JP7446798B2 - shunt resistance module - Google Patents

Description

The present invention relates to a shunt resistance module including a shunt resistor.

For example, shunt resistors are used to detect current in power semiconductor devices and the like.

Patent Document 1 discloses a structure of a shunt resistor including a resistor and electrodes on both sides thereof, and a bus bar (wiring member) is connected to the electrodes. Further, the shunt resistor is provided with a voltage detection terminal for measuring the voltage value between the electrodes.

Japanese Patent Application Publication No. 2016-217829

When current flows through the shunt resistor, the resistor generates heat, making it impossible to accurately measure the current value. In particular, in high voltage applications (current detection) such as power semiconductor devices, a large current flows through the shunt resistor, resulting in a very large amount of heat generated by the resistor. Conventionally, sufficient heat dissipation measures have not been taken. There wasn't.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a shunt resistance module that can improve the heat dissipation of a resistor.

A shunt resistance module according to one aspect of the present invention includes a shunt resistor including a resistor and electrodes provided at both ends of the resistor, and a bus bar connected to each electrode, and the bus bar is provided with a fixing hole, and the length from the fixing hole of the bus bar to the end face on the side where each bus bar faces is equal to the length from the fixing hole of the electrode to the end face on the side contacting the resistor. The position of the fixing hole is determined so that the length is longer than the length of the bus bar, and a second heat dissipating member is interposed between each bus bar, and the fixing member is inserted into the fixing hole to connect the electrode and the The bus bar is fixed to the resistor, and the bus bar extends toward the resistor from a joint between the electrode and the resistor to be connected, and a part of the bus bar overlaps the resistor in plan view. It is characterized by

According to the shunt resistance module of the present invention, since a part of the wiring member is arranged so as to overlap the resistor in a plan view, heat of the resistor can be easily radiated to the wiring member side. Therefore, the heat dissipation of the resistor can be improved, and current measurement can be performed with high precision.

FIG. 1A is a perspective view of the shunt resistance module of this embodiment, and FIG. 1B is a side view of the shunt resistance module. 1B is a partially enlarged side view of the shunt resistance module of FIG. 1B; FIG. It is an exploded perspective view of the shunt resistance module of this embodiment.

Hereinafter, a shunt resistance module according to the present embodiment will be described with reference to the accompanying drawings.

<Shunt resistance module 1 of this embodiment>
As a result of extensive research, the inventors of the present invention have developed the present invention in order to provide a structure in which heat from a resistor can be easily dissipated to a wiring member connected to a shunt resistor.

That is, the shunt resistance module 1 of this embodiment has the following features.
(1) A shunt resistor 2 including a resistor 5 and electrodes 6 and 7 provided at both ends of the resistor,
(2) having wiring members 8 and 9 connected to each electrode 6 and 7;
(3) In plan view A, a part of the wiring members 8 and 9 overlaps with the resistor 5.
Hereinafter, the structure of the shunt resistance module 1 of this embodiment will be specifically explained.

FIG. 1A is a perspective view of the shunt resistance module of this embodiment, and FIG. 1B is a side view of the shunt resistance module. FIG. 2 is a partially enlarged side view of the shunt resistance module of FIG. 1B. FIG. 3 is an exploded perspective view of the shunt resistance module of this embodiment.

As shown in FIGS. 1 to 3, the shunt resistance module 1 according to the present embodiment fixes a shunt resistor 2, wiring members 8 and 9, a heat dissipation member 10, and fixes the shunt resistor 2 and the wiring member 3. and a fixing member 11. In addition, below, the expressions "upper surface", "lower surface", "upper", and "lower" will be used, but "upper surface" and "upper" refer to the upper surface or direction in the drawing, as viewed from the shunt resistor 2. , refers to the side opposite to the side on which the wiring members 8 and 9 are arranged. Further, "lower surface" and "lower side" refer to the lower surface or direction in the drawing, and refer to the side where the wiring members 8 and 9 are arranged when viewed from the shunt resistor 2.

(Shunt resistor 2)
As shown in FIGS. 1 to 3, the shunt resistor 2 includes a resistor 5, a first electrode 6 provided at one end of the resistor 5, and a first electrode 6 provided at the other end of the resistor 5. It is configured with a second electrode 7. The first electrode 6 and the second electrode 7 have lower electrical resistance values than the resistor 5. Although the material is not limited, for example, the resistor 5 is made of a metal such as Cu-Ni, Cu-Mn, or Ni-Cr, and the electrodes 6 and 7 are made of a metal such as Cu. .

The shunt resistor 2 has a substantially flat plate shape, but in this embodiment, the thickness t1 of the electrodes 6 and 7 is thicker than the thickness t2 of the resistor 5, so that the upper surface of the shunt resistor 2 2a is a substantially flat surface, while on the lower surface 2b of the shunt resistor 2, electrodes 6 and 7 protrude below the resistor 5. For this reason, a recess 2c is provided on the lower surface 2b side of the shunt resistor 2, where the resistor 5 is recessed relative to the electrodes 6 and 7.

As shown in FIG. 3, each electrode 6, 7 has a fixing hole 6a, 7a formed therein. As shown in FIGS. 1 to 3, voltage detection terminals 12a and 12b are formed on the upper surfaces of the first electrode 6 and the second electrode 7, respectively. These voltage detection terminals 12a and 12b have, for example, a pin shape that projects upward. The voltage detection terminals 12a, 12b can be attached to the upper surfaces of the first electrode 6 and the second electrode 7 by welding or the like.

(Wiring members 8, 9)
The wiring members 8 and 9 are, for example, bus bars, and are connected to the lower surfaces of the electrodes 6 and 7, respectively, as shown in FIGS. 1 and 2. Although the shape of the wiring members 8 and 9 is not limited, it is preferable that they have a flat shape as shown in FIGS. 1 and 3. The wiring members 8 and 9 are formed with fixing holes 8a and 9a that communicate with fixing holes 6a and 7a provided in each electrode 6 and 7, respectively. Although not shown, for example, one of the wiring members 8 and 9 is connected to a battery, and the other is driven by the battery or connected to various devices.

As shown in FIG. 2, a portion of each wiring member 8, 9 connected to each electrode 6, 7 faces directly below the resistor 5. That is, each of the opposing ends 8b, 9b of each wiring member 8, 9 overlaps with the resistor 5 in plan view A (in the direction of the arrow pointing toward the upper surface 2a of the shunt resistor 2 shown in FIG. 2). In order to overlap the ends 8b, 9b of each wiring member 8, 9 and the resistor 5 in plan view A, from the fixing hole 8a, 9a of each wiring member 8, 9 to the end face 8c, 9c. The length L1 is formed to be longer than the length from the fixing holes 6a, 7a of the electrodes 6, 7 to the end surfaces 6c, 7c on the side in contact with the resistor 5.

(Heat radiation member 10)
As shown in FIGS. 1 to 3, in this embodiment, the heat dissipation member 10 is sandwiched between the lower surface of the resistor 5 and the upper surface of the ends 8b, 9b of each wiring member 8, 9. The term "heat radiating member" refers to a member that receives heat emitted from the resistor 5 and radiates it to the wiring members 8 and 9.

In this embodiment, the heat dissipation member 10 is an electrically insulating heat dissipation sheet. Thereby, it is possible to electrically insulate between the resistor 5 and each wiring member 8, 9, and between each wiring member 8, 9. Although the material of the heat dissipating member 10 does not matter, the material should have a thermal conductivity that is at least higher than that of air. A commercially available heat dissipation sheet can be used for the heat dissipation member 10. In the present embodiment, the heat radiating member 10 includes a first heat radiating member 10a interposed between the wiring members 8 and 9 and the resistor 5, and a second heat radiating member 10b interposed between the wiring members 8 and 9. It has a substantially T-shaped form that is integrally formed.

In this embodiment, a recess 2c is provided on the lower surface 2b side of the shunt resistor 2, where the resistor 5 of the shunt resistor 2 is recessed relative to the electrodes 6 and 7. Therefore, as shown in FIG. As shown, a gap is formed between the lower surface of the resistor 5 and the upper surfaces of the wiring members 8 and 9. Therefore, the first heat radiating member 10a can be interposed in this gap. Furthermore, since there is a predetermined gap between the ends 8b and 9b of the wiring members 8 and 9, the second heat dissipation member 10b can be interposed in the gap formed between each of the wiring members 8 and 9. Can be done.

As shown in FIG. 1B, it is preferable that the second heat dissipation member 10b be formed with a length extending downward from the lower surface of each wiring member 8, 9, in order to further enhance the heat dissipation effect.

(Assembling shunt resistance module 1)
As shown in FIG. 3, the first heat dissipating member 10a constituting the heat dissipating member 10 is disposed in the recess 2c provided on the lower surface 2b of the shunt resistor 2 and facing the resistor 5, and the second heat dissipating member With the member 10b sandwiched therebetween, each wiring member 8, 9 is placed on the lower surface of each electrode 6, 7 with each fixing hole 6a, 7a, 8a, 9a aligned.

Then, the wiring members 8 and 9 are fixedly supported by the fixing member 11 to each electrode 6 and 7 of the shunt resistor 2. In this embodiment, the fixing member 11 is a combination of a bolt and a nut, but is not limited to this.

During current measurement, a current is passed between the wiring members 8 and 9 via the shunt resistor 2. At this time, the voltage value between the voltage detection terminals 12a and 12b, that is, the voltage value between the electrodes 6 and 7 of the shunt resistor 2 is measured. Since the resistance value of the resistor 5 of the shunt resistor 2 is known, the current value can be detected according to Ohm's law.

<About the effects of this embodiment>
When a current flows through the shunt resistor 2, heat is generated mainly from the resistor 5 having a large resistance value, but in this embodiment, the ends 8b and 9b of each wiring member 8 and 9 and the resistor 5 are In plan view A, since they are arranged one on top of the other, the heat of the resistor 5 can be radiated to the wiring members 8 and 9 side. At this time, since the wiring members 8 and 9 are made of metal and have high thermal conductivity, the heat dissipation of the resistor 5 can be effectively improved. As a result, current measurement can be performed with high precision. In addition, in this embodiment, a heat dissipation effect can be obtained with a simple structure. That is, in this embodiment, the arrangement is improved so that the ends 8b, 9b of the wiring members 8, 9 overlap with the resistor 5 in plan view A, and in this way, the arrangement of the existing components is improved. It is possible to improve the heat dissipation structure to obtain an optimal heat dissipation structure, and to minimize the number of parts.

In this embodiment, as shown in FIG. 2 etc., the electrodes 6 and 7 are made to protrude below the resistor 5 on the lower surface 2b side of the shunt resistor 2, and the recess 2c is formed on the lower surface side of the resistor 5. has been established. As a result, when the wiring members 8 and 9 are fixed to the electrodes 6 and 7 of the shunt resistor 2, there is a gap between the resistor 5 and the wiring members 8 and 9 due to the recess 2c. It is possible to prevent the wiring members 8 and 9 from coming into contact with each other. This allows current to flow appropriately between the electrodes 6 and 7 of the shunt resistor 2 and the wiring members 8 and 9.

Furthermore, in this embodiment, the first heat dissipation member 10a is arranged in the gap between the resistor 5 of the shunt resistor 2 and the wiring members 8 and 9. The first heat dissipation member 10a is an electrically insulating member, and can more reliably electrically insulate between the resistor 5 and the wiring members 8 and 9, and also dissipate the heat generated by the resistor 5. , heat can be effectively radiated to the wiring members 8 and 9 via the first heat radiating member 10a.

Furthermore, in this embodiment, a second heat radiating member 10b is provided between the wiring members 8 and 9. Thereby, the heat from the resistor 5 can be easily radiated downward to the wiring members 8 and 9 via the second heat radiating member 10b. In particular, it can be effectively applied to high voltage applications (current detection) such as power semiconductor devices where a large current flows through the shunt resistor 2.

In this embodiment, the first heat radiating member 10a and the second heat radiating member 10b can be provided separately, but as shown in FIG. It is preferable to integrally form the shunt resistance module 1 because it can enhance the heat dissipation effect and facilitate the assembly of the shunt resistance module 1.

As described above, the present embodiment and the modified examples have been described, but the above embodiments and the modified examples may be combined in whole or in part as other embodiments.

Further, the present embodiment is not limited to the above-described embodiments and modified examples, and may be variously changed, replaced, and modified without departing from the spirit of the technical idea. Further, if the technical idea can be realized in a different manner due to advances in technology or other derived technologies, the invention may be implemented using that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical spirit.

For example, in this embodiment, the heat dissipation member 10 may not be disposed, and a gap serving as an air layer may be interposed between the resistor 5 and the wiring members 8 and 9. According to this configuration, the heat emitted from the resistor 5 can be radiated to the wiring members 8 and 9 via the air layer. In this embodiment, since it is sufficient to leave a gap between the resistor 5 and the wiring members 8, 9 to the extent that these members do not come into contact with each other, the gap between the resistor 5 and the wiring members 8, 9 is The heat dissipation effect can be enhanced by making it as narrow as possible. However, it is preferable to interpose the first heat radiating member 10a in the gap between the resistor 5 and the wiring members 8 and 9, as this can further enhance the heat radiating effect.

Further, the lower surfaces of the resistor 5 and the electrodes 6 and 7 constituting the shunt resistor 2 may be located at substantially the same position, and the lower surface 2b of the shunt resistor 2 may be a substantially flat surface. In this configuration, the shunt resistor 2 and the wiring members 8, 9 are arranged with a gap between them so that there is a gap between the resistor 5 of the shunt resistor 2 and the wiring members 8, 9, and the electrode 6 , 7 and the wiring members 8, 9 are required to be electrically connected. At this time, it is preferable to interpose the first heat radiating member 10a in the gap provided between the resistor 5 and the wiring members 8 and 9. Further, by using the fixing member 11 as a conductive member, it is possible to fix and support each electrode 6, 7 and each wiring member 8, 9, and also to make them conductive.

Further, the heat dissipation member 10 may be composed of only the first heat dissipation member 10a interposed between the resistor 5 of the shunt resistor 2 and the wiring members 8 and 9, but in order to further enhance the heat dissipation effect, It is preferable that the second heat radiating member 10b is arranged between each wiring member 8, 9, and that the first heat radiating member 10a and the second heat radiating member 10b are integrally formed.
The characteristic points of the above embodiment are summarized below.

The shunt resistance module described in the above embodiment includes a shunt resistor including a resistor and electrodes provided at both ends of the resistor, and a wiring member connected to each electrode, In a plan view, a part of the wiring member overlaps the resistor.

Moreover, in the shunt resistance module of this embodiment, it is preferable that the wiring member and the resistor are not in contact with each other.

Further, in the shunt resistance module of the present embodiment, it is preferable that the electrode protrudes toward the wiring member rather than the resistor.

Moreover, in the shunt resistance module of this embodiment, it is preferable that a first heat dissipation member is interposed between the wiring member and the resistor.

Moreover, in the shunt resistance module of this embodiment, it is preferable that a second heat dissipation member is interposed between each wiring member.

Moreover, in the shunt resistance module of this embodiment, it is preferable that the first heat radiating member and the second heat radiating member interposed between each wiring member are integrally formed.

As explained above, the shunt resistance module of the present invention has excellent heat dissipation properties and can perform current detection with high accuracy, and can be applied to, for example, current detection for control purposes such as power semiconductor devices, and battery energy management. Can be done.

1: Shunt resistance module 2: Shunt resistor 2a: Top surface 2b: Bottom surface 2c: Recess 3: Wiring member 5: Resistor 6: First electrode 7: Second electrode 8, 9: Wiring member 10: Heat dissipation member 10a : First heat radiation member 10b : Second heat radiation member 11 : Fixed members 12a, 12b : Voltage detection terminal 12b : Voltage detection terminal A : Planar view

Claims (5)

a shunt resistor comprising a resistor and electrodes provided at both ends of the resistor;
A bus bar connected to each electrode,
Fixing holes are provided in the electrode and the bus bar,
The fixing holes are arranged such that the length from the fixing hole of the bus bar to the end face on the side where each bus bar faces is longer than the length from the fixing hole of the electrode to the end face on the side that contacts the resistor. The location is determined,
A second heat dissipation member is interposed between each bus bar,
A fixing member is inserted into the fixing hole to fix the electrode and the bus bar, and the bus bar extends toward the resistor from the joint between the electrode and the resistor to be connected, and when viewed from above, . A shunt resistance module, wherein a part of the bus bar overlaps the resistor. The shunt resistance module according to claim 1, wherein the bus bar and the resistor are not in contact with each other. 3. The shunt resistance module according to claim 1, wherein the electrode projects further toward the bus bar than the resistor. The shunt resistance module according to any one of claims 1 to 3, wherein a first heat dissipation member is interposed between the bus bar and the resistor. The shunt resistance module according to claim 4, wherein the first heat radiating member and the second heat radiating member are integrally formed.

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