Current detection device

Abstract

This current detection device is provided with: a lamination-structure resistor having plate-like first electrode and second electrode, and a plate-like resistor disposed between the first electrode and the second electrode; and a voltage detection substrate having plate-like first conductor and second conductor which are connected to the resistor, plate-like first voltage terminal and second voltage terminal which detect a voltage, and a first voltage detection pattern and a second voltage detection pattern. The first conductor is connected to the first electrode via a flat portion of the first voltage terminal, and the second conductor is connected to the second electrode via a flat portion of the second voltage terminal. The resistor is laminated between the flat portion of the first voltage terminal and the flat portion of the second voltage terminal and between the first conductor and the second conductor. A connection portion of the first voltage terminal is connected to one end of the first voltage detection pattern, a connection portion of the second voltage terminal is connected to one end of the second voltage detection pattern, and the voltage detection substrate is interposed between the connection portion of the first voltage terminal and the connection portion of the second voltage terminal.

Description

Current detection device

[0001] The present invention relates to a current detection device.

[0002] In recent years, as the currents used in electronic devices have become larger, there has been active development of power modules, which convert and control power by switching power semiconductors. Power modules often use high-heat-dissipation substrates capable of carrying large currents, such as ceramic substrates called DBC substrates, which are formed by directly bonding copper to an alumina substrate. In some cases, components such as power semiconductors and shunt resistors are directly mounted on plate-shaped wiring (bus bars or lead frames) made of copper or other materials.

[0003] JP 2001-358283 A JP 2022-066642 A

[0004] The current detection shunt resistor described in Patent Document 1 aims to improve heat dissipation and reliability and to shorten the wiring length, but is not suitable for passing large currents because it requires bonding and connecting multiple wires.

[0005] Therefore, in order to pass a large current through such a vertically structured shunt resistor, a surface mounting method using an L-shaped electrode member has been devised as described in Patent Document 2. Patent Document 2 describes a method for drawing out a voltage signal by wire bonding in such a configuration.

[0006] On the other hand, in order to detect even larger currents, cases are being considered in which vertical shunt resistors are connected by being sandwiched between plate-shaped wiring such as bus bars or lead frames. In such cases, issues arise regarding how to extract the voltage signal required for accurate current detection and how to connect to the control circuit board.

[0007] The present invention has been made to solve such problems, and aims to provide a configuration for detecting current more accurately when a shunt resistor is connected by being sandwiched between plate-shaped wiring such as a bus bar or a lead frame.

[0008] An example of a current detection device according to the present invention comprises: a resistor having a laminated structure, the resistor having plate-shaped first and second electrodes and a plate-shaped resistive element arranged between the first and second electrodes; first and second plate-shaped conductors through which a current to be measured flows and which are connected to the resistor; first and second plate-shaped voltage terminals for detecting voltage; and a voltage detection board having an insulating substrate and a first and second voltage detection pattern, the first voltage detection pattern being arranged on one surface of the insulating substrate, and the second voltage detection pattern being arranged on the other surface of the insulating substrate, the first voltage terminal and the second voltage terminal both having a flat portion and a connection portion formed by extending a part of a side surface, the first conductor being connected to the first electrode via the flat portion of the first voltage terminal, and the second conductor being connected to the second electrode via the flat portion of the second voltage terminal, The resistor is arranged in a stacked manner between the flat portion of the first voltage terminal and the flat portion of the second voltage terminal, and between the first conductor and the second conductor; the connection portion of the first voltage terminal is connected to one end of the first voltage detection pattern; the connection portion of the second voltage terminal is connected to one end of the second voltage detection pattern; and the voltage detection board is arranged sandwiched between the connection portion of the first voltage terminal and the connection portion of the second voltage terminal.

[0009] In one example, the first voltage detection pattern and the second voltage detection pattern are arranged so as to overlap each other when viewed from the stacking direction of the voltage detection board.

[0010] In one example, in at least one of the first voltage terminal and the second voltage terminal, the resistivity of the material of the first portion including the connection portion is higher than the resistivity of the material of the second portion including at least a part of the flat portion.

[0011] An example of a current detection device according to the present invention comprises: a laminated resistor having plate-shaped first and second electrodes and a plate-shaped resistive element arranged between the first and second electrodes; plate-shaped first and second conductors through which a current to be measured flows and which are connected to the resistor; and a voltage detection board having an insulating substrate and a first voltage detection pattern and a second voltage detection pattern, wherein the first voltage detection pattern is arranged on one side of the insulating substrate and the second voltage detection pattern is arranged on the other side of the insulating substrate, and the first and second voltage detection patterns are arranged so that at least a portion of the first and second voltage detection patterns overlap when viewed from the stacking direction of the insulating substrate, the first conductor is connected to the first electrode, and the second conductor is connected to the second electrode, the resistor is arranged in a laminated structure between the first and second conductors, and one end of the first voltage detection pattern is connected to the first electrode.

[0012] In one example, one end of the second voltage detection pattern is connected to the second electrode.

[0013] In one example, one end of the second voltage detection pattern is connected to the second conductor.

[0014] In one example, the first electrode, the second electrode, the first voltage detection pattern, and the second voltage detection pattern each have an exposed portion on a side surface, the resistor and the voltage detection board are arranged parallel to each other, the exposed portion of the first electrode is connected to the exposed portion of the first voltage detection pattern, and the exposed portion of the second electrode is connected to the exposed portion of the second voltage detection pattern.

[0015] In one example, the first electrode and the second electrode have voltage detection pattern connection portions formed by extending a portion of their side surfaces, the resistor and the voltage detection board are arranged in parallel, and the voltage detection board is arranged sandwiched between the voltage detection pattern connection portion of the first electrode and the voltage detection pattern connection portion of the second electrode.

[0016] In one example, at least one of the resistor and the voltage detection board has a slit extending from a side surface, and the resistor and the voltage detection board intersect and are fixed to each other by being inserted into the slit.

[0017] The current detection device of the present invention has a simplified structure in which a vertical shunt resistor is sandwiched and connected to plate-shaped wiring such as a bus bar or lead frame, and has a voltage signal extraction structure that enables high-precision voltage detection, and can be easily connected to a control circuit board.

[0018] Furthermore, in the current detection device according to the present invention, the heat dissipation of the shunt resistor is improved, and excellent detection accuracy is achieved even in the case of a large current.

[0019] 12 is a perspective view showing a configuration example of a resistor 10 according to a first embodiment of the present invention. FIG. 13 is a side view showing a configuration example of a current detection device 100. FIG. 14 is a top view of the current detection device 100 of FIG. 2. FIG. 15 is a bottom view of the voltage detection board 30 of FIG. 2. FIG. 16 is a side view showing a configuration example of a current detection device 100 according to a modified example of the first embodiment. FIG. 17 is a view showing a further modified example of the second voltage terminal 22 of FIG. 5. FIG. 18 is a view showing a further modified example of the second voltage terminal 22 of FIG. 5. FIG. 19 is a side view showing a configuration example of a current detection device 100 according to a modified example of the second embodiment of the present invention. FIG. 19 is a plan view showing a configuration example of a current detection device 100 according to a modified example of the second embodiment. FIG. 20 is a side view of the current detection device 100 of FIG. 9. FIG. 21 is a perspective view showing a configuration example of a current detection device 100 according to another modified example of the second embodiment. FIG. 22 is a perspective view showing a configuration example of a current detection device 100 according to yet another modified example of the second embodiment. FIG. 23 is a perspective view of the current detection device 100 of FIG. 12 when viewed from a direction different from that of FIG. 12.

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0021] 1 is a perspective view showing an example of the configuration of a resistor 10 according to a first embodiment of the present invention.

[0022] The resistor 10 is a laminated resistor having a plate-shaped first electrode 12 and a plate-shaped second electrode 13, and a plate-shaped resistive element 11 disposed between the first electrode 12 and the second electrode 13. The resistor 10 is, for example, a resistor for current detection or a shunt resistor. In particular, the resistor 10 can be said to be a shunt resistor with a vertical structure. In the example of FIG. 1, the resistive element 11 is formed in a square or rectangular shape, but the shape can be designed arbitrarily.

[0023] The material of the first electrode 12 and the second electrode 13 is a highly conductive metal material such as Cu. The material of the resistor 11 is a metal material suitable for current detection, such as Cu-Ni, Cu-Mn, or Ni-Cr, or a composite material containing a metal material. The dimensions of the resistor 10 are, for example, 5 mm x 5 mm x 0.5 mm thick. The thicknesses of the first electrode 12 and the second electrode 13 are each, for example, 0.1 mm. The thickness of the resistor 11 is, for example, 0.3 mm.

[0024] FIG. 1 shows an example of a resistor 10, but other configurations are possible, and for example, a current detection resistor disclosed in Japanese Patent Application Laid-Open No. 2018-170478 may be used.

[0025] 2 to 4 show an example of the configuration of the current detection device 100. Fig. 2 is a side view of the current detection device 100, Fig. 3 is a top view of the current detection device 100, and Fig. 4 is a bottom view of only the voltage detection board 30. Note that Fig. 2 shows a cross section of the via hole 34 only in the portion of the via hole 34 described below.

[0026] Current detection device 100 includes resistor 10, plate-shaped first voltage terminal 21, plate-shaped second voltage terminal 22, plate-shaped bus bar 23 (first conductor), plate-shaped Cu frame 24 (second conductor), and voltage detection board 30. A current to be measured flows through bus bar 23 and Cu frame 24. Bus bar 23 and Cu frame 24 are connected to resistor 10. First voltage terminal 21 and second voltage terminal 22 are used to detect a voltage corresponding to the current to be measured.

[0027] The first voltage terminal 21 has a flat portion 21 a and a connecting portion 21 b formed by extending a portion of the side surface. Similarly, the second voltage terminal 22 has a flat portion 22 a and a connecting portion 22 b formed by extending a portion of the side surface.

[0028] A bus bar 23 is connected to the first electrode 12 via the flat portion 21 a of the first voltage terminal 21. The connection between the first electrode 12 and the first voltage terminal 21 can be achieved by joining using, for example, welding, soldering, brazing, low-temperature sintering, etc. It is preferable that this connection does not use wire bonding. The connection between the first voltage terminal 21 and the bus bar 23 can be achieved by joining using, for example, welding, soldering, brazing, low-temperature sintering, etc. Similarly, a Cu frame 24 is connected to the second electrode 13 via the flat portion 22 a of the second voltage terminal 22.

[0029] With this structure, the resistor 10 is stacked and disposed between the flat portion 21 a of the first voltage terminal 21 and the flat portion 22 a of the second voltage terminal 22 , and between the bus bar 23 and the Cu frame 24 .

[0030] The voltage detection board 30 has an insulating substrate 31 and conductive first and second voltage detection patterns 32 and 33. The first voltage detection pattern 32 is disposed on one surface of the insulating substrate 31, and the second voltage detection pattern 33 is disposed on the other surface of the insulating substrate 31.

[0031] Via holes 34 are formed in the voltage detection board 30, penetrating the voltage detection board 30 in the stacking direction (or thickness direction, the same applies below). The second voltage detection pattern 33 is connected to the second voltage output portion 35 through the via holes 34. This connection is preferably made without using wire bonding.

[0032] The voltage detection board 30 is sandwiched between the connection portion 21b of the first voltage terminal 21 and the connection portion 22b of the second voltage terminal 22. The connection portion 21b of the first voltage terminal 21 is connected to one end of the first voltage detection pattern 32. This connection can be achieved by joining using, for example, welding, soldering, brazing, low-temperature sintering, or the like. It is preferable that this connection does not use wire bonding. Similarly, the connection portion 22b of the second voltage terminal 22 is connected to one end of the second voltage detection pattern 33.

[0033] In this specification, "one end" of a structure may mean, for example, one of the two ends to which the structure extends, and may particularly mean the terminal end, but it may also mean not only a part that includes the strict terminal end, but also a part that can essentially be considered to be the terminal end, such as the area to which connection portion 21b is connected in first voltage detection pattern 32 in Figure 3.

[0034] As described above, in the current detection device 100, the first voltage terminal 21 and the second voltage terminal 22 are connected to the first electrode 12 and the second electrode 13 of the vertically structured resistor 10, respectively. The first voltage terminal 21 and the second voltage terminal 22 are connected to a control circuit (not shown) via the first voltage detection pattern 32 and the second voltage detection pattern 33 of the voltage detection board 30. This configuration makes it possible to transmit a voltage signal to the control circuit.

[0035] With this configuration, it is possible to detect the current with higher accuracy. For example, the voltage can be extracted by the plate-shaped first voltage terminal 21 and second voltage terminal 22 without using wire bonding, which improves accuracy.

[0036] In this embodiment, the first voltage detection pattern 32 and the second voltage detection pattern 33 are arranged close to each other. That is, as shown in Fig. 3, when viewed from the stacking direction of the voltage detection board 30, at least a portion of the first voltage detection pattern 32 and at least a portion of the second voltage detection pattern 33 are arranged to overlap each other. This configuration can reduce the influence of external noise.

[0037] Fig. 5 is a side view showing an example of the configuration of a current detection device 100 according to a modified example of the first embodiment. The first voltage terminal 21 and the second voltage terminal 22 are made of a composite material, and the material of the flat portions 21a and 22a is different from the material of the connecting portions 21b and 22b. In Fig. 5, patterns are particularly added to the connecting portions 21b and 22b to illustrate that the materials are different (the same applies to Figs. 6 and 7 below).

[0038] The resistivity (ρ) of the material of the connecting portions 21b and 22b is higher than the resistivity of the material of the flat portions 21a and 22a. By increasing the resistivity of the connecting portions 21b and 22b, the temperature coefficient of resistance (TCR) of the current detection device 100 can be controlled.

[0039] In the first voltage terminal 21, the flat portion 21a and the connecting portion 21b may be joined by butt welding, or may be joined by a method such as machining a thin groove in the flat portion 21a and embedding the thin connecting portion 21b therein.

[0040] Due to the difference in resistivity, the path along arrow A in Figure 5 becomes dominant as the current path. Voltage is detected from the point farthest from the current path, and in this case, the TCR shifts to the negative side. This is because a large potential difference occurs within the first voltage terminal 21, making it difficult for current to flow near the connection part 21b (current density becomes low), and the TCR value changes. The same is true for the second voltage terminal 22.

[0041] The connecting portions 21b and 22b are preferably formed of a material with a significantly higher resistivity than the flat portions 21a and 22a. For example, if the flat portions 21a and 22a are formed of oxygen-free Cu (1.7 μΩ cm) and the connecting portions 21b and 22b are formed of a CuMn-based alloy (20 to 130 μΩ cm), a CuNi-based alloy (10 to 50 μΩ cm), a CuZn-based alloy (20 to 40 μΩ cm), a Ni-based alloy (80 to 140 μΩ cm), or the like, a resistivity ratio of 10 times or more can be obtained depending on the configuration.

[0042] In this modified example, both the first voltage terminal 21 and the second voltage terminal 22 are made of a composite material, but if at least one of the first voltage terminal 21 and the second voltage terminal 22 is made of such a material, the same effect can be obtained.

[0043] Figure 6 shows a further modified example of the second voltage terminal 22 of Figure 5. Figure 6(a) shows a bottom view, and Figure 6(b) shows a side view. The second voltage terminal 22 is made of a composite material and includes a first portion 22c and a second portion 22d. The second portion 22d is preferably made of a material with a significantly higher resistivity than the first portion 22c.

[0044] The first portion 22c includes at least a part of the flat portion 22a. The second portion 22d includes the connecting portion 22b. In this example, the first portion 22c and the second portion 22d do not overlap at all when viewed from the stacking direction.

[0045] The resistivity of the material of the second portion 22d is higher than the resistivity of the material of the first portion 22c. By increasing the resistivity of the second portion 22d, the temperature coefficient of resistance (TCR) of the current detection device 100 can be controlled.

[0046] When the second portion 22d is enlarged relative to the first portion 22c, the voltage extraction portion is brought closer to the current path, and the TCR shifts to the positive side. For example, when the boundary between the second portion 22d and the first portion 22c is moved toward the first portion 22c (i.e., in the direction of arrow B in FIG. 6A), the TCR shifts to the positive side.

[0047] It is preferable that the second voltage terminal 22 be in a state that allows easy joining, such as soldering, to the second electrode 13, Cu frame 24, voltage detection board 30, etc., and it is preferable, for example, to apply Ni plating or Au flash plating to the entire second voltage terminal 22.

[0048] 6 shows only the second voltage terminal 22, but the first voltage terminal 21 can also be configured in a similar manner. Furthermore, if the voltage detection board 30 is a flexible board, this increases the degree of freedom in connection with the control circuit, which is more preferable.

[0049] Figure 7 shows a further modification of the second voltage terminal 22 of Figure 5. Figure 7(a) shows a bottom view, and Figure 7(b) shows a side view.

[0050] In this example, the position of connection portion 22b has been moved in the lateral direction (a direction perpendicular to the extension direction of connection portion 22b and the thickness direction of second voltage terminal 22), and in particular, it is now located at the lateral end of connection portion 22b. The distribution of first portion 22c and second portion 22d has also been changed, and in particular, the lateral dimension of second portion 22d has been reduced, forming a rectangular area in the plan view that is an extension of connection portion 22b. In this example, as shown in FIG. 7B , first portion 22c and second portion 22d partially overlap each other when viewed in the stacking direction.

[0051] In this example, when the second portion 22d is enlarged relative to the first portion 22c, the TCR shifts to the positive side. For example, when the boundary between the first portion 22c and the second portion 22d is moved toward the first portion 22c (i.e., in the direction of arrow B or arrow C in FIG. 7A), the TCR shifts to the positive side.

[0052] 7 shows only the second voltage terminal 22, the first voltage terminal 21 can also be configured in a similar manner. By changing the configurations of the first voltage terminal 21 and the second voltage terminal 22 in this way, it becomes possible to control the TCR more flexibly.

[0053] In Figures 6 and 7, the first portion 22c and the second portion 22d may be joined by butt welding, or by forming a thin groove in the first portion 22c and embedding the thin second portion 22d therein.

[0054] 8 is a side view showing a configuration example of a current detection device 100 according to a second embodiment of the present invention. Hereinafter, the second embodiment will be described, but the description of parts common to the first embodiment may be omitted.

[0055] The resistor 10 and the voltage detection board 30 are arranged parallel to each other. The first voltage terminal 21 and the second voltage terminal 22 of the first embodiment ( FIG. 1 ) are not provided in the second embodiment, and instead, a bus bar 23 is connected to the first electrode 12 of the resistor 10. Similarly, a Cu frame 24 is connected to the second electrode 13 of the resistor 10. For example, the first electrode 12 and the bus bar 23 may be in direct contact with each other, or may be joined by welding, soldering, brazing, low-temperature sintering, or the like. This connection is preferably made without using wire bonding. The same applies to the second electrode 13 and the Cu frame 24. This structure allows the resistor 10 to be stacked between the bus bar 23 and the Cu frame 24 in a simpler structure.

[0056] One end of the first voltage detection pattern 32 is connected to the first electrode 12. For example, the side of the first electrode 12 (the side of the first electrode 12 in FIG. 8 that faces the voltage detection board 30) and the side of the first voltage detection pattern 32 (the side of the first voltage detection pattern 32 in FIG. 8 that faces the resistor 10) are joined directly by welding or by soldering using a joining material. This joining is preferably not performed by wire bonding. Similarly, one end of the second voltage detection pattern 33 is connected to the second electrode 13.

[0057] As described above, the first electrode 12, the second electrode 13, the first voltage detection pattern 32, and the second voltage detection pattern 33 each have an exposed portion on their side surface. The exposed portion of the first electrode 12 is bonded to the exposed portion of the first voltage detection pattern 32, and the exposed portion of the second electrode 13 is bonded to the exposed portion of the second voltage detection pattern 33. This connection is preferably made without using wire bonding.

[0058] In this embodiment, the resistor 10 and the voltage detection board 30 have the same or almost the same thickness. The resistor 11 and the insulating board 31, the first electrode 12 and the first voltage detection pattern 32, and the second electrode 13 and the second voltage detection pattern 33 also have the same or almost the same thickness. This configuration facilitates bonding.

[0059] In the second embodiment, the current can be detected with higher accuracy, similar to the first embodiment. For example, the voltage can be extracted without using wire bonding, which improves accuracy.

[0060] An example of the configuration of a current detection device 100 according to a modified example of the second embodiment will be described with reference to Fig. 9 and Fig. 10. Fig. 9 is a plan view, and Fig. 10 is a side view.

[0061] The first electrode 12 has a voltage detection pattern connection portion 12a formed by extending a portion of its side surface. Similarly, the second electrode 13 has a voltage detection pattern connection portion 13a formed by extending a portion of its side surface.

[0062] The resistor 10 and the voltage detection board 30 are arranged in parallel, and in particular, the voltage detection board 30 is arranged sandwiched between the voltage detection pattern connection portion 12a of the first electrode 12 and the voltage detection pattern connection portion 13a of the second electrode 13. With this configuration, the voltage detection board 30 can be stably fixed by the voltage detection pattern connection portions 12a and 13a.

[0063] An example of the configuration of a current detection device 100 according to another modification of the second embodiment will be described with reference to Fig. 11 . The resistor 10 has a slit 10a extending inward from its side surface. The slit 10a is, for example, rectangular. The slit 10a is formed by forming a slit in each of the corresponding regions of the resistive element 11, the first electrode 12, and the second electrode 13.

[0064] Similarly, the voltage detection board 30 has a slit 30a extending inward from the side surface thereof. The slit 30a is, for example, rectangular. The slit 30a is formed in, for example, an insulating board 31.

[0065] The resistor 10 and the voltage detection board 30 are arranged to intersect (for example, perpendicular to) each other and are fixed to each other by being inserted into the slits. In the example of Fig. 11, they are arranged so that the slit positions of each other are aligned, i.e., the voltage detection board 30 is inserted into the slit 10a of the resistor 10, and the resistor 10 is inserted into the slit 30a of the voltage detection board 30.

[0066] 11, the connection for drawing out the voltage is realized by, for example, soldering. For example, one end of the first voltage detection pattern 32 and the first electrode 12 are connected by soldering. It is preferable that this connection does not use wire bonding.

[0067] With this configuration, positioning can be performed via the slit, making the assembly process easier.

[0068] 11, both the resistor 10 and the voltage detection board 30 have slits, but only one of them may have a slit. Even if only one of them has a slit, they can be inserted so that they cross each other as shown in FIG.

[0069] 12 and 13, a configuration example of a current detection device 100 according to yet another modification of the second embodiment will be described. Fig. 12 is a perspective view seen from the same direction as Fig. 11, and Fig. 13 is a perspective view seen from a different direction.

[0070] In this example, at the longitudinal ends of the bus bar 23 and the Cu frame 24, the resistor 10 (particularly the first electrode 12) extends longer than the bus bar 23, and the Cu frame 24 extends longer than the resistor 10 (particularly the second electrode 13).

[0071] A step portion 30b is formed on the voltage detection board 30. The voltage detection board 30 is disposed in the same orientation as in FIG. 11 (a direction intersecting with the resistor 10). In particular, the side of the step portion 30b is disposed in contact with the upper surface of the resistor 10 (i.e., the upper surface of the first electrode 12), and a portion of the side surface other than the step portion 30b is disposed in contact with the upper surface of the Cu frame 24. As in FIG. 11, the resistor 10 may have a slit 10a extending inward from the side surface, and the voltage detection board 30 may be inserted into the slit 10a of the resistor 10. In the examples of FIGS. 12 and 13, the resistor 10 has the slit 10a and the voltage detection board 30 has the step portion 30b, but only one of the slit 10a and the step portion 30b may be disposed.

[0072] 12 , the first voltage detection pattern 32 is connected to the first electrode 12 by soldering via solder 41. Furthermore, as shown in FIG. 13 , one end of the second voltage detection pattern 33 is connected to the Cu frame 24 by soldering via solder 42. These connections are preferably made without using wire bonding. As described above, the Cu frame 24 is connected to the second electrode 13, and therefore the second voltage detection pattern 33 is connected to the second electrode 13 as a result.

[0073] DESCRIPTION OF SYMBOLS 10...resistor 10a...slit 11...resistor 12...first electrode 12a...voltage detection pattern connection portion 13a...voltage detection pattern connection portion 13...second electrode 21...first voltage terminal 21a...flat portion 21b...connection portion 21c...first portion 21d...second portion 22...second voltage terminal 22a...flat portion 22b...connection portion 22c...first portion 22d...second portion 23...bus bar (first conductor) 24...Cu frame (second conductor) 30...voltage detection board 30a...slit 30b...step portion 31...insulating board 32...first voltage detection pattern 33...second voltage detection pattern 34...via hole 35...second voltage extraction portion 100...current detection device

Claims

1. A resistor having a laminated structure, the resistor having plate-shaped first and second electrodes and a plate-shaped resistive element disposed between the first and second electrodes; plate-shaped first and second conductors through which a current to be measured flows and which are connected to the resistor; plate-shaped first and second voltage terminals for detecting voltage; and a voltage detection board having an insulating substrate and a first and second voltage detection pattern, the first voltage detection pattern being disposed on one surface of the insulating substrate, and the second voltage detection pattern being disposed on the other surface of the insulating substrate, the first voltage terminal and the second voltage terminal both having a flat portion and a connection portion formed by extending a portion of a side surface, the first conductor being connected to the first electrode via the flat portion of the first voltage terminal, and the second conductor being connected to the second electrode via the flat portion of the second voltage terminal, a connection portion of the first voltage terminal connected to one end of the first voltage detection pattern; a connection portion of the second voltage terminal connected to one end of the second voltage detection pattern; and a voltage detection board sandwiched between the connection portion of the first voltage terminal and the connection portion of the second voltage terminal.

2. The current detection device according to claim 1, wherein at least a portion of the first voltage detection pattern and at least a portion of the second voltage detection pattern are arranged to overlap when viewed from the stacking direction of the voltage detection board.

3. A current detection device as described in claim 1 or 2, wherein in at least one of the first voltage terminal and the second voltage terminal, the resistivity of the material of the first portion including the connection portion is higher than the resistivity of the material of the second portion including at least a part of the flat portion.

4. A current detection device comprising: a resistor with a laminated structure having plate-shaped first and second electrodes and a plate-shaped resistive element arranged between the first and second electrodes; plate-shaped first and second conductors through which a current to be measured flows and which are connected to the resistor; an insulating substrate; and a voltage detection board having a first voltage detection pattern and a second voltage detection pattern, wherein the first voltage detection pattern is arranged on one surface of the insulating substrate and the second voltage detection pattern is arranged on the other surface of the insulating substrate, and wherein at least a portion of the first voltage detection pattern and at least a portion of the second voltage detection pattern overlap when viewed from the lamination direction of the insulating substrate, the first conductor is connected to the first electrode, and the second conductor is connected to the second electrode, the resistor is arranged in a laminated manner between the first conductor and the second conductor, and one end of the first voltage detection pattern is connected to the first electrode.

5. The current detection device according to claim 4, wherein one end of the second voltage detection pattern is connected to the second electrode.

6. The current detection device according to claim 4, wherein one end of the second voltage detection pattern is connected to the second conductor.

7. The current detection device described in claim 5, wherein the first electrode, the second electrode, the first voltage detection pattern and the second voltage detection pattern each have an exposed portion on a side surface, the resistor and the voltage detection board are arranged parallel to each other, the exposed portion of the first electrode is connected to the exposed portion of the first voltage detection pattern, and the exposed portion of the second electrode is connected to the exposed portion of the second voltage detection pattern.

8. A current detection device as described in claim 5, wherein the first electrode and the second electrode have voltage detection pattern connection portions formed by extending a portion of their side surfaces, the resistor and the voltage detection board are arranged in parallel, and the voltage detection board is sandwiched between the voltage detection pattern connection portion of the first electrode and the voltage detection pattern connection portion of the second electrode.

9. A current detection device as claimed in any one of claims 4 to 6, wherein at least one of the resistor and the voltage detection board has a slit extending from a side surface, and the resistor and the voltage detection board intersect and are fixed to each other by being inserted into the slit.

Images