JP2014060463A - Chip resistor and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip resistor having sufficient strength, and excelling in heat radiation capability.SOLUTION: A chip resistor "A" comprises: a resistive element 1; and a pair of electrodes 2 jointed to one surface of the resistive element 1. Slit parts 1a are formed in parts of the resistive element 1 to be an area between the pair of the electrodes 2. Reinforcing material 4 is jointed to the other surface of the resistor element 1 on a side opposite to the surface where the pair of the electrodes 2 is jointed to. The resistive element 1 and the reinforcing material 4 are jointed to each other via an insulating adhesive layer 3.

Description

  The present invention relates to a chip resistor and a manufacturing method thereof.

  As a conventional chip resistor, there is one disclosed in Patent Document 1. The chip resistor disclosed in this document is configured by providing a pair of electrodes on one side of a resistor. The pair of electrodes are directly joined to one side of the resistor in a state of being insulated from each other. An overcoat layer is formed on one surface of the resistor that is opposite to the surface to which the electrodes are bonded so as to protect the resistor. In such a chip resistor, when a metal plate made of an alloy having a small resistance temperature coefficient (TCR) is used as a resistor, an extremely low resistance of several mΩ can be realized in addition to a reduction in TCR. In order to realize a resistance higher than an ultra-low resistance of several mΩ, for example, a resistance of several tens to several hundreds mΩ, a part of the resistor is partially thinned by laser trimming or etching. Try to remove.

  However, in the conventional chip resistor, when the resistor is thinned or partially removed, the resistor itself is made of a relatively thin metal plate, and the overcoat layer has a sufficient thickness to support the resistor and the electrode. Therefore, such a metal plate or overcoat layer alone is insufficient in strength to support a pair of electrodes. In addition, when energized, the resistor generates heat, and heat tends to be trapped in the narrow part and the removed part, so that there is a problem that the heat dissipation is inferior.

JP 2007-49207 A

  The present invention has been conceived under the above circumstances, and an object thereof is to provide a chip resistor having sufficient strength and excellent heat dissipation. Another object of the present invention is to provide a chip resistor manufacturing method suitable for mass production of such chip resistors.

  The chip resistor provided by the 1st side of the present invention is a chip resistor provided with a resistor and a pair of electrodes joined to one side of this resistor, and between the above-mentioned pair of electrodes The resistor portion is provided with a notch, and a reinforcing material is bonded to one side of the resistor that is opposite to the surface to which the pair of electrodes are bonded. Yes.

  The chip resistor provided by the second aspect of the present invention is a chip resistor comprising a plurality of resistors and a pair of electrodes joined to one side of these resistors, wherein the plurality of resistors The body is arranged in a direction orthogonal to the direction in which the pair of electrodes are opposed to each other, and a notch is provided in each portion of the resistor between the pair of electrodes. The reinforcing material is bonded to the entire one surface of the plurality of resistors on the opposite side to the surface to which the electrode is bonded.

  In a preferred embodiment of the present invention, the resistor and the reinforcing material are joined via an insulating adhesive layer.

The method of manufacturing a chip resistor provided by the third aspect of the present invention includes a step of bonding one or a plurality of metal plates serving as a resistor material and a substrate serving as a reinforcing material, and etching the metal plate. A step of forming a protective film so as to cover a part of the metal plate, a step of forming a plurality of electrodes by plating on the portion of the metal plate exposed from the protective film, and at least a pair of the electrodes. And a step of dividing the one or more metal plates and the substrate, and the protective film integrated so as to form a rectangular or long rectangular chip.

  In a preferred embodiment of the present invention, when the metal plate is etched, a notch is formed in a portion of the metal plate between the pair of electrodes.

  According to such a configuration, it is possible to provide sufficient strength by supporting the resistor and the electrode with the reinforcing material, and it is possible to realize a chip resistor excellent in heat dissipation through the reinforcing material. In addition, a chip resistor manufacturing method suitable for mass production of such chip resistors can be realized.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 and 2 show an embodiment of a chip resistor according to the present invention, and FIGS. 3 to 5 show an example of a manufacturing method thereof. As shown in FIGS. 1 and 2, the chip resistor A of this embodiment includes a resistor 1, a pair of electrodes 2, an adhesive layer 3, a reinforcing material 4, and an electrode insulator 5 (not shown in FIG. 1). It is configured. This chip resistor A is suitable for surface mounting, and is configured as a low resistance of about several tens mΩ to several hundreds mΩ.

  The resistor 1 is made of a metal plate having a relatively low temperature resistance coefficient (TCR), such as a Ni—Cr alloy, a Ni—Cu alloy, a Fe—Cr alloy, or a Cu—Mn alloy, and has a thickness of 10 to 100 μm. It has a thickness of about. The resistor 1 has a cut portion 1a removed by etching to adjust to a desired resistance value, but is continuous from one electrode 2 to the other electrode 2.

  The pair of electrodes 2 are directly joined to one surface of the resistor 1 and are separated from each other with the electrode insulator 5 interposed therebetween. A solder layer (not shown) is formed on the lower surface of the electrode 2 to improve solderability. Such an electrode 2 has a thickness of about 50 to 200 μm, and is formed, for example, by plating Cu as described later.

  The adhesive layer 3 is provided between the resistor 1 and the reinforcing material 4 and plays a role of firmly joining the resistor 1 and the reinforcing material 4. Further, the adhesive layer 3 has an insulating property, and when the reinforcing material 4 is made of a conductive material, it also serves to electrically insulate it from the resistor 1. Such an adhesive layer 3 has a thickness of about 60 to 100 μm, and is made of, for example, a prepreg (insulating adhesive film) obtained by impregnating a glass fiber with an adhesive resin as described later.

  The reinforcing material 4 is bonded to one surface of the resistor 1 on the side opposite to the surface to which the electrode 2 is bonded via the adhesive layer 3. The reinforcing material 4 is made of, for example, alumina, glass epoxy resin, or conductive Cu, and plays a role of increasing the strength of the resistor 1 and efficiently dissipating heat generated in the resistor 1 when energized. Also has. Such a reinforcing material 4 has a thickness of about 200 to 400 μm.

The electrode insulator 5 is provided between the pair of electrodes 2 so as to insulate the pair of electrodes 2, and an electrically insulating material such as an epoxy resin insulating material is applied to a portion between the pair of electrodes 2. Formed with.

Next, an example of a manufacturing method of the chip resistor A will be described with reference to FIGS.

  First, as shown in FIG. 3A, a prepreg 30 serving as an adhesive layer 3 is sandwiched between a metal plate 10 serving as a material of the resistor 1 and a substrate 40 serving as a reinforcing material 4. The metal plate 10, the substrate 40, and the prepreg 30 are joined by a high pressure vacuum press. The metal plate 10, the substrate 40, and the prepreg 30 have such a size that a plurality of chip resistors A can be taken, and correspond to the thicknesses of the resistor 1, the reinforcing material 4, and the adhesive layer 3. .

  Next, as shown in FIG. 3B, the continuous resistor 1 is formed by performing an etching process on the metal plate 10. The resistor 1 formed in this way has a plurality of rows in a form connected in a predetermined direction (lateral direction in the figure) while having a cut portion 1a in a predetermined portion.

  Next, as shown in FIG. 4A, a protective film 50 is applied in a stripe shape so as to cover the cut portion 1 a of the resistor 1. The protective film 50 corresponds to the electrode insulator 5 described above. At this time, on both outer sides of the protective film 50, the portion of the resistor 1 that is the place where the electrode 2 is formed is exposed.

  Next, as shown in FIG. 4 (b), copper plating is applied to the integrated body of the resistor 1, the prepreg 30, the substrate 40, and the protective film 50 by so-called rack plating. As a result, the electrode layer 20 to be the electrode 2 is formed in the portion where the resistor 1 is exposed on both outer sides of the protective film 50. Furthermore, if it is necessary to improve solderability, a solder layer (not shown) such as Sn may be formed on the surface of the electrode layer 20 by plating.

  Finally, as shown in FIG. 5, the resistor 1 and the prepreg 30 are cut by cutting along a longitudinal cutting line L <b> 1 along the electrode layer 20 and a transverse cutting line L <b> 2 passing between the electrode layer 20 and the electrode layer 20. The substrate 40, the protective film 50, and the electrode layer 20 are integrated into a chip shape. Thereby, a plurality of chip resistors A as shown in FIGS. 1 and 2 can be obtained.

  Therefore, according to the chip resistor A of the present embodiment, since the resistor 1 and the electrode 2 are supported by the reinforcing material 4 even if the resistor 1 has poor strength due to the cut portion 1a, the chip resistor The entire vessel A can have sufficient strength. Further, the heat dissipation can be improved by the reinforcing material 4 having a larger volume than the resistor 1. According to the chip resistor manufacturing method of the present embodiment, the chip resistor A having the above-described excellent effects can be easily mass-produced.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the chip resistor according to the present invention can be varied in design in various ways.

  For example, as another embodiment, a chip resistor B as shown in FIG. 6 may be used. In this chip resistor B, two electrodes 2 are separately provided on both ends of the resistor 1. According to such a configuration, since the area where the solder contacts during mounting is increased, solderability can be further improved.

As still another embodiment, a chip resistor C as shown in FIG. 7 may be used. The chip resistor C has a configuration in which a plurality of chip resistors A in FIG. 1 are arranged. That is, the chip resistor C has a long rectangular shape as a whole, and has a configuration in which a plurality of resistors 1 are arranged in a direction (longitudinal direction) orthogonal to the direction in which the pair of electrodes 2 face each other. The chip resistor C has the same basic structure as the chip resistor A described above. For example, the reinforcing material 4 is bonded over the entire surface of the resistor 1 on the side opposite to the surface to which the electrode 2 is bonded. Joined through layer 3. In such a chip resistor C, for example, electrodes 2 on both sides are bonded to two electrode pads formed on a wiring board. As a result, the plurality of resistors 1 are collectively connected in parallel.

  In the manufacturing process shown in FIG. 5 described above, the chip resistor C is formed along the longitudinal cutting line L1 along the electrode layers 20 arranged vertically without cutting between the adjacent metal plates 10. A plurality of chips can be obtained as long rectangular chips.

  Therefore, according to the chip resistor C of the present embodiment, the reinforcing material 4 can be enlarged and given a sufficient strength by having a long rectangular shape as a whole. In the manufacturing method, since it is not necessary to cut | disconnect between the metal plates 10 adjacent, it can mass-produce more easily.

It is a perspective view which shows one Embodiment of the chip resistor concerning this invention. It is sectional drawing which follows the II-II line of FIG. It is explanatory drawing for demonstrating the manufacturing method of the chip resistor shown in FIG. It is explanatory drawing for demonstrating the manufacturing method of the chip resistor shown in FIG. It is explanatory drawing for demonstrating the manufacturing method of the chip resistor shown in FIG. It is a perspective view which shows other embodiment of the chip resistor concerning this invention. It is a perspective view which shows other embodiment of the chip resistor concerning this invention.

A, B, C Chip resistor 1 Resistor 1a Notch 2 Electrode 3 Adhesive layer 4 Reinforcing material 5 Electrical insulator 10 Metal plate 20 Electrode layer 30 Prepreg 40 Substrate 50 Protective film

Claims (5)

A chip resistor comprising a resistor and a pair of electrodes joined to one side of the resistor,
A notch is provided in the portion of the resistor that is between the pair of electrodes, and a reinforcing material is bonded to one side of the resistor that is opposite to the surface to which the pair of electrodes are bonded. A chip resistor, characterized in that A chip resistor comprising a plurality of resistors and a pair of electrodes joined to one side of these resistors,
The plurality of resistors are arranged in a direction orthogonal to the direction in which the pair of electrodes face each other, and a cut portion is provided in each portion of the resistor between the pair of electrodes. A chip resistor is characterized in that a reinforcing material is bonded to the entire one surface of the plurality of resistors on the opposite side to the surface where the pair of electrodes are bonded.   The chip resistor according to claim 1, wherein the resistor and the reinforcing material are joined via an insulating adhesive layer. Joining one or more metal plates as a material of the resistor and a substrate as a reinforcing material;
Etching the metal plate; and
Forming a protective film so as to cover a part of the metal plate;
Forming a plurality of electrodes by plating on the portion of the metal plate exposed from the protective film;
Dividing the one or more metal plates and the substrate and the protective film integrated into a rectangular or long rectangular chip including at least a pair of the electrodes; and
A method of manufacturing a chip resistor, comprising:   The method for manufacturing a chip resistor according to claim 4, wherein when the metal plate is etched, a cut portion is formed in a portion of the metal plate between the pair of electrodes.

Images