JP6893296B2 - Metal plate resistor - Google Patents

Description

The present invention relates to a metal plate resistor used for current detection of information communication devices such as smartphones and tablets.

FIG. 6 is a cross-sectional view of a conventional metal plate resistor.

As shown in FIG. 6, a conventional metal plate chip resistor has a resistor 1 made of a metal plate, a pair of electrodes 2a and 2b formed on the lower surface of the resistor 1, and improved solderability. The solder layer 3 for the purpose, the first insulator 4 formed between the pair of electrodes 2a and 2b on the lower surface of the resistor 1, and the second insulator 5 formed on the upper surface of the resistor 1. It consisted of.

As the prior art document information regarding the invention of this application, for example, Patent Document 1 is known.

Japanese Unexamined Patent Publication No. 2004-31747

In recent years, resistors for current detection applications are required to have a lower resistance value. In the above-mentioned conventional configuration, since the current flows only in the vicinity of the lower surface between the pair of electrodes 2a and 2b of the resistor 1, there is a problem that the resistance value cannot be lowered.

Therefore, the present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a metal plate resistor capable of lowering a resistance value.

In order to solve the above object, the present invention includes a pair of electrodes formed on both ends of the lower surface of the resistor and a conductor electrode formed on the upper surface of the resistor, and the conductor electrode is used as the specific resistance of the resistor. It is made of a metal material having a lower specific resistance and is located at a position facing the pair of electrodes in a top view.

In the metal plate resistor of the present invention, a conductor electrode having a low specific resistance allows a current to flow from a pair of electrodes toward the conductor electrode along the thickness direction of the resistor, so that the cross-sectional area of the current path is increased. It can be easily increased, which has the effect of lowering the resistance value.

Cross-sectional view of a metal plate resistor according to an embodiment of the present invention. Top view of another example of the same metal plate resistor Top view of another example of the same metal plate resistor Top view of another example of the same metal plate resistor Top view of another example of the same metal plate resistor Sectional view of a conventional metal plate resistor

FIG. 1 is a cross-sectional view of a metal plate resistor according to an embodiment of the present invention.

As shown in FIG. 1, the metal plate conductor according to the embodiment of the present invention includes a resistor 11 made of a metal plate having upper and lower surfaces spaced apart in the thickness direction, and a lower surface of the resistor 11. A protective film 13 that covers the resistor 11 between the pair of electrodes 12a and 12b formed at both ends and the pair of electrodes 12a and 12b, and a conductor electrode 14 formed on the upper surface of the resistor 11 are provided. The conductor electrode 14 is made of a metal having a specific resistance lower than that of the resistor 11, and at least a part of the conductor electrode 14 is viewed from above on the upper surface of the resistor 11 with the pair of electrodes 12a. It is located at a location facing 12b.

In the above configuration, the resistor 11 is composed of a metal plate made of nichrome, copper nickel, manganin, or the like.

When adjusting the resistance value, the lower surface side of the resistor 11 is cut. Since a current flows through the resistor 11 between the pair of electrodes 12a and 12b without passing through the conductor electrode 14, the current path can be cut off and the resistance value can be increased by forming a cut groove in this portion.

Alternatively, as shown in FIG. 2, the resistance value may be adjusted by providing a notch 15 in which a part of the resistor 11 is exposed around the conductor electrode 14 in a part of the conductor electrode 14. Since the resistance value between the pair of electrodes 12a and 12b and the conductor electrode 14 is substantially inversely proportional to the area where the conductor electrode 14 and the pair of electrodes 12a and 12b overlap, the portion of the portion facing the pair of electrodes 12a and 12b The resistance value can be adjusted by removing a part of the conductor electrode 14.

Therefore, it is preferable to form the cutout portion 15 at a position facing the pair of electrodes 12a and 12b in a top view. If the notch 15 is formed in another place, the resistance value hardly changes, so that not only the resistance value cannot be adjusted, but also the resistance value of the conductor electrode 14 made of a material having poor resistance temperature characteristics becomes high. The resistance temperature characteristics of the product deteriorate.

The notch portion 15 is composed of one notch portion 15 formed at a portion facing one pair of electrodes 12a and the other notch portion 15 formed at a portion facing the other pair of electrodes 12b. To. By providing the notches 15 at both ends of the conductor electrode 14 in this way, the resistance value of the resistor 11 in the vicinity of one pair of electrodes 12a and the resistance value of the resistor 11 in the vicinity of the other pair of electrodes 12b are the same. Therefore, the heat generated by the resistor 11 can be uniformly released, and the hot spots can be prevented from being biased.

Further, as shown in FIG. 3, at least one of one notch 15 and the other notch 15 may be formed so as to be parallel to the direction in which the current flows.

At this time, as shown in FIG. 4, if the slit 16 is formed so as to be orthogonal to the notch portion 15, the resistance value can be adjusted by changing the number of slits 16 intersecting with the notch portion 15, and further, less cutting is performed. Since the area of the effective conductor electrode 14 can be greatly changed by the amount, the resistance value can be finely adjusted efficiently.

Here, as shown in FIG. 5, a protruding portion 15a may be provided in a part of the notch portion 15 so as to be orthogonal to the current. If the slit 16 is formed so as to intersect the protruding portion 15a, the resistance value can be finely adjusted with a smaller amount of cutting, which is preferable.

Further, when forming the slit 16, if the distance between one adjacent notch portions 15 and the distance between the other adjacent notch portions 15 are different, resistance is formed at a place where the distance between the notch portions 15 is wide. Since rough adjustment of the value and fine adjustment can be performed in a place where the interval is narrow, the resistance value accuracy can be improved. In FIGS. 3, 4, and 5, one notch 15 and the other notch 15 have different intervals between adjacent notches 15, but a plurality of notches 15 in one notch 15 are spaced from each other. Regarding the portion 15, the distance between the adjacent notch portions 15 may be different. The same applies to the other notch portion 15.

Further, the pair of electrodes 12a and 12b are provided at both ends of the lower surface of the resistor 11 and are made of a thick film material made of copper, silver or the like. A solder layer (not shown) for improving solderability may be formed on the lower surfaces of the pair of electrodes 12a and 12b.

Further, the protective film 13 is provided between the pair of electrodes 12a and 12b so as to cover the resistor 11, and is made of a thick film material made of an epoxy resin or the like.

The conductor electrode 14 is made of a metal such as copper, which has a lower specific resistance than the metal plate used in the resistor 11. Further, the conductor electrode 14 is formed on the upper surface of the resistor 11, and a part of the conductor electrode 14 is provided at a position facing the pair of electrodes 12a and 12b in a top view. The current mainly flows through the conductor electrode 14.

Furthermore, the conductor electrode 14 is not exposed from the resistor 11 in top view, and its outer peripheral edge is located inside the resistor 11. In particular, by preventing both ends of the conductor electrode 14 from being exposed from the resistor 11, the mounting solder formed on the end face 11a side of the resistor 11 adheres to the conductor electrode 14, and the current flows directly to the conductor electrode 14. Therefore, it is possible to suppress fluctuations in the resistance value. Further, if both ends of the conductor electrode 14 are covered with an insulator, it is possible to more reliably prevent the mounting solder from adhering to the conductor electrode 14. At this time, the upper surface of the conductor electrode 14 may also be covered with an insulator.

As described above, in the metal plate resistor according to the embodiment of the present invention, the specific resistance is lower than that of the metal plate used in the resistor 11 at a position where the pair of electrodes 12a and 12b and the resistor 11 are opposed to each other with the resistor 11 interposed therebetween. Since the conductor electrode 14 made of metal is provided, the conductor electrode 14 having a low specific resistance causes a current to flow from the pair of electrodes 12a and 12b toward the conductor electrode 14 along the thickness direction of the resistor 11. As a result, the cross-sectional area of the current path can be easily increased, so that the resistance value can be lowered.

The metal plate resistor according to the present invention has the effect of being able to lower the resistance value, and is used as a metal plate resistor or the like used for current detection of information and communication equipment represented by smartphones and tablets. It is useful.

11 Resistors 12a, 12b Pair of electrodes 14 Conductor electrodes

Claims (5)

A resistor made of a metal plate having upper and lower surfaces spaced apart in the thickness direction, a pair of electrodes formed on both ends of the lower surface of the resistor, and a resistor joined to the upper surface of the resistor. A metal plate resistor formed in a resistor and provided with a conductor electrode having a notch in a part thereof, and the conductor electrode is made of a metal having a specific resistance lower than the specific resistance of the resistor. The metal plate resistor according to claim 1 , wherein the cutout portion is formed at a position facing the pair of electrodes in a top view. The metal plate resistor according to claim 1 , wherein a plurality of cutout portions are formed in parallel with the direction in which an electric current flows. The metal plate resistor according to claim 3 , wherein a slit is formed so as to intersect the plurality of notches. The metal plate resistor according to claim 4 , wherein the distance between one adjacent notch and the distance between the other adjacent notches are different.

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