Current detection device and method for manufacturing the same, and resistive element part

Abstract

This suppresses changes in resistance characteristics caused by variations in the dimensions of the resistive element. [Solution] The current detection device 1 comprises a circuit board 10, a resistive element section 20 including a resistor 21 having a first surface and a second surface in the thickness direction Dt, a mounting section formed on the circuit board 10 to which the second surface side of the resistor 21 is fixed, a clip or busbar constituting a terminal member connected to the first surface side of the resistor 21, and a detection line fixed to the terminal member for detecting the voltage of the resistive element section 20. The terminal member or circuit board 10 has a position indicator section that identifies the mounting position of the resistive element section 20 and serves as a reference for the fixing position of the detection line to the terminal member.

Description

Technical Field

[0006] , , , ,

[0001] The present invention relates to a current detection device, a method for manufacturing the same, and a resistance element section.

Background Art

[0002] Patent Document 1 discloses a shunt resistor including an electrode member having a slit formed at a contact portion contacting a resistor body.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a current detection device including a resistance element section corresponding to the above-described shunt resistor, one surface of the resistance element section is fixed to the mounting portion of the circuit board, a terminal member such as a clip or a bus bar is fixed to the other surface, and a detection line for detecting the voltage of the resistance element section is fixed thereon. In such a configuration, due to variations in the dimensions of the resistance element section mounted on the circuit board, the resistance temperature coefficient (TCR) of the resistance element section changes significantly depending on the positional relationship between the fixing position of the detection line with respect to the terminal member and the mounting position of the resistance element section. The inventors have found this.

[0005] Therefore, the present invention has been made paying attention to the above-described problems, and an object thereof is to suppress changes in resistance characteristics caused by variations in the dimensions of the resistance element section.

Means for Solving the Problems

[0006] According to a first aspect of the present invention, the current detection device comprises a circuit board, a resistive element portion including a resistor having a first surface and a second surface in the thickness direction, a mounting portion formed on the circuit board to which the second surface side of the resistor is fixed, a terminal member connected to the first surface side of the resistor, and a detection line fixed to the terminal member for detecting the voltage of the resistive element portion. The terminal member or the circuit board has a position indicator portion that identifies the mounting position of the resistive element portion and serves as a reference for the fixing position of the detection line relative to the terminal member.

[0007] According to a second aspect of the present invention, the method for manufacturing the current detection device described in the first aspect comprises the steps of: confirming the position indicator; calculating the fixing position of the detection line using the position indicator as a reference position; and fixing the detection line to the terminal member.

[0008] According to a third aspect of the present invention, the resistive element portion includes a resistor, and a terminal member for fixing a detection wire for detecting voltage is connected to the first surface side of the resistor and to the mounting portion of the circuit board, which is connected to the second surface side of the resistor. The mounting position of the resistive element portion is determined by the terminal member or the position indicator portion of the circuit board, which serves as a reference for the fixing position of the detection wire relative to the terminal member. [Effects of the Invention]

[0009] According to these embodiments, it becomes possible to accurately identify the mounting position of the resistive element by utilizing the position indicator provided on the terminal member or the circuit board, and furthermore, it becomes possible to appropriately define the fixing position of the detection line on the terminal member based on the position indicator.

[0010] Therefore, it becomes possible to adjust the positional relationship between the mounting position of the resistive element and the fixed position of the detection line to a positional relationship that is less likely to change the resistive characteristics. Consequently, it is possible to suppress changes in resistive characteristics caused by variations in the dimensions of the resistive element. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a perspective view showing the external appearance of the current detection device according to the first embodiment. [Figure 2] Figure 2 is an exploded view of the current detection device shown in Figure 1. [Figure 3] Figure 3 is an exploded view of the resistive element section shown in Figure 1. [Figure 4] Figure 4 shows the region where TCR variability is easily suppressed. [Figure 5A] Figure 5A is a diagram illustrating the first simulation conditions for TCR. [Figure 5B] Figure 5B illustrates the second simulation condition for TCR. [Figure 6] Figure 6 shows the analysis results obtained under the conditions shown in Figures 5A and 5B. [Figure 7] Figure 7 is a flowchart showing how to mount components onto a circuit board. [Figure 8] Figure 8 illustrates the process of mounting components onto a circuit board. [Figure 9] Figure 9 is a flowchart showing how to secure a voltage detection wire to a clip. [Figure 10] Figure 10 illustrates how the voltage detection wire is secured to the clip. [Figure 11] Figure 11 is a perspective view showing a modified example of the resistive element section. [Figure 12] Figure 12 is a perspective view showing a modified example of a current detection device. [Figure 13] Figure 13 is a top view showing a first modified example of the position indicator unit. [Figure 14] Figure 14 is a top view showing a second modified example of the position indicator unit. [Figure 15] Figure 15 is a top view showing a third modified example of the position indicator unit. [Figure 16] Figure 16 is a perspective view showing the configuration of the current detection device according to the second embodiment. [Figure 17] Figure 17 is a flowchart showing a method for manufacturing a current detection device. [Figure 18] Figure 18 is a diagram for explaining the state of the manufacturing method shown in FIG. 18. [Figure 19] Figure 19 is a perspective view showing the configuration of the current detection device according to the third embodiment. [Figure 20] Figure 20 is a flowchart showing a method of manufacturing the current detection device. [Figure 21] Figure 21 is a diagram for explaining the state of the manufacturing method shown in FIG. 20.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In this specification, the same reference numerals are given to the same or equivalent elements throughout.

[0013] Figure 1 is a perspective view showing the appearance of the current detection device according to the first embodiment. Figure 2 is an exploded view of the current detection device shown in FIG. 1. Figure 3 is an exploded view of the resistance element portion of the current detection device shown in FIG. 1.

[0014] The current detection device 1 is a device for detecting the current flowing through the circuit board 10 on which components are mounted. The current detection device 1 of the first embodiment is composed of a circuit board 10, a resistance element portion 20, a clip 30, and a voltage detection line 40.

[0015] The circuit board 10 is a board on which electronic components are mounted on pre-formed wirings. The circuit board 10 of the first embodiment has a pair of wiring patterns 11 and 12 and a pair of detection patterns 13 and 14.

[0016] The pair of wiring patterns 11 and 12 are wiring patterns for forming a current path. In the circuit board 10 of the first embodiment, for example, the current to be detected flows from the wiring pattern 11 toward the wiring pattern 12. Based on the magnitude of this current, for example, the control of various devices mounted on an automobile is performed.

[0017] The wiring pattern 11 functions as a mounting area on the circuit board 10 where the clip 30 is mounted, and the wiring pattern 12 functions as a mounting area on the circuit board 10 where the resistor element 20 is mounted.

[0018] The pair of detection patterns 13 and 14 are wiring patterns for detecting the voltage generated in the resistive element section 20. Detection pattern 13 is a wiring pattern drawn out from wiring pattern 12 to the pair of wiring patterns. On the other hand, detection pattern 14 consists of a pad 141 to which one end of the voltage detection line 40 is connected, and a wiring pattern 142 drawn out from the pad 141.

[0019] Next, the configuration of the resistive element section 20 will be explained.

[0020] The resistive element section 20 is a columnar shunt resistor including a plate-shaped resistor 21 having a predetermined thickness and width, and is formed, for example, as a rectangular parallelepiped. In this embodiment, the resistive element section 20 is formed in a rectangular columnar shape with one side of the surface being several [mm], and includes a pair of thin plate-shaped electrodes 22 and 23 in addition to the thin plate-shaped resistor 21.

[0021] Examples of materials for the resistor 21 include low-resistance alloy materials such as Cu-Mn-Ni alloys and Ni-Cr alloys. Examples of materials for the electrodes 22 and 23 include highly conductive metals, and in this embodiment, copper (Cu) is used.

[0022] As shown in Figure 3, the resistor 21 has a first surface 21a and a second surface 21b, which is the surface opposite to the first surface 21a, in the thickness direction Dt. Electrode 22 is connected to the first surface 21a of the resistor 21, and electrode 23 is connected to the second surface 21b of the resistor 21. That is, electrode 22, resistor 21, and electrode 23 are stacked in this order in the thickness direction Dt of the resistive element portion 20.

[0023] The electrode 23 connected to the second surface 21b of the resistor 21 is connected to the wiring pattern 12. That is, the wiring pattern 12 formed on the circuit board 10 serves as the mounting area, to which the second surface 21b side of the resistor 21 is fixed. On the other hand, the electrode 22 connected to the first surface 21a of the resistor 21 is connected to the clip 30.

[0024] The clip 30 functions as a terminal member connected to the first surface 21a side of the resistor 21. The clip 30 is connected to the resistive element 20 by welding such as pressure welding, solder, metal nanoparticles, or other connecting means. The metal nanoparticle connecting means refers to connection methods using silver paste with silver nanoparticles or copper paste with copper nanoparticles.

[0025] In this embodiment, the clip 30 is connected to the resistive element portion 20 using solder. The clip 30 comprises a rectangular body portion 31 and leg portions 32 extending in the thickness direction Dt from a part of the body portion 31. The body portion 31 and the leg portions 32 are integrally formed with each other.

[0026] The clip 30 has a contact surface 30a between the clip 30 and the resistive element portion 20, and a surface 30b that is opposite to the contact surface 30a. A voltage detection wire 40 is fixed to the clip 30.

[0027] The voltage detection line 40 is a detection line for detecting the voltage of the resistive element section 20, and in this embodiment, it is realized by a bonding wire. In this embodiment, the voltage detection line 40 is bonded to a fixed area of ​​surface 30b of the contact surface 30a of the clip 30 that corresponds to the connection area to which the electrode 22 is connected. The fixed area of ​​surface 30b is subjected to a surface treatment such as NiP plating or Ni plating.

[0028] In such a current detection device 1, the clip 30 has a position indicator that serves as a reference for determining the positional relationship between the resistive element section 20 and the voltage detection line 40 via the clip 30, from the viewpoint of suppressing variations in TCR.

[0029] In this embodiment, the main body 31 of the clip 30 has a notch 33 formed near the resistive element 20, having opposing surfaces (101, 331). This notch 33 forms a reference surface 101 on the clip 30 that functions as a position indicator. The position indicator is a marker for identifying the mounting position of the resistive element 20 and also functions as a reference for the fixed position of the voltage detection line 40 relative to the clip 30.

[0030] The reference surface 101 is formed on the main body portion 31 of the clip 30 at a position corresponding to the side end portion 201 of the resistive element portion 20 that is closer to the De direction of extension in which the clip 30 extends. The side end portion 201 of the resistive element portion 20 is a portion having a predetermined thickness that includes the side end surface 20a of the clip 30 that is closer to the De direction of extension.

[0031] In this embodiment, the reference surface 101 of the notch 33, which is on the base end side Db opposite to the extension direction De, is formed to coincide with the side end surface 20a of the clip 30 in the resistive element portion 20 on the extension direction De side in the thickness direction Dt.

[0032] In other words, the reference surface 101 is formed on the clip 30 so as to coincide with the side end surface 20a, which is the edge of the side end 201 of the resistive element portion 20, in the thickness direction Dt. Therefore, the reference surface 101 of the clip 30 functions as a position indicator related to the position of the resistive element portion 20, which serves as the reference for the fixed position of the voltage detection line 40 on the clip 30.

[0033] In this way, by providing a reference surface 101 near the side end face 20a of the resistive element portion 20 of the clip 30, it becomes possible to appropriately adjust the positional relationship between the clip 30 and the resistive element portion 20 so that fluctuations in the TCR of the current detection device 1 are suppressed.

[0034] Next, the fixing position of the voltage detection wire 40 relative to the surface 30b of the clip 30 will be explained with reference to Figure 4.

[0035] Figure 4 shows an example of a fluctuation suppression region 31c within the fixed region 31b of the voltage detection line 40 in the clip 30, in which fluctuations of the TCR of the current detection device 1 are suppressed.

[0036] The fluctuation suppression region 31c here is defined as a region where the TCR of the current detection device 1 is approximately 0 [ppm / K]. Furthermore, the fixed region 31b has a larger area than the resistive element portion 20, and in the vertical direction (width direction of the clip 30) in Figure 4(b), the width of the clip 30 is greater than that of the resistive element portion 20. Also, in the horizontal direction (length direction of the clip 30) in Figure 4(b), the end of the clip 30 in the base end direction Db extends beyond the resistive element portion 20.

[0037] In Figure 4, the direction Di of current flow in the current detection device 1 is shown by a dashed line. For the sake of ease of understanding the diagram, the detection pattern 13 derived from the wiring pattern 12 will be omitted below.

[0038] Figure 4(a) shows a side view of the current detection device 1 as seen from a direction parallel to the circuit board 10, and Figure 4(b) shows a top view of the current detection device 1 as seen from a direction perpendicular to the circuit board 10.

[0039] As shown in Figure 4, in this embodiment, the clip 30 is mounted on the electrode 22 of the resistive element portion 20 such that the reference surface 101 provided on the clip 30 coincides with the side end surface 20a of the resistive element portion 20 in the thickness direction Dt.

[0040] In this configuration, it is desirable to fix the voltage detection line 40 in the fluctuation suppression region 31c, which extends from the center of the fixed region 31b to a position a predetermined distance from the side end face 20a with respect to the extending direction De of the clip 30. This makes it possible to bring the TCR of the current detection device 1 closer to 0 [ppm / K].

[0041] Next, the change in the TCR of the current detection device 1 due to variations in the length dimension of the resistive element section 20 will be explained with reference to Figures 5A, 5B, and 6.

[0042] Figures 5A and 5B show the conditions for the positional relationship between the resistive element 20 and the clip 30 in response to changes in the dimensions of the resistive element 20 when simulating the TCR of the current detection device 1.

[0043] In this simulation, the external dimensions of the resistive element section 20 are set to a length of 3.0 [mm] in the extending direction De, a depth of 3.5 [mm], and a thickness of 0.6 [mm]. The thickness of the resistor 21 is set to 0.4 [mm], the thickness of each electrode 22 and 23 is set to 0.1 [mm], and the resistivity of the resistor 21 is set to 270 [μΩ·cm].

[0044] Furthermore, the thickness of each of the pair of wiring patterns 11 and 12 is set to 0.5 [mm], and the thickness of the solder used to connect the resistive element 20 between the clip 30 and the wiring pattern 12 is set to 0.05 [mm]. The fixing position of the voltage detection line 40, which is placed on the surface 30b of the clip 30, is set to a position moved 0.9 [mm] in the extending direction De from the center Pc of the resistive element 20 in the extending direction De of the main body 31.

[0045] Figure 5A is a diagram illustrating the first simulation condition. In the first simulation condition, the position of the side end face 20a in the extending direction De and the opposite side end face 20b are fixed in accordance with the dimensional change of the resistive element portion 20, and the position of the side end face 20a is moved by 0.1 [mm] in the base end direction Db.

[0046] Figure 5B illustrates the second simulation condition. Under the second simulation condition, the position of the side end face 20a is fixed in accordance with the dimensional change of the resistive element portion 20, while the position of the side end face 20b in the base end direction Db is moved by 0.1 [mm] in the extension direction De.

[0047] Figure 6 shows the results obtained under the first simulation conditions shown in Figure 5A and the second simulation conditions shown in Figure 5B.

[0048] As shown in Figure 6, with the position of the voltage detection line 40 fixed, the amount of change in TCR increases significantly as the position of the side end face 20a approaches the voltage detection line 40, as shown in Figure 5A. The rate of increase is approximately 30 ppm for a change of 0.1 mm.

[0049] On the other hand, as shown in Figure 5B, as the position of the side end face 20b on the farther side of the voltage detection line 40 approaches the voltage detection line 40, the amount of change in TCR also increases. The rate of increase is approximately 3 ppm for a change of 0.1 mm, which is about one-tenth of that under the first simulation conditions.

[0050] Thus, the inventors have found that even if the position of the side end face 20a in the fluctuation suppression region 31c of the clip 30 is shifted by an order of 0.1 mm, the TCR changes significantly.

[0051] To address this issue, in this embodiment, a notch 33 having a reference surface 101 is formed in the clip 30 as a position indicator that defines the position of the side end face 20a of the resistive element portion 20 relative to the clip 30, in order to suppress individual differences in the TCR of the current detection device 1.

[0052] Next, a method for manufacturing the current detection device 1 will be described.

[0053] First, the method for mounting the resistor element 20 and clip 30 on the circuit board 10 will be explained with reference to Figures 7 and 8.

[0054] Figure 7 is a flowchart showing a mounting method for sequentially mounting the resistor element 20 and clip 30 onto the circuit board 10. Figure 8 is a diagram illustrating the sequential mounting of the resistor element 20 and clip 30 onto the circuit board 10.

[0055] In step S1 shown in Figure 7, a clip 30 is prepared with a reference surface 101 formed as a position indicator, as shown in Figure 8(a).

[0056] In step S2, the resistive element 20 is mounted on the circuit board 10. In this embodiment, the electrodes 23 of the resistive element 20 are connected to the wiring pattern 12 of the circuit board 10 by solder. That is, the second surface 21b side of the resistor 21 is fixed to the wiring pattern 12 formed on the circuit board 10.

[0057] In step S3, the position of the side end face 20a of the resistive element 20 is confirmed. In this embodiment, as shown in Figure 8(b), a camera 91 installed above the resistive element 20 generates image data showing the top surface of the resistive element 20. This image data is analyzed by a control device of the production line (not shown), and the coordinate position of the side end face 20a of the resistive element 20 is identified in coordinate data representing the production line, which is expressed in two-dimensional or three-dimensional coordinates. Alternatively, the position of the side end face 20a of the resistive element 20 may be confirmed visually by an operator.

[0058] In step S4, the reference surface 101 of the clip 30 is aligned with the side end face 20a of the resistive element portion 20. In this embodiment, as shown in Figure 8(c), solder is applied to the wiring pattern 11 and the electrodes 22 of the resistive element portion 20, and the clip 30 is attracted by the suction nozzle 92. The position of the clip 30 is then adjusted so that the reference surface 101 of the clip 30 coincides with the side end face 20a of the resistive element portion 20, which was confirmed in step S3, in the thickness direction Dt.

[0059] In step S5, the clip 30 is mounted on the resistive element portion 20. In this embodiment, as shown in Figure 8(d), the clip 30 is fixed to the wiring pattern 11 and the electrodes 22 of the resistive element portion 20 such that the reference surface 101 of the clip 30 coincides with the side end surface 20a of the resistive element portion 20.

[0060] When step S5 is completed, the method for mounting the resistor element 20 and clip 30 to the circuit board 10 is finished.

[0061] Next, the method for securing the voltage detection wire 40 to the clip 30 will be explained with reference to Figures 9 and 10.

[0062] Figure 9 is a flowchart showing the method for fixing the voltage detection wire 40 to the clip 30. Figure 10 is a diagram illustrating how the voltage detection wire 40 is fixed to the clip 30.

[0063] In step S11 shown in Figure 9, the voltage detection wire 40 is prepared. In this embodiment, a bonding wire is prepared as the voltage detection wire.

[0064] In step S12, the position of the reference surface 101, which functions as a position indicator for the clip 30, is confirmed. In other words, step S12 is a confirmation step to confirm the position of the position indicator.

[0065] In this embodiment, as shown in Figure 10(a), similar to step S3, the coordinate position of the reference plane 101 of the clip 30 is determined in a control device (not shown) based on image data from the camera 91 or input data from the operator.

[0066] In step S13, the fixed position 41 of the voltage detection line 40 is determined based on the position of the reference surface 101 on the clip 30 obtained in step S12. In other words, step S13 is a calculation step in which the fixed position 41 of the voltage detection line 40 is calculated using the position display unit as the reference position.

[0067] In this embodiment, the fixed position 41 is determined to be a position located a predetermined distance away from the side end face 20a of the resistive element portion 20 in the base end direction Db, as shown in Figure 10(b), and is located at the center of the short side of the clip 30. In Figure 10(b), the offset from the reference plane 101 and the fixed position 41 are shown by dashed lines. The predetermined distance is determined appropriately according to the shape and material of the resistive element portion 20 and the clip 30.

[0068] In step S14, the voltage detection wire 40 is fixed to the fixing position 41 of the clip 30 determined in step S13. In other words, step S14 is a fixing step in which the voltage detection wire 40 is fixed to the clip 30 that constitutes the terminal member. In this embodiment, as shown in Figure 10(c), the wire used as the voltage detection wire 40 is bonded at the fixing position 41.

[0069] When step S14 is completed, the method for securing the voltage detection wire 40 to the clip 30 is finished.

[0070] Next, a brief explanation of modified components of the current detection device 1 will be given with reference to Figures 11 and 12.

[0071] Figure 11 is a perspective view showing the external appearance of a current detection device 1A relating to a modified example of the resistive element section 20.

[0072] The current detection device 2 has the same basic configuration as the current detection device 1 shown in Figures 1 and 2, and instead of the resistive element section 20, it is equipped with a resistive element section 200 in which the electrode 22 is omitted. Thus, it is also possible to mount the clip 30 having the reference surface 101 of this embodiment on the first surface 21a of the resistor 21 of the resistive element section 200.

[0073] Instead of the resistive element section 200 to which the clip 30 is connected, a resistive element section in which electrode 23 of the electrodes 22 and 23 of the resistive element section 20 shown in Figure 1 is omitted, or a resistive element section in which both electrodes 22 and 23 are omitted, may be used.

[0074] Thus, the resistive element portion mounted on the circuit board 10 only needs to include a resistor 21 having a first surface 21a and a second surface 21b in the thickness direction Dt.

[0075] Figure 12 is a perspective view showing the external appearance of a current detection device 1B related to a modified example of the terminal member.

[0076] Current detection device 2 has the same basic configuration as current detection device 1 shown in Figure 1, but instead of clips 30, it is equipped with busbars 60. Other components are the same as those of current detection device 1, and are therefore given the same reference numerals, and their explanation is omitted here.

[0077] In the current detection device 2, the busbar 60 functions as a terminal member connected to the first surface 21a side of the resistor 21, and the busbar 60 has a notch 63, similar to the notch 33 of the clip 30. The notch 63 identifies the mounting position of the resistive element and forms a reference surface 101, which serves as a position indicator for the fixed position of the voltage detection line 40 relative to the busbar 60.

[0078] The reference surface 101 of the notch 63 allows the busbar 60 to coincide with the side end face 20a of the resistive element 20 in the thickness direction Dt, so that the busbar 60 is connected to the electrodes 22 of the resistive element 20 and to the wiring pattern 11. Furthermore, the voltage detection line 40 is fixed to a fixed area on the surface 60b of the busbar 60 with reference to the reference surface 101 of the notch 63.

[0079] In this way, the busbar 60 is fixed to the first surface 21a side of the resistor 21 of the resistor element 20 mounted on the circuit board 10 so as to suppress variations in the TCR of the current detection device 2.

[0080] Next, a modified example of the position display unit will be briefly explained with reference to Figures 13 and 15.

[0081] Figure 13 is a top view showing a first modified example of the clip 30. The clip 301 according to the first modified example has a through hole 34 that extends in a direction perpendicular to the extending direction De of the clip 301.

[0082] The through-hole 34 is formed by a reference surface 102 that functions as a position indicator to identify the mounting position of the resistive element portion 20.

[0083] By utilizing the reference surface 102 of the clip 301, it becomes possible to mount the clip 301 on the resistive element 20 and the wiring pattern 11 such that the reference surface 102 and the side end surface 20a of the resistive element 20 coincide with each other in the thickness direction Dt.

[0084] Therefore, the reference surface 102 is formed on the clip 301 so as to coincide with the side end surface 20a, which is the edge of the side end 201 of the resistive element portion 20, in the thickness direction Dt. The fixing position of the voltage detection line 40 with respect to the clip 301 is determined with reference to the reference surface 102.

[0085] This allows the positional relationship between the mounting position of the resistive element 20 below the clip 301 and the fixing position of the voltage detection line 40 relative to the clip 301 to be adjusted to a predetermined positional relationship that suppresses variations in the TCR of the current detection device 1.

[0086] Figure 14 is a top view showing a second modified example of the clip 30. The clip 301A according to the second modified example has a through hole 34A formed at a different position from the through hole 34 shown in Figure 13.

[0087] The through-hole 34A is formed in the portion of the clip 301A where the clip 301A and the resistive element portion 20 come into contact. The through-hole 34A is formed by the reference surface 102A, which functions as a position indicator to identify the mounting position of the resistive element portion 20.

[0088] The reference plane 102A is formed in the thickness direction Dt at the position of the clip 302A corresponding to the side end 201 of the resistive element portion 20. This allows the side end 201 of the resistive element portion 20 to be identified through the through hole 34A of the clip 301A, and the fixing position of the voltage detection line 40 relative to the clip 301A is determined with reference to the reference plane 102A that defines the through hole 34A.

[0089] Therefore, the positional relationship between the mounting position of the resistive element section 20 below the clip 301 and the fixing position of the voltage detection line 40 relative to the clip 301 can be adjusted to a predetermined positional relationship that suppresses variations in the TCR of the current detection device 1.

[0090] Figure 15 is a top view showing a third modified example of the clip 30. The clip 302 according to the third modified example has a notch 33A. The notch 33A is formed by a reference surface 103 that functions as a position indicator to identify the mounting position of the resistive element portion 20 below the clip 302.

[0091] As shown in Figure 15, the reference surface 103 is formed such that the position of the side end 201 of the resistive element portion 20 fits within the gap of the notch 33A. By forming the reference surface 103 on the clip 302 in this way, the reference surface 102 is formed at the position of the clip 302 corresponding to the side end 201 of the resistive element portion 20 in the thickness direction Dt, similar to the first embodiment. The fixing position of the voltage detection line 40 with respect to the clip 302 is then determined with respect to the reference surface 103.

[0092] This allows the corner of the resistive element 20 to be seen through the notch 33A of the clip 302, making it possible to determine the positional relationship between the resistive element 20 and the clip 302. It is also possible to check whether the resistive element 20 is mounted at an angle relative to the wiring pattern 12. In the case of a twisted state where the resistive element 20 is mounted at an angle relative to the wiring pattern 12, the angle of the clip 302 can be adjusted to match the twist of the resistive element 20 so that the positional relationship between the resistive element 20 and the clip 302 is appropriate.

[0093] Therefore, the positional relationship between the mounting position of the resistive element 20 below the clip 302 and the fixing position of the voltage detection line 40 relative to the clip 302 can be adjusted to a predetermined positional relationship that suppresses variations in the TCR of the current detection device 1.

[0094] Next, the position indicator unit according to the second embodiment will be described with reference to Figures 16 to 18.

[0095] Figure 16 is a perspective view showing the configuration of the current detection device 2 according to the second embodiment.

[0096] The current detection device 2 is equipped with a clip 303 having a reference position 110, instead of the clip 30 having a reference surface 101 that functions as a position indicator for the current detection device 1 shown in Figures 1 and 2.

[0097] Note that the other components are the same as those of the current detection device 1, and are denoted by the same reference numerals as those shown in Figures 1 and 2, and their explanation here is omitted.

[0098] In this embodiment, the reference position 110 is provided on the clip 303. The reference position 110 corresponds to the position indicator section formed by the reference surface 101 of the clip 30 shown in Figures 1 and 2.

[0099] As described above, in this embodiment, a reference position 110 is provided on the clip 303 as a position indicator. Even in this case, it is possible to accurately determine the mounting position of the resistive element 20 below the clip 303 by using the reference position 110 on the clip 303, and then appropriately define the fixed position of the voltage detection line 40 on the clip 303 with respect to the reference position 110.

[0100] Figure 17 is a flowchart illustrating a method for manufacturing the current detection device 1 according to the second embodiment. Figure 18 is a diagram illustrating the manufacturing process of the current detection device 1 according to the second embodiment.

[0101] In step S21 shown in Figure 17, the resistive element 20 is mounted on the circuit board 10. In this embodiment, as shown in Figure 18(a), one electrode 23 of the resistive element 20 is fixed to the wiring pattern 12 of the circuit board 10 by solder.

[0102] In step S22, the clip 303 is mounted on the resistive element portion 20. In this embodiment, as shown in Figure 18(b), the clip 303 is fixed to the wiring pattern 11 and the other electrode 22 of the resistive element portion 20 by solder.

[0103] In step S23, the position of the resistive element 20 is confirmed. In this embodiment, as shown in Figure 18(c), a camera 91 installed near the resistive element 20 generates image data showing the position of one corner 20c and one side 20d of the resistive element 20. The generated image data is analyzed by a control device on a production line (not shown), and the mounting position of the resistive element 20 is determined based on the analysis results of the corner 20c and side 20d of the resistive element 20.

[0104] In order to determine the position of the resistive element portion 20, at least two pieces of positional information are required. Therefore, in this embodiment, image data showing the positions of each corner and side of the resistive element portion 20 was acquired. However, this is not limited to this, and for example, image data showing at least two corners or two sides of the resistive element portion 20 may be acquired.

[0105] Based on the determination of the position of the resistive element 20, the coordinate position of the side end face 20a of the resistive element 20 is identified in coordinate data representing the production line, which is expressed in two-dimensional or three-dimensional coordinates. Alternatively, the position of the side end face 20a of the resistive element 20 may be confirmed visually by an operator.

[0106] In step S24, the reference position 110 is printed on the clip 303. In this embodiment, based on the determination result of identifying the mounting position of the resistive element 20 in step S23, the reference position 110, which functions as a position indicator, is engraved, for example, by a laser. That is, the reference position 110 has the function of identifying the mounting position of the resistive element 20.

[0107] Furthermore, the reference position 110, like the reference plane 101 shown in Figure 10, is also used as a reference for the fixed position of the voltage detection line 40 relative to the clip 303. For this reason, the reference position 110 provided on the clip 303 functions as a position indicator that identifies the mounting position of the resistive element 20 and serves as a reference for the fixed position of the voltage detection line 40 relative to the clip 303.

[0108] Next, the position indicator unit according to the third embodiment will be described with reference to Figures 19 to 21.

[0109] Figure 19 is a perspective view showing the configuration of the current detection device 3 according to the third embodiment.

[0110] The current detection device 3 includes a clip 304 that does not have a reference surface 101, instead of the reference surface 101 of the clip 30 that functions as a position indicator for the current detection device 1 shown in Figures 1 and 2, and a reference position 120 provided on the circuit board 10.

[0111] Note that the other components are the same as those of the current detection device 1, and are denoted by the same reference numerals as those shown in Figures 1 to 4, and their explanation here is omitted.

[0112] In this embodiment, the reference position 120 is provided around the wiring pattern 12 on the circuit board 10. The reference position 120 corresponds to the position indicator unit, which is composed of the reference surface 101 of the clip 30 in the current detection device 1 shown in Figures 1 and 2.

[0113] As described above, in this embodiment, a reference position 120 is provided on the circuit board 10 as a position indicator. Even in this case, it is possible to accurately determine the mounting position of the resistor element 20 under the clip 304 by using the reference position 120 on the circuit board 10, and then appropriately define the fixed position of the voltage detection line 40 on the clip 304 with respect to the reference position 120.

[0114] Figure 20 is a flowchart illustrating the manufacturing method of the current detection device 3. Figure 21 is a diagram illustrating the manufacturing process of the current detection device 3.

[0115] In step S31 shown in Figure 20, the resistor element 20 is mounted on the circuit board 10 in accordance with the reference position 120, which functions as a position indicator provided on the circuit board 10.

[0116] In this embodiment, a control device (not shown) determines the coordinate position of a reference position 120 formed around the wiring pattern 12 on the circuit board 10 based on image data from the camera 91 or input data from the operator. Thus, the reference position 120 has the function of identifying the mounting position of the resistor element 20.

[0117] Then, as shown in Figure 21(a), according to the instructions of the control device, one electrode 23 of the resistive element 20 is mounted on the wiring pattern 12 of the circuit board 10 in accordance with the reference position 120 of the circuit board 10. In other words, the reference position 120 in this embodiment has the function of identifying the mounting position of the resistive element 20 and defining the resistive element 20 at the identified mounting position.

[0118] In step S32, the clip 304 is mounted on the resistive element portion 20. In this embodiment, as shown in Figure 21(b), the clip 304 is fixed to the wiring pattern 11 and the other electrode 22 of the resistive element portion 20 by solder.

[0119] In step S33, the voltage detection line 40 is fixed with reference to the reference position 120 on the circuit board 10. That is, the reference position 120 is also used as the reference for the fixing position of the voltage detection line 40 on the clip 30.

[0120] In this embodiment, the fixed position 42 of the voltage detection line 40 is determined based on the reference position 120 on the circuit board 10 obtained in step S31. The fixed position 42 is determined to be a position separated by a predetermined distance in the base end direction Db from the side end face 20a of the resistive element portion 20, and is located at the center of the short side of the clip 304, similar to Figure 10(b).

[0121] The predetermined distance mentioned above is determined appropriately according to the shape and material of the resistive element 20 and the clip 304. In this embodiment, as shown in Figure 21(c), the wire used as the voltage detection line 40 is bonded at a fixed position 42 determined by a control device (not shown).

[0122] Thus, the reference position 120 provided on the circuit board 10 identifies the mounting position of the resistive element 20 and functions as a position indicator that serves as a reference for the fixing position of the voltage detection line 40 relative to the clip 304.

[0123] In this embodiment, the reference position 120 is formed near the wiring pattern 12 on the circuit board 10, but this is not the only option. Any location that allows for the identification of the position of the resistive element 20 may be used as the reference position 120, such as a corner of the wiring pattern 12 on the circuit board 10 or a specific location such as a silkscreen print.

[0124] Next, the effects and benefits of the above embodiment will be described.

[0125] In the above embodiment, the current detection device 1 comprises a circuit board 10, a resistor element portion 20 or 200 composed of a resistor 21 having a first surface 21a and a second surface 21b in the thickness direction Dt, and a wiring pattern 12 formed on the circuit board 10, which constitutes a mounting portion to which the second surface 21b side of the resistor 21 is fixed.

[0126] Furthermore, the current detection device 1 includes a terminal member connected to the first surface 21a side of the resistor 21, and a voltage detection line 40 fixed to the terminal member for detecting the voltage of the resistive element portion 20. The terminal member is realized, for example, by the clips 30, 301, 301A, 302, 303, or 304 of the above embodiment.

[0127] Furthermore, clips 30, 301, 301A, or 302 have reference surfaces 101, 102, 102A, or 103 that identify the mounting position of the resistive element section 20 and serve as a reference position indicator for the fixed position of the voltage detection line 40 relative to clips 30, 301, 301A, or 302.

[0128] Furthermore, the current detection device 1B of the above embodiment is equipped with a busbar 60 instead of the clips 30, 301, 301A, 302, 303, or 304 as terminal members. The busbar 60 has a reference surface 101 which identifies the mounting position of the resistive element section 20 or 200 and serves as a reference position indicator for the fixed position of the voltage detection line 40 relative to the busbar 60.

[0129] Furthermore, in the second and third embodiments, the current detection devices 2 and 3 are equipped with a reference position 110 or 120 as a position indicator, instead of the reference surfaces 101, 102, 102A, or 103.

[0130] Thus, the reference planes 101, 102, 102A, or 103, or the reference position 110 or 120, function as position indicators related to the position of the resistive element section 20 or 200, which serve as the reference for the fixed position of the voltage detection line 40 on the terminal member.

[0131] Furthermore, in the above embodiment, the resistive element section 20 includes a resistor 21, and a terminal member for fixing a voltage detection line 40 for detecting voltage is connected to the first surface 21a side of the resistor 21, and the wiring pattern 12 constituting the mounting section of the circuit board 10 is connected to the second surface 21b side of the resistor 21. The terminal member is realized, for example, by the clips 30, 301, 301A, 302, 303 or 304 of the above embodiment or by a busbar 60.

[0132] The mounting position of the resistive element 20 or 200 is determined by the clips 30, 301, 302, 302A, which serve as a reference for the fixed position of the voltage detection line 40 relative to the terminal member, or the reference surfaces 101, 102, 102A, or 103 of the busbar 60, or the reference position 110 or 120 of the circuit board 10.

[0133] With these configurations, it becomes possible to accurately identify the mounting position of the resistor element 20 or 200 by utilizing the position indicator provided on the terminal member or the circuit board 10. In addition, it becomes possible to appropriately define the fixed position of the voltage detection line 40 on the terminal member based on the position indicator.

[0134] Therefore, the positional relationship between the mounting position of the resistive element 20 and the fixed position of the voltage detection line 40 can be adjusted to a positional relationship that is less likely to change the resistive characteristics. Consequently, changes in resistive characteristics caused by variations in the dimensions of the resistive element 20 or 200 can be suppressed.

[0135] Furthermore, in the above embodiment, the position indicator is formed on the clip 30, 301, 301A, or 302, or the bus bar 60, at a position corresponding to the side end 201 of the resistive element portion 20 or 200 that is closer to the extending direction De, to which the clip 30, 301, 301A, 302, or the bus bar 60 extends.

[0136] As shown in Figure 6, misalignment of the side end 201 of the resistive element portion 20 or 200 closer to the extension direction De has a significant impact on the change in TCR. To address this, according to this embodiment, for example, as shown in Figure 15, by specifying the position of the side end 201 of the resistive element portion 20 or 200, variations in TCR can be suppressed compared to specifying the position of the side end opposite to the side end 201 of the resistive element portion 20 or 200 using the position display unit.

[0137] Furthermore, the current detection device 1 or 1B has a structure in which terminal members such as clips 30 or busbars 60 are interposed between the resistive element 20 and the voltage detection line 40. Therefore, in order to ensure current detection accuracy, it is necessary to maintain the positional accuracy of the resistive element 20 and the terminal members connected thereto.

[0138] However, when the terminal member is fixed onto the resistive element 20 after the resistive element 20 is mounted on the circuit board 10, variations in the mounting position of the resistive element 20 or 200 and variations in the mounting position of the terminal member will occur. In addition, the resistive element 20 or 200 may be hidden by the terminal member, making it impossible to determine the mounting position of the resistive element 20 or 200, and thus difficult to determine the fixing position of the voltage detection line 40. As a result, it is conceivable that the variation in TCR will increase for each current detection device 1, 1A, 1B, 2, or 3.

[0139] In contrast, with the above configuration, the mounting position of the resistive element section 20 or 200 below the terminal member can be identified using the position indicator section, and the fixed position of the voltage detection line 40 on the terminal member can be defined using this position indicator section as a reference position. This makes it possible to adjust the positional relationship between the fixed position of the voltage detection line 40 and the mounting position of the resistive element section 20 or 200 to a positional relationship that suppresses variations in TCR.

[0140] Therefore, variations in resistance characteristics caused by the presence of a terminal member interposed between the fixed position of the voltage detection line 40 and the mounting position of the resistive element section 20 or 200 can be suppressed.

[0141] Furthermore, in the above embodiment, the resistive element portion 20 or 200 is rectangular columnar in shape, and the reference surfaces 101, 102, 102A, or 103, which serve as position indicators, are formed on the clips 30, 301, 301A, 302, or busbars 60 so as to coincide with the side end surface 20a, which is the edge of the side end 201 of the resistive element portion 20 or 200, in the thickness direction Dt.

[0142] Regarding the change in TCR, as shown in Figure 6, the misalignment of the side end face 20a of the side end 201 of the resistive element portion 20 or 200 contributes significantly. Therefore, by accurately identifying the side end face 20a of the resistive element portion 20 or 200 using the reference surfaces 101, 102, 102A, or 103 of the clips 30, 301, 301A, 302, or the busbar 60, the variation in TCR can be reduced with greater accuracy compared to identifying the position of the side end 201.

[0143] Furthermore, according to the first modified example of the position indicator, as shown in Figure 13, the current detection device 1 is formed in the clip 301 and has a through hole 34 that extends in a direction perpendicular to the extending direction De of the clip 301. The reference surface 102 or 102A, which functions as a position indicator to identify the side end face 20a of the resistive element portion 20 in the thickness direction Dt, is formed by the through hole 34 or 34A.

[0144] With this configuration, the through-hole 34 or 34A prevents the voltage detection line 40 from being fixed in a region where the TCR is particularly prone to change. This makes it possible to avoid excessive changes in the TCR and to position the voltage detection line 40 at an appropriate fixing position that suppresses variations in the TCR.

[0145] Furthermore, the manufacturing method of the current detection device 1 in the first embodiment includes the steps of: confirming the reference surface 101 of the clip 30 which functions as a position indicator (S12); calculating the fixed position of the voltage detection line 40 using the reference surface 101 as the reference position (S13); and fixing the voltage detection line 40 to the clip 30 which serves as a terminal member (S14).

[0146] With this configuration, the mounting position of the resistive element section 20 or 200 is accurately determined using the reference surface 101 of the clip 30, and the fixing position of the voltage detection line 40 is appropriately fixed to the clip 30 with respect to the reference surface 101.

[0147] This makes it possible to adjust the positional relationship between the mounting position of the resistive element section 20 or 200 and the fixed position of the voltage detection line 40 to a positional relationship that minimizes TCR variation, thereby suppressing changes in resistance characteristics caused by variations in the dimensions of the resistive element section 20 or 200.

[0148] Although this embodiment has been described above, the above embodiment is merely one example of how the present invention can be applied, and it is not intended to limit the technical scope of the present invention to the specific configuration of the above embodiment. [Explanation of symbols]

[0149] 1, 1A, 1B, 2, 3 Current detection devices 10 Circuit boards 12 Wiring Pattern (Implementation Section) 20, 200 Resistor element section 20a Side end face (edge ​​of the side end face) 21 Resistor 21a 1st surface 21b 2nd surface 30, 301, 302, 302A, 303, 304 Clips (terminal components) 34, 34A through hole 40 Voltage detection line (detection line) 60 Busbars (Terminal Components) 101, 102, 102A, 103 Reference plane (position display section) 110, 120 Reference position (position display section) 201 Side end (side end from the direction of extension) Dt thickness direction De extension direction S12~S14 (confirmation process, calculation process, fixed process)

Claims

1. Circuit board and A resistive element portion including a resistor having a first surface and a second surface in the thickness direction, A mounting portion formed on the circuit board, to which the second surface side of the resistor is fixed, A terminal member connected to the first surface side of the resistor, The terminal member is fixed to the aforementioned terminal member and includes a detection wire for detecting the voltage of the resistive element, The terminal member or the circuit board has a position indicator that identifies the mounting position of the resistive element and serves as a reference for the fixing position of the detection line relative to the terminal member. Current detection device.

2. A current detection device according to claim 1, The position indicator portion is formed on the terminal member at a position corresponding to the side end of the resistive element portion that is closer to the extending direction of the terminal member. Current detection device.

3. A current detection device according to claim 2, The resistive element portion is rectangular in shape, The position indicator portion is formed on the terminal member so as to coincide with the edge of the side end of the resistive element portion in the thickness direction. Current detection device.

4. A current detection device according to claim 3, The terminal member has a through hole formed therein, which extends in a direction perpendicular to the extending direction of the terminal member, The position indicator section is formed by the through hole. Current detection device.

5. A method for manufacturing a current detection device according to any one of claims 1 to 4, A confirmation step to confirm the position display unit, A calculation step of calculating the fixed position of the detection line using the position display unit as the reference position, A fixing step of fixing the detection wire to the terminal member, A manufacturing method that includes the following features.

6. A resistor element portion comprising a resistor, wherein a terminal member for fixing a detection line for detecting voltage is connected to the first surface side of the resistor, and the second surface side of the resistor is connected to the mounting portion of the circuit board, The mounting position of the resistive element is determined by the position indicator of the terminal member or the circuit board, which serves as a reference for the fixing position of the detection line relative to the terminal member. Resistor element section.

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