Shunt resistor and method for manufacturing shunt resistor

Abstract

To provide a shunt resistor in which formation of burrs is suppressed.SOLUTION: A shunt resistor 100 has a resistor 10 and an electrode 20. The resistor 10 has a main surface 10f, a back surface 10g, and connection surfaces 10a and 10b. The back surface 10g is located on an opposite side of the main surface 10f. The connection surfaces 10a and 10b connect the main surface 10f and the back surface 10b. The electrode 20 is connected to the connection surfaces 10a and 10b. A polishing trace T is formed on the main surface 10f.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a shunt resistor and a method for manufacturing the shunt resistor.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2017-174843 (Patent Document 1) discloses a shunt resistor having a resistor body and electrodes. After manufacturing the shunt resistor, the electrical resistance value of the shunt resistor is adjusted by trimming.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] A shunt resistor according to one aspect of the present disclosure includes a resistor body and electrodes. The resistor body has a main surface, a back surface, and a connection surface. The back surface is located on the opposite side of the main surface. The connection surface connects the main surface and the back surface. The electrodes are connected to the connection surface. Abrasion marks are formed on the main surface.

[0005] A method for manufacturing a shunt resistor according to one aspect of the present disclosure includes a step of preparing electrodes and a resistor body, and a step of trimming the resistor body. The resistor body has a main surface, a back surface, and a connection surface. The back surface is located on the opposite side of the main surface. The connection surface connects the main surface and the back surface. The electrodes are connected to the connection surface. In the trimming step, abrasion marks are formed on the main surface using a tool.

Brief Description of the Drawings

[0006]

Figure 1

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[0007] (Embodiment 1) FIG. 1 is a schematic perspective view of a shunt resistor 100 according to Embodiment 1. FIG. 2 is a schematic plan view of the shunt resistor 100 according to Embodiment 1. FIG. 3 is a schematic bottom view of the shunt resistor 100 according to Embodiment 1. FIG. 4 is a schematic front view of the shunt resistor 100 according to Embodiment 1. As shown in FIGS. 1 to 4, the shunt resistor 100 is a four-terminal shunt resistor. The shunt resistor 100 includes a resistor body 10 and a pair of electrodes 20. The electrode 20 includes a first electrode 21 and a second electrode 22.

[0008] As shown in FIG. 1, the resistor 10 is plate-shaped. The thickness direction of the resistor 10 is defined as the z-direction. The direction perpendicular to the z-direction is defined as the x-direction. The direction perpendicular to the z-direction and the x-direction is defined as the y-direction. The resistor 10 is, for example, rectangular in a plan view.

[0009] The resistor 10 has a main surface 10f, a back surface 10g, a connection surface, and side surfaces. The main surface 10f and the back surface 10g are end surfaces of the resistor 10 in the z-direction. The back surface 10g is located on the opposite side of the main surface 10f. As shown in FIG. 2, in the plan view of the main surface 10f, the main surface 10f is surrounded by a first connection surface 10a, a second connection surface 10b, a first side surface 10c, and a second side surface 10d. Also, the main surface 10f is disposed between a first electrode 21 and a second electrode 22 in the x-direction.

[0010] The connection surface includes a first connection surface 10a and a second connection surface 10b. The first connection surface 10a and the second connection surface 10b are end surfaces of the resistor 10 in the y-direction. The second connection surface 10b is located on the opposite side of the first connection surface 10a. Each of the first connection surface 10a and the second connection surface 10b connects the main surface 10f and the back surface 10g.

[0011] The side surfaces include a first side surface 10c and a second side surface 10d. The first side surface 10c and the second side surface 10d are end surfaces of the resistor 10 in the x-direction. The second side surface 10d is located on the opposite side of the first side surface 10c. Each of the first side surface 10c and the second side surface 10d connects the main surface 10f and the back surface 10g. Each of the first side surface 10c and the second side surface 10d connects the first connection surface 10a and the second connection surface 10b. That is, each of the first side surface 10c and the second side surface 10d is continuous with the main surface 10f, the back surface 10g, and the connection surface.

[0012] A recess 10e is formed in the first side surface 10c. The recess 10e, for example, extends along the x-direction from the first side surface 10c toward the second side surface 10d. The recess 10e penetrates the resistor 10 along the z-direction so as to reach from the main surface 10f to the back surface 10g.

[0013] The resistor 10 is a conductor. The material constituting the resistor 10 may be, for example, any one of a copper (Cu)-manganese (Mn)-tin (Sn) alloy (e.g., Constantan (registered trademark): CuMn7Sn), a copper-manganese-nickel (Ni) alloy (e.g., Manganin (registered trademark): CuMn12Ni), and a nickel-chromium (Cr)-aluminum (Al) alloy (e.g., Evanohm (registered trademark)). The material constituting the resistor 10 may be a material other than the above. The material constituting the resistor 10 may be appropriately selected according to characteristics such as specific resistance and temperature coefficient of resistance. The width of the first electrode 21 in the x direction and the width of the second electrode 22 in the x direction are, for example, equal to the width of the resistor 10 in the x direction.

[0014] The first electrode 21 is connected to the first connection surface 10a. The second electrode 22 is connected to the second connection surface 10b. The first electrode 21, the second electrode 22, and the resistor 10 may be joined, for example, by welding.

[0015] Each of the first electrode 21 and the second electrode 22 has a first end 20a, a second end 20b, and an inner surface 20s. Each of the first electrode 21 and the second electrode 22 is bent inward such that the second end 20b of the first electrode 21 and the second end 20b of the second electrode 22 face each other with a gap in the y direction. Note that the second end 20b of the first electrode 21 and the second end 20b of the second electrode 22 face the back surface 10g with a gap in the z direction.

[0016] Specifically, the first end 20a is an end face connected to the resistor 10. The second end 20b is an end face located on the opposite side of the first end 20a. A slit 20c is formed in each of the first electrode 21 and the second electrode 22. The slit 20c penetrates the first electrode 21 along the thickness direction. The slit 20c penetrates the second electrode 22 along the thickness direction.

[0017] As shown in FIG. 4, the inner surface 20s is a surface facing the back surface 10g of the resistor 10. The inner surface 20s is continuous with the second end 20b. The inner surface 20s of the first electrode 21 has a first inner surface 21s1 and a second inner surface 21s2 (not shown). The first inner surface 21s1 and the second inner surface 21s2 are arranged to be spaced apart from each other via the slit 20c. The inner surface 20s of the second electrode 22 has a first inner surface 22s1 and a second inner surface 22s2. The first inner surface 22s1 and the second inner surface 22s2 are arranged to be spaced apart from each other via the slit 20c.

[0018] The position of the slit 20c in the x direction is on the first side surface 10c side rather than at the center of the resistor 10 in the x direction. As shown in FIG. 3, the distance in the x direction from the first side surface 10c to the slit 20c is smaller than the distance in the x direction from the second side surface 10d to the slit 20c. By doing so, even if the region in which the recess 10e extends in the x direction expands, it is possible to reduce the amount of change in the surface temperature of the main surface 10f and the amount of change in the temperature coefficient of resistance during energization.

[0019] In each of the first electrode 21 and the second electrode 22, the portion on the first side surface 10c side as viewed from the slit 20c may be a terminal to which a wiring for measuring a voltage is connected. In each of the first electrode 21 and the second electrode 22, the portion on the second side surface 10d side as viewed from the slit 20c may be connected to a wiring through which a constant current flows. That is, by passing a constant current through the shunt resistor 100, the value of the current flowing through the shunt resistor 100 is detected based on the value of the voltage between the terminal of the first electrode 21 and the terminal of the second electrode 22.

[0020] Each of the first electrode 21 and the second electrode 22 may be a conductor. The material constituting the first electrode 21 and the second electrode 22 may be, for example, either copper or a copper alloy.

[0021] The resistance temperature coefficient (TCR: Temperature Coefficient of Resistance) of the shunt resistor 100 is, for example, not less than -50 ppm / °C and not more than 50 ppm / °C. The resistance temperature coefficient of the shunt resistor 100 is measured, for example, using the RM3543 manufactured by Hioki Electric Co., Ltd. The resistance temperature coefficient of the shunt resistor 100 is measured, for example, in a state where it is mounted on a substrate.

[0022] Here, the feature of the shunt resistor 100 according to the first embodiment is that, as shown in FIGS. 1 and 2, a polishing mark T is formed on the main surface 10f. In this way, it is possible to obtain the shunt resistor 100 in which the burrs are not formed on the main surface 10f and the back surface 10g and the electrical resistance value is adjusted. Here, the polishing mark T is a processing mark formed by trimming the main surface 10f of the resistor 10, and is, for example, a portion having a surface roughness larger than that of the back surface 10g (the surface that has not been trimmed) of the resistor 10.

[0023] In the conventional shunt resistor, the electrical resistance value of the shunt resistor was adjusted by trimming the first side surface 10c or the second side surface 10d. However, burrs are generated on the main surface 10f and the back surface 10g by trimming the first side surface 10c or the second side surface 10d. In the shunt resistor having the configuration shown in FIG. 1, the first electrode 21 and the second electrode 22 are bent inward so that the second end 20b of the first electrode 21 and the second end 20b of the second electrode 22 face each other with a space therebetween in the y direction. Therefore, the first electrode 21 and the second electrode 22 interfere with the operation of bringing a deburring tool or the like into contact with the back surface 10g, and as a result, it becomes difficult to remove the burrs generated on the back surface 10g.

[0024] As will be described later, in the shunt resistor 100 according to the first embodiment, by trimming the main surface 10f (specifically, polishing at least a part of the main surface 10f using a tool), the electrical resistance value in the shunt resistor 100 is adjusted. Therefore, no burrs are generated on the back surface 10g of the resistor 10.

[0025] Also, when trimming the side surface, depending on the amount of trimming, changes occur in the temperature coefficient of resistance of the shunt resistor 100 and the distribution of the surface temperature on the main surface 10f. On the other hand, when trimming the main surface 10f as in the shunt resistor 100 according to the first embodiment, the changes in the temperature coefficient of resistance of the shunt resistor 100 and the distribution of the surface temperature on the main surface 10f due to the trimming amount in the thickness direction (z direction) of the resistor body 10 are small. By trimming the main surface 10f in this way, a polishing mark T is formed on the main surface 10f.

[0026] The area or position of the region where the polishing mark T is formed may be adjusted according to the adjustment amount of the electrical resistance value of the shunt resistor 100. The polishing mark T may be formed on 30% or more of the main surface 10f. That is, the region where the polishing mark T is formed may be 30% or more of the area of the main surface 10f. The polishing mark T may be formed only on a part of the main surface 10f. For example, the polishing mark T may be formed in the central portion, and a region where the polishing mark T is not formed may be arranged at the outer peripheral portion of the main surface 10f. As shown in FIG. 2, the polishing mark T may be formed on the entire main surface 10f.

[0027] In the trimming step (S2) described later, the polishing mark T may have an arbitrary shape. As shown in FIG. 2, in a plan view of the main surface 10f, the shape of the polishing mark T may be concentric. In a plan view of the main surface 10f, the shape of the polishing mark T may be curved or linear.

[0028] The main surface 10f is trimmed to adjust the electrical resistance value of the shunt resistor 100. Therefore, when the electrical resistance value of the shunt resistor 100 is 1.0 mΩ, the thickness of the resistor body 10 in the z direction may be 0.3 mm or more. When the electrical resistance value of the shunt resistor 100 is 1.0 mΩ, the thickness of the resistor body 10 in the z direction may be 0.35 mm or more. From a different perspective, the value obtained by dividing the thickness of the resistor body 10 in the z direction by the electrical resistance value may be 0.3 mm / mΩ or more, or 0.35 mm / mΩ or more. By doing so, it is possible to suppress the surface temperature on the main surface 10f from rising during energization.

[0029] The surface roughness of the main surface 10f in the region where the polishing marks T are formed is, for example, 30 μm or less. From a different perspective, the region on the main surface 10f where the surface roughness is 30 μm or less may be regarded as the region where the polishing marks T are formed. In the trimming step (S2), the surface roughness of the main surface 10f is adjusted by the tool 3 used. Here, the "surface roughness" is calculated as the root mean square height. The surface roughness of the region on the main surface 10f where the polishing marks T are formed can be measured, for example, by a 3D shape measuring instrument (model number: VR-6000) manufactured by Keyence Corporation.

[0030] <Manufacturing method of shunt resistor> Hereinafter, the manufacturing method of the shunt resistor 100 of the present embodiment will be described. FIG. 5 is a flowchart in the manufacturing method of the shunt resistor 100 of Embodiment 1. As shown in FIG. 5, the manufacturing method of the shunt resistor 100 includes a step (S1) of preparing the electrode 20 and the resistor body 10, and a step (S2) of trimming the resistor body 10. The trimming step (S2) is performed after the preparation step (S1).

[0031] First, the step (S1) of preparing the electrode 20 and the resistor body 10 is performed. The preparation step (S1) includes a rolling step (S11), a welding step (S12), and a pressing step (S13).

[0032] First, a plurality of shunt resistors 100 are prepared. The welding step (S12) is performed after the rolling step (S11). The pressing step (S13) is performed after the welding step (S12).

[0033] First, the rolling step (S11) is performed. In this step (S11), the first plate member 11, the second plate member 23, and the third plate member 24 are rolled. In this way, the thicknesses of the first plate member 11, the second plate member 23, and the third plate member 24 are adjusted. By rolling the first plate member 11, the second plate member 23, and the third plate member 24, the warpage of the first plate member 11, the second plate member 23, and the third plate member 24 is corrected. The material constituting the first plate member 11 is the same as the material constituting the resistor 10. The material constituting the second plate member 23 is the same as the material constituting the first electrode 21. The material constituting the third plate member 24 is the same as the material constituting the second electrode 22. The longitudinal directions of the first plate member 11, the second plate member 23, and the third plate member 24 are along the x direction.

[0034] Next, the welding step (S12) is performed. FIG. 6 is a schematic perspective view showing one step in the method for manufacturing the shunt resistor 100 according to the first embodiment. In this step (S12), as shown in FIG. 6, the second plate member 23 and the third plate member 24 are welded to the first plate member 11. As shown in FIG. 6, the first plate member 11, the second plate member 23, and the third plate member 24 are arranged along the y direction. Specifically, the first plate member 11 is arranged so as to be sandwiched between the second plate member 23 and the third plate member 24 in the y direction.

[0035] Next, the boundary between the first plate member 11 and the second plate member 23 and the boundary between the first plate member 11 and the third plate member 24 are welded. The first plate member 11 and the second plate member 23 are joined by scanning the laser L1 along the boundary between the first plate member 11 and the second plate member 23. The first plate member 11 and the third plate member 24 are joined by scanning the laser L1 along the boundary between the first plate member 11 and the third plate member 24.

[0036] Next, the pressing step (S13) is performed. The pressing step (S13) includes a punching step (S131), a bending step (S132), and a separating step (S133). The bending step (S132) is performed after the punching step (S131). The separating step (S133) is performed after the bending step (S132).

[0037] First, the punching step (S131) is performed. FIG. 7 is a schematic perspective view showing the next step of the step shown in FIG. 6 in the manufacturing method of the shunt resistor 100 according to the first embodiment. In this step (S131), a plurality of slits are formed in the first plate member 11, the second plate member 23, and the third plate member 24 using a mold. Specifically, a plurality of slits 10t are formed in the first plate member 11. The plurality of slits 10t are formed so as to be arranged at intervals in the x direction. A plurality of slits 20t are formed in the second plate member 23 and the third plate member 24. The plurality of slits 20t are formed so as to be arranged at intervals in the x direction. Next, as shown in FIG. 7, the second plate member 23 and the third plate member 24 are divided into a plurality of electrodes 20. Specifically, the second plate member 23 is divided into a plurality of first electrodes 21. The third plate member 24 is divided into a plurality of second electrodes 22.

[0038] Next, the bending step (S132) is performed. FIG. 8 is a schematic perspective view showing the next step of the step shown in FIG. 7 in the manufacturing method of the shunt resistor 100 according to the first embodiment. In this step (S132), as shown in FIG. 8, the first electrode 21 and the second electrode 22 are bent inward so that the second ends 20b of the first electrode 21 and the second electrode 22 face each other with a space therebetween in the y direction.

[0039] Next, a step of fragmenting (S133) is performed. FIG. 9 is a schematic perspective view showing the next step of the step shown in FIG. 8 in the manufacturing method of the shunt resistor 100 according to the first embodiment. In this step (S133), the first plate member 11 is cut, whereby a plurality of shunt resistors 100 shown in FIG. 9 are obtained. The slit 10t becomes the recess 10e. The slit 20t becomes the slit 20c.

[0040] Next, a trimming step (S2) is performed. FIG. 10 is a schematic plan view showing the next step of the step shown in FIG. 9 in the manufacturing method of the shunt resistor 100 according to the first embodiment. FIG. 11 is a schematic side view showing the next step of the step shown in FIG. 9 in the manufacturing method of the shunt resistor 100 according to the first embodiment. In this step (S2), as shown in FIGS. 10 and 11, in order to adjust the electrical resistance value in the shunt resistor 100, the main surface 10f is polished using the tool 3. Examples of the tool 3 for polishing the main surface 10f include a brush, a grinding stone, and a sander. The brush used may be, for example, a cylindrical brush. The grinding stone used may be a rubber grinding stone. The sander used may be, for example, a wheel sander. The particle size (displayed in accordance with JIS B 4130:1998 A method) of the tool 3 used may be, for example, 80 / 100 or more and 325 / 400 or less.

[0041] As shown in FIG. 10, the tool 3 may rotate about the rotation axis A1 in the rotation direction R1 shown in FIG. 10. The rotation axis A1 extends along the direction (z direction) perpendicular to the main surface 10f, as shown in FIG. 11. When polishing the main surface 10f, the position of the tool 3 (the position of the rotation axis A1) in the x direction and the y direction may be fixed. Here, the rotation axis A1 extending along the direction perpendicular to the main surface 10f includes not only the case where the rotation axis A1 is perpendicular to the main surface 10f but also the case where the inclination angle of the rotation axis A1 with respect to the perpendicular line of the main surface 10f is 0° or more and 20° or less.

[0042] In this way, concentric polishing marks T are formed in a plan view of the main surface 10f as shown in FIGS. 1 and 2. As a result, without burrs being formed on the main surface 10f and the back surface 10g, the shunt resistor 100 shown in FIGS. 1 to 4 with an adjusted electrical resistance value can be obtained.

[0043] Note that after the trimming step (S2) is performed, cleaning and rust prevention treatment may be performed on the surface of the shunt resistor 100.

[0044] (Modification Example 1 of the Trimming Step) FIG. 12 is a schematic plan view showing the next step of the step shown in FIG. 9 in Modification Example 1 of the manufacturing method of the shunt resistor 100 according to Embodiment 1. FIG. 13 is a schematic side view showing the next step of the step shown in FIG. 9 in Modification Example 1 of the manufacturing method of the shunt resistor 100 according to Embodiment 1. FIG. 14 is a schematic plan view of the shunt resistor 100 obtained by Modification Example 1 of the manufacturing method of the shunt resistor 100 according to Embodiment 1.

[0045] In the trimming step (S2), while moving the tool 3 in the direction D1 shown in FIGS. 12 and 13, the main surface 10f may be polished. The direction D1 is parallel to the main surface 10f. The direction D1 is along the x direction. The rotation axis A1 of the tool 3 moves in the direction D1. By doing so, as shown in FIG. 14, curved polishing marks T are formed on the main surface 10f such that a plurality of concentric polishing marks T overlap each other.

[0046] (Modification Example 2 of the Trimming Step) FIG. 15 is a schematic plan view showing the next step of the step shown in FIG. 9 in Modification Example 2 of the manufacturing method of the shunt resistor 100 according to Embodiment 1. FIG. 16 is a schematic side view showing the next step of the step shown in FIG. 9 in Modification Example 2 of the manufacturing method of the shunt resistor 100 according to Embodiment 1. FIG. 17 is a schematic plan view of the shunt resistor 100 obtained by Modification Example 2 of the manufacturing method of the shunt resistor 100 according to Embodiment 1.

[0047] The rotation axis A2 of the tool 3 may be along a direction parallel to the main surface 10f. Specifically, as shown in FIGS. 15 and 16, the rotation axis A2 of the tool 3 is along the y direction. That is, the rotation axis A2 is along a direction perpendicular to the direction D1 in which the tool moves. In this state, the tool 3 rotates about the rotation axis A2 in the rotation direction R2 shown in FIG. 16. In the trimming step (S2), the main surface 10f may be polished while moving the tool 3 in the direction D1 shown in FIGS. 15 and 16. By doing so, as shown in FIG. 17, a plurality of linear polishing marks T along the x direction are formed on the main surface 10f. The plurality of linear polishing marks T are arranged in the y direction. Here, the rotation axis A2 being along a direction parallel to the main surface 10f includes not only the case where the rotation axis A2 is parallel to the main surface 10f, but also the case where the inclination angle of the rotation axis A2 with respect to the main surface 10f is 0° or more and 20° or less.

[0048] (Modification Example 3 of the Trimming Step) FIG. 18 is a schematic plan view showing the next step of the step shown in FIG. 9 in Modification Example 3 of the manufacturing method of the shunt resistor 100 of Embodiment 1. FIG. 19 is a schematic front view showing the next step of the step shown in FIG. 9 in Modification Example 3 of the manufacturing method of the shunt resistor 100 of Embodiment 1. FIG. 20 is a schematic plan view of the shunt resistor 100 obtained by Modification Example 3 of the manufacturing method of the shunt resistor 100 of Embodiment 1.

[0049] As shown in FIGS. 18 and 19, the rotation axis A3 of the tool 3 may be along the x direction. That is, the rotation axis A3 may be along the same direction as the direction D1 in which the tool moves. By doing so, the tool 3 rotates about the rotation axis A3 in the rotation direction R3 shown in FIG. 19. In the trimming step (S2), the main surface 10f may be polished while moving the tool 3 in the direction D1 shown in FIGS. 18 and 19. By doing so, as shown in FIG. 20, linear polishing marks T along the y direction are formed on the main surface 10f. The plurality of linear polishing marks T are arranged in the x direction. As shown in FIGS. 18 and 19, when the tool 3 is moved in the direction D1 while being rotated, the polishing marks T are formed only in the region that overlaps the rotation axis A3 of the tool 3 in the plan view of the main surface 10f (that is, the region where the tool 3 contacts the main surface 10f). In the arrangement of the tool 3 shown in FIGS. 18 and 19, the polishing marks T are formed in the region where the position in the y direction overlaps with the concave portion 10e in the plan view of the main surface 10f. As shown in FIG. 20, when polishing the entire surface of the main surface 10f with the tool 3, the operation of shifting the position of the tool 3 in the y direction and further moving the tool 3 in the x direction may be repeated.

[0050] As described above, the shape of the polishing marks T formed on the main surface 10f may be changed by the tool 3 used in the trimming step (S2). Table 1 shows the shapes of the polishing marks T that can be formed on the main surface 10f by the tool 3 used. As shown in Table 1, when the tool 3 is either a brush (including a cylindrical brush) or a grindstone, concentric circular or curved polishing marks T as shown in FIG. 2 or FIG. 14 can be formed on the main surface 10f in the plan view. In particular, the curved polishing marks T as shown in FIG. 14 can be formed by moving the rotation axis A1 of the tool 3. When the tool 3 is either a grindstone (including a rubber grindstone) or a sander (including a wheel sander), linear polishing marks T along the x direction as shown in FIG. 17 or linear polishing marks T along the y direction as shown in FIG. 20 can be formed on the main surface 10f in the plan view.

[0051]

Table 1

[0052] (Function and Effect) The shunt resistor 100 according to the present disclosure includes a resistor body 10 and electrodes 20. The resistor body 10 has a main surface 10f, a back surface 10g, and connection surfaces 10a and 10b. The back surface 10g is located on the side opposite to the main surface 10f. The connection surfaces 10a and 10b connect the main surface 10f and the back surface 10g. The electrodes 20 are connected to the connection surfaces 10a and 10b. Abrasion marks T are formed on the main surface 10f.

[0053] In this way, it is possible to obtain a shunt resistor 100 in which burrs are not formed on the main surface 10f and the back surface 10g and the electrical resistance value is adjusted.

[0054] In the shunt resistor 100, the electrode 20 has an inner surface 20s. The inner surface 20s faces the back surface 10g.

[0055] In this case, since the main surface 10f of the resistor body 10 is polished so that the abrasion marks T are formed on the main surface 10f and the electrical resistance value of the shunt resistor 100 is adjusted, it is not necessary to perform deburring processing or the like on the back surface 10g of the resistor body 10 as in the prior art. Therefore, the configuration of the shunt resistor 100 according to the present disclosure is particularly effective for the shunt resistor 100 configured such that the inner surface 20s of the electrode 20 faces the back surface 10g of the resistor body 10. Further, the change in the temperature distribution on the main surface 10f can be suppressed more than in the case of forming a recess for adjusting the electrical resistance value by trimming the first side surface 10c or the second side surface 10d of the resistor body 10. Therefore, it is possible to suppress the occurrence of problems such as the surface temperature on the main surface 10f becoming locally high during energization.

[0056] In the shunt resistor 100, the resistor body 10 has side surfaces 10c and 10d. The side surfaces 10c and 10d are continuous with the main surface 10f, the back surface 10g, and the connection surfaces 10a and 10b. Recesses 10e are formed in the side surfaces 10c and 10d.

[0057] By doing so, it is possible to suppress the surface temperature on the main surface 10f from increasing during energization.

[0058] In the shunt resistor 100, the polishing marks T are formed on 30% or more of the main surface 10f.

[0059] By doing so, it is possible to obtain the shunt resistor 100 in which burrs are not formed on the main surface 10f and the back surface 10g and the electrical resistance value is adjusted.

[0060] In the shunt resistor 100, the polishing marks T are formed over the entire main surface 10f. By doing so, it is possible to obtain the shunt resistor 100 in which burrs are not formed on the main surface 10f and the back surface 10g and the electrical resistance value is adjusted.

[0061] Regarding the shunt resistor 100, in a plan view of the main surface 10f, the shape of the polishing marks T is concentric.

[0062] In this case, by polishing the main surface 10f using a brush or a grindstone, the shunt resistor 100 according to the present disclosure can be obtained.

[0063] Regarding the shunt resistor 100, in a plan view of the main surface 10f, the shape of the polishing marks T is curved.

[0064] In this case, by polishing the main surface 10f using a brush or a grindstone, the shunt resistor 100 according to the present disclosure can be obtained.

[0065] Regarding the shunt resistor 100, in a plan view of the main surface 10f, the shape of the polishing marks T is linear.

[0066] In this case, by polishing the main surface 10f using sandpaper or a grindstone, the shunt resistor 100 according to the present disclosure can be obtained.

[0067] In the shunt resistor 100, the direction perpendicular to the main surface 10f is defined as the z direction. The thickness of the resistor body 10 in the z direction is 0.3 mm or more.

[0068] In this way, it is possible to suppress the increase in the surface temperature on the main surface 10f during energization.

[0069] The manufacturing method of the shunt resistor 100 according to the present disclosure includes a step (S1) of preparing the electrode 20 and the resistor body 10, and a step (S2) of trimming the resistor body 10. The main surface 10f, the back surface 10g, and the connection surfaces 10a and 10b are provided. The back surface 10g is located on the opposite side of the main surface 10f. The connection surfaces 10a and 10b connect the main surface 10f and the back surface 10g. The electrode 20 is connected to the connection surfaces 10a and 10b. In the trimming step (S2), polishing marks T are formed on the main surface 10f using the tool 3.

[0070] In this way, it is possible to obtain the shunt resistor 100 in which the burrs are not formed on the main surface 10f and the back surface 10g and the electrical resistance value is adjusted.

[0071] Regarding the manufacturing method of the shunt resistor 100, in the trimming step (S2), the rotation axis A1 of the tool 3 is along the direction perpendicular to the main surface 10f.

[0072] In this way, in the plan view of the main surface 10f, the shape of the polishing marks T is concentric or curved.

[0073] In the manufacturing method of the shunt resistor 100, in the plan view of the main surface 10f, the shape of the polishing marks T is concentric.

[0074] In this way, when the main surface 10f is polished using a brush or a grindstone, the shape of the polishing marks T is concentric.

[0075] Regarding the manufacturing method of the shunt resistor 100, in the trimming step (S2), the rotation axis A1 of the tool 3 moves in the direction D1 parallel to the main surface 10f.

[0076] In this way, in a plan view of the main surface 10f, the shape of the polishing mark T becomes curved. In the manufacturing method of the shunt resistor 100, in a plan view of the main surface 10f, the shape of the polishing mark T is curved.

[0077] In this case, by polishing the main surface 10f using a brush or a grindstone, the shunt resistor 100 according to the present disclosure can be obtained.

[0078] Regarding the manufacturing method of the shunt resistor 100, in the trimming step (S2), the rotation axis A2 of the tool 3 is along the direction parallel to the main surface 10f.

[0079] In this way, in a plan view of the main surface 10f, the shape of the polishing mark T becomes linear. Regarding the manufacturing method of the shunt resistor 100, in the trimming step (S2), the rotation axis A2 of the tool 3 moves in the direction parallel to the main surface 10f.

[0080] In this way, in a plan view of the main surface 10f, the shape of the polishing mark T becomes linear. In the manufacturing method of the shunt resistor 100, in a plan view of the main surface 10f, the shape of the polishing mark T is linear.

[0081] In this case, by polishing the main surface 10f using a grindstone or a sandpaper, the shunt resistor 100 according to the present disclosure can be obtained.

[0082] In the manufacturing method of the shunt resistor 100, the tool 3 is any one of a brush, a grindstone, and a sandpaper.

[0083] In this way, in the trimming step (S2), the surface roughness of the main surface 10f in the region where the polishing marks T are formed by the tool 3 to be used becomes 30 μm or less.

[0084] (Embodiment 2) FIG. 21 is a schematic perspective view of the shunt resistor 100 according to Embodiment 2. FIG. 21 corresponds to FIG. 1. The shunt resistor 100 shown in FIG. 21 basically has the same configuration as the shunt resistor 100 shown in FIGS. 1 to 4 and can obtain the same effects, but is different in that the slit 20c (see FIG. 1) is not formed.

[0085] The inner surface 20s includes the inner surface 21s of the first electrode 21 and the inner surface 22s of the second electrode 22. That is, the number of terminals in the shunt resistor 100 may be two. In this way, the shunt resistor 100 according to the second embodiment is used as a two-terminal shunt resistor.

[0086] Hereinafter, various aspects of the present disclosure will be collectively described as appendices. (Appendix 1) A resistor having a main surface, a back surface located on the opposite side of the main surface, and a connection surface connecting the main surface and the back surface, and an electrode connected to the connection surface. A shunt resistor in which polishing marks are formed on the main surface. (Appendix 2) The shunt resistor according to Appendix 1, wherein the electrode has an inner surface facing the back surface. (Appendix 3) The resistor has a side surface continuous with the main surface, the back surface, and the connection surface, and a concave portion is formed on the side surface. The shunt resistor according to Appendix 1 or Appendix 2. (Appendix 4) The shunt resistor according to any one of Appendices 1 to 3, wherein the polishing marks are formed on 30% or more of the main surface. (Appendix 5) The shunt resistor according to Supplementary Note 4, wherein the polishing marks are formed over the entire main surface. (Supplementary Note 6) The shunt resistor according to any one of Supplementary Notes 1 to 5, wherein in a plan view of the main surface, the shape of the polishing marks is concentric. (Supplementary Note 7) The shunt resistor according to any one of Supplementary Notes 1 to 5, wherein in a plan view of the main surface, the shape of the polishing marks is curved. (Supplementary Note 8) The shunt resistor according to any one of Supplementary Notes 1 to 5, wherein in a plan view of the main surface, the shape of the polishing marks is linear. (Supplementary Note 9) When the direction perpendicular to the main surface is defined as the z direction, The shunt resistor according to any one of Supplementary Notes 1 to 8, wherein the thickness of the resistor body in the z direction is 0.3 mm or more. (Supplementary Note 10) A step of preparing an electrode and a resistor body, A step of trimming the resistor body, and The resistor body has a main surface, a back surface located on the opposite side of the main surface, and a connection surface connecting the main surface and the back surface, The electrode is connected to the connection surface, A method for manufacturing a shunt resistor, wherein in the trimming step, polishing marks are formed on the main surface using a tool. (Supplementary Note 11) In the trimming step, The method for manufacturing a shunt resistor according to Supplementary Note 10, wherein the rotation axis of the tool is along the direction perpendicular to the main surface. (Supplementary Note 12) The method for manufacturing a shunt resistor according to Supplementary Note 11, wherein in a plan view of the main surface, the shape of the polishing marks is concentric. (Supplementary Note 13) In the trimming step, The method for manufacturing a shunt resistor according to Supplementary Note 11, wherein the rotation axis of the tool moves in a direction parallel to the main surface. (Supplementary Note 14) The method for manufacturing a shunt resistor according to Supplementary Note 13, wherein in a plan view of the main surface, the shape of the polishing marks is curved. (Supplementary Note 15) In the step of trimming, The method for manufacturing a shunt resistor according to Supplementary Note 10, wherein the rotation axis of the tool is along a direction parallel to the main surface. (Supplementary Note 16) In the step of trimming, The method for manufacturing a shunt resistor according to Supplementary Note 15, wherein the rotation axis of the tool moves in a direction parallel to the main surface. (Supplementary Note 17) The method for manufacturing a shunt resistor according to Supplementary Note 15 or Supplementary Note 16, wherein in a plan view of the main surface, the shape of the polishing marks is linear. (Supplementary Note 18) The method for manufacturing a shunt resistor according to any one of Supplementary Notes 10 to 17, wherein the tool is any one of a brush, a grindstone, and sandpaper.

[0087] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The basic scope of the present disclosure is indicated by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

Explanation of Reference Numerals

[0088] 3 Tool, 10 Resistor, 10a First Connection Surface, 10b Second Connection Surface, 10a,10b Connection Surfaces, 10c First Side Surface, 10d Second Side Surface, 10c,10d Side Surfaces, 10e Recess, 10f Main Surface, 10g Back Surface, 10t,20t,20c Slit, 11 First Plate Member, 20 Electrode, 20a First End, 20b Second End, 20s,21s,22s Inner Surfaces, 21 First Electrode, 21s1,22s1 First Inner Surfaces, 21s2,22s2 Second Inner Surfaces, 22 Second Electrode, 23 Second Plate Member, 24 Third Plate Member, 100 Shunt Resistor, A1,A2,A3 Rotation Axis, D1 Direction, L1 Laser, R1,R2,R3 Rotation Direction, T Polishing Marks.

Claims

1. A resistor having a main surface, a back surface located on the opposite side of the main surface, and a connecting surface connecting the main surface and the back surface, and an electrode connected to the connecting surface, wherein a polishing mark is formed on the main surface, a shunt resistor.

2. The shunt resistor according to claim 1, wherein the electrode has an inner surface facing the back surface.

3. The resistor has a side surface continuous with the main surface, the back surface, and the connecting surface, and a concave portion is formed on the side surface, the shunt resistor according to claim 1 or claim 2.

4. The shunt resistor according to claim 1 or claim 2, wherein the polishing mark is formed on 30% or more of the main surface.

5. The shunt resistor according to claim 4, wherein the polishing mark is formed on the entire main surface.

6. The shunt resistor according to claim 1 or claim 2, wherein in a plan view of the main surface, the shape of the polishing mark is concentric.

7. The shunt resistor according to claim 1 or claim 2, wherein in a plan view of the main surface, the shape of the polishing mark is curved.

8. The shunt resistor according to claim 1 or claim 2, wherein in a plan view of the main surface, the shape of the polishing mark is linear.

9. When the direction perpendicular to the main surface is defined as the z direction, the shunt resistor according to claim 1 or claim 2, wherein the thickness of the resistor in the z direction is 0.3 mm or more.

10. A step of preparing an electrode and a resistor, and a step of trimming the resistor, wherein the resistor has a main surface, a back surface located on the opposite side of the main surface, and a connecting surface connecting the main surface and the back surface, the electrode is connected to the connecting surface, and in the trimming step, a polishing mark is formed on the main surface using a tool, a method for manufacturing a shunt resistor.

11. In the trimming step, the method for manufacturing a shunt resistor according to claim 10, wherein the rotation axis of the tool is along a direction perpendicular to the main surface.

12. The method for manufacturing a shunt resistor according to claim 11, wherein in a plan view of the main surface, the shape of the polishing mark is concentric.

13. In the trimming step, the method for manufacturing a shunt resistor according to claim 11, wherein the rotation axis of the tool moves in a direction parallel to the main surface.

14. The manufacturing method of the shunt resistor according to claim 13, wherein in a plan view of the main surface, the shape of the polishing marks is curved.

15. In the step of trimming, The manufacturing method of the shunt resistor according to claim 10, wherein the rotation axis of the tool is along a direction parallel to the main surface.

16. In the step of trimming, The manufacturing method of the shunt resistor according to claim 15, wherein the rotation axis of the tool moves in a direction parallel to the main surface.

17. The manufacturing method of the shunt resistor according to claim 15, wherein in a plan view of the main surface, the shape of the polishing marks is linear.

18. The manufacturing method of the shunt resistor according to any one of claims 10 to 17, wherein the tool is any one of a brush, a grindstone, and a sander.

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