. As shown in Figure 7, the thickness of the main substrate 5 in the vertical Z direction is defined as thickness H. Thickness H is, for example, 0.6 mm. Thickness H may be, for example, 0.1 mm or more, 0.3 mm or more, or 0.4 mm or more. The upper limit of thickness H is set appropriately based on wafer process constraints or dimensional constraints of the current sensor 100. Specifically, the upper limit of thickness H is, for example, 2 mm or less. The thickness of the first element 3 in the vertical Z direction is, for example, 200 nm.

[0050] The first wiring section 71 includes a first connecting member 112 and a first wiring member 111. The first connecting member 112 is in contact with the first insulating film 41 and the first inner circumferential end portion 18 of the first element 3. The thickness of the first connecting member 112 in the vertical direction Z is, for example, 200 nm. The first wiring member 111 is connected to the first connecting member 112. The first connecting member 112 is located between the first wiring member 111 and the first inner circumferential end portion 18. The thickness of the first wiring member 111 in the vertical direction Z is, for example, 100 nm. The second wiring section 72 is provided on the first main surface 51 of the main substrate 5.

[0051] The first insulating film 41 protects the first element 3. The first insulating film 41 is composed of, for example, silicon oxide (SiO2) or silicon nitride (Si3N4). In terms of protecting the first element 3, it is preferable that the first insulating film 41 be composed of Si3N4, which has high density and coating performance. The first insulating film 41 may have a laminated structure of an SiO2 film and a Si3N4 film. The thickness of the first insulating film 41 in the vertical direction Z is, for example, 400 nm.

[0052] As shown in Figure 7, the first insulating film 41 has a first inner surface 141. On the first inner surface 141, the first insulating film 41 is in contact with the first connecting member 112. The first inner surface 141 surrounds the first connecting member 112. In the space enclosed by the first inner surface 141, the first inner end portion 18 of the first element 3 is exposed from the first insulating film 41. In other words, the first inner surface 141 forms a contact hole.

[0053] The third insulating film 43 protects the first wiring portion 71. The third insulating film 43 is made of the same material as, for example, the first insulating film 41. The thickness of the third insulating film 43 in the vertical direction Z is, for example, 400 nm.

[0054] (Manufacturing method for current sensors) Next, the manufacturing method of the current sensor 100 will be described with reference to Figures 8 to 10.

[0055] As shown in Figure 8, the method for manufacturing the current sensor 100 according to Embodiment 1 mainly comprises a substrate structure manufacturing step (S10) and an assembly step (S20).

[0056] First, the substrate structure fabrication process (S10) is carried out. Figure 9 is a schematic cross-sectional view showing the state in which the first element 3 and the first insulating film 41 are formed on the main substrate 5. The schematic cross-sectional view shown in Figure 9 corresponds to the schematic cross-sectional view shown in Figure 7. The main substrate 5 is cleaned. The first conductive film is formed on the first main surface 51 of the main substrate 5 using the sputtering method. The first conductive film is composed of, for example, Cu. In the sputtering method, for example, argon (Ar) gas is used. The thickness of the first conductive film in the vertical direction Z is, for example, 200 nm. The resistivity of the first conductive film is, for example, 2.2 μΩ·cm.

[0057] A photoresist pattern is formed on the first conductive film using photogravure technology. The photoresist pattern functions as a mask when etching the first conductive film. For example, the first conductive film is etched using ion beam etching (IBE). The photoresist pattern is removed. As described above, the first conductive film is etched, and the first element 3 and the second wiring section 72 are formed on the first main surface 51 of the main substrate 5.

[0058] A first insulating film 41 is formed on the first element 3, the second wiring section 72, and the first main surface 51 of the main substrate 5 using the Chemical Vapor Deposition (CVD) method. Next, the first insulating film 41 is etched. Reactive ion etching (RIE) is used for etching the first insulating film 41. As the etching gas in the RIE method, a gas containing, for example, fluorine (F), sulfur hexafluoride (SF6), or carbon tetrafluoride (CF4) is used. This forms the first inner circumferential surface 141. As shown in Figure 9, the first inner circumferential surface 141 forms a contact hole 99. The first inner circumferential end 18 of the first element 3 is exposed in the contact hole 99.

[0059] A second conductive film is formed on the first inner circumferential end portion 18 and the first insulating film 41 of the first element 3 using a sputtering method. In the sputtering method for forming the second conductive film, a gas containing, for example, Ar and hydrogen atoms (H) is used. Specifically, a gas mixed with hydrogen (H2) gas or water vapor (H2O) and Ar is used in the sputtering method. The second conductive film is composed of, for example, amorphous ITO. In other words, the second conductive film is composed of amorphous ITO.

[0060] Next, the second conductive film is etched. For etching the second conductive film, for example, a wet etching method is used. Oxalic acid solution is used as the chemical in the wet etching method. Oxalic acid solution is weakly acidic. Therefore, oxalic acid solution does not etch Cu and alloys mainly composed of Cu. As a result, even if pinholes or the like are formed in the first insulating film 41, etching of the first element 3 can be suppressed. As a result, the occurrence of defects in the current sensor 100 can be suppressed.

[0061] The main substrate 5, the first element 3, the first insulating film 41, and the second conductive film are heat-treated. The temperature of the second conductive film during heat treatment is, for example, between 150°C and 200°C. The atmosphere during heat treatment is, for example, filled with air, vacuum, Ar gas, or nitrogen (N2) gas. Through heat treatment, the amorphous ITO constituting the second conductive film becomes polycrystalline. This forms the first wiring portion 71.

[0062] A third insulating film 43 is formed on the first insulating film 41 and the first wiring portion 71, respectively, using the CVD method. Since the first insulating film 41, the third insulating film 43, and the first wiring portion 71 are each made of a light-transmitting material, the shape of the first element 3 can be clearly seen through the first insulating film 41, the third insulating film 43, and the first wiring portion 71.

[0063] As described above, the substrate structure 200 shown in Figures 6 and 7 is manufactured. The substrate structure manufacturing step (S10) may also include a step for manufacturing the measurement circuit 50 in addition to the steps described above. If the main substrate 5 is made of glass that does not contain alkali metal elements, contamination of the semiconductor material by alkali ions can be suppressed. Therefore, the measurement circuit 50 containing the semiconductor material can be formed simultaneously with the formation of the first element 3.

[0064] Next, the assembly process (S20) is carried out. Figure 10 is a schematic cross-sectional view showing the state in which the second substrate fixing member 82 and the substrate structure 200 are arranged on the first core portion 10 in the assembly process according to Embodiment 1. The schematic cross-sectional view shown in Figure 10 corresponds to the schematic cross-sectional view shown in Figure 3.

[0065] As shown in Figure 10, the second substrate fixing member 82 is placed on the second surface 21 of the second core portion 20. The substrate structure 200 is placed on the second substrate fixing member 82. Specifically, the substrate structure 200 is placed such that, when viewed in the first direction 101, the center of the first element 3 coincides with the center of the second surface 21.

[0066] The first substrate fixing member 81 is placed on the substrate structure 200. The first core portion 10 is placed on the second core portion 20 and the first substrate fixing member 81. Adhesive is applied to at least one of the first adhesive surface 15 and the second adhesive surface 25. The first adhesive surface 15 of the first core portion 10 is in contact with the second adhesive surface 25 of the second core portion 20. The first surface 11 of the first core portion 10 is in contact with the first substrate fixing member 81. The first core portion 10 and the second core portion 20 are bonded together by the adhesive. Depending on the application, a package housing (not shown) or the like is attached. Current wires 8 are placed between the first core portion 10 and the second core portion 20. In this manner, the current sensor 100 shown in Figures 1 to 5 is manufactured.

[0067] Next, the effects and benefits of the current sensor 100 according to Embodiment 1 will be described. Figure 11 is a schematic cross-sectional diagram illustrating the magnetic flux generated when current flows through the current line 8. The schematic cross-sectional diagram shown in Figure 11 corresponds to the schematic cross-sectional diagram shown in Figure 3. As shown in Figure 11, a magnetic flux signal 108 is generated in the magnetic core 1 when the current to be measured flows through the current line 8. In this specification, the first arrow 108 schematically illustrates the magnetic flux signal 108. The direction of the magnetic flux signal 108 is clockwise when viewed in the direction of the current to be measured. The magnetic flux density of the magnetic flux signal 108 is proportional to the current value of the current to be measured.

[0068] In gap 2, the magnetic flux signal 108 leaks out of the magnetic core 1. This generates leakage flux 109. In this specification, the second arrow 109 schematically visualizes the flow of leakage flux 109. The direction of leakage flux 109 is, for example, along the vertical direction Z. The first element 3 surrounds the leakage flux 109. In other words, the leakage flux 109 penetrates the space enclosed by the first element 3. In other words, the leakage flux 109 is linked with the first element 3.

[0069] A voltage signal is generated in the first element 3. Specifically, an induced electromotive force is generated in the first element 3 due to the time change in the magnetic flux density of the leakage flux 109. In other words, an induced electromotive force is generated in the first element 3 due to the time change in the magnetic flux density in the space surrounded by the first element 3. The magnitude of the induced electromotive force generated in the first element 3 is proportional to the magnitude of the time change in the magnetic flux density of the leakage flux 109. The measurement circuit 50 measures the current value or the energy of the current to be measured based on the voltage signal generated in the first element 3. In this way, the current sensor 100 measures the current value or the energy of the current to be measured.

[0070] If a misalignment occurs between the first surface 11 and the second surface 21 of the magnetic core 1 and the first element 3, the induced electromotive force generated in the first element 3 will be smaller compared to when there is no misalignment. As a result, the detection accuracy and detection sensitivity of the current sensor 100 may change. In other words, variations in the detection accuracy and detection sensitivity of the current sensor 100 may occur. This may reduce the reliability of the current sensor 100.

[0071] According to the current sensor 100 of Embodiment 1, the main substrate 5 is made of a light-transmitting material. Therefore, in the assembly process (S20), the outer edges of the first surface 11 and the second surface 21 of the magnetic core and the first element 3 can be simultaneously viewed through the main substrate 5. This makes it easy to accurately align each of the first surface 11 and the second surface 21 with the first element 3. As a result, the detection sensitivity of the current sensor 100 can be improved. Furthermore, the detection accuracy of the current sensor 100 can be improved. This makes it possible to improve the reliability of the current sensor 100.

[0072] According to the current sensor 100 of Embodiment 1, a measurement circuit 50 is provided on the main board 5. Therefore, the number of components for connecting the first element 3 and the measurement circuit 50 can be reduced. This makes it possible to suppress the influence of external noise on the detection accuracy and detection sensitivity of the current sensor 100.

[0073] Furthermore, the number of circuit boards other than the main board 5 for providing the measurement circuit 50 can be reduced. This reduces both the size and cost of the current sensor 100.

[0074] If the main board 5 is easily deformed, it may deform due to forces applied to it during assembly or use. Specifically, the main board 5 may deform due to stress applied to it during assembly, thermal stress due to heat generated in the first element 3 during current measurement, gravity which changes depending on the orientation of the current sensor 100 during actual use, vibrations due to road traffic conditions in the usage environment, or vibrations from other vibration sources. As a result, the first element 3 may tilt with respect to the first surface 11 and the second surface 21 of the magnetic core 1. In this case, the magnetic flux density of the leakage flux 109 penetrating the first element 3 decreases compared to the case where the first element 3 is not tilted with respect to the first surface 11 and the second surface 21. Therefore, the reliability of the current sensor 100 may decrease.

[0075] According to the current sensor 100 of Embodiment 1, the main substrate 5 is made of glass. Glass is as hard and resistant to deformation as fine ceramics such as barium titanate (BaTiO3), alumina (Al2O3), and boron nitride (BN). Therefore, deformation of the main substrate 5 can be suppressed. As a result, a decrease in the reliability of the current sensor 100 can be suppressed.

[0076] Furthermore, glass can be manufactured at a lower cost than fine ceramics such as BaTiO3, Al2O3, and BN. This reduces the cost of the current sensor 100.

[0077] Normally, stress is applied to the main substrate 5 during the manufacturing process of the current sensor 100, such as in a wafer process. Furthermore, external forces are applied to the main substrate 5 in the actual operating environment of the current sensor 100. In the current sensor 100 according to Embodiment 1, the main substrate 5 is made of glass. Therefore, when the thickness H of the main substrate 5 in the vertical direction Z is 0.3 mm or more, deformation of the main substrate 5 can be sufficiently suppressed in both the manufacturing process of the current sensor 100 and in the actual operating environment of the current sensor 100. Furthermore, when the thickness H of the main substrate 5 in the vertical direction Z is 0.4 mm or more, deformation of the main substrate 5 can be suppressed more effectively in both the manufacturing process of the current sensor 100 and in the actual operating environment of the current sensor 100.

[0078] Typically, when forming coil patterns on printed circuit boards made of glass epoxy or similar materials, printing methods such as screen printing, flexographic printing, and inkjet printing are used. However, using these printing methods makes it difficult to reduce the fineness of the coil pattern lines and the pitch of the coil pattern.

[0079] In the current sensor 100 according to Embodiment 1, the main substrate 5 is made of glass. Glass has higher heat resistance than printed circuit boards. Therefore, a semiconductor manufacturing process (wafer process) based on a photogravure process can be used in the formation of the first element 3, etc. This makes it possible to miniaturize the first element 3 compared to the case in which the first element 3 is formed using a printing method. In other words, the number of turns of the first coil pattern portion 17 of the first element 3 can be increased, and the accuracy of the shape and position of the first coil pattern portion 17 can be improved. As a result, the detection accuracy and detection sensitivity of the current sensor 100 can be improved.

[0080] Leakage flux 109 located outside the first surface 11 and the second surface 21 in a direction perpendicular to the vertical direction Z is susceptible to external environmental influences. Therefore, when the first element 3 detects leakage flux 109 located outside the first surface 11 and the second surface 21, the reliability of the current sensor 100 may decrease. In the current sensor 100 according to Embodiment 1, when viewed in the first direction 101, the first element 3 is located inside the outer edges of the first surface 11 and the second surface 21. Therefore, a decrease in the reliability of the current sensor 100 can be suppressed.

[0081] (Modified version of Embodiment 1) Although the configuration of the current sensor 100 according to Embodiment 1 has been described above, this disclosure is not limited to the above configuration. Specifically, for example, the current sensor 100 does not have to have a substrate fixing portion 80. Referring to Figure 12, the configuration of a modified current sensor 100 according to Embodiment 1 will be described. The schematic cross-sectional diagram shown in Figure 12 corresponds to the schematic cross-sectional diagram shown in Figure 3.

[0082] As shown in Figure 12, the substrate structure 200 may be directly sandwiched between the magnetic core 1. Alternatively, the substrate structure 200 may be in contact with the magnetic core 1 on each of the first surface 11 and the second surface 21 of the magnetic core 1. The second main surface 52 of the main substrate 5 may be in contact with the second surface 21. On the first surface 11, the third insulating film 43 may be in contact with the magnetic core 1. In this case, the distance between the first surface 11 and the second surface 21 in the vertical direction Z can be reduced. This can suppress the diffusion of leakage flux 109 (see Figure 11). In other words, the amount of leakage flux 109 dissipating to the outside of each of the first surface 11 and the second surface 21 in the direction perpendicular to the vertical direction Z can be reduced. As a result, the reliability of the current sensor 100 can be improved.

[0083] The main substrate 5 may be made of, for example, quartz glass, crystallized glass, or amorphous soda-lime glass. The main substrate 5 may also be made of, for example, acrylic or plastic. The main substrate 5 may be fixed in its outer peripheral region 86 by fixing members (not shown).

[0084] The magnetic core 1 may be composed of a single component. In other words, the first core portion 10 and the second core portion 20 may be a single component connected to each other.

[0085] Each of the first core portion 10 and the second core portion 20 of the magnetic core 1 may be made of garnet-type ferrite. The magnetic core 1 may be made of a metallic material containing one or more ferromagnetic elements, such as iron (Fe), cobalt (Co), and nickel (Ni).

[0086] Each of the first substrate fixing member 81 and the second substrate fixing member 82 may be made of the same material as the main substrate 5, for example. Each of the first substrate fixing member 81 and the second substrate fixing member 82 may be made of fine ceramics such as BaTiO3, Al2O3, or BN, for example.

[0087] The first element 3 may be made of, for example, a Cu alloy containing additive elements. The additive elements are at least one metallic element selected from the group consisting of, for example, titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), and molybdenum (Mo). Preferably, the amount of additive elements in the Cu alloy is 0.1 atomic percent or more and less than 20 atomic percent. In this case, the resistivity of the first element 3 can be less than 5 μΩ·cm. Furthermore, the adhesion between the first element 3 and the main substrate 5 can be improved. In addition, the corrosion resistance and oxidation resistance of the first element 3 can be improved. The first element 3 may be a Hall element or a magnetoresistive (MR) element.

[0088] An underlayer may be provided between each of the first element 3 and the first insulating film 41 and the main substrate 5. The underlayer is made of, for example, SiO2 or Si3N4. This improves the adhesion between the main substrate 5 and the first element 3. The underlayer is formed, for example, by sputtering or CVD.

[0089] The first element 3 may contain oxygen atoms. This can improve the adhesion between the main substrate 5 and the first element 3. In the sputtering method for forming the first conductive film in the substrate structure fabrication process (S10), the first element 3 containing oxygen atoms can be formed by using a mixed gas of Ar and oxygen (O2). In this case, the ratio of the partial pressure of O2 gas to the pressure of the mixed gas is preferably 0.1% or more and less than 5%. If the ratio of the partial pressure of O2 gas to the pressure of the mixed gas is less than 0.1%, the adhesion between the main substrate 5 and the first element 3 may not be sufficiently improved. If the ratio of the partial pressure of O2 gas to the pressure of the mixed gas is 5% or more, the resistivity of the first element 3 may increase.

[0090] When the diameter of the main substrate 5 is 6 inches or more, or when one side of the main substrate 5 exceeds 150 cm, it becomes difficult to uniformly etch the entire surface of the first conductive film using the IBE method. For this reason, when the size of the main substrate 5 is large as described above, it is preferable to use a wet etching method such as chemical immersion or chemical spraying. It is preferable to use a cerium ammonium nitrate (CAN)-based chemical solution or a hydrogen peroxide (H2O2)-based chemical solution as the chemical solution.

[0091] Each of the first insulating film 41 and the third insulating film 43 may be formed using the spin-on-glass (SOG) method. Each of the first insulating film 41 and the third insulating film 43 may be composed of an epoxy resin or an acrylic resin. In this case, each of the first insulating film 41 and the third insulating film 43 may be formed, for example, by a coating method.

[0092] The substrate structure 200 does not necessarily have a third insulating film 43. From another point of view, the first wiring portion 71 may be exposed. Polycrystalline ITO has high chemical stability. Specifically, polycrystalline ITO has high chemical resistance to the point that it does not dissolve in most acidic chemicals other than aqua regia-based chemicals. Therefore, even when the first wiring portion 71 is exposed, the occurrence of defects in the first wiring portion 71 can be suppressed.

[0093] The first wiring section 71 may be made of a material that does not transmit light. Specifically, the first wiring section 71 may be made of, for example, Cu, Al, a Cu alloy, or an Al alloy.

[0094] Embodiment 2. Next, with reference to Figure 13, the configuration of the current sensor 100 according to Embodiment 2 will be described. The configuration of the current sensor 100 according to Embodiment 2 differs from the configuration of the current sensor 100 according to Embodiment 1 mainly in that the current sensor 100 has a first alignment mark 61, a second alignment mark 62, and a third alignment mark 63. In other respects, it is substantially the same as the configuration of the current sensor 100 according to Embodiment 1. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 1.

[0095] (Current sensor configuration) Figure 13 is an enlarged schematic plan view of the area around the first element 3 in the current sensor 100. For ease of explanation, the first core portion 10, the substrate fixing portion 80, the first insulating film 41, and the third insulating film 43 are not shown in Figure 13. In Figure 13, the shaded area represents the first element 3. As shown in Figure 13, the substrate structure 200 may further have a first alignment mark 61 and a second alignment mark 62. The current sensor 100 may further have a third alignment mark 63. The first alignment mark 61, the second alignment mark 62, and the third alignment mark 63 are each used to align the main substrate 5 with the magnetic core 1.

[0096] A first alignment mark 61 is provided on the main substrate 5. Viewed in the first direction 101, the shape of the first alignment mark 61 is, for example, a cross shape. The first alignment mark 61 is located at the corner of the detection area 85 of the main substrate 5. The first alignment mark 61 is aligned with the second surface 21. Specifically, viewed in the first direction 101, the first alignment mark 61 is located at the corner of the second surface 21 of the second core portion 20. In other words, viewed in the first direction 101, the first alignment mark 61 overlaps with the third outer surface 93 of the second core portion 20. The first alignment mark 61 may also be aligned with the first surface 11 of the first core portion 10 (see Figures 3 and 4). From another point of view, the first alignment mark 61 is aligned with at least one of the first surface 11 and the second surface 21. The first alignment mark 61 is made of the same material as, for example, the first element 3.

[0097] A second alignment mark 62 is provided on the main substrate 5. Viewed in the first direction 101, the second alignment mark 62 is located inside the detection area 85 of the main substrate 5. Viewed in the first direction 101, the second alignment mark 62 is, for example, at the center of the detection area 85. The second alignment mark 62 is surrounded by the first element 3. Viewed in the first direction 101, the second alignment mark 62 overlaps the second surface 21. Viewed in the first direction 101, the shape of the second alignment mark 62 is, for example, a rectangle. The second alignment mark 62 is made of, for example, the same material as the first element 3.

[0098] A third alignment mark 63 may be provided on the second surface 21. The second alignment mark 62 is aligned with the third alignment mark 63. Specifically, when viewed in the first direction 101, the third alignment mark 63 surrounds the second alignment mark 62. When viewed in the first direction 101, the third alignment mark 63 is surrounded by the first element 3. When viewed in the first direction 101, the shape of the third alignment mark 63 is, for example, annular.

[0099] (Manufacturing method for current sensors) Next, a method for manufacturing the current sensor 100 according to Embodiment 2 will be described.

[0100] In the substrate structure fabrication process (S10), the first alignment mark 61 and the second alignment mark 62 are formed simultaneously with the first element 3. Specifically, in the substrate structure fabrication process (S10), the first alignment mark 61 and the second alignment mark 62 are formed by etching the first conductive film.

[0101] Next, the effects and benefits of the current sensor 100 according to Embodiment 2 will be described. According to the current sensor 100 of Embodiment 2, a first alignment mark 61 is formed on the main substrate 5. The first alignment mark 61 is aligned with at least one of the first surface 11 and the second surface 21. Therefore, in the assembly process (S20), the alignment of the main substrate 5 with at least one of the first surface 11 and the second surface 21 can be performed more accurately. This allows for more accurate alignment of the first element 3 with at least one of the first surface 11 and the second surface 21.

[0102] According to the current sensor 100 of Embodiment 2, a second alignment mark 62 is formed on the main substrate 5. A third alignment mark 63 is formed on the second surface 21. The second alignment mark 62 is aligned with the third alignment mark 63. Therefore, in the assembly process (S20), by aligning the second alignment mark 62 and the third alignment mark 63, the main substrate 5 and the second surface 21 can be aligned more accurately. This allows for more accurate alignment between the first element 3 and the second surface 21.

[0103] (Modified version of Embodiment 2) In the above description, a configuration in which the third alignment mark 63 is provided on the second surface 21 has been explained, but this disclosure is not limited to the above configuration. Specifically, for example, the third alignment mark 63 may be provided on the second substrate fixing member 82. When viewed in the first direction 101, the second substrate fixing member 82 and the second surface 21 may be aligned. This allows the second alignment mark 62 and the third alignment mark 63 to be aligned even when the second substrate fixing member 82 is not translucent. As a result, the alignment of the first element 3 and the second surface 21 can be made more accurate.

[0104] When the magnetic core 1 is composed of a single component, the alignment of the first surface 11, the second surface 21, and the first element 3 is performed by viewing each of them from an oblique angle. Even when alignment is performed by viewing from an oblique angle in this way, misalignment between the first surface 11, the second surface 21, and the first element 3 can be suppressed by using alignment marks formed on the main substrate 5 or the magnetic core 1.

[0105] Embodiment 3. Next, the configuration of the current sensor 100 according to Embodiment 3 will be described with reference to Figures 14 to 16. The current sensor 100 according to Embodiment 3 differs from the configuration of the current sensor 100 according to Embodiment 2 mainly in that it has a flexible printed circuit 9, but in other respects it is substantially the same as the configuration of the current sensor 100 according to Embodiment 2. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 2.

[0106] For the sake of clarity, the first insulating film 41, the third insulating film 43, the measurement circuit 50, and the substrate fixing part 80 are not shown in Figure 14. The schematic cross-sectional diagram shown in Figure 16 corresponds to the schematic cross-sectional diagram shown in Figure 3.

[0107] (Current sensor configuration) As shown in Figures 14, 15, and 16, the substrate structure 200 may have a flexible printed circuit 9. The flexible printed circuit 9 is in contact with the main substrate 5. Specifically, the flexible printed circuit 9 is in contact with the main substrate 5 in the outer peripheral region 86 of the main substrate 5. The first element 3 and the flexible printed circuit 9 are electrically connected by connecting wiring 7. A measuring circuit 50, not shown, may be provided in the flexible printed circuit 9. The flexible printed circuit 9 is deformable.

[0108] The current sensor 100 according to Embodiment 3 has a flexible printed circuit 9. A measurement circuit 50 is provided in the flexible printed circuit 9. As a result, the size of the main board 5 as seen in the first direction 101 can be reduced. This makes it possible to suppress deformation of the main board 5 when force is applied to it.

[0109] Furthermore, the flexible printed circuit 9 is deformable. Therefore, when force is applied to the flexible printed circuit 9, the transmission of force from the flexible printed circuit 9 to the main board 5 can be suppressed. This suppresses deformation of the main board 5.

[0110] According to the current sensor 100 of Embodiment 3, the size of the main substrate 5 as seen in the first direction 101 can be reduced. Therefore, even if the thickness H (see Figure 7) of the main substrate 5 is thin, deformation of the main substrate 5 can be sufficiently suppressed. Specifically, the thickness H may be less than 0.3 mm, for example. Therefore, the distance between the first surface 11 and the second surface 21 of the magnetic core 1 in the vertical direction Z can be shortened. This makes it possible to suppress the outward diffusion of the leakage flux 109 from the first element 3. As a result, the detection accuracy and detection sensitivity of the current sensor 100 can be more effectively improved.

[0111] If the main substrate 5 is made of glass, after forming the first element 3 on the main substrate 5, the main substrate 5 can be etched by a wet etching method using a fluorine acid (HF)-based chemical solution. This allows the main substrate 5 to be thinned to a thickness H of approximately 0.1 mm.

[0112] (Modified example of Embodiment 3) Although the configuration of the current sensor 100 according to Embodiment 3 has been described above, this disclosure is not limited to the above configuration. The substrate structure 200 may further include a printed circuit board (not shown). The printed circuit board may be connected to the main substrate 5 via a flexible printed circuit 9. A measurement circuit 50 may be provided on the printed circuit board. The measurement circuit 50 may be connected to the first element 3 via the flexible printed circuit 9 and connecting wiring 7.

[0113] Embodiment 4. Next, the configuration of the current sensor 100 according to Embodiment 4 will be described with reference to Figure 17. The current sensor 100 according to Embodiment 4 differs from the configuration of the current sensor 100 according to Embodiment 2 mainly in that the substrate structure 200 has an auxiliary substrate 6, and in other respects, it is substantially the same as the configuration of the current sensor 100 according to Embodiment 2. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 2. Note that the schematic cross-sectional diagram shown in Figure 17 corresponds to the schematic cross-sectional diagram shown in Figure 3.

[0114] (Current sensor configuration) As shown in Figure 17, the substrate structure 200 further includes an auxiliary substrate 6 and an adhesive portion 83. The auxiliary substrate 6 is located between the first surface 11 and the second surface 21 of the magnetic core 1. In other words, the auxiliary substrate 6 is located in the gap 2 (see Figure 2). The auxiliary substrate 6 protects the first element 3.

[0115] The auxiliary substrate 6 is provided on the third insulating film 43. The auxiliary substrate 6 covers the first element 3. In the left-right direction X, the end of the auxiliary substrate 6 may be located on the current line 8 side of the first outer peripheral surface 91. In the left-right direction X, the end of the auxiliary substrate 6 may be located on the current line 8 side of the third outer peripheral surface 93.

[0116] The main substrate 5 may have an exposed area 87. The exposed area 87 is the area of ​​the main substrate 5 that is not covered by the auxiliary substrate 6. From another perspective, in a direction perpendicular to the vertical direction Z, the exposed area 87 is outside the auxiliary substrate 6. An external mounting board, such as a flexible printed circuit 9 or integrated circuit components (not shown), may be attached to the main substrate 5 in the exposed area 87.

[0117] The auxiliary substrate 6 is made of a translucent material. The auxiliary substrate 6 may be transparent. The auxiliary substrate 6 is made of the same material as the main substrate 5, for example. The auxiliary substrate 6 has a third main surface 53 and a fourth main surface 54. The third main surface 53 faces the first main surface 51 of the main substrate 5. On the third main surface 53, the auxiliary substrate 6 is in contact with the third insulating film 43. The fourth main surface 54 is on the opposite side of the third main surface 53. On the fourth main surface 54, the auxiliary substrate 6 is in contact with the first substrate fixing member 81.

[0118] The adhesive portion 83 bonds the main substrate 5 and the auxiliary substrate 6. Specifically, the adhesive portion 83 bonds the first main surface 51 of the main substrate 5 and the third main surface 53 of the auxiliary substrate 6. The adhesive portion 83 is made of, for example, a thermosetting resin. The adhesive portion 83 may also be made of, for example, an ultraviolet curing resin.

[0119] Next, the effects and benefits of the current sensor 100 according to Embodiment 4 will be described. The current sensor 100 according to Embodiment 4 has an auxiliary substrate 6. The auxiliary substrate 6 covers the first element 3. Therefore, when stress or external force is applied to the main substrate 5, the main substrate 5 and the auxiliary substrate 6 become one, thereby suppressing deformation and vibration of the main substrate 5. This makes it possible to more effectively suppress misalignment between the first surface 11 and the second surface 21 of the magnetic core 1 and the first element 3. As a result, the detection sensitivity and detection accuracy of the current sensor 100 can be further improved.

[0120] Embodiment 5. Next, the configuration of the current sensor 100 according to Embodiment 5 will be described with reference to Figures 18 to 22. The configuration of the current sensor 100 according to Embodiment 5 differs from the configuration of the current sensor 100 according to Embodiment 4 mainly in that the second element 4 is provided on the auxiliary substrate 6, and in other respects, it is substantially the same as the configuration of the current sensor 100 according to Embodiment 4. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 4.

[0121] The schematic cross-sectional diagram shown in Figure 18 corresponds to the schematic cross-sectional diagram shown in Figure 17. For the sake of explanation, the auxiliary substrate 6, the first insulating film 41, and the second insulating film 42 are not shown in Figure 19. In Figure 20, the first insulating film 41, the second insulating film 42, the first conductive material 75, and the second conductive material 76 are not shown. The enlarged schematic cross-sectional diagram shown in Figure 21 corresponds to the enlarged schematic cross-sectional diagram shown in Figure 7. The cross-section shown in Figure 22 is parallel to the vertical Z direction and the horizontal X direction, and intersects with the first wiring section 71 and the second wiring section 72, respectively.

[0122] (Current sensor configuration) As shown in Figure 18, the substrate structure 200 further comprises a second element 4, a second insulating film 42, and a first conductive material 75. The second element 4 is provided on the auxiliary substrate 6. Specifically, the second element 4 is provided on the third main surface 53 of the auxiliary substrate 6. The second element 4 faces the first element 3. The second element 4 detects the magnetic flux generated by the current flowing through the current line 8. Specifically, the time change in magnetic flux density in the space surrounded by the second element 4 induces an electromotive force, which is generated in the second element 4 as a voltage signal. The second element 4 is, for example, a coil pattern. The second element 4 is made of, for example, the same material as the first element 3.

[0123] A second insulating film 42 is provided on the auxiliary substrate 6. The second insulating film 42 protects the second element 4. In the vertical direction Z, the second insulating film 42 is located between the auxiliary substrate 6 and the first insulating film 41. The second insulating film 42 is in contact with the third main surface 53, the second element 4, and the first insulating film 41. The second element 4 is located between the auxiliary substrate 6 and the second insulating film 42. The second insulating film 42 is made of the same material as, for example, the first insulating film 41. The thickness of the second insulating film 42 in the vertical direction Z is, for example, 400 nm.

[0124] The first conductive material 75 is in contact with the first element 3, the second element 4, the first insulating film 41, and the second insulating film 42. The first conductive material 75 electrically connects the first element 3 and the second element 4.

[0125] As shown in Figure 19, when viewed in the first direction 101, the second element 4 overlaps the first element 3. When viewed in the first direction 101, the second element 4 is located within the detection region 85 of the main substrate 5. From another perspective, when viewed in the first direction 101, the second element 4 overlaps the first surface 11 (see Figure 18) and the second surface 21 (see Figure 18), respectively. When viewed in the first direction 101, the adhesive portion 83 is located within the outer peripheral region 86 of the main substrate 5.

[0126] Figure 20 is an enlarged schematic plan view showing the auxiliary substrate 6 in a shifted position. The arrows in Figure 20 indicate that the portion of the substrate structure 200 at the base of the arrow is positioned at the tip of the arrow.

[0127] As shown in Figures 19 and 20, the substrate structure 200 further has a fourth alignment mark 64 and a fifth alignment mark 65. Each of the fourth alignment mark 64 and the fifth alignment mark 65 is used to align the main substrate 5 and the auxiliary substrate 6. The fourth alignment mark 64 is provided on the main substrate 5. The fifth alignment mark 65 is provided on the auxiliary substrate 6. Viewed in the first direction 101, the fifth alignment mark 65 is aligned with the fourth alignment mark 64.

[0128] The second element 4 has a third coil pattern portion 37, a third outer peripheral end portion 39, and a third inner peripheral end portion 38. Viewed in the first direction 101, the third coil pattern portion 37 is arranged in a spiral shape. Specifically, viewed in the first direction 101, the shape of the third coil pattern portion 37 is a spiral shape formed on the same plane. Viewed in the first direction 101, the winding direction of the third coil pattern portion 37 is opposite to the winding direction of the first coil pattern portion 17. Specifically, viewed in the first direction 101, the first coil pattern portion 17 is, for example, a clockwise spiral shape from the center outwards. Viewed in the first direction 101, the third coil pattern portion 37 is, for example, a counterclockwise spiral shape from the center outwards.

[0129] The third outer circumference end 39 is connected to the third coil pattern portion 37. Viewed in the first direction 101, the third outer circumference end 39 overlaps with the first wiring portion 71. The third outer circumference end 39 is electrically connected to the first wiring portion 71. The third inner circumference end 38 is connected to the third coil pattern portion 37. The third inner circumference end 38 is surrounded by the third coil pattern portion 37. Viewed in the first direction 101, the third inner circumference end 38 overlaps with the first inner circumference end 18. The third inner circumference end 38 is electrically connected to the first inner circumference end 18.

[0130] The first element 3 and the second element 4 are electrically connected in series. Specifically, the first element 3 and the second element 4 are connected such that the induced currents generated in each of them flow in the same direction. More specifically, the induced currents generated in each of the first element 3 and the second element 4 flow, for example, from the second wiring section 72 towards the first wiring section 71.

[0131] As shown in Figures 19 and 21, the first conductive material 75 electrically connects the first inner circumferential end 18 of the first element 3 and the third inner circumferential end 38 of the second element 4. The first conductive material 75 is in contact with the first inner circumferential end 18, the third inner circumferential end 38, the first insulating film 41, and the second insulating film 42, respectively.

[0132] The second insulating film 42 has a second inner surface 142. Each of the first inner surface 141 and the second inner surface 142 surrounds the first conductive material 75. In the space surrounded by the second inner surface 142, the third inner end portion 38 of the second element 4 is exposed from the second insulating film 42. In other words, the second inner surface 142 forms a contact hole.

[0133] As shown in Figures 19 and 22, the substrate structure 200 further includes a second conductive material 76. The second conductive material 76 electrically connects the third outer peripheral end 39 of the second element 4 to the first wiring section 71. The first wiring section 71 is provided on the first main surface 51 of the main substrate 5. The first wiring section 71 is made of the same material as, for example, the first element 3.

[0134] The first insulating film 41 has a third inner surface 143. The third inner surface 143 surrounds the second conductive material 76. In the space enclosed by the third inner surface 143, the first wiring portion 71 is exposed from the first insulating film 41. In other words, the third inner surface 143 forms a contact hole.

[0135] The second insulating film 42 has a fourth inner circumferential surface 144. The fourth inner circumferential surface 144 surrounds the second conductive material 76. In the space enclosed by the fourth inner circumferential surface 144, the third outer circumferential end portion 39 is exposed from the second insulating film 42. In other words, the fourth inner circumferential surface 144 forms a contact hole.

[0136] (Manufacturing method for current sensors) Next, a method for manufacturing the current sensor 100 according to Embodiment 5 will be described.

[0137] In the substrate structure fabrication process (S10), the first wiring section 71 is formed simultaneously with the first element 3. The second element 4 is formed by substantially the same process as the first element 3. Specifically, for example, the second element 4 is formed on the third main surface 53 of the auxiliary substrate 6 using a photolithography process and an etching method. The second insulating film 42 is formed by substantially the same process as the first insulating film 41. Specifically, for example, the second insulating film 42 is formed on the third main surface 53 of the auxiliary substrate 6 using a CVD method. The first conductive material 75 is placed in the space surrounded by the first inner circumferential surface 141 of the first insulating film 41. The second conductive material 76 is placed in the space surrounded by the third inner circumferential surface 143 of the first insulating film 41.

[0138] An adhesive portion 83 is formed on the first main surface 51 of the main substrate 5 using a printing method. The auxiliary substrate 6 is placed on the main substrate 5. If the adhesive portion 83 is a thermosetting resin, the adhesive portion 83 is heated to a temperature of 100°C to 150°C. If the adhesive portion 83 is an ultraviolet resin, ultraviolet light is irradiated onto the adhesive portion 83. As a result, the main substrate 5 and the auxiliary substrate 6 are bonded together. In this way, the substrate structure 200 is formed.

[0139] Next, the effects and benefits of the current sensor 100 according to Embodiment 5 will be described. According to the current sensor 100 of Embodiment 5, a second element 4 is provided on the auxiliary substrate 6. Viewed in the first direction 101, the second element 4 overlaps with the first surface 11 and the second surface 21, respectively. The first element 3 and the second element 4 are electrically connected in series. Therefore, the number of turns of the coil pattern in the substrate structure 200 can be increased. This makes it possible to more effectively improve the detection accuracy and detection sensitivity of the current sensor 100.

[0140] (Modified version of Embodiment 5) Although the configuration of the current sensor 100 according to Embodiment 5 has been described above, this disclosure is not limited to the above configuration. Specifically, the adhesive portion 83 may bond the main substrate 5 and the second insulating film 42. The adhesive portion 83 may bond the first insulating film 41 and the auxiliary substrate 6. The adhesive portion 83 may bond the first insulating film 41 and the second insulating film 42. The second element 4 may be a Hall element or a magnetoresistive (MR) element.

[0141] Embodiment 6. Next, with reference to Figure 23, the configuration of the current sensor 100 according to Embodiment 6 will be described. The current sensor 100 according to Embodiment 6 differs from the configuration of the current sensor 100 according to Embodiment 4 mainly in that it has a magnetic material 60, but in other respects it is substantially the same as the configuration of the current sensor 100 according to Embodiment 4. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 4.

[0142] (Current sensor configuration) Figure 23 is an enlarged schematic cross-sectional view of the area around the first element 3 in the current sensor 100 according to Embodiment 6. The cross-section shown in Figure 23 is parallel to the vertical Z direction and the left-right X direction, and intersects with the first element 3. As shown in Figure 23, the current sensor 100 may further include a magnetic body 60. The magnetic body 60 has a first magnetic body portion 78 and a second magnetic body portion 79.

[0143] The first magnetic material portion 78 is located between the first substrate fixing member 81 and the first surface 11 of the magnetic core 1. The first magnetic material portion 78 is located between the first surface 11 and the first element 3. The first magnetic material portion 78 is in contact with both the first substrate fixing member 81 and the first surface 11. The first magnetic material portion 78 is bonded to the first surface 11, for example, by an adhesive (not shown).

[0144] In a direction perpendicular to the vertical direction Z, the first magnetic material portion 78 is located inside the outer edges of the first surface 11 and the second surface 21, respectively. In other words, in a direction perpendicular to the vertical direction Z, the first magnetic material portion 78 is located inside the outer edges of the first outer peripheral surface 91 and the third outer peripheral surface 93 of the magnetic core 1. Preferably, in a direction perpendicular to the vertical direction Z, the first magnetic material portion 78 is located inside the region surrounded by the first element 3.

[0145] The first magnetic material portion 78 is composed of, for example, a first flat plate member 161 and an alignment mark member 163. The alignment mark member 163 is spaced apart from the first flat plate member 161. The alignment mark member 163 is used to align the main substrate 5 and the magnetic core 1. The alignment mark member 163 may form a third alignment mark 63 (see Figure 13). The thickness of the first magnetic material portion 78 in the vertical direction Z is preferably, for example, 1 μm or more.

[0146] The second magnetic material portion 79 is located between the second substrate fixing member 82 and the second surface 21 of the magnetic core 1. The second magnetic material portion 79 is located between the second surface 21 and the first element 3. In other words, the magnetic material 60 is located at least one of the spaces between the first surface 11 and the first element 3 and between the second surface 21 and the first element 3. The second magnetic material portion 79 is in contact with both the second surface 21 and the second substrate fixing member 82. The second magnetic material portion 79 is bonded to the second surface 21, for example, by an adhesive (not shown).

[0147] In a direction perpendicular to the vertical direction Z, the second magnetic material portion 79 is located inside the outer edges of the first surface 11 and the second surface 21, respectively. In other words, in a direction perpendicular to the vertical direction Z, the second magnetic material portion 79 is located inside the outer edges of the first outer surface 91 and the third outer surface 93 of the magnetic core 1, respectively. Preferably, in a direction perpendicular to the vertical direction Z, the second magnetic material portion 79 is located inside the region surrounded by the first element 3.

[0148] The second magnetic material portion 79 is composed of a second flat plate member 162 and an alignment mark member 163. The alignment mark member 163 is spaced apart from the second flat plate member 162. The thickness of the second magnetic material portion 79 in the vertical direction Z is preferably, for example, 1 μm or more.

[0149] The saturation magnetic flux density of the magnetic material 60 is higher than that of the magnetic core 1. Preferably, the relative permeability of the magnetic material 60 is higher than that of the magnetic core 1. The magnetic material 60 may be composed of at least one metallic element selected from the group consisting of Fe, Co, and Ni. The magnetic material 60 may be composed of an alloy mainly composed of at least one metallic element selected from the group consisting of Fe, Co, and Ni. Specifically, the magnetic material 60 may be composed of polycrystalline alloy materials such as Fe-Si (silicon) alloy (silicon steel), Fe-Al-Si alloy (commonly known as Sendust®), Ni-Fe alloy (commonly known as Permalloy), Ni-Fe-Mo alloy (commonly known as Supermalloy), and Fe-Co-V alloy (commonly known as Permendur). The magnetic material 60 may be composed of amorphous soft magnetic materials such as Fe-Si-B (boron) alloy, Fe-Co-Si-B alloy, Fe-Zr (zirconium) alloy, Fe-Co-Zr alloy, or Co-Zr-Nb (niobium) alloy.

[0150] The magnetic material 60 is composed of, for example, an Fe-Al-Si alloy. The amount of Al added to the magnetic material 60 is, for example, between 4 atomic percent and 6 atomic percent. The amount of Si added to the magnetic material 60 is, for example, between 8 atomic percent and 10 atomic percent. The saturation magnetic flux density of the magnetic material 60 is, for example, between 1.0 T and 1.3 T. The relative permeability of the magnetic material 60 is, for example, between 5000 and 10000.

[0151] (Manufacturing method for current sensors) Next, a method for manufacturing the current sensor 100 according to Embodiment 6 will be described. The magnetic material 60 is formed, for example, by cutting it from an ingot of Fe-Al-Si alloy or a thin strip of Fe-Al-Si alloy. The ingot of Fe-Al-Si alloy is produced, for example, by a melting method or a sintering method. The thin strip of Fe-Al-Si alloy is produced, for example, by a quenching method. If the thickness of the magnetic material 60 in the vertical direction Z is less than 20 μm, the magnetic material 60 may be formed on the first surface 11 and the second surface 21, respectively, using a vacuum deposition method such as sputtering or vapor deposition.

[0152] When the magnetic material 60 is formed using a rapid cooling method or a vacuum deposition method, the magnetic material 60 is formed from an amorphous alloy. Amorphous magnetic alloys have almost no crystalline magnetic anisotropy energy derived from their crystal structure. Therefore, when the magnetic material 60 is formed using a rapid cooling method or a vacuum deposition method, the relative permeability of the magnetic material 60 can be improved.

[0153] Next, the effects and benefits of the current sensor 100 according to Embodiment 6 will be described. As shown in Figure 24, according to the current sensor 100 of Embodiment 4, a portion of the leakage flux 109 diffuses to the outside of the magnetic core 1. Specifically, in the direction perpendicular to the vertical direction Z, a portion of the leakage flux 109 passes outside the first surface 11 and the second surface 21 of the magnetic core 1, respectively. From another point of view, a portion of the leakage flux 109 passes outside the first element 3.

[0154] The current sensor 100 according to Embodiment 6 has a magnetic body 60. The magnetic body 60 is located in at least one of the spaces between the first surface 11 and the first element 3, and between the second surface 21 and the first element 3. The saturation magnetic flux density of the magnetic body 60 is higher than that of the magnetic core 1. Therefore, as shown in Figure 25, the magnetic flux signal 108 is concentrated toward the magnetic body 60. Leakage flux 109 occurs between the first magnetic body portion 78 and the second magnetic body portion 79. Therefore, the magnetic flux density of the leakage flux 109 penetrating the space surrounded by the first element 3 can be increased. This makes it possible to more effectively increase the sensitivity of the first element 3 to changes in magnetic flux over time. As a result, the detection accuracy and detection sensitivity of the current sensor 100 can be improved.

[0155] According to the current sensor 100 of Embodiment 6, the relative permeability of the magnetic material 60 is higher than that of the magnetic core 1. Therefore, the magnetic flux signal 108 can be collected in the magnetic material 60 with high efficiency. In other words, the decrease in the magnetic flux density of the magnetic flux passing through the magnetic material 60 can be suppressed. Therefore, the decrease in the magnetic flux density of the leakage flux 109 can be suppressed. This improves the detection accuracy and detection sensitivity of the current sensor 100.

[0156] (Modified version of Embodiment 6) Although the configuration of the current sensor 100 according to Embodiment 6 has been described above, this disclosure is not limited to the above configuration. The configuration of a modified current sensor 100 according to Embodiment 6 will be described with reference to Figures 26 to 29. The enlarged cross-sectional schematic diagrams shown in Figures 26 to 29 correspond to the enlarged cross-sectional schematic diagram shown in Figure 23. For convenience of explanation, in Figures 27 and 29, the first substrate fixing member 81 and the second substrate fixing member 82 are shown by dashed lines. For convenience of explanation, in Figure 28, the substrate structure 200 is shown by dashed lines.

[0157] First, the configuration of the current sensor 100 according to the first modified example of Embodiment 6 will be described. As shown in Figure 26, a substrate structure 200 may be sandwiched between the first magnetic body portion 78 and the second magnetic body portion 79. In other words, the magnetic body 60 may fix the substrate structure 200. On the fourth main surface 54, the first magnetic body portion 78 may be in contact with the auxiliary substrate 6. On the second main surface 52, the second magnetic body portion 79 may be in contact with the main substrate 5.

[0158] Next, the configuration of the current sensor 100 according to the second modified example of Embodiment 6 will be described. As shown in Figure 27, a first magnetic material portion 78 may be provided on the fourth main surface 54 of the auxiliary substrate 6. A second magnetic material portion 79 may be provided on the second main surface 52 of the main substrate 5.

[0159] An insulating film, not shown, may be formed on the second main surface 52 of the main substrate 5 and the fourth main surface 54 of the auxiliary substrate 6. The insulating film covers the first magnetic material portion 78 and the second magnetic material portion 79, respectively. The insulating film protects the first magnetic material portion 78 and the second magnetic material portion 79. The insulating film is permeable. The insulating film is made of, for example, SiO2 or Si3N4.

[0160] Next, a method for manufacturing the current sensor 100 according to a second modified example of Embodiment 6 will be described. An Fe-Al-Si alloy film is formed on the second main surface 52 of the main substrate 5 using a sputtering method. The second magnetic body portion 79 is formed by etching the Fe-Al-Si alloy film. For etching the Fe-Al-Si alloy film, for example, an immersion wet etching method using a chemical solution containing ferric chloride (FeCl3) is used. A first magnetic body portion 78 is formed on the fourth main surface 54 of the auxiliary substrate 6 using a similar process.

[0161] Next, the effects of the current sensor 100 according to the second modification of Embodiment 6 will be described. According to the current sensor 100 according to the second modification of Embodiment 6, the distance between the first magnetic body part 78 and the second magnetic body part 79 in the vertical direction Z can be shortened. As a result, the diffusion of leakage flux 109 between the first magnetic body part 78 and the second magnetic body part 79 can be suppressed more effectively. This makes it possible to more effectively increase the sensitivity of the first element 3 to changes in magnetic flux over time.

[0162] Next, the configuration of the current sensor 100 according to the third modified example of Embodiment 6 will be described. As shown in Figure 28, the first substrate fixing member 81 may be provided with a first magnetic material portion 78. The first magnetic material portion 78 may be located between the first substrate fixing member 81 and the second substrate fixing member 82. The second substrate fixing member 82 may be provided with a second magnetic material portion 79. The second magnetic material portion 79 may be located between the first substrate fixing member 81 and the second substrate fixing member 82.

[0163] Next, the configuration of the current sensor 100 according to the fourth modification of Embodiment 6 will be described. As shown in Figure 29, each of the first magnetic body portion 78 and the second magnetic body portion 79 may be composed of a plurality of island-shaped patterns. Specifically, each of the first magnetic body portion 78 and the second magnetic body portion 79 may be composed of a plurality of individual pieces 164. Each of the plurality of individual pieces 164 is spaced apart from one another. Similar to the current sensor 100 according to the second modification of Embodiment 6, insulating films, not shown, may be formed on each of the second main surface 52 of the main substrate 5 and the fourth main surface 54 of the auxiliary substrate 6.

[0164] Next, the effects of the current sensor 100 according to the fourth modification of Embodiment 6 will be described. When the magnetic body 60 is separated from the magnetic core 1, a demagnetizing field is generated within the magnetic body 60 due to the surface magnetic poles generated on both end faces of the magnetic body 60 in the vertical direction Z. As a result, the magnetic body 60 may not be sufficiently magnetized. Consequently, the effect of concentrating the leakage magnetic flux 109 by the magnetic body 60 may not be sufficiently obtained. Normally, the magnitude of the effect of the demagnetizing field depends on the shape of the magnetic body 60. Specifically, the effect of the demagnetizing field increases as the ratio of the surface area of ​​both end faces of the magnetic body 60 to the thickness of the magnetic body 60 in the vertical direction Z increases.

[0165] According to the current sensor 100 of the fourth modification of Embodiment 6, each of the first magnetic body portion 78 and the second magnetic body portion 79 is composed of multiple island-like patterns. Therefore, the ratio of the surface area of ​​both end faces of the magnetic body 60 to the thickness of the magnetic body 60 in the vertical direction Z can be reduced. This makes it possible to more effectively concentrate the leakage magnetic flux 109 in the space surrounded by the first element 3. As a result, the detection accuracy and detection sensitivity of the current sensor 100 can be improved.

[0166] In the above description, the current sensor 100 according to Embodiment 6 and the current sensor 100 according to the first to fourth modified examples of Embodiment 6 were described in which the magnetic material 60 is located between the first surface 11 and the first element 3, and between the second surface 21 and the first element 3, respectively. However, this disclosure is not limited to the above configuration. Specifically, the current sensor 100 may have the magnetic material 60 only between the first surface 11 and the first element 3, or between the second surface 21 and the first element 3. In other words, the current sensor 100 may have only one of the first magnetic material portion 78 and the second magnetic material portion 79.

[0167] Depending on the material of the magnetic material 60, selective etching in wet etching may be difficult. Specifically, when forming the first element 3 using the wet etching method, the magnetic material 60 may be etched. In this case, it is preferable to use dry etching when forming the first element 3.

[0168] Embodiment 7. Next, the configuration of the current sensor 100 according to Embodiment 7 will be described with reference to Figures 30 to 34. The current sensor 100 according to Embodiment 7 differs from the current sensor 100 according to Embodiment 1 mainly in that the gap 2 of the magnetic core 1 has a first gap portion 171 and a second gap portion 172. In other respects, it is substantially the same as the current sensor 100 according to Embodiment 1. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 1.

[0169] For the sake of clarity, the substrate fixing portion 80, the first insulating film 41, and the third insulating film 43 are not shown in Figure 30. The schematic cross-sectional diagram shown in Figure 32 corresponds to the schematic cross-sectional diagram shown in Figure 3. For the sake of clarity, the substrate fixing portion 80, the first insulating film 41, and the third insulating film 43 are not shown in Figure 33. For the sake of clarity, the first core portion 10, the substrate fixing portion 80, the first insulating film 41, and the third insulating film 43 are not shown in Figure 34.

[0170] As shown in Figure 30, the first core portion 10 is spaced apart from the second core portion 20. In the vertical direction Z, the main substrate 5 is located between the first core portion 10 and the second core portion 20. The gap 2 has a first gap portion 171 and a second gap portion 172. The second gap portion 172 is spaced apart from the first gap portion 171. The first element 3 has a first element portion 31 and a second element portion 32. The first element portion 31 is located in the first gap portion 171. The second element portion 32 is spaced apart from the first element portion 31. The second element portion 32 is located in the second gap portion 172.

[0171] The connecting wiring 7 has a third wiring section 73. The third wiring section 73 is spaced apart from the first wiring section 71 and the second wiring section 72, respectively. The third wiring section 73 electrically connects the first element section 31 and the second element section 32. The first wiring section 71 electrically connects the second element section 32 and the measurement circuit 50. The second wiring section 72 electrically connects the first element section 31 and the measurement circuit 50. The second wiring section 72 may be made of, for example, ITO. The third wiring section 73 may be made of, for example, the same material as either the first wiring section 71 or the second wiring section 72.

[0172] As shown in Figure 31, the first gap 171 and the second gap 172 are each formed between the first core 10 and the second core 20. The annular region formed by the magnetic core 1, the first gap 171 and the second gap 172 surrounds the current line 8.

[0173] The first surface 11 has a first portion 95 and a second portion 96. The first portion 95 is formed by a first protrusion 13 of the first core portion 10. The first portion 95 is connected to the first outer surface 91. The second portion 96 is formed by a second protrusion 14 of the first core portion 10. The second portion 96 is connected to the second outer surface 92. The second portion 96 is spaced apart from the first portion 95. The second portion 96 may be substantially parallel to the first portion 95. The first portion 95 and the second portion 96 may be substantially coplanar.

[0174] The second surface 21 has a third portion 97 and a fourth portion 98. The third portion 97 is formed by the third protrusion 23 of the second core portion 20. The third portion 97 is connected to the third outer surface 93. The third portion 97 faces the first portion 95. The direction from the first portion 95 toward the third portion 97 is the first direction 101. The third portion 97 may be substantially parallel to the first portion 95.

[0175] The fourth portion 98 is formed by the fourth protrusion 24 of the second core portion 20. The fourth portion 98 is connected to the fourth outer surface 94. The fourth portion 98 is spaced apart from the third portion 97. The fourth portion 98 faces the second portion 96. The direction from the second portion 96 toward the fourth portion 98 is the first direction 101. The fourth portion 98 may be substantially parallel to the second portion 96. The fourth portion 98 may be substantially parallel to the third portion 97. The third portion 97 and the fourth portion 98 may be substantially coplanar.

[0176] The first gap portion 171 is formed between the first portion 95 and the third portion 97. The second gap portion 172 is formed between the second portion 96 and the fourth portion 98.

[0177] As shown in Figure 32, the first substrate fixing member 81 has a first member 181 and a second member 182. The first member 181 is located between the first portion 95 of the first surface 11 and the third portion 97 of the second surface 21. In other words, the first member 181 is located in the first gap portion 171 (see Figure 31). The first member 181 is in contact with the first portion 95 and the third insulating film 43, respectively.

[0178] In a direction perpendicular to the vertical direction Z, the first member 181 is along the outer edge of the first portion 95. In other words, in a direction perpendicular to the vertical direction Z, the first member 181 is along the first outer surface 91. In a direction perpendicular to the vertical direction Z, the first member 181 may be inside the first portion 95. In other words, in a direction perpendicular to the vertical direction Z, the first member 181 may be inside the first outer surface 91.

[0179] The second member 182 is spaced apart from the first member 181. The second member 182 is located between the second portion 96 of the first surface 11 and the fourth portion 98 of the second surface 21. In other words, the second member 182 is located in the second gap 172 (see Figure 31). The second member 182 is in contact with the second portion 96 and the third insulating film 43, respectively.

[0180] In a direction perpendicular to the vertical direction Z, the second member 182 is along the outer edge of the second portion 96. In other words, in a direction perpendicular to the vertical direction Z, the second member 182 is along the second outer surface 92. In a direction perpendicular to the vertical direction Z, the second member 182 may be inside the second portion 96. In other words, in a direction perpendicular to the vertical direction Z, the second member 182 may be inside the second outer surface 92.

[0181] The second substrate fixing member 82 has a third member 183 and a fourth member 184. The third member 183 is located between the first portion 95 of the first surface 11 and the third portion 97 of the second surface 21. In other words, the third member 183 is located in the first gap portion 171 (see Figure 31). The third member 183 is in contact with the third portion 97 and the main substrate 5, respectively.

[0182] In a direction perpendicular to the vertical direction Z, the third member 183 is along the outer edge of the third portion 97. In other words, in a direction perpendicular to the vertical direction Z, the third member 183 is along the third outer surface 93. In a direction perpendicular to the vertical direction Z, the third member 183 may be inside the third portion 97. In other words, in a direction perpendicular to the vertical direction Z, the third member 183 may be inside the third outer surface 93.

[0183] The fourth member 184 is spaced apart from the third member 183. The fourth member 184 is located between the second portion 96 of the first surface 11 and the fourth portion 98 of the second surface 21. In other words, the fourth member 184 is located in the second gap portion 172 (see Figure 31). The fourth member 184 is in contact with both the fourth portion 98 and the main substrate 5.

[0184] In a direction perpendicular to the vertical direction Z, the fourth member 184 is along the outer edge of the fourth portion 98. In other words, in a direction perpendicular to the vertical direction Z, the fourth member 184 is along the fourth outer surface 94. In a direction perpendicular to the vertical direction Z, the fourth member 184 may be inside the fourth portion 98. In other words, in a direction perpendicular to the vertical direction Z, the fourth member 184 may be inside the fourth outer surface 94.

[0185] On the main substrate 5, the first element portion 31 and the second element portion 32 of the first element 3 are provided. The first element portion 31 is located between the first portion 95 of the first surface 11 and the third portion 97 of the second surface 21. In other words, the first element portion 31 is located in the first gap portion 171 (see Figure 31). The second element portion 32 is located between the second portion 96 of the first surface 11 and the fourth portion 98 of the second surface 21. In other words, the second element portion 32 is located in the second gap portion 172 (see Figure 31). In the vertical direction Z, the current line 8 is located between the main substrate 5 and the second core portion 20.

[0186] As shown in Figures 33 and 34, the first element portion 31 is arranged in a spiral shape when viewed in the first direction 101. Specifically, when viewed in the first direction 101, the shape of the first element portion 31 is a spiral shape formed on the same plane. When viewed in the first direction 101, the first element portion 31 overlaps with the first portion 95 of the first surface 11 and the third portion 97 of the second surface 21. In other words, when viewed in the direction from the first portion 95 to the third portion 97, the first element portion 31 overlaps with the first portion 95 of the first surface 11 and the third portion 97 of the second surface 21.

[0187] Viewed in the first direction 101, the first element portion 31 is preferably located inside the outer edges of the first portion 95 and the third portion 97. In other words, viewed in the first direction 101, the first element portion 31 is preferably located inside the first outer surface 91 and the third outer surface 93. Viewed in the first direction 101, the center of the first element portion 31 is preferably substantially coincided with the centers of the first portion 95 and the third portion 97.

[0188] As shown in Figures 33 and 34, the second element portion 32 is arranged in a spiral shape when viewed in the first direction 101. Specifically, when viewed in the first direction 101, the shape of the second element portion 32 is a spiral shape formed on the same plane. When viewed in the first direction 101, the second element portion 32 overlaps with the second portion 96 of the first surface 11 and the fourth portion 98 of the second surface 21. In other words, when viewed in the direction from the second portion 96 to the fourth portion 98, the second element portion 32 overlaps with the second portion 96 of the first surface 11 and the fourth portion 98 of the second surface 21.

[0189] Viewed in the first direction 101, the second element portion 32 is preferably located inside the outer edges of the second portion 96 and the fourth portion 98, respectively. From another point of view, viewed in the first direction 101, the second element portion 32 is preferably located inside the second outer surface 92 and the fourth outer surface 94, respectively. Viewed in the first direction 101, the center of the second element portion 32 is preferably substantially coincided with the centers of the second portion 96 and the fourth portion 98, respectively.

[0190] As shown in Figures 33 and 34, the detection region 85 has a first detection section 88 and a second detection section 89. The first detection section 88 is a region of the main substrate 5 located inside the outer edge of the third portion 97 of the second surface 21, as viewed in the first direction 101. The first element section 31 is located within the first detection section 88, as viewed in the first direction 101. The second detection section 89 is a region of the main substrate 5 located inside the outer edge of the fourth portion 98 of the second surface 21, as viewed in the first direction 101. The second detection section 89 is spaced apart from the first detection section 88. The second element section 32 is located within the second detection section 89, as viewed in the first direction 101.

[0191] As shown in Figure 33, when viewed in the first direction 101, the first core portion 10 may be located inside the outer edge of the main substrate 5. As shown in Figure 34, when viewed in the first direction 101, the second core portion 20 may be located inside the outer edge of the main substrate 5.

[0192] (Configuration of the substrate structure) Next, the configuration of the substrate structure 200 according to Embodiment 7 will be described with reference to Figures 35 to 37. For the sake of clarity, the first insulating film 41 and the third insulating film 43 are not shown in Figure 35. In Figure 35, the shaded area represents the first element 3. The cross-section shown in Figure 36 is parallel to the vertical Z direction and the left-right X direction and intersects with the first wiring section 71 and the second wiring section 72. The cross-section shown in Figure 37 is parallel to the vertical Z direction and the left-right X direction and intersects with the third wiring section 73.

[0193] As shown in Figure 35, the first element portion 31 has a fifth coil pattern portion 57, a fifth outer peripheral end portion 59, and a fifth inner peripheral end portion 58. Viewed in the first direction 101, the fifth coil pattern portion 57 is arranged in a spiral shape. Specifically, viewed in the first direction 101, the shape of the fifth coil pattern portion 57 is a spiral shape formed on the same plane. Viewed in the first direction 101, the fifth coil pattern portion 57 is, for example, a clockwise spiral shape from the center outwards. The fifth outer peripheral end portion 59 is connected to the fifth coil pattern portion 57. The fifth inner peripheral end portion 58 is connected to the fifth coil pattern portion 57. The fifth inner peripheral end portion 58 is surrounded by the fifth coil pattern portion 57.

[0194] The second element portion 32 has a sixth coil pattern portion 67, a sixth outer circumference end portion 69, and a sixth inner circumference end portion 68. Viewed in the first direction 101, the sixth coil pattern portion 67 is arranged in a spiral shape. Specifically, viewed in the first direction 101, the shape of the sixth coil pattern portion 67 is a spiral shape formed on the same plane. Viewed in the first direction 101, the winding direction of the sixth coil pattern portion 67 is the same as the winding direction of the fifth coil pattern portion 57. Specifically, viewed in the first direction 101, the sixth coil pattern portion 67 is, for example, a clockwise spiral shape from the center outwards. The sixth outer circumference end portion 69 is connected to the sixth coil pattern portion 67. The sixth inner circumference end portion 68 is connected to the sixth coil pattern portion 67. The sixth inner circumference end portion 68 is surrounded by the sixth coil pattern portion 67.

[0195] Viewed in the first direction 101, a portion of the first wiring section 71 overlaps with the second element section 32. Viewed in the first direction 101, a portion of the second wiring section 72 overlaps with the first element section 31. Viewed in the first direction 101, the third wiring section 73 intersects with both the first element section 31 and the second element section 32.

[0196] The first element section 31 and the second element section 32 are electrically connected in series. Specifically, the first element section 31 and the second element section 32 are connected such that the induced currents generated in each of them flow in the same direction. More specifically, the induced currents generated in each of the first element section 31 and the second element section 32 flow, for example, from the second wiring section 72 towards the first wiring section 71.

[0197] As shown in Figure 36, the second wiring section 72 includes a second wiring member 121 and a second connecting member 122. The second wiring member 121 is in contact with the first insulating film 41 and the third insulating film 43, respectively. The second connecting member 122 is connected to the second wiring member 121. The second connecting member 122 is in contact with the fifth outer peripheral end 59 of the first element section 31 and the first insulating film 41, respectively. The second connecting member 122 is located between the second wiring member 121 and the fifth outer peripheral end 59.

[0198] The first connecting member 112 of the first wiring section 71 is in contact with the sixth outer peripheral end 69 and the first insulating film 41 of the second element section 32, respectively. The first connecting member 112 is located between the first wiring member 111 and the sixth outer peripheral end 69.

[0199] The first insulating film 41 has a fifth inner circumferential surface 145 and a sixth inner circumferential surface 146. The fifth inner circumferential surface 145 surrounds the first connecting member 112. In the space enclosed by the fifth inner circumferential surface 145, the sixth outer circumferential end portion 69 of the second element portion 32 is exposed from the first insulating film 41. In other words, the fifth inner circumferential surface 145 forms a contact hole.

[0200] The sixth inner surface 146 surrounds the second connecting member 122. In the space enclosed by the sixth inner surface 146, the fifth outer peripheral end 59 of the first element portion 31 is exposed from the first insulating film 41. In other words, the sixth inner surface 146 forms a contact hole.

[0201] As shown in Figure 37, the third wiring section 73 includes a third wiring member 131, a third connecting member 132, and a fourth connecting member 133. The third wiring member 131 is in contact with the first insulating film 41 and the third insulating film 43, respectively. The third connecting member 132 is connected to the third wiring member 131. The third connecting member 132 is in contact with the fifth inner circumferential end 58 and the first insulating film 41 of the first element section 31, respectively. The third connecting member 132 is located between the third wiring member 131 and the fifth inner circumferential end 58.

[0202] The fourth connecting member 133 is connected to the third wiring member 131. The fourth connecting member 133 is in contact with the sixth inner circumference end 68 and the first insulating film 41 of the second element portion 32. The fourth connecting member 133 is spaced apart from the third connecting member 132. The fourth connecting member 133 is located between the third wiring member 131 and the sixth inner circumference end 68.

[0203] The first insulating film 41 has a seventh inner surface 147 and an eighth inner surface 148. The seventh inner surface 147 surrounds the third connecting member 132. In the space enclosed by the seventh inner surface 147, the fifth inner end portion 58 of the first element portion 31 is exposed from the first insulating film 41. In other words, the seventh inner surface 147 forms a contact hole.

[0204] The eighth inner surface 148 surrounds the fourth connecting member 133. In the space enclosed by the eighth inner surface 148, the sixth inner end portion 68 of the second element portion 32 is exposed from the first insulating film 41. In other words, the eighth inner surface 148 forms a contact hole.

[0205] Next, with reference to Figure 38, the operation and effects of the current sensor 100 according to Embodiment 7 will be described. In Figure 38, the shaded area indicates the first element 3.

[0206] As shown in Figure 38, leakage flux 109 is generated in the first detection unit 88 and the second detection unit 89. The direction of the leakage flux 109 in the first detection unit 88 is opposite to the direction of the leakage flux 109 in the second detection unit 89. Specifically, the direction of the leakage flux 109 in the first detection unit 88 is, for example, the first direction 101. The direction of the leakage flux 109 in the second detection unit 89 is, for example, the second direction 102. Looking at the first direction 101, the direction of the induced current flowing in the first element unit 31 is, for example, counterclockwise. The direction of the induced current flowing in the second element unit 32 is, for example, clockwise. Note that in Figure 38, the arrows schematically visualize the direction of the induced current flowing in the substrate structure 200.

[0207] The fifth inner circumference end 58 of the first element section 31 and the sixth inner circumference end 68 of the second element section 32 are connected. Therefore, the induced current generated in the first element section 31 and the induced current generated in the second element section 32 flow in the direction from the second wiring section 72 to the first wiring section 71. As a result, the induced electromotive force generated in the first element section 31 and the induced electromotive force generated in the second element section 32 are added together. The added induced electromotive force is sent to the measurement circuit 50 as a voltage signal. From another perspective, the sensitivity of the first element 3 to time changes in magnetic flux density can be improved. As a result, the detection accuracy and detection sensitivity of the current sensor 100 can be improved more effectively.

[0208] Embodiment 8. Next, the configuration of the current sensor 100 according to Embodiment 8 will be described with reference to Figures 39 to 43. The configuration of the current sensor 100 according to Embodiment 8 differs from the configuration of the current sensor 100 according to Embodiment 1 mainly in that the first element 3 has a second coil pattern portion 27, and in other respects it is substantially the same as the configuration of the current sensor 100 according to Embodiment 1. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 1.

[0209] Figure 40 is a schematic plan view showing the state in which the positions of the second coil pattern portion 27, the second inner circumference end portion 28, and the second outer circumference end portion 29 are shifted. The arrows shown in Figure 40 indicate that the respective parts of the second coil pattern portion 27, the second inner circumference end portion 28, and the second outer circumference end portion 29 at the base of the arrow are positioned at the tip of the arrow. In Figures 39 and 40, the shaded areas indicate the first coil pattern portion 17, the first inner circumference end portion 18, and the first outer circumference end portion 19.

[0210] As shown in Figures 39 and 40, the first element 3 further includes a second coil pattern portion 27, a second inner circumference end portion 28, and a second outer circumference end portion 29. Viewed in the first direction 101, the second coil pattern portion 27 is arranged in a spiral shape. Specifically, viewed in the first direction 101, the shape of the second coil pattern portion 27 is a spiral shape formed on the same plane. Viewed in the first direction 101, the winding direction of the second coil pattern portion 27 is opposite to the winding direction of the first coil pattern portion 17. Viewed in the first direction 101, the second coil pattern portion 27 is, for example, a counterclockwise spiral from the center outwards.

[0211] Viewed in the first direction 101, the second coil pattern portion 27 has a portion that does not overlap with the first coil pattern portion 17. Viewed in the first direction 101, the ratio of the area of ​​the portion of the second coil pattern portion 27 that does not overlap with the first coil pattern portion 17 to the total area of ​​the second coil pattern portion 27 is, for example, 90% or more.

[0212] The second outer circumference end 29 is connected to the second coil pattern section 27. Viewed in the first direction 101, the second outer circumference end 29 overlaps with the first wiring section 71. The second outer circumference end 29 is electrically connected to the first wiring section 71. The second inner circumference end 28 is connected to the second coil pattern section 27. The second inner circumference end 28 is surrounded by the second coil pattern section 27. Viewed in the first direction 101, the second inner circumference end 28 overlaps with the first inner circumference end 18. The second inner circumference end 28 is electrically connected to the first inner circumference end 18.

[0213] As shown in Figures 39 and 41, the first element 3 has a first connection portion 26. The first connection portion 26 electrically connects the first coil pattern portion 17 and the second coil pattern portion 27 in series. The first connection portion 26 is connected to the second inner circumference end portion 28. The first connection portion 26 is in contact with the first inner circumference end portion 18 and the first insulating film 41. The first connection portion 26 is located between the first inner circumference end portion 18 and the second inner circumference end portion 28. The first connection portion 26 is surrounded by the first inner circumference surface 141.

[0214] The second coil pattern portion 27 is in contact with the first insulating film 41 and the third insulating film 43, respectively. The first insulating film 41 is located between the first coil pattern portion 17 and the second coil pattern portion 27. From another perspective, the first insulating film 41 separates the first coil pattern portion 17 and the second coil pattern portion 27. A fourth insulating film 44 is provided on the third insulating film 43. The fourth insulating film 44 is made of, for example, the same material as the first insulating film 41.

[0215] As shown in Figure 42, the first insulating film 41 has a ninth inner surface 149. The ninth inner surface 149 surrounds the second connecting member 122. In the space enclosed by the ninth inner surface 149, the first outer peripheral end 19 of the first element 3 is exposed from the first insulating film 41. In other words, the ninth inner surface 149 forms a contact hole.

[0216] The third insulating film 43 has a tenth inner surface 150 and an eleventh inner surface 151. The tenth inner surface 150 surrounds the second connecting member 122. In the space enclosed by the tenth inner surface 150, the second wiring member 121 is exposed from the third insulating film 43. In other words, the tenth inner surface 150 forms a contact hole.

[0217] The 11th inner surface 151 surrounds the first connecting member 112. In the space enclosed by the 11th inner surface 151, the second outer peripheral end 29 of the first element 3 is exposed from the third insulating film 43. In other words, the 11th inner surface 151 forms a contact hole. The fourth insulating film 44 covers the first wiring portion 71 and the second wiring portion 72, respectively.

[0218] Figure 43 is an enlarged schematic cross-sectional view of the area around the first element 3 of the current sensor 100 according to Embodiment 8. The cross-section shown in Figure 43 is parallel to the vertical Z direction and the horizontal X direction, and intersects with the first coil pattern portion 17 and the second coil pattern portion 27, respectively. As shown in Figure 43, the second coil pattern portion 27 is located between the first coil pattern portion 17 and the first surface 11. The first coil pattern portion 17 is located between the second coil pattern portion 27 and the second surface 21.

[0219] The second coil pattern portion 27, the second inner circumference end portion 28, and the second outer circumference end portion 29 are each formed, for example, using a photoengraving process. Since the main substrate 5 is made of glass, the second coil pattern portion 27, the second inner circumference end portion 28, and the second outer circumference end portion 29 can be easily formed using a photoengraving process.

[0220] Next, the effects and benefits of the current sensor 100 according to Embodiment 8 will be described. According to the current sensor 100 of Embodiment 8, the first insulating film 41 separates the first coil pattern portion 17 and the second coil pattern portion 27. Viewed in the first direction 101, the second coil pattern portion 27 has a portion that does not overlap with the first coil pattern portion 17. Therefore, the portion of the second coil pattern portion 27 that does not overlap with the first coil pattern portion 17 is at a greater distance from the first coil pattern portion 17 compared to the portion of the second coil pattern portion 27 that overlaps with the first coil pattern portion 17. As a result, the insulation between the first coil pattern portion 17 and the second coil pattern portion 27 can be improved. This makes it possible to reduce the failure rate of the current sensor 100.

[0221] In the above description, the first element 3 was described in which it has a two-layer structure consisting of a first coil pattern portion 17 and a second coil pattern portion 27. However, this disclosure is not limited to the above configuration. Specifically, for example, the first element 3 may have a multilayer coil pattern of three or more layers. The first element 3 of the current sensor 100 according to each of Embodiments 2 to 7 may have a multilayer coil pattern.

[0222] Embodiment 9. Next, the configuration of the current sensor 100 according to Embodiment 9 will be described with reference to Figures 44 and 45. The current sensor 100 according to Embodiment 9 differs from the current sensor 100 according to Embodiment 5 mainly in that the second element 4 has a fourth coil pattern portion 47, and in other respects, it is substantially the same as the current sensor 100 according to Embodiment 5. The following description will focus on the differences from the configuration of the current sensor 100 according to Embodiment 5.

[0223] Figure 44 is an enlarged schematic cross-sectional view of the area around the first element 3 of the current sensor 100 according to Embodiment 9. The cross-section shown in Figure 44 is parallel to the vertical Z direction and the horizontal X direction, and intersects with the first element 3 and the second element 4, respectively. As shown in Figure 44, the substrate structure 200 has a fifth insulating film 45. The fifth insulating film 45 is in contact with the second insulating film 42 and the third insulating film 43, respectively. The second element 4 has a fourth coil pattern portion 47, a fourth inner circumference end portion 48, and a second connection portion 46.

[0224] The fourth coil pattern portion 47 is located between the third coil pattern portion 37 and the second surface 21. The fourth coil pattern portion 47 is in contact with the second insulating film 42 and the fifth insulating film 45, respectively. The second insulating film 42 is located between the third coil pattern portion 37 and the fourth coil pattern portion 47. From another perspective, the second insulating film 42 separates the third coil pattern portion 37 and the fourth coil pattern portion 47. The fifth insulating film 45 covers the fourth coil pattern portion 47. The configuration of the first element 3 is substantially the same as the configuration of the first element 3 of the current sensor 100 according to Embodiment 8.

[0225] Figure 45 is a schematic plan view illustrating the configuration of the second element 4 as seen in the first direction 101. In Figure 45, the shaded areas represent the fourth coil pattern portion 47, the fourth outer peripheral end portion 49, and the fourth inner peripheral end portion 48.

[0226] As shown in Figures 44 and 45, the second connection portion 46 electrically connects the third coil pattern portion 37 and the fourth coil pattern portion 47 in series. The second connection portion 46 is connected to the fourth inner circumference end portion 48. The second connection portion 46 is in contact with the third inner circumference end portion 38.

[0227] The second element 4 has a fourth outer peripheral end 49. The fourth outer peripheral end 49 is connected to the fourth coil pattern portion 47. The fourth inner peripheral end 48 is connected to the fourth coil pattern portion 47. When viewed in the first direction 101, the fourth coil pattern portion 47 has a portion that does not overlap with the third coil pattern portion 37. When viewed in the first direction 101, the ratio of the area of ​​the portion of the fourth coil pattern portion 47 that does not overlap with the third coil pattern portion 37 to the total area of ​​the fourth coil pattern portion 47 is, for example, 90% or more.

[0228] Next, the effects and benefits of the current sensor 100 according to Embodiment 9 will be described. According to the current sensor 100 of Embodiment 9, the second insulating film 42 separates the third coil pattern portion 37 and the fourth coil pattern portion 47. Viewed in the first direction 101, the fourth coil pattern portion 47 has a portion that does not overlap with the third coil pattern portion 37. Therefore, the portion of the fourth coil pattern portion 47 that does not overlap with the third coil pattern portion 37 is at a greater distance from the third coil pattern portion 37 compared to the portion of the fourth coil pattern portion 47 that overlaps with the third coil pattern portion 37. As a result, the insulation between the third coil pattern portion 37 and the fourth coil pattern portion 47 can be improved. This makes it possible to reduce the failure rate of the current sensor 100.

[0229] The embodiments and examples disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description, and all modifications within the scope of the claims are intended to be included in the meaning of equivalents and within the scope. [Explanation of symbols]

[0230] 1 Magnetic core, 2 Gap, 3 First element, 4 Second element, 5 Main board, 6 Auxiliary board, 7 Connection wiring, 8 Current line, 9 Flexible printed circuit, 10 First core section, 11 First surface, 12 First core member, 13 First protrusion, 14 Second protrusion, 15 First adhesive surface, 17 First coil pattern section, 18 First inner circumference end, 19 First outer circumference end, 20 Second core section, 21 Second surface, 22 Second core member, 23 Third protrusion, 24 Fourth protrusion, 25 Second adhesive surface, 26 First connection section, 27 Second coil pattern section, 28 Second inner circumference end, 29 Second outer circumference end, 31 First element section, 32 Second element section, 37 Third coil pattern section, 38 Third inner circumference end, 39 Third outer circumference end, 41 First insulating film, 42 Second insulating film, 43 Third insulating film, 44 Fourth insulating film, 45 5th insulating film, 46 2nd connection part, 47 4th coil pattern part, 48 4th inner circumference end, 49 4th outer circumference end, 50 measurement circuit, 51 1st main surface, 52 2nd main surface, 53 3rd main surface, 54 4th main surface, 57 5th coil pattern part, 58 5th inner circumference end, 59 5th outer circumference end, 60 magnetic material, 61 1st alignment mark, 62 2nd alignment mark, 63 3rd alignment mark, 64 4th alignment mark, 65 5th alignment mark, 67 6th coil pattern part, 68 6th inner circumference end, 69 6th outer circumference end, 71 1st wiring part, 72 2nd wiring part, 73 3rd wiring part, 75 1st conductive material, 76 2nd conductive material, 78 1st magnetic material part, 79 2nd magnetic material part, 80 substrate fixing part, 81 1st substrate fixing member, 82 2nd substrate fixing member, 83 85 Adhesive part, 86 Detection area, 87 Outer peripheral area, 88 First detection part, 89 Second detection part, 91 First outer peripheral surface, 92 Second outer peripheral surface, 93 Third outer peripheral surface, 94 Fourth outer peripheral surface, 95 First part, 96 Second part, 97 Third part, 98 Fourth part, 99 Contact hole, 100 Current sensor, 101 First direction, 102 Second direction, 108 Magnetic flux signal (first arrow), 109 Leakage flux (second arrow), 111 First wiring member, 112 First connecting member, 121 Second wiring member, 122 Second connecting member, 131 Third wiring member, 132 Third connecting member, 133 Fourth connecting member, 141 First inner peripheral surface, 142 Second inner peripheral surface, 143 Third inner peripheral surface, 144 Fourth inner peripheral surface, 145 Fifth inner peripheral surface, 1466th inner surface, 147 7th inner surface, 148 8th inner surface, 149 9th inner surface, 150 10th inner surface, 151 11th inner surface, 161 1st flat plate member, 162 2nd flat plate member, 163 Alignment mark member, 164 Individual piece section, 171 1st gap section, 172 2nd gap section, 181 1st member, 182 2nd member, 183 3rd member, 184 4th member, 200 Substrate structure, H Thickness, X Left-right direction, Y Front-back direction, Z Up-down direction.

Claims

1. Current lines and, A magnetic core with a gap, A substrate structure placed in the aforementioned gap, It comprises a fixing portion that is positioned in the gap and is located between the magnetic core and the substrate structure, The magnetic core has a first surface and a second surface facing the first surface. The gap is formed between the first surface and the second surface, The magnetic core and the gap surround the current line. The aforementioned substrate structure is The main substrate is located in the gap, The main substrate is provided with a first element that detects the magnetic flux generated by the current flowing through the current line, Viewed in the direction from the first surface toward the second surface, the first element overlaps with the first surface and the second surface, The main substrate is made of translucent glass or translucent acrylic. The substrate structure and the fixing portion are sandwiched between the magnetic core. The fixing portion has a magnetic material located at least one of the spaces between the first surface and the first element and between the second surface and the first element. A current sensor wherein the saturation magnetic flux density of the magnetic material is higher than the saturation magnetic flux density of the magnetic core.

2. The current sensor according to claim 1, wherein the substrate structure has alignment marks provided on the main substrate and aligned with at least one of the first surface and the second surface.

3. The current sensor according to claim 1, wherein the relative permeability of the magnetic material is higher than the relative permeability of the magnetic core.

4. The substrate structure further comprises an auxiliary substrate covering the first element, The current sensor according to claim 1 or 2, wherein the auxiliary substrate is made of a light-transmitting material.

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