JP2012222012A - Chine type chip resistor - Google Patents

Abstract

An object of the present invention is to provide a rectangular chip resistor capable of supporting high power.
A rectangular chip resistor according to the present invention includes an insulating substrate 11, a pair of upper surface electrodes 12a and a pair of rear surface electrodes 12b provided on both ends of the upper surface and the back surface of the insulating substrate 11, and the pair of The upper surface resistor 13a and the back surface resistor 13b are provided so as to be electrically connected to the upper surface electrode 12a and the pair of back surface electrodes 12b, respectively, and the area of the upper surface resistor 13a is the area of the back surface resistor 13b. Further, the length of the upper surface resistor 13a between the pair of upper surface electrodes 12a is made longer than the length of the back surface resistor 13b between the pair of back surface electrodes 12b.
[Selection] Figure 1

Description

  The present invention relates to a rectangular chip resistor used in various electronic devices, and more particularly to a rectangular chip resistor having a resistor on both sides and having a low resistance value.

  As shown in FIG. 2, a conventional square chip resistor of this type includes a pair of upper surface electrodes 2a and a pair of rear surface electrodes formed on the upper surface and the back surface of an insulating substrate 1 made of alumina or the like, each made of silver or copper. 2b, the upper surface resistor 3a and the back surface resistor 3b made of copper nickel formed between the pair of upper surface electrodes 2a and the pair of back surface electrodes 2b, and the upper surface resistor 3a and the back surface resistor 3b, respectively. A side electrode 5 electrically connected to the top electrode 2a and the back electrode 2b at both ends of the insulating substrate 1, and a plating layer 6 formed on the surface of the side electrode 5. It was. And the upper surface resistor 3a and the back surface resistor 3b were formed in the position which mutually overlaps in top view. Further, trimming grooves (not shown) for adjusting the resistance value are provided in the upper surface resistor 3a and the back surface resistor 3b as necessary.

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

Japanese Patent Laid-Open No. 11-191502

  In the conventional square chip resistor described above, when mounted on a mounting substrate, the backside resistor 3b has good heat dissipation because the distance between the back surface resistor 3b and the land pattern 8 of the mounting substrate 7 is short, as shown in FIG. Since the upper surface resistor 3a is far from the land pattern 8, the heat generated by the upper surface resistor 3a is not easily radiated by the land pattern 8 and is radiated in the air having poor heat conduction. Therefore, compared with the back surface resistor 3b, the heat radiation property of the top surface resistor 3a is deteriorated, and when high power is applied, there is a problem that a problem such as a change in the resistance value of the top surface resistor 3a occurs. It was. The square chip resistor and the land pattern 8 are connected by mounting solder (not shown).

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a rectangular chip resistor that can handle high power.

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, there is provided an insulating substrate, a pair of upper surface electrodes and a pair of back electrodes provided on both ends of the upper surface and the back surface of the insulating substrate, the pair of upper surface electrodes and the pair of upper surfaces. An upper surface resistor and a back surface resistor provided so as to be electrically connected to the back surface electrodes, respectively, wherein the area of the top surface resistor is larger than the area of the back surface resistor and between the pair of top surface electrodes The length of the top surface resistor is made longer than the length of the back surface resistor between the pair of back surface electrodes, and according to this configuration, the area of the top surface resistor can be increased. Since the area that can dissipate heat increases and the length of the top resistor is increased, the distance between the top resistor and the land pattern of the mounting board can be shortened. Heat dissipation Therefore, since the length of the upper surface resistor is increased, the length of the pair of upper surface electrodes can be shortened, so that the TCR of the upper surface electrode is a square chip. Since the influence on the entire resistor can be reduced, the TCR of the square chip resistor can be reduced.

  According to a second aspect of the present invention, there is provided an insulating substrate, a pair of upper surface electrodes and a pair of rear surface electrodes provided on both ends of the upper surface and the rear surface of the insulating substrate, the pair of upper surface electrodes and the pair of upper surfaces. A back surface resistor and a back surface resistor provided so as to be electrically connected to the back surface electrode, respectively, wherein the resistance value of the back surface resistor is smaller than the resistance value of the top surface resistor. According to this, since a large amount of current flows through the back surface resistor having a small resistance value, it is possible to suppress the heat generation of the top surface resistor, thereby having the effect of being able to cope with high power.

  As described above, the rectangular chip resistor of the present invention can increase the area of the upper surface resistor, so that the area of the upper surface resistor that can dissipate heat into the air increases, and the upper surface resistance between the pair of upper surface electrodes. Since the body length is longer than the length of the backside resistor between the pair of backside electrodes, the distance between the topside resistor and the mounting board can be shortened. As a result, the heat generated by the topside resistor is effective. Since the heat can be radiated automatically, it is possible to cope with high power, and since the length of the upper surface resistor is increased, the length of the pair of upper surface electrodes can be shortened. Can reduce the influence on the entire rectangular chip resistor, and therefore has an excellent effect that the TCR of the rectangular chip resistor can be reduced.

Sectional drawing of the square chip resistor in one embodiment of this invention Cross-sectional view of a conventional square chip resistor Sectional view showing mounting state of equiangular chip resistor

  Hereinafter, a rectangular chip resistor according to an embodiment of the present invention will be described with reference to the drawings.

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

  As shown in FIG. 1, a rectangular chip resistor according to an embodiment of the present invention includes an insulating substrate 11, a pair of upper surface electrodes 12a provided on both ends of the upper surface and the back surface of the insulating substrate 11, and a pair of A back surface electrode 12b, a top surface resistor 13a and a back surface resistor 13b are provided so as to be electrically connected to the pair of top surface electrodes 12a and the pair of back surface electrodes 12b, respectively.

  Then, the area of the upper surface resistor 13a is made larger than the area of the back surface resistor 13b, and the length of the upper surface resistor 13a between the pair of upper surface electrodes 12a is set to be the back surface resistor 13b between the pair of back surface electrodes 12b. It is longer than the length of.

  In the above configuration, the insulating substrate 11 has a rectangular shape and is made of alumina having a purity of about 96%.

  The pair of upper surface electrodes 12 a are provided at both ends of the upper surface of the insulating substrate 11, and the pair of back surface electrodes 12 b are provided at both ends of the rear surface of the insulating substrate 11. The pair of upper surface electrodes 12a and the pair of back surface electrodes 12b are made of a metal whose main component is silver or copper. Further, the length of the pair of upper surface electrodes 12a is made shorter than the length of the pair of rear surface electrodes 12b, whereby the length of the upper surface resistor 13a between the pair of upper surface electrodes 12a is reduced. The length is longer than 13b.

  The top resistor 13 a is formed between the pair of top electrodes 12 a on the top surface of the insulating substrate 11, and the back resistor 13 b is formed between the pair of back electrodes 12 b on the back surface of the insulating substrate 11. The top surface resistor 13a and the back surface resistor 13b are made of an alloy such as copper nickel, and the area of the top surface resistor 13a is larger than the area of the back surface resistor 13b. At this time, if the width of the upper surface resistor 13a is made equal to the width of the back surface resistor 13b, and the length of the upper surface resistor 13a is made longer than the length of the back surface resistor 13b as described above, the area of the upper surface resistor 13a is reduced. Can be big.

  The top surface resistor 13a and the back surface resistor 13b are formed with a trimming groove 14 by laser irradiation in order to adjust to a desired resistance value.

  Further, since the area of the upper surface resistor 13a is larger than the area of the back surface resistor 13b, the resistance value of the upper surface resistor 13a and the resistance value of the back surface resistor 13b are different. The resistance value of the resistor 13b may be the same. Here, in order to make the resistance value of both the same, the thickness of the upper surface resistor 13a is increased or the material constituting the upper surface resistor 13a is used. There is a method of using a material having high conductivity. And when both resistance values are the same, since a combined resistance value becomes 1/2 of the resistance values of the upper surface resistor 13a and the back surface resistor 13b and can be easily calculated, manufacturing is facilitated.

  If the resistance value of the back surface resistor 13b is made smaller than the resistance value of the top surface resistor 13a, a large amount of current flows through the back surface resistor 13b having a small resistance value, so that heat generation of the top surface resistor 13a can be suppressed. Thereby, since heat can be dissipated more effectively, higher power can be handled.

  Further, a protective layer 15 made of resin is formed so as to cover the entire top surface resistor 13a, the entire back surface resistor 13b, a part of the top surface electrode 12a, and a part of the back surface electrode 12b. Then, an end face electrode 16 made of silver for electrically connecting the upper surface electrode 12 a and the back surface electrode 12 b is formed at both ends of the insulating substrate 11, and thereafter, a plating layer 17 is formed on the surface of the end face electrode 16. In addition, the plating layer 17 is normally composed of a two-layer structure of a nickel plating layer and a solder or tin plating layer.

  As described above, in the rectangular chip resistor according to the embodiment of the present invention, since the area of the upper surface resistor 13a can be increased, the area of the upper surface resistor 13a that can dissipate heat into the air is increased. Since the length of the upper surface resistor 13a between the pair of upper surface electrodes 12a is longer than the length of the back surface resistor 13b between the pair of back surface electrodes 12b, the distance between the upper surface resistor 13a and the land pattern of the mounting substrate is shortened. As a result, since the heat generated in the upper surface resistor 13a can be effectively dissipated, there is an effect that it can cope with high power.

  Further, since the length of the upper surface resistor 13a is increased, the length of the pair of upper surface electrodes 12a can be shortened, thereby reducing the influence of the TCR of the upper surface electrode 12a on the entire square chip resistor. Therefore, the TCR of the square chip resistor can be reduced.

  That is, since the area of the upper surface resistor 13a can be increased compared with the case where the area of the upper surface resistor 13a is the same as the area of the back surface resistor 13b, more heat can be radiated from the upper surface resistor 13a to the air. Furthermore, since the length of the upper surface resistor 13a can be increased as compared with the case where the length of the upper surface resistor 13a is the same as the length of the back surface resistor 13b, the upper surface resistor 13a includes the upper surface electrode 12a and the end surface. The distance between the land pattern of the mounting substrate connected via the electrode 16 and the plating layer 17 and both ends of the upper surface resistor 13a can be shortened, and thereby heat that can be radiated from the upper surface resistor 13a to the mounting substrate. Will increase. As a result, since the heat dissipation of the upper surface resistor 13a can be improved, it is possible to suppress the occurrence of problems such as a change in the resistance value of the upper surface resistor 13a even when high power is applied.

  In addition, since almost no current flows through the pair of back surface electrodes 12b, the influence of the TCR exerted on the square chip resistor by the back surface electrode 12b is small, whereas current flows through the pair of top surface electrodes 12a. The influence of the TCR that the electrode 12a has on the entire square chip resistor is large, and since the upper surface electrode 12a is made of an alloy, the TCR is very large. Since the length is increased, the length of the pair of upper surface electrodes 12a can be shortened, whereby the influence of the TCR of the upper surface electrode 12a on the entire rectangular chip resistor can be reduced.

  The rectangular chip resistor according to the present invention is advantageous in that it can cope with high power, and is particularly useful when applied to a rectangular chip resistor or the like that requires high accuracy with a low resistance value. is there.

11 Insulating substrate 12a Upper surface electrode 12b Back surface electrode 13a Upper surface resistor 13b Back surface resistor

Claims (2)

An insulating substrate, a pair of upper surface electrodes and a pair of back electrodes provided on both ends of the upper surface and the back surface of the insulating substrate, and the pair of upper surface electrodes and the pair of back electrodes, respectively, are electrically connected An upper surface resistor and a back surface resistor provided, the area of the upper surface resistor is larger than the area of the back surface resistor, and the length of the upper surface resistor between the pair of upper surface electrodes is set to the pair of back surfaces A square chip resistor that is longer than the length of the backside resistor between the electrodes. An insulating substrate, a pair of upper surface electrodes and a pair of back electrodes provided on both ends of the upper surface and the back surface of the insulating substrate, and the pair of upper surface electrodes and the pair of back electrodes, respectively, are electrically connected A square chip resistor comprising a provided upper surface resistor and a back surface resistor, wherein a resistance value of the back surface resistor is smaller than a resistance value of the upper surface resistor.

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