JP2005353627A - Resistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resistor having a low resistance value which can be more reduced in size with good thermal conductivity and high productivity. <P>SOLUTION: The resistor has a resistance element 3 constituted by bending to form a belt-like metal plate in a U shape from a pair of terminal regions 1, 1 and a resistance region 2 interposed between the terminal regions 1 and 1. The respective terminal regions 1, 1 have a side electrode 1a standing to the upper part from the front surface of the resistance region 2 for constituting the end face electrode of the resistance element 3, and a connecting electrode 1b swelled in a leg-like state from the rear surface of the resistance region 2 to the lower part. An insulation ceramic plate 4 charged between both side electrodes 1a and 1a and a connecting material 5 filled in the gap of the rear side of the connecting electrode 1b are connected to the resistance element 3. A heatsink insulator material 6 is filled in the gap interposed between the pair of the terminal regions formed on the rear side of the resistance region 2 in the resistor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resistor having a low resistance value for current detection.

  A resistor having a low resistance value is conventionally used for current detection, and its structure is formed by cutting a metal plate or bending a metal wire or metal plate and treating both ends as electrodes. In many cases, however, a region other than the electrode is coated and molded in order to prevent a short circuit accident with other elements due to exposure of the current-carrying portion (see, for example, the following patent document).

Japanese Patent Laid-Open No. 2001-217101 Japanese Patent Laid-Open No. 2004-22921

  However, in the resistor shown in Patent Document 1, the presence of the insulating cover member not only hinders downsizing required today, but also fixes the resistor in the cover member using an encapsulant, In addition, the structure in which the electrode portion of the resistor is taken out from the enclosure includes a relatively complicated manufacturing process. Also, cement used as an encapsulant is relatively inferior in thermal conductivity and is inconvenient as a resistor having a low resistance value that requires high heat dissipation.

  This invention is made | formed in view of the said actual condition, Comprising: It aims at provision of the resistor with the low resistance value which can be reduced in size which has favorable thermal conductivity and high productivity.

  The first resistor according to the present invention, which has been made to solve the above-mentioned problems, comprises a pair of terminal regions and a resistance region interposed between the terminal regions by bending a band-shaped metal plate into a U-shape. Each of the terminal regions is provided with a side electrode portion that rises above the surface of the resistance region and forms an end face electrode of the resistance element, and a leg that extends downward from the back surface of the resistance region. A bonding electrode portion swelled in a shape, the insulating ceramic plate loaded between the two side electrode portions, and a bonding material filled in a gap on the back side of the bonding electrode portion are bonded to the resistance element, and This is a resistor formed by filling a heat-resistant insulating material in a gap formed between the pair of terminal regions and formed on the back side of the resistance region.

  The second resistor according to the present invention, which has been made to solve the above problems, is configured by bending a band-shaped metal plate into a U-shape by bending a pair of terminal regions and a resistance region interposed between the terminal regions. In the resistor including the resistance element, each terminal region hangs down from both ends of the resistance region to the side electrode portion constituting the end surface electrode of the resistance element, and is opposed to the lowest position of the side electrode portion. A leg-shaped joining electrode part bent to the side electrode part side is provided, and an insulating ceramic plate loaded between the two electrode parts is joined to the resistance element, and the surface of the resistance region is covered with a heat-resistant insulating material. This is a resistor. As the bonding material, a conductive bonding material such as conductive resin or solder, or a heat resistant resin is used. In any of the resistors, an internal electrode that is electrically connected to the bonding electrode may be provided on the insulating ceramic plate as a part of the bonding material.

  According to the resistor of the present invention, the resistance element itself that integrally includes the terminal region and the resistance region is subjected to bending forming into a substantially U-shaped frame-like structure, and the inner side of the U-shaped Since the insulating ceramic plate and the bonding material are filled into the gaps and the shape is retained, the size can be easily reduced as compared with the resistor having the conventional structure. In addition, each process at the time of manufacture is constituted by simple work compared to the conventional, before if the strip-shaped metal plate to be a resistance element is cut to the required length as a resistance element, It can also be used as a support frame in the bending process or the molding process, and after the surplus part is cut, the side electrode part becomes an end face electrode and a solder fillet is formed at the time of mounting. Can be maintained. Furthermore, since the insulating ceramic used as the bulk of the filler is a material having good thermal conductivity, it is possible to stably obtain a low resistance value due to its high heat diffusing property. Thus, a high-quality resistor can be efficiently manufactured.

Embodiments of a resistor according to the present invention will be described below with reference to the drawings.
In the present invention, a pair of terminal regions 1 and 1 and a resistance region 2 interposed between the terminal regions 1 and 1 are formed as a band-shaped metal plate (thickness: about 0.1 mm to 0.8 mm. Including width and length). In other words, the resistance elements 3 having symmetrical shapes are provided on the front, rear, left, and right, which are formed by bending a U-shape into a U-shape.

  In the first embodiment shown in FIG. 1, each of the terminal regions 1, 1 stands at a right angle above the surface of the resistance region 2 and constitutes an end electrode of the resistance element 3, A joining electrode portion 1b is formed below the side of the resistance region 2 below the side electrode portion 1a. Examples of the material to be formed on the resistance element 3 include a metal plate made of a strip-like copper nickel alloy, manganin alloy, nichrome alloy, iron chromium alloy, or the like.

  In the space formed inside the U-shape formed by the resistance element 3, an insulating ceramic plate (thickness: about 0.3 mm to 0.8 mm) 4 loaded between the both side electrode portions 1a and 1a, In addition, a bonding material 5 made of conductive resin, heat-resistant resin, solder, or the like filled in a gap on the front side of the bonding electrode portion 1b is provided in a state of being bonded to the resistance element as a filling material. The filler includes, for example, rectangular internal electrodes 8 that extend substantially across the width of the ceramic plate at both ends of the back surface of the rectangular insulating ceramic plate 4 made of alumina, aluminum nitride, or the like. It is formed as a portion and is plated in the same manner as the plating layer described later. The interior electrode 8 may be, for example, one obtained by printing and baking a conductive paste such as Ag or Ag—Pd in the rectangular shape.

  When the resistance element 3 and the filler formed as described above are loaded into the space formed inside the foam of the resistance element 3, the internal electrode 8 of the filler is connected to the resistance element 3. And a heat conductive resin (for example, between the insulating ceramic plate 4 of the filler and the upper surfaces of the side electrode portions 1a and 1a of the resistance element 3 and the resistance region 2). A mixture of a powder of metal, alumina, MgO or the like and a resin), a heat-resistant resin, or an adhesive layer 11 such as solder, which is bonded and fixed by heat curing, and the interior electrode 8 and the bonding electrode portion The inner surface of 1b is joined with a conductive resin, a heat resistant resin, solder, or the like.

  For the resistance element 3, a trimming process for finely adjusting the resistance value by mechanically or chemically removing a part of the resistance region 2 after the bonding process of the resistance element 3 and the filler. Has been done.

  Further, in order to ensure insulation and protect, the entire surface of the resistor 9 made of the resistance element 3 and the filler is coated or molded with a heat-resistant insulating material such as a heat-resistant resin, and the side electrode portion 1a and the joining electrode are coated. The layer of the heat-resistant insulating material formed on the surface of the resistor 9 is ground and molded to a predetermined dimension as necessary, such as exposing the portion 1b. At this time, for the convenience of mounting, a slight step with respect to the bonding electrode portion 1b should be provided in a region sandwiched between a pair of terminal regions 1 and 1 formed on the back side of the resistance region 2. A gap is formed by grinding. Since the metal scrap generated during mounting or the like easily enters the gap, at least the resistance region is used to prevent a short circuit between the two terminal regions 1 and 1. Is preferably left in a state filled with the heat-resistant insulating material 6.

  In the second embodiment shown in FIG. 2, each of the terminal regions 1, 1 hangs down from both ends of the resistance region 2 to the back side, and constitutes an end surface of the resistance element 3. A leg-like bonding electrode portion 1b bent from the lowest portion of the portion 1a to the side electrode portion 1a facing each other is provided. Examples of the material to be molded into the resistance element 3 include a metal plate made of a strip-like copper nickel alloy, manganin alloy, nichrome alloy, iron chromium alloy, or the like, as in the first embodiment. .

  In the space formed inside the U-shape formed by the resistance element 3, the same filler as that of the first embodiment loaded between the both-side electrode portions 1 a, 1 a is added. It is decorated in a state where it is joined to.

  When the resistance element 3 and the filler formed as described above are loaded into the space formed inside the foam of the resistance element 3, the bonding electrode portion 1b is still formed by bending. However, it is in a state where it hangs continuously from the lowermost portion of the side electrode portion 1a. Therefore, after the filler is loaded into the space formed inside the foam of the resistance element 3, the back surface of the resistance region 2 and the surface on which the interior electrode (bonding material 5) 8 of the filler is not formed. In between, the adhesive layer 11 such as a heat conductive resin, a heat resistant resin, or solder is interposed and fixed by heat curing, and a portion continuously suspended from the lowermost portion of the side electrode portion 1a is As described above, the joined electrode portion 1b is formed by bending to be folded on the lower surface of the internal electrode 8.

  In addition, you may take the aspect fixed by interposing the said contact bonding layer 11 between the said joining electrode part 1b formed in this way and the said filler. In addition, the bonding element 1b may be bent before the resistance element 3 and the filler are integrated, and the filler may be fitted to the resistance element 3 after the bending. .

  After the steps so far, the trimming step is applied to the resistance region as described above, and the heat-resistant insulating material 7 such as a heat-resistant resin is applied to the entire surface of the resistor element 9 and the resistor 9 made of the filler. Is formed as necessary so as to leave at least the surface of the resistance element 3 and to expose the side electrode portions 1a and 1a and the bonding electrode portion 1b in order to ensure insulation and protect. A layer of the heat-resistant insulating material is ground and molded to a predetermined dimension.

  Finally, a series of plating films 10 are attached to the side electrode portions 1a and 1a, the bonding electrode portion 1b, and the interior electrode 8 so as to integrate them. In this example, three layers (copper) are formed by sequentially performing copper plating for securing conductivity, nickel plating for protecting the copper plating layer, and tin plating for improving soldering at the time of mounting. : About 10 μm to 20 μm, nickel: about 5 μm, tin: about 5 μm to 10 μm). In any of the embodiments, the width of the metal plate is smaller than or equal to the width of the insulating ceramic plate 4. Moreover, the same plating process may be performed on the interior electrode 8 in the first embodiment as necessary.

  This contributes to the provision of resistors with low resistance that can be miniaturized with good thermal conductivity and high productivity.

It is a figure which shows an example in the manufacturing process of the 1st resistor by this invention, Comprising: (A) is a bottom view of a filler, (B) is a longitudinal cross-sectional view of a filler, (C) is a resistive element. (D) is a longitudinal sectional view of the resistor, (E) is a longitudinal sectional view of the completed resistor, and (F) is an end view of the completed resistor. It is a figure which shows an example in the manufacturing process of the 2nd resistor by this invention, Comprising: (A) is a top view of a filler, (B) is a longitudinal cross-sectional view of a filler, (C) is a resistive element. (D) is a longitudinal sectional view of the resistor, (E) is a longitudinal sectional view of the completed resistor, and (F) is an end view of the completed resistor.

Explanation of symbols

1 terminal area, 2 resistance area, 3 resistance element, 4 insulating ceramic plate,
5 Bonding material, 6 Heat-resistant insulating material, 7 Heat-resistant insulating material,
8 Internal electrodes,
9 resistor, 10 plated film, 11 adhesive layer,

Claims (2)

A resistance element (3) formed by bending a band-shaped metal plate into a U-shape, a pair of terminal areas (1, 1) and a resistance area (2) interposed between the terminal areas (1, 1). In a resistor comprising:
Each terminal region (1, 1) rises above the surface of the resistance region (2) and forms a side electrode portion (1a) constituting the end face electrode of the resistance element (3), and the resistance region (2) A bonding electrode portion (1b) that bulges downward from the back surface of
The insulating ceramic plate (4) loaded between the both side electrode portions (1a, 1a) and the bonding material (5) filled in the gap on the back side of the bonding electrode portion (1b) are used as the resistance element (3). And a resistor formed by filling a heat-resistant insulating material (6) in a gap formed between the pair of terminal regions formed on the back side of the resistance region (2). A resistance element (3) formed by bending a band-shaped metal plate into a U-shape, a pair of terminal areas (1, 1) and a resistance area (2) interposed between the terminal areas (1, 1). In a resistor comprising:
Each terminal region (1, 1) hangs down from both ends of the resistance region (2) to the back side, and constitutes an end face electrode of the resistance element (3), and the side electrode portion (1a) A leg-shaped bonding electrode portion (1b) bent toward the side electrode portion (1a) opposite to each other from the lowest position of
The insulating ceramic plate (4) loaded between the electrode parts (1a, 1a) is joined to the resistance element (3), and the surface of the resistance region (2) is covered with a heat-resistant insulating material (7). A resistor.

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