Patent Description:
A shunt resistor is widely used in current detection applications. Such a shunt resistor includes a resistance element and electrodes joined to both ends of the resistance element. In general, the resistance element is made of resistance alloy such as copper-nickel alloy, copper-manganese alloy, iron-chromium alloy, or nickel-chromium alloy. The electrodes are made of highly conductive metals such as copper. A voltage detecting portion is provided on the electrode, and the voltage generated at the both ends of the resistance element is detected by connecting a conducting wire (e.g., aluminum wire) to the voltage detecting portion.

<FIG> and <FIG> show an example of a conventional shunt resistor. As shown in <FIG> and <FIG>, the shunt resistor <NUM> includes a plate-shaped resistance element <NUM> having a predetermined thickness and width and made of a resistive alloy, and a pair of electrodes <NUM> and <NUM> made of highly conductive metal connected to both ends of the resistance element <NUM>. Bolt holes <NUM> and <NUM> for fixing the shunt resistor <NUM> with screws or the like are formed in the electrodes <NUM> and <NUM>, respectively.

The shunt resistor <NUM> further includes voltage detecting portions <NUM> and <NUM> for measuring a voltage of the resistance element <NUM>. In the example shown in <FIG>, the voltage detecting portions <NUM> and <NUM> are formed integrally with the electrodes <NUM> and <NUM>, respectively. The voltage detecting portions <NUM> and <NUM> extend in a width direction of the electrodes <NUM> and <NUM> from side surfaces of the electrodes <NUM> and <NUM>. The voltage detecting portions <NUM> and <NUM> are arranged near the resistance element <NUM>.

In the example shown in <FIG>, the voltage detecting portions <NUM> and <NUM> are pins extending vertically from the surfaces of the electrodes <NUM> and <NUM>, respectively. The voltage detecting portions <NUM> and <NUM> are arranged near the resistance element <NUM>.

<CIT> and <CIT> show examples of shunt resistors. Furthermore, <CIT> relates to a current detecting resistor comprising a low resistance metal resistor having a pair of current terminals and a pair of voltage terminals. Further, prior art can be found in documents <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

A temperature coefficient of resistance (TCR) characteristic is important in the shunt resistor to allow current detection under a condition that is less affected by a temperature fluctuation. The temperature coefficient of resistance is an index that indicates a rate of change in a resistance value due to temperature. Accordingly, it is an object of the present invention to provide a shunt resistor having a simple structure and capable of reducing the temperature coefficient of resistance. Furthermore, it is an object of the present invention to provide a method for manufacturing such a shunt resistor and a current detection device including such a shunt resistor.

In accordance with the invention, a plate shunt resistor and a method for manufacturing the same as set forth in the appended claims are provided. The plate shunt resistor according to claim <NUM> which can be used in current detection inter alia comprises: a resistance element; and a pair of electrodes connected to both ends of the resistance element in a first direction, the shunt resistor has: a projecting portion formed on a first side surface of the shunt resistor, the first side surface being parallel to the first direction; and a recessed portion formed on a second side surface of the first side surface of the shunt resistor, the second side surface being an opposite side of the first side surface, the recessed portion extending in the same direction as the projecting portion, the projecting portion has a portion of the resistance element and portions of the pair of electrodes, and the recessed portion has a side of the resistance element parallel to the first direction.

In an embodiment, a length of the recessed portion in the second direction perpendicular to the first direction is the same as a length of the projecting portion in the second direction.

In an embodiment, the projecting portion comprises a pair of voltage detecting portions connected to both ends of the resistance element in the first direction.

In an embodiment, the projecting portion and the recessed portion have a rectangular shape.

The method for manufacturing the shunt resistor according to claim <NUM> inter alia comprises: preparing a long shunt resistor base material in which the pair of electrodes are connected to the both ends of the resistance element in a first direction; forming a projecting portion of a first shunt resistor having a portion of the resistance element of the first shunt resistor and portions of the pair of electrodes of the first shunt resistor by cutting the shunt resistor base material in the first direction in a convex shape; and forming a recessed portion of the first shunt resistor extending in the same direction as the projecting portion and a projecting portion of a second shunt resistor by cutting the shunt resistor base material in the first direction into a convex shape spaced apart from the projecting portion, the projecting portion of the second shunt resistor has a portion of the resistance element of the second shunt resistor and portions of the pair of electrodes of the second shunt resistor.

In an embodiment, there is provided a current detection device comprising: a shunt resistor of any one of claims <NUM> to <NUM> and a current detection circuit substrate having a voltage signal wiring transmitting a voltage signal from the shunt resistor, the voltage signal wiring is electrically connected to a projecting portion of the shunt resistor.

In an embodiment, the current detection circuit substrate further has a voltage terminal pad, and the voltage terminal pad is connected to the projecting portion and the voltage signal wiring.

In an embodiment, the current detection device further includes an output terminal outputting a voltage signal from the shunt resistor, and the output terminal is attached to a recessed portion of the shunt resistor.

It is possible to reduce the temperature coefficient of resistance of the shunt resistor while maintaining a desired resistance value with a simple structure in which the projecting portion having the portion of the resistance element and the portions of the pair of electrodes is formed on the first side surface of the shunt resistor, and the recessed portion having the side surface of the resistance element parallel to the first direction is formed on the second side of the shunt resistor.

In the drawings described hereinbelow, the same symbols are used to refer to the same or equivalent components or elements, and a duplicate description thereof is omitted. In a plurality of embodiments described below, configurations of one embodiment not specifically described are the same as the other embodiments, so its redundant description is omitted.

<FIG> is a perspective view showing one embodiment of a shunt resistor <NUM>, and <FIG> is a plan view of the shunt resistor <NUM> shown in <FIG>. As shown in <FIG>, the shunt resistor <NUM> includes a resistance element <NUM> made of a resistor alloy plate material having a predetermined thickness and width, and a pair of electrodes <NUM> and <NUM> made of a highly conductive metal connected to both ends (i.e., both connecting surfaces) 5a and 5b of the resistance element <NUM> in a first direction. The electrode <NUM> has a contact surface 6a that contacts one end (one connecting surface) 5a of the resistance element <NUM>, and the electrode <NUM> has a contact surface 7a that contacts the other end (other connecting surface) 5b of the resistance element <NUM>. Bolt holes <NUM> and <NUM> for fixing the shunt resistor <NUM> with screws or the like are formed in the electrodes <NUM> and <NUM>, respectively.

The first direction is a length direction of the resistance element <NUM>, and corresponds to the length direction of the shunt resistor <NUM>. The length direction of the shunt resistor <NUM> is a direction in which the electrode <NUM>, the resistance element <NUM>, and the electrode <NUM> are arranged in this order. A direction perpendicular to this first direction is a second direction. The second direction is a width direction of the shunt resistor <NUM>. As shown in <FIG>, the electrodes <NUM> and <NUM> have the same structure, and are arranged symmetrically with respect to the resistance element <NUM>.

The both ends 5a and 5b of the resistance element <NUM> are connected (bonded) to the electrodes <NUM> and <NUM> by means of welding (e.g., electron beam welding, laser beam welding, or brazing), respectively. An example of the material of the resistance element <NUM> is a low-resistance alloy material such as a Cu-Mn alloy. An example of the material of the electrodes <NUM> and <NUM> is copper (Cu).

The shunt resistor <NUM> has a projecting portion <NUM> formed on a side surface 1a of the shunt resistor <NUM>, and a recessed portion <NUM> formed on a side surface 1b of the shunt resistor <NUM>. The projecting portion <NUM> extends outward from the side surface 1a, and the recessed portion <NUM> extends inward (toward a center of the shunt resistor <NUM>) from the side surface 1b. Both the projecting portion <NUM> and the recessed portion <NUM> extend in the same direction (second direction). The projecting portion <NUM> and the recessed portion <NUM> have a rectangular shape when viewed from above (when viewed from a direction perpendicular to both the first direction and the second direction).

The side surface 1a is a surface of the shunt resistor <NUM> parallel to the first direction, and has a side surface 6c of the electrode <NUM> and a side surface 7c of the electrode <NUM>. The side surface 1b is a surface of the shunt resistor <NUM> parallel to the first direction, and the surface opposite to the side surface 1a. The side surface 1b has a side surface 6b of the electrode <NUM> and a side surface 7b of the electrode <NUM>. The side surfaces 6b and 7b are surfaces parallel to the side surfaces 6c and 7c.

<FIG> is an enlarged view of the projecting portion <NUM> and the recessed portion <NUM>. The projecting portion <NUM> has a portion of the resistance element <NUM> and portions of the electrodes <NUM> and <NUM>. Specifically, the projecting portion <NUM> has a portion <NUM> which is a portion of the resistance element <NUM> and voltage detecting portions <NUM> and <NUM> for measuring voltages generated at the both ends 5a and 5b of the resistance element <NUM>. The length of the portion <NUM> in the second direction is represented by a length t1 (the length t1 of the projecting portion <NUM> in the second direction) that is a distance from the side surfaces 6c and 7c of the electrodes <NUM> and <NUM> to the side surface 5c of the resistance element <NUM>.

The voltage detecting portions <NUM> and <NUM> are portions of the electrodes <NUM> and <NUM>, respectively. That is, the electrode <NUM> has the voltage detecting portion <NUM>, and the electrode <NUM> has the voltage detecting portion <NUM>. The voltage detecting portion <NUM> extends outward from the side surface 6c of the electrode <NUM>, and the voltage detecting portion <NUM> extends outward from the side surface 7c of the electrode <NUM>. The voltage detecting portions <NUM> and <NUM> are connected to the both ends 5a and 5b of the resistance element <NUM>, respectively. The voltage detecting portions <NUM> and <NUM> are arranged symmetrically with respect to the portion <NUM>. The length of the voltage detecting portions <NUM> and <NUM> in the second direction is also represented by the length t1.

The recessed portion <NUM> has a side surface 5d of the resistance element <NUM> parallel to the first direction. Specifically, in the present embodiment, the side surface 12c of the recessed portion <NUM> in the first direction (see <FIG>) is composed of a side surface 6d of the electrode <NUM>, a side surface 5d of the resistance element <NUM>, and a side surface 7d of the electrode <NUM>. In this embodiment, a width W1 (a length of the projecting portion <NUM> in the first direction) of the projecting portion <NUM> and a width W2 (a length of the recessed portion <NUM> in the first direction) of the recessed portion <NUM> are the same, and the length t1 of the projecting portion <NUM> in the second direction (i.e., the width direction of the shunt resistor <NUM>) and the length t2 of the recessed portion <NUM> in the second direction are the same. A position of the projecting portion <NUM> in the first direction and a position of the recessed portion <NUM> in the first direction are the same. That is, a side surface 11a of the projecting portion <NUM> is arranged on an extension line of the side surface 12a of the recessed portion <NUM>, and a side surface 11b of the projecting portion <NUM> is arranged on an extension line of the side surface 12b of the recessed portion <NUM>.

<FIG> is a perspective view showing an embodiment of a current detection device <NUM> including the shunt resistor <NUM>. The current detection device <NUM> further includes a voltage output device <NUM> that outputs a voltage (the voltage generated at the both ends 5a and 5b of the resistance element <NUM>) of the resistance element <NUM>. The voltage output device <NUM> is connected to the shunt resistor <NUM>. The voltage output device <NUM> includes a non-conductive case <NUM> covering the resistance element <NUM>, and an output terminal <NUM> (output connector <NUM>) for outputting a voltage signal (voltage of the resistance element <NUM>) from the shunt resistor <NUM>. The output connector <NUM> includes a first terminal, a second terminal, and a ground terminal (not shown).

<FIG> is a perspective view showing the current detection device <NUM> when the case <NUM> of the voltage output device <NUM> is removed. As shown in <FIG>, the voltage output device <NUM> further includes a current detection circuit substrate <NUM>. The current detection circuit substrate <NUM> has voltage signal wirings <NUM> and <NUM> for transmitting the voltage signal (voltage of the resistance element <NUM>) from the shunt resistor <NUM> to the output terminal <NUM> and a ground wiring <NUM>. A current detection circuit substrate <NUM> is arranged on the shunt resistor <NUM>, and an output terminal <NUM> is attached to the recessed portion <NUM>.

The current detection circuit substrate <NUM> further has voltage terminal pads <NUM> and <NUM> (copper foil portions <NUM> and <NUM>). One end of the voltage signal wiring <NUM> is connected to the voltage terminal pad <NUM>, and the other end is connected to the first terminal of the output connector <NUM>. One end of the voltage signal wiring <NUM> is connected to the voltage terminal pad <NUM>, and the other end is connected to the second terminal of the output connector <NUM>. The voltage signal wirings <NUM> and <NUM> are bent and wired from the second direction (see <FIG>) to the first direction (see <FIG>) above the projecting portion <NUM>. One end of the ground wiring <NUM> is connected to the voltage terminal pad <NUM>, and the other end is connected to the ground terminal of the output connector <NUM>. The voltage signal wirings <NUM> and <NUM>, the ground wiring <NUM>, and the voltage terminal pads <NUM> and <NUM> are made of a highly conductive metal (copper in this embodiment).

The voltage terminal pad <NUM> is connected to the voltage detecting portion <NUM> (see <FIG>) of the voltage detecting portion <NUM> of the projecting portion <NUM> via an internal wiring not shown on the current detection circuit substrate <NUM>. Similarly, the voltage terminal pad <NUM> is connected to a voltage detecting position <NUM> (see <FIG>) of the voltage detecting portion <NUM> of the projecting portion <NUM> via the internal wiring not shown. In other words, the voltage signal wirings <NUM> and <NUM> are electrically connected to the voltage detecting positions <NUM> and <NUM> of the projecting portion <NUM>, respectively. The above-described internal wiring and the voltage detecting portions <NUM> and <NUM> are connected by soldering or other methods. An operator connects a cable including a connector that mates with the output terminal <NUM> to measure the voltage generated at the both ends 5a and 5b of the resistance element <NUM>. This configuration allows for easy measurement of the voltage of the resistance element <NUM>. In one embodiment, an operational amplifier (amplifier), an A/D converter, and/or a temperature sensor for amplifying the voltage signal from the shunt resistor <NUM> may be mounted on the current detection circuit substrate <NUM>.

In one embodiment, as shown in <FIG>, voltage detection terminals <NUM> and <NUM> may be provided on the voltage detecting portions <NUM> and <NUM>, respectively. The voltage detection terminals <NUM> and <NUM> are conductive pins extending vertically from the surfaces of the voltage detecting portions <NUM> and <NUM>, respectively. Specifically, the voltage detection terminals <NUM> and <NUM> are connected to the voltage detecting positions <NUM> and <NUM> of the voltage detecting portions <NUM> and <NUM> by soldering or the like, respectively. The voltage generated at the both ends of the resistance element <NUM> is measured by connecting conductive wires (e.g., aluminum wires) to the voltage detection terminals <NUM> and <NUM>, respectively, or inserting the voltage detection terminals <NUM> and <NUM> into through holes formed in a circuit substrate to electrically connect to the wiring formed in the circuit substrate. With such a configuration, the voltage of the resistance element <NUM> can be measured with a simple configuration.

<FIG> is a graph showing a rate of change in a resistance value of the shunt resistor <NUM> due to the temperature change. A horizontal axis of <FIG> indicates the temperature of the shunt resistor <NUM>, and a vertical axis of <FIG> indicates the rate of change in the resistance value of the shunt resistor <NUM>. A curve indicated by a solid line indicates the rate of change in the resistance value of the shunt resistor <NUM> of this embodiment, and a curve indicated by a dotted line indicates the rate of change in the resistance value of the conventional shunt resistor (the shunt resistor <NUM> shown in <FIG>). <FIG> shows results when a copper-manganese alloy is used as the resistance element <NUM>.

As is clear from a comparison of a fluctuation range of the rate of change in the resistance value of the shunt resistor <NUM> of the present embodiment and a fluctuation range of the rate of change in the resistance value of the conventional shunt resistor, the shunt resistor <NUM> of the present embodiment can reduce the fluctuation range of the rate of change in the resistance value due to the temperature change. That is, results of <FIG> show that the shunt resistor <NUM> can reduce the temperature coefficient of resistance (TCR). By forming the projecting portion <NUM> having the portion of the resistance element <NUM> and the portions of the electrodes <NUM> and <NUM> as described above, equipotential lines are distorted, and as a result, the temperature coefficient of resistance of the shunt resistor <NUM> can be reduced.

<FIG> is a plan view of one embodiment of a shunt resistor <NUM> without the recessed portion <NUM>. Configurations of the shunt resistor <NUM> are the same as the shunt resistor <NUM> except that it does not have the recessed portion <NUM>. That is, the shunt resistor <NUM> includes a resistance element <NUM> corresponding to the resistance element <NUM> of the shunt resistor <NUM>, and a pair of electrodes <NUM> and <NUM> connected to both ends of the resistance element <NUM>. The electrodes <NUM> and <NUM> correspond to the electrodes <NUM> and <NUM> of the shunt resistor <NUM>. The shunt resistor <NUM> has a projecting portion <NUM> corresponding to the projecting portion <NUM> of the shunt resistor <NUM>, and the projecting portion <NUM> has a portion of the resistance element <NUM> and portions of the electrodes <NUM> and <NUM>. The projecting portion <NUM> includes voltage detecting portions <NUM> and <NUM> that are portions of the electrodes <NUM> and <NUM> arranged symmetrically with respect to the resistance element <NUM>.

<FIG> is a graph showing a relationship between a length t3 of the projecting portion <NUM> in the second direction and the rate of change in the resistance value of the shunt resistor <NUM>. <FIG> shows results when a copper-manganese alloy is used as the resistance element <NUM> for a shape of the shunt resistor shown in <FIG>. A vertical axis of <FIG> indicates the rate of change in the resistance value when the temperature of the shunt resistor <NUM> rises from <NUM> to <NUM>. The results of <FIG> show that the rate of change in the resistance value of the shunt resistor <NUM> depends on the length t3. More specifically, as the length t3 increases, the rate of change in the resistance value decreases.

<FIG> is a graph showing the relationship between the length t1 of the projecting portion <NUM> of the shunt resistor <NUM> and the rate of change in the resistance value of the shunt resistor <NUM>. <FIG> shows results when a copper-manganese alloy is used as the resistance element <NUM> for a shape of the shunt resistor shown in <FIG>. The length t2 of the recessed portion <NUM> is the same as the length t1. The vertical axis of <FIG> indicates the rate of change in the resistance value when the temperature of the shunt resistor <NUM> rises from <NUM> to <NUM>. Similar to the results in <FIG>, the results in <FIG> indicates that the rate of change in the resistance value of the shunt resistor <NUM> depends on the length t1, and the length t1 increases, the rate of change in the resistance value decreases. For example, when the length t1 is <NUM>, the rate of change in the resistance value of the shunt resistor <NUM> is about <NUM>%.

As shown in <FIG>, a rate at which the rate of change in the resistance value of the shunt resistor <NUM> decreases is the same as a rate at which the rate of change in the resistance value of the shunt resistor <NUM> shown in <FIG> decreases. That is, the results of <FIG> show that the rate of change in the resistance value depending on the temperature of the shunt resistor <NUM> depends on the length t1 of the projecting portion <NUM> rather than the recessed portion <NUM>. Therefore, the results of <FIG> show that the temperature coefficient of resistance of the shunt resistor <NUM> can be corrected and reduced by adjusting the length t1.

<FIG> is a graph showing the rate of change in the resistance value of each of shunt resistor <NUM> and the shunt resistor <NUM>. <FIG> shows the rates of change of the resistance value of the shunt resistors <NUM> and <NUM> due to changes in the lengths t1 and t3 of the projecting portion <NUM> and <NUM> at a predetermined temperature (constant temperature). The length t2 of the recessed portion <NUM> is the same as the length t1. The results of <FIG> show that the resistance value of the shunt resistor <NUM> without the recessed portion <NUM> varies greatly depending on the length t3 of the projecting portion <NUM>. For example, the resistance value of the shunt resistor <NUM> when the length t3 is <NUM> is approximately <NUM> % lower than the resistance value when the length t3 is <NUM>. This is because the formation of the projecting portion <NUM> increases the length of the resistance element <NUM> in the second direction and changes the resistance value of the resistance element <NUM>.

As shown in <FIG>, in the shunt resistor <NUM> having the recessed portion <NUM>, the change in the resistance value of the shunt resistor <NUM> due to the change in the length t1 is suppressed. This is because the length of the resistance element <NUM> in the second direction is kept constant by forming the recessed portion <NUM> having the side surfaces 5d of the resistance element <NUM>. That is, it is possible to suppress the change in the resistance value of the shunt resistor <NUM> due to a formation of the projecting portion <NUM> by forming the recessed portion <NUM>.

Therefore, by adjusting the length t1 of the projecting portion <NUM> and the length t2 of the recessed portion <NUM> of the shunt resistor <NUM> according to a size and a shape of the shunt resistor <NUM>, the desired TCR can be satisfied while maintaining the desired resistance value. Therefore, according to this embodiment, with a simple structure in which the projecting portion <NUM> having the portion of the resistance element <NUM> and the portions of the electrodes <NUM> and <NUM> is formed on the side surface 1a of the shunt resistor <NUM>, and in which the recessed portion <NUM> having the side surface 5d of the resistance element <NUM> is formed on the side surface 1b of the shunt resistor <NUM>, it is possible to reduce the temperature coefficient of resistance of the shunt resistor <NUM> while maintaining a desired resistance value.

<FIG> is a perspective view showing another embodiment of the shunt resistor <NUM>, and <FIG> is an enlarged view of the projecting portion <NUM> of <FIG>. Configurations of this embodiment, which will not be particularly described, are the same as those of the embodiments described with reference to <FIG>, and redundant descriptions thereof will be omitted. The resistance element <NUM> of this embodiment has a cut portion <NUM>. The cut portion <NUM> extends parallel to the end surfaces 5a and 5b (in the second direction shown in <FIG>). The cut portion <NUM> has a slit-like shape extending linearly. The cut portion <NUM> is formed on the side surface 5c of the resistance element <NUM> and linearly extends from the side surface 5c toward an inside of the shunt resistor <NUM> (the central portion of the shunt resistor <NUM>).

The resistance value of the shunt resistor can be adjusted by forming the cut portion <NUM> in the resistance element <NUM>, and in addition, the TCR of the shunt resistor <NUM> can be finely adjusted. Specifically, the TCR can be increased by narrowing a width W3 of the cut portion <NUM> in the first direction and increasing a length t4 in the second direction. Also in this embodiment, the current detection device <NUM> described with reference to <FIG> and <FIG> and the voltage detection terminals <NUM> and <NUM> described with reference to <FIG> can be applied.

Next, a method for manufacturing the shunt resistor <NUM> will be described. <FIG> are views showing an example of manufacturing processes of the shunt resistor <NUM>. The bolt holes <NUM> and <NUM> are omitted in <FIG>.

First, as shown in <FIG>, a long (belt-shaped) shunt resistor base material <NUM> (metal plate material) in which the electrodes <NUM> and <NUM> are connected to the both ends of the resistance element <NUM> in the first direction is prepared. Next, as shown in <FIG>, the shunt resistor base material <NUM> is cut in a direction in which the electrode <NUM>, the resistance element <NUM>, and the electrode <NUM> are arranged (i.e., the first direction). Specifically, the shunt resistor base material <NUM> is cut in the first direction in a convex shape. The convex shape is a shape corresponding to the projecting portion <NUM> of the shunt resistor <NUM>. The side surface 1a and the projecting portion <NUM> of the shunt resistor <NUM> (first shunt resistor 1A) are formed (<FIG>) by cutting the shunt resistor base material <NUM> in the first direction in the convex shape.

Next, as shown in <FIG>, spacing in the second direction from the projecting portion <NUM> and the side surface 1a, and the shunt resistor base material <NUM> is cut in the first direction and in a convex shape, as in <FIG>. As a result, the first shunt resistor 1A is separated from the shunt resistor base material <NUM>, and the side surface 1b of a first shunt resistor 1A, the recessed portion <NUM> of the first shunt resistor 1A, the projecting portion <NUM> of the other shunt resistor <NUM> (second shunt resistor 1B), and the side surface 1a of the second shunt resistor 1B are formed (<FIG>).

Next, as shown in <FIG>, spacing in the second direction from the projecting portion <NUM> and the side surface 1a of the second shunt resistor 1B, and the shunt resistor base material <NUM> is cut in the first direction and in a convex shape, as in <FIG>. As a result, the second shunt resistor 1B is separated from the shunt resistor base material <NUM>, and the side surface 1b of the second shunt resistor 1B and the recessed portion <NUM> of the second shunt resistor 1B are formed. A plurality of shunt resistors <NUM> are manufactured by repeating steps of <FIG>.

By manufacturing methods shown in <FIG>, the shunt resistor <NUM> can be manufactured in a simple manner, and the shunt resistor base material <NUM> can be used without waste. As a result, cost reduction can be achieved.

<FIG> are schematic views showing still another embodiment of the shunt resistor <NUM>. Configurations of this embodiment, which will not be particularly described, are the same as those of the embodiments described with reference to <FIG>, and redundant descriptions thereof will be omitted. In <FIG>, the bolt holes <NUM> and <NUM> are omitted. In the embodiments shown in <FIG>, the current detection device <NUM> described with reference to <FIG> and <FIG>, and the voltage detection terminals <NUM> and <NUM> described with reference to <FIG> can be applied.

In one embodiment, as shown in <FIG>, the side surfaces 11a and 11b of the projecting portion <NUM> and the side surfaces 12a and 12b of the recessed portion <NUM> may be formed obliquely with respect to the second direction (see <FIG>). In an example shown in <FIG>, the side surfaces 11a and 11b extend away from the resistance element <NUM>. The side surface 12a is formed parallel to the side surface 11a, and the side surface 12b is formed parallel to the side surface 11b.

In one embodiment, as shown in <FIG>, the voltage detecting portions <NUM> and <NUM> may have cut portions 20a and 20b extending from the side surface 11a and 11b toward the resistance element <NUM>, respectively. In one embodiment, as shown in <FIG>, the width W2 of the recessed portion <NUM> may be larger than the width W1 of the projecting portion <NUM>. As shown in <FIG>, and the width W2 may be smaller than the width W1.

<FIG> is a schematic view showing another embodiment of the manufacturing method of the shunt resistor <NUM>. As shown in <FIG>, the shunt resistor <NUM> may be manufactured by punching the shunt resistor base material <NUM> into an external shape of the shunt resistor <NUM>. As shown in <FIG>, the shunt resistor <NUM> of the embodiment shown in <FIG> may be manufactured by the same method as described with reference to <FIG>.

The previous description of embodiments is provided to enable a person skilled in the art to make and use the present invention. Moreover, various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments. Therefore, the present invention is not intended to be limited to the embodiments described herein but is to be accorded to the appended claims.

Claim 1:
A plate shunt resistor (<NUM>) used in current detection comprising:
a resistance element (<NUM>); and
a pair of electrodes (<NUM>, <NUM>) connected to both ends of the resistance element (<NUM>) in a first direction,
wherein the shunt resistor (<NUM>) comprises:
a first side surface (1a) disposed on a first side of the shunt resistor (<NUM>) and extending parallel to the first direction,
a second side surface (1b) disposed on a second side of the shunt resistor (<NUM>) extending parallel to the first direction, the second side being opposite to the first side of the shunt resistor,
a projecting portion (<NUM>) formed on the first side surface (1a) of the shunt resistor (<NUM>) and projecting in a second direction perpendicular to the first direction, and
a recessed portion (<NUM>) formed on the second side surface (1b) of the shunt resistor (<NUM>) and recessed in the second direction,
wherein the projecting portion (<NUM>) has a portion of the resistance element (<NUM>) and portions of the pair of electrodes (<NUM>, <NUM>), and
wherein the recessed portion (<NUM>) has a side of the resistance element (<NUM>) parallel to the first direction.