Current detection device

Abstract

To provide a construction for detecting a current with better accuracy when connecting a shunt resistor with a bus bar, a lead frame or the like.SOLUTION: A current detection device comprises: a resistor of a stacked structure including first and second tabular electrodes, and a tabular resistor located between the first and second electrodes; and a first tabular conductor in which the current to be measured flows and which is connected to the resistor. The first conductor includes a thick-plate part having a first thickness in the stacking direction and a thin-plate part whose thickness in the stacking direction is thinner than the first thickness in a region overlapping the first electrode as seen from the stacking direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] In recent years, as the current used in electronic devices has become larger, modules known as power modules, which convert and control power by switching power semiconductors, have been actively developed. Power modules often use highly heat-dissipating substrates that can handle large currents, such as ceramic substrates called DBC substrates, which are formed by directly bonding copper to an alumina substrate. In addition, power semiconductors, shunt resistors, and other components may be directly mounted on plate-shaped wiring (bus bars or lead frames) made of copper plates or other materials. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-358283 A [Patent Document 2] Patent Publication No. 2022-066642 Summary of the Invention [Problem to be solved by the invention]

[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 of drawing out a voltage signal by wire bonding in such a configuration.

[0006] On the other hand, there may be cases where the bus bar or lead frame is directly connected to a vertical shunt resistor to extract the current outside the power module. In that case, the method of extracting the voltage signal to detect the current with high accuracy and the method of connecting to the control circuit board become issues.

[0007] The present invention has been made to solve such problems, and has an object to provide a configuration for detecting current with greater accuracy when a shunt resistor is joined to a bus bar, a lead frame, or the like. [Means for solving the problem]

[0008] An example of a current detection device according to the present invention is a resistor having a laminated structure including first and second plate-shaped electrodes and a plate-shaped resistive element disposed between the first and second electrodes, the resistor being laminated in a thickness direction; a plate-shaped first conductor through which a current to be measured flows and which is connected to the resistor; A current detection device comprising: The current detection device is connected to a power module; The power module comprises: a plate-shaped second conductor through which the current to be measured flows and which is connected to the resistor; a first voltage detection terminal and a second voltage detection terminal; Equipped with an upper surface of the first electrode and a lower surface of the end side of the first conductor are connected; a lower surface of the second electrode and an upper surface of the second conductor are connected, the resistor is disposed in a stack between the first conductor and the second conductor; the second voltage detection terminal is connected to the second conductor or the second electrode; The first conductor is A thick plate portion having a first thickness in a stacking direction; a thin plate portion having a thickness in a stacking direction smaller than the first thickness in a region overlapping with the first electrode as viewed from the stacking direction; Equipped with The upper surface of the thin plate portion and the first voltage detection terminal are connected by a wire.

[0009] In one example, the thin plate portion is provided at an end of the first conductor.

[0010] In one example, the thin plate portion has a through hole penetrating the first conductor in a stacking direction, The wire is connected between a side surface of the first conductor and the through hole.

[0011] In one example, the thin plate portion has a slit extending inward from a side surface of the first conductor, and the wire is connected between another side surface of the first conductor and the slit.

[0012] In one example, the thin plate portion has an extension portion extending in a lateral direction, and the wire is connected to the extension portion.

[0013] An example of a current detection device according to the present invention is a resistor having a laminated structure, the resistor having a plate-like first electrode and a plate-like second electrode, and a plate-like resistive body disposed between the first electrode and the second electrode, the resistor being laminated in a thickness direction; a plate-shaped first conductor through which a current to be measured flows and which is connected to the resistor; A current detection device comprising: The current detection device is connected to a power module; The power module comprises: a plate-shaped second conductor through which the current to be measured flows and which is connected to the resistor; a first voltage detection terminal and a second voltage detection terminal; Equipped with an upper surface of the first electrode and a lower surface of the end side of the first conductor are connected; a lower surface of the second electrode and an upper surface of the second conductor are connected, the resistor is disposed in a stack between the first conductor and the second conductor; the second voltage detection terminal is connected to the second conductor or the second electrode; the first electrode includes an exposed portion in which a part of an upper surface of the first electrode is exposed from the first conductor; The upper surface of the exposed portion and the first voltage detection terminal are connected by a wire.

[0014] In one example, the first conductor has a slit extending inward from a side surface, and the exposed portion is exposed within the slit.

[0015] In one example, the exposed portion protrudes upward from the first electrode, A step is provided on the upper surface of the first electrode between a portion connected to the first conductor and the exposed portion. Effect of the Invention

[0016] According to the present invention, the structure in which a vertical shunt resistor is joined to a bus bar or lead frame and connected to a high heat dissipation power module substrate is simplified, and highly accurate voltage detection is possible.

[0017] In addition, the heat dissipation of the shunt resistor is improved, and excellent detection accuracy is achieved even in the case of a large current.

[0018] In addition, since the absolute value of the temperature coefficient of resistance (TCR) can be made small (TCR can be made close to zero) by using a voltage extraction method, excellent detection accuracy is achieved. [Brief description of the drawings]

[0019] [Figure 1] 1 is a perspective view of a configuration example of a resistor 10 according to a first embodiment of the present invention. [Diagram 2] 1 is a top view of an example configuration including a current detection device 100. FIG. [Diagram 3] FIG. 3 is a side view of the configuration of FIG. 2 . [Figure 4] 3 is a diagram for explaining TCR control in the current detection device 100. [Figure 5A] FIG. [Figure 5B]FIG. 13 is a top view of another modified example of the first embodiment. [Figure 6] FIG. 5B is a side view of the example of FIG. 5A. [Figure 7] FIG. 13 is a top view of another modified example of the first embodiment. [Figure 8A] FIG. 13 is a top view of another modified example of the first embodiment. [Figure 8B] FIG. 13 is a top view of another modified example of the first embodiment. [Figure 8C] FIG. 13 is a top view of another modified example of the first embodiment. [Figure 9] FIG. 11 is a top view including a current detection device 100 according to a second embodiment. [Figure 10] FIG. 11 is a side view including a current detection device 100 according to a second embodiment. [Figure 11] FIG. 13 is a top view of a modified example of the second embodiment. [Figure 12] FIG. 13 is a top view of another modified example of the second embodiment. [Figure 13] FIG. 11 is a top view of a configuration example including a current detection device 100 according to a third embodiment. [Figure 14] FIG. 11 is a side view of a configuration example including a current detection device 100 according to a fourth embodiment. [Figure 15] FIG. 11 is a top view of a configuration example including a current detection device 100 according to a fourth embodiment. [Figure 16] Partially exploded view of Figure 14. [Figure 17] A diagram of a portion of the configuration extracted from Figure 15. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. [Example 1] 1 is a perspective view of a configuration example of a resistor 10 according to a first embodiment of the present invention.

[0021] The resistor 10 has a plate-like first electrode 12 and a plate-like second electrode 13, and a plate-like resistive body 11 disposed between the first electrode 12 and the second electrode 13, and is a resistor with a laminated structure laminated in the thickness direction. The resistor 10 is, for example, a resistor for detecting current 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 body 11 is formed in a square or rectangular shape, but the shape can be designed arbitrarily.

[0022] 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, Ni-Cr, or a composite material containing a metal. 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, for example, 0.1 mm each. The thickness of the resistor 11 is, for example, 0.3 mm.

[0023] FIG. 1 shows an example of resistor 10, but other configurations are possible, for example a current sensing resistor disclosed in JP 2018-170478 A may be used.

[0024] 2 is a top view of an example configuration including the current detection device 100. The current detection device 100 is connected to a power module 200.

[0025] The current detection device 100 includes a plate-shaped bus bar 20 (first conductor). A current to be measured flows through the bus bar 20. The bus bar 20 is connected to the resistor 10. The thickness of the bus bar 20 is, for example, 2 mm. The bus bar 20 is, for example, a U-terminal, a V-terminal, or a W-terminal of a three-phase AC.

[0026] 2, the resistor 10 does not actually appear, but for the sake of convenience, a pattern is added to indicate the position of the resistor 10. The position of the resistor 10 may be indicated by the same pattern in the drawings described later.

[0027] The power module 200 includes plate-shaped bus bars 21 and 22. The bus bar 21 is a negative terminal, and the bus bar 22 is a positive terminal. The power module 200 also includes plate-shaped wiring 23 (second conductor), wiring 24, and wiring 25. The wirings 23 to 25 are made of copper, for example, and are, for example, thick copper patterns. The thickness of the wirings 23 to 25 is, for example, within a range of 0.3 mm to 0.8 mm, and is 0.5 mm as a specific example. A current to be measured flows through the wiring 23. The wiring 23 is connected to the resistor 10.

[0028] The power module 200 includes one or more power devices 30. Each power device 30 is connected to wirings 23 to 25 directly or via a bonding wire 40. The bonding wire 40 is made of, for example, Au, Ag, Cu, Al, or the like.

[0029] Power module 200 includes a case 45, and the inside and outside of case 45 are connected via bus bars 20-22.

[0030] The power module 200 includes an insulating substrate 26. The insulating substrate 26 is made of, for example, ceramics, and more specifically, silicon nitride, aluminum nitride, alumina, zirconia, or the like. In these cases, the thickness of the insulating substrate 26 is, for example, within a range of 0.1 mm to 1 mm, and a specific example is 0.3 mm. As another specific example, the insulating substrate 26 is made of glass epoxy, polyimide, or Teflon (registered trademark). In these cases, the thickness of the insulating substrate 26 is within a range of 0.4 mm to 1.6 mm, and a specific example is 1.6 mm.

[0031] The power module 200 includes a first voltage detection terminal 51 and a second voltage detection terminal 52. A voltage signal for measuring a current is output to the outside via the first voltage detection terminal 51 and the second voltage detection terminal 52. The first voltage detection terminal 51 is connected to the bus bar 20 via a wire bonding 41 (wire), and the second voltage detection terminal 52 is connected to the lower surface of the second electrode 13 or to the wiring 23 via a wiring 42 (the wiring 42 may be omitted depending on the arrangement of the second voltage detection terminal 52).

[0032] In this way, when the busbar 20 is directly connected to the resistor 10, the thickness of the busbar 20 is determined by the connection conditions between the power module 200 and the external configuration and the current value used. For this reason, it is difficult to adjust the thickness of the busbar 20 to match the resistor 10, and a relatively thick busbar (for example, 2 mm thick) is often connected. If a thick busbar 20 is used, the difference in height between the upper surface of the busbar 20 and the first voltage detection terminal 51 becomes large, and a problem is expected in which wire bonding cannot be performed appropriately. For example, if wire bonding is performed at a location with a large difference in height, the inclination of the loop shape becomes steep, which is not appropriate. Furthermore, in order to make the inclination of the loop shape gentler, the distance between the connections needs to be increased, which is not appropriate because the wire becomes long. One of the objectives of the current detection device 100 according to this embodiment is to solve such problems.

[0033] Fig. 3 shows a side view of the configuration of Fig. 2. This side view is seen from the top of the paper of Fig. 2, and therefore the left-right direction on the paper is reversed from that of Fig. 2. In particular, the joint between the current detection device 100 and the power module 200 and its surroundings are shown. The wiring 23, the first voltage detection terminal 51, and the second voltage detection terminal 52 are formed on the insulating substrate 26. The resistor 10 is arranged in a layered manner between the bus bar 20 and the wiring 23.

[0034] The resistor 10 is laminated on the upper side of the wiring 23, and in particular, the lower surface of the second electrode 13 is connected to the upper surface of the wiring 23. This connection is realized by bonding using, for example, soldering, welding, low-temperature sintering, etc. It is preferable that this connection does not use wire bonding.

[0035] Furthermore, a bus bar 20 is laminated on the upper side of the resistor 10, and in particular, the upper surface of the first electrode 12 is connected to the lower surface of the bus bar 20 on the side surface 20a side. In the example of Fig. 3, the side surface 20a is the side surface that constitutes the longitudinal end of the bus bar 20. This connection is realized by bonding using, for example, soldering, welding, low-temperature sintering, or the like. It is preferable that this connection does not use wire bonding.

[0036] The busbar 20 includes a thick plate portion 20b and a thin plate portion 20c. The thin plate portion 20c is provided on the side surface 20a of the busbar 20 (i.e., in a region including the side surface 20a or at least a part of the side surface 20a).

[0037] The thick plate portion 20b has a first thickness in the stacking direction (or thickness direction, the same applies below). The thin plate portion 20c has a thickness in the stacking direction that is thinner than the first thickness (second thickness) in a region that overlaps with the first electrode 12 when viewed from the stacking direction, and a step ΔT is formed between the upper surface of the thick plate portion 20b and the upper surface of the thin plate portion 20c.

[0038] The upper surface of the thin plate portion 20c and the first voltage detection terminal 51 are connected by wire bonding 41. By forming the thin plate portion 20c on the bus bar 20 in this manner, the height difference between the upper surface of the bus bar 20 and the first voltage detection terminal 51 in the wiring 23 is reduced, and appropriate connection can be made using short wire bonding 41. Note that the height difference between the first voltage detection terminal 51 in the wiring 23 is preferably 1.5 mm or less.

[0039] The control of the TCR in the current detection device 100 will be described with reference to FIG. 4. FIG. 4 is a view from the top of FIG. 2, as in FIG. 3, and therefore the left-right direction on the paper is reversed from that in FIG. 2. The thinner the thin plate portion 20c is (or the larger the step ΔT is), the closer the connection position of the wire bonding 41 is to the resistor 11, and therefore the closer the TCR is to the TCR of the resistor 11. Also, the thicker the thin plate portion 20c is (or the smaller the step ΔT is), the farther the connection position of the wire bonding 41 is from the resistor 11, and the larger the TCR is due to the influence of the bus bar 20 (first conductor) made of a material such as copper, which has a large TCR. That is, the TCR can be changed by changing the thickness of the thin plate portion 20c.

[0040] Because the current mainly flows along current path A, the current density is high near current path A and decreases as it moves away from current path A. The current density in thin plate portion 20c decreases as it approaches side surface 20a due to its positional relationship with current path A. Due to the relationship between the current density in thin plate portion 20c and the TCR of thin plate portion 20c (busbar 20 or first conductor), the TCR in current detection device 100 can be changed by the connection position of wire bonding 41.

[0041] Therefore, by changing the thickness of the thin plate portion 20c (the magnitude of the step ΔT) and / or the connection position of the wire bonding 41 on the thin plate portion 20c, the temperature coefficient of resistance (TCR) of the current detection device 100 can be controlled to perform accurate current detection. For example, when the step ΔT is increased, the TCR of the current detection device 100 changes in the negative direction. Also, for example, when the connection position of the wire bonding 41 on the thin plate portion 20c is moved closer to the side surface 20a, the TCR of the current detection device 100 changes in the negative direction. The thickness of the thin plate portion 20c (the magnitude of the step ΔT) has a larger effect on the temperature coefficient of resistance (TCR) of the current detection device 100 than the connection position of the wire bonding 41 on the thin plate portion 20c.

[0042] Thus, according to the current detection device 100 of this embodiment, by changing the thickness of the thin plate portion 20c (the magnitude of the step ΔT) and / or the connection position of the wire bonding 41 on the thin plate portion 20c, the TCR of the current detection device 100 can be controlled to perform accurate current detection.

[0043] Modifications of the first embodiment are shown in Fig. 5A, Fig. 5B, and Fig. 6. Fig. 5A and Fig. 5B are top views showing different modifications, and Fig. 6 is a side view corresponding to Fig. 5A. Fig. 6 is a view seen from the top of Fig. 5A, and therefore the left-right direction on the paper is reversed from Fig. 5A. Fig. 6 shows a cross-sectional view of the busbar 20 taken along a cross section passing through the through hole 20d. In the busbar 20, the thin plate portion 20c has a through hole 20d penetrating the busbar 20 in the lamination direction. The top surface of the resistor 10 (i.e., the top surface of the first electrode 12) is exposed within the through hole 20d.

[0044] In the example of FIG. 5A, the side surface 20a refers to a side surface constituting a longitudinal end of the busbar 20, and in the example of FIG. 5B, the side surface 20a refers to a side surface constituting a widthwise end of the busbar 20. Here, the "width direction" refers to a direction perpendicular to both the longitudinal direction and the lamination direction. The wire bonding 41 is connected between the side surface 20a of the busbar 20 and the through hole 20d. In other words, in the example of FIG. 5A, the wire bonding 41 is connected to the longitudinal end side of the through hole 20d, not to the thick plate portion 20b side, and in the example of FIG. 5B, the wire bonding 41 is connected to the widthwise end side of the through hole 20d. In this way, the current density in the vicinity of the connection position of the wire bonding 41 becomes lower, and the control effect of the TCR becomes greater.

[0045] Fig. 7 shows a top view of another modified example of the first embodiment. The thin plate portion 20c and / or the resistor 10 includes an extension portion 20e extending in a lateral direction (a direction perpendicular to the stacking direction). In the example of Fig. 7, the extension portion 20e extends in a width direction (a direction perpendicular to the stacking direction and perpendicular to the longitudinal direction of the busbar 20). The wire bonding 41 is connected to the extension portion 20e (for example, to its upper surface). In this way, the current density in the vicinity of the connection position of the wire bonding 41 becomes lower, and the control effect of the TCR becomes greater.

[0046] 7, the upper surface of the extension portion 20e is covered by the bus bar 20, but in a modified example, the upper surface of the extension portion 20e may be exposed and not covered by the bus bar 20. Alternatively, in the example of Fig. 7, the resistor 10 also has a shape having an extension portion along the extension portion 20e, but the resistor 10 may be rectangular like the first embodiment (Fig. 2).

[0047] 8A to 8C show top views of various modified examples of Example 1. In the example of FIG. 8A, the side surface constituting the longitudinal end of busbar 20 is referred to as side surface 20a, and in the examples of FIGS. 8B and 8C, the side surface constituting the widthwise end of busbar 20 is referred to. Thin plate portion 20c has slit 20f extending from side surface 20a of busbar 20 toward the inside of busbar 20. Slit 20f is a slit that penetrates busbar 20 in the thickness direction, and the upper surface of resistor 10 (i.e., the upper surface of first electrode 12) is exposed within slit 20f.

[0048] Wire bonding 41 is connected between a side surface of busbar 20 (however, a side surface different from the side surface on which slit 20f is formed) and slit 20f. That is, in the example of FIG. 8A, slit 20f is formed in side surface 20a constituting a longitudinal end of busbar 20, and wire bonding 41 is connected between slit 20f and a side surface constituting a widthwise end of busbar 20. In the example of FIG. 8B, slit 20f is formed in side surface 20a constituting a widthwise end of busbar 20, and wire bonding 41 is connected between slit 20f and a side surface constituting a longitudinal end of busbar 20. In the example of FIG. 8C, slit 20f is formed in side surface 20a constituting a widthwise end of busbar 20, and wire bonding 41 is connected between slit 20f and a side surface constituting the opposite widthwise end of busbar 20.

[0049] In this way, the current density in the vicinity of the connection position of the wire bonding 41 becomes lower, and the TCR control effect becomes greater.

[0050] In the example of FIG. 8A, the bonding wire 41 is connected to the first voltage detection terminal 51 side with respect to the slit 20f, but may be connected to the side opposite to the first voltage detection terminal 51 with respect to the slit 20f.

[0051] [Example 2] In the second embodiment, a step is formed on the first electrode 12 of the resistor 10. The second embodiment will be described below, but the description of the parts common to the first embodiment may be omitted.

[0052] 9 and 10 show an example of a configuration including a current detection device 100 according to a second embodiment. FIG. 9 is a top view, and FIG. 10 is a side view. FIG. 10 is a view seen from the top of FIG. 9, and therefore the left-right direction on the page is reversed from that in FIG. 9. The first electrode 12 of the resistor 10 has an exposed portion 12a. The exposed portion 12a is a portion of the upper surface of the first electrode 12 that is not covered by the bus bar 20 and is exposed from the bus bar 20. The upper surface of the exposed portion 12a and a first voltage detection terminal 51 are connected by wire bonding 41.

[0053] 10, exposed portion 12a protrudes upward from first electrode 12. Therefore, an electrode step 12b is provided on the upper surface of first electrode 12 between the portion connected to bus bar 20 and exposed portion 12a. This configuration makes it easy to position first electrode 12 and bus bar 20.

[0054] In the second embodiment as well, it is possible to control the TCR of the current detection device 100. For example, when the step difference ΔT between the bus bar 20 and the exposed portion 12a of the first electrode 12 is increased, the TCR of the current detection device 100 changes in the negative direction.

[0055] Fig. 11 shows a top view of a modification of Example 2. The position of exposed portion 12a is changed. That is, while exposed portion 12a is disposed on the longitudinal side of busbar 20 in Example 2 (Fig. 10), exposed portion 12a is disposed on the width direction side of busbar 20 in this modification.

[0056] 12 shows a top view of another modified example of Example 2. Bus bar 20 has slits 20g extending inward from the side surface, and exposed portion 12a is exposed within slits 20g.

[0057] In the above-mentioned second embodiment and its modified examples, it is possible to adopt a configuration in which exposed portion 12a does not protrude upward, that is, a configuration in which electrode step 12b is not formed and exposed portion 12a is flush with other portions.

[0058] [Example 3] In the third embodiment, the power module 200 in the first or second embodiment is configured by direct lead bonding. Hereinafter, the third embodiment will be described, but the description of the parts common to the first or second embodiment may be omitted.

[0059] 13 is a top view of a configuration example including a current detection device 100 according to Example 3. The current detection device 100 is connected to a power module 200. The power module 200 includes a lead frame 27 (second conductor), and the resistor 10, each power device 30, and the like are connected via the lead frame 27.

[0060] The lead frame 27 is, for example, a Cu frame, and has a thickness of, for example, 0.1 mm or more, specifically, 0.5 mm.

[0061] Resistor 10 is laminated on the upper side of lead frame 27, and in particular, the lower surface of second electrode 13 is connected to the upper surface of lead frame 27. This connection is realized by joining using soldering or welding, for example. Lead frame 27 and second voltage detection terminal 52 are connected by wire bonding 43, and the voltage on the second electrode 13 side of current detection device 100 is extracted from lead frame 27 by wire bonding 43.

[0062] [Example 4] Example 4 is similar to Example 3 in that a printed circuit board is used as part of the power module 200. Example 4 will be described below, but descriptions of parts common to any of Examples 1 to 3 may be omitted.

[0063] 14 to 17 show an example of a configuration including a current detection device 100 according to a fourth embodiment. Fig. 14 is a side view (partially including a cross-sectional view), Fig. 15 is a top view, Fig. 16 is a partially exploded view of Fig. 14, and Fig. 17 is a view of a part of the configuration extracted from Fig. 15. Fig. 14 is a view seen from the right side of the paper surface of Fig. 15.

[0064] The power module 200 includes a printed circuit board 60. A groove is formed in the lead frame 27, and the printed circuit board 60 is fitted into this groove (FIG. 16). The printed circuit board 60 includes an insulating substrate 61 (e.g., a PCB substrate) and a conductive pattern 62 (e.g., copper foil). The insulating substrate 61 has a thickness of, for example, 0.3 mm, and the conductive pattern 62 has a thickness of, for example, 18 μm.

[0065] 14, the lower surface of the second electrode 13 of the resistor 10 is connected to the upper surface of the conductive pattern 62. This connection is realized by joining using, for example, soldering or welding. The conductive pattern 62 and the second voltage detection terminal 52 are connected by a bonding wire 43, and the voltage on the side of the second electrode 13 in the current detection device 100 is extracted from the conductive pattern 62 by the bonding wire 43.

[0066] In the third embodiment, the wire bonding 43 is directly bonded to the lead frame 27, but if such a configuration cannot be adopted, it is also possible to bond a printed circuit board 60 for voltage extraction and connect the wire bonding 43 to this, as in the fourth embodiment. [Explanation of symbols]

[0067] 10...Resistor 11…Resistor 12...1st electrode 12a...Exposed part 12b...electrode step 13…Second electrode 20...Busbar (first conductor) 20a…Side 20b…Thick plate section 20c...Thin plate part 20d...Through hole 20e...Extension part 20f…Slit 20g…Slit 21…Busbar 22…Busbar 23...Wiring (second conductor) 24…Wiring 25…Wiring 26...Insulating substrate 27...Lead frame (second conductor) 30…Power device 40…Wire bonding 41...Wire bonding (wire) 42…Wiring 43…Wire bonding 45…Case 51...First voltage detection terminal 52…Second voltage detection terminal 60...Printed circuit board 61...Insulating substrate 62...Conductive pattern 100...Current detection device 200…Power module A…Current path ΔT…step

Claims

1. a resistor having a laminated structure including first and second plate-shaped electrodes and a plate-shaped resistor disposed between the first and second electrodes, the resistor being laminated in a thickness direction; a plate-shaped first conductor through which a current to be measured flows and which is connected to the resistor; A current detection device comprising: The current detection device is connected to a power module; The power module comprises: a plate-shaped second conductor through which the current to be measured flows and which is connected to the resistor; a first voltage detection terminal and a second voltage detection terminal; Equipped with an upper surface of the first electrode and a lower surface of the end side of the first conductor are connected to each other; a lower surface of the second electrode and an upper surface of the second conductor are connected to each other; the resistor is disposed in a stack between the first conductor and the second conductor; the second voltage detection terminal is connected to the second conductor or the second electrode; The first conductor is A thick plate portion having a first thickness in a stacking direction; a thin plate portion having a thickness in a stacking direction smaller than the first thickness in a region overlapping with the first electrode as viewed from the stacking direction; Equipped with The upper surface of the thin plate portion and the first voltage detection terminal are connected by a wire. Current detection device.

2. The current detection device according to claim 1 , wherein the thin plate portion is provided at an end of the first conductor.

3. the thin plate portion has a through hole penetrating the first conductor in a stacking direction, The current detection device according to claim 1 , wherein the wire is connected between a side surface of the first conductor and the through hole.

4. the thin plate portion has a slit extending inward from a side surface of the first conductor, The current detection device according to claim 1 , wherein the wire is connected between another side surface of the first conductor and the slit.

5. The current detection device according to claim 1 , wherein the thin plate portion has an extension portion extending in a lateral direction, and the wire is connected to the extension portion.

6. a resistor having a laminated structure including first and second plate-shaped electrodes and a plate-shaped resistor disposed between the first and second electrodes, the resistor being laminated in a thickness direction; a plate-shaped first conductor through which a current to be measured flows and which is connected to the resistor; A current detection device comprising: the current detection device is connected to a power module; The power module comprises: a plate-shaped second conductor through which the current to be measured flows and which is connected to the resistor; a first voltage detection terminal and a second voltage detection terminal; Equipped with an upper surface of the first electrode and a lower surface of the end side of the first conductor are connected to each other; a lower surface of the second electrode and an upper surface of the second conductor are connected to each other; The resistor is disposed in a stack between the first conductor and the second conductor, the second voltage detection terminal is connected to the second conductor or the second electrode; the first electrode includes an exposed portion in which a part of an upper surface of the first electrode is exposed from the first conductor; The upper surface of the exposed portion and the first voltage detection terminal are connected by a wire. Current detection device.

7. The current detection device according to claim 6 , wherein the first conductor has a slit extending inward from a side surface thereof, and the exposed portion is exposed within the slit.

8. The exposed portion protrudes upward from the first electrode, The current detection device according to claim 6 , wherein a step is provided on the upper surface of the first electrode between a portion connected to the first conductor and the exposed portion.

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