JP2021122067A - Resistor - Google Patents

Abstract

To provide a resistor that can adjust a target resistance value with higher accuracy while utilizing existing manufacturing equipment.SOLUTION: A resistor A2 includes a resistance body 1, a pair of electrodes 4 arranged so as to sandwich the resistance body 1 therebetween in a first direction (direction X), and a protective film 5 that covers a part of the resistance body 1. The resistance body 1 is formed with a first slit and a second slit that penetrate the resistance body 1 in the thickness direction thereof and extend in a second direction (direction Y). The second slit is located to be adjacent to the first slit in the first direction, and overlaps the first slit when viewed along the first direction. A first groove (groove 16) extending in the first direction and a second groove (groove 16) extending in the second direction are formed on a surface 11 of the resistance body 1. The first groove is located to be adjacent to either the first slit or the second slit in the first direction. The second groove is located between either the first slit or the second slit and a peripheral edge of the resistance body 1 in the second direction.SELECTED DRAWING: Figure 16

Description

The present invention relates to resistors used in various electronic devices.

As a low resistance value resistor suitable for current detection applications, a resistor that achieves a low resistance value in mΩ units by using a metal plate resistor made of Cu—Ni alloy, Ni—Cr alloy, etc. is known. ..

In such a resistor, a trimming groove is formed in a portion of a metal plate resistor sandwiched between a pair of electrodes by laser processing using a laser trimming device or the like, and adjustment is performed to obtain a target resistance value. .. With regard to resistors, with the demand for further sophistication of products, further improvement in the accuracy of resistance values is required.

For example, Patent Document 1 discloses a method of adjusting to a target resistance value of a resistor by forming a trimming groove in a portion of a metal plate resistor by punching instead of laser processing. However, in this method, the position and shape of the punched hole to be the trimming groove are determined based on the sheet-shaped metal plate which is an aggregate of the metal resistance plates, so that the resistance value is highly accurate based on the individual metal resistance plates. It is difficult to adjust. In addition, since a dedicated device for forming the punched hole is required separately, there is a problem that investment and device development for new manufacturing equipment are required when introducing the device.

Japanese Patent No. 5544824

In view of the above-mentioned circumstances, it is an object of the present invention to provide a resistor capable of adjusting a target resistance value with higher accuracy while utilizing existing manufacturing equipment.

The resistor provided by the first aspect of the present invention is arranged on both sides of a resistor having a surface and a mounting surface facing opposite to each other, and is conductive with the resistor. A resistor including a pair of electrodes and a protective film that covers a part of the resistor, characterized in that a plurality of grooves that do not penetrate the resistor are formed on the surface of the resistor. It is said.

In the practice of the present invention, the direction of the plurality of grooves is preferably a direction orthogonal to the direction of the current flowing through the resistor.

In the practice of the present invention, the distance between the plurality of grooves is preferably 50 to 100 μm.

In the practice of the present invention, the plan view shape of the resistor is preferably a serpentine shape.

In the practice of the present invention, the thickness of the resistor is preferably 50 to 150 μm.

In the practice of the present invention, the resistor preferably comprises an alloy containing Cu, Mn, and Ni.

In the practice of the present invention, the pair of electrodes preferably cover a part of the resistor and the protective film.

In the practice of the present invention, preferably, the pair of electrodes are an internal electrode that conducts with the resistor and covers a part of the protective film, an intermediate electrode that covers the internal electrode, and an external electrode that covers the intermediate electrode. And have.

In the practice of the present invention, the internal electrode is preferably made of a Ni—Cr alloy.

In the practice of the present invention, the intermediate electrode and the external electrode preferably consist of a plating layer.

In the practice of the present invention, the external electrode preferably comprises a Sn plating layer.

In the practice of the present invention, the intermediate electrode preferably has a first intermediate electrode covering the internal electrode and a second intermediate electrode covering the first intermediate electrode.

In the practice of the present invention, the first intermediate electrode preferably comprises a Cu plating layer.

In the practice of the present invention, the second intermediate electrode preferably comprises a Ni plating layer.

In the practice of the present invention, the protective film is preferably made of a thermosetting resin.

In the practice of the present invention, the protective film is preferably made of a polyimide resin.

In the practice of the present invention, preferably, a substrate having a main surface and a mounting surface facing each other is further provided, and the resistor is in a state in which the mounting surface of the resistor and the mounting surface of the substrate face each other. It is mounted on the substrate.

In the practice of the present invention, the substrate is preferably an electrical insulator.

In the practice of the present invention, the substrate is preferably made of alumina.

In the practice of the present invention, the substrate is preferably made of a glass epoxy resin.

In the practice of the present invention, the resistor is preferably mounted on the substrate in a state of being embedded in the substrate.

In the practice of the present invention, an adhesive layer interposed between the mounting surface of the substrate and the mounting surface of the resistor is further provided.

In the practice of the present invention, the adhesive layer is preferably an electrical insulator.

In the practice of the present invention, the adhesive layer preferably contains an epoxy resin.

The method for manufacturing a resistor provided by the second aspect of the present invention includes a step of preparing a sheet-like resistor in which a plurality of resistor regions are assembled and has a surface and a mounting surface facing opposite to each other. A step of forming a plurality of non-penetrating grooves for adjusting the resistance value on the surface of the plurality of resistor regions for each of the resistor regions, and the plurality of resistors on the surface of the sheet-shaped resistor. A step of forming a protective film body that covers a part of the region, and a step of forming a conductive layer on the surface of the sheet-shaped resistor in an exposed portion of the plurality of resistor regions that are not covered by the protective film body. By dividing the sheet-shaped resistor into individual pieces for each resistor region, a pair of internal electrodes conducting with the resistor region are formed on both sides of the resistor region. It is characterized by having.

In the practice of the present invention, the step of forming the plurality of grooves preferably includes a step of forming a trimming groove penetrating the resistor region for each of the resistor regions.

In the practice of the present invention, preferably, in the step of forming the plurality of grooves, the plurality of grooves are formed by a laser trimming device.

In the practice of the present invention, preferably, in the step of forming the plurality of grooves, the plurality of grooves are formed in each of the plurality of compartments set for each of the resistor regions.

In the practice of the present invention, preferably, in the step of forming the plurality of grooves, the plurality of grooves are formed in order from the compartment located outside the resistor region toward the inside of the resistor region. ..

In the practice of the present invention, preferably, in the step of forming the plurality of grooves, the plurality of grooves are located between the center of the resistor region and the internal electrode of one of the pair of internal electrodes. After the compartment, the compartments located between the center of the resistor region and the other internal electrode of the pair of internal electrodes are formed in this order and alternately.

In the practice of the present invention, preferably, in the step of forming the conductive layer, the conductive layer is formed by a method using vapor deposition or printing.

In the practice of the present invention, the vapor deposition is preferably a sputtering method.

In carrying out the present invention, preferably, the individual piece further includes a step of forming an intermediate electrode covering the pair of internal electrodes and an external electrode covering the intermediate electrode.

In the practice of the present invention, preferably, in the step of forming the intermediate electrode and the external electrode, the intermediate electrode and the external electrode are formed by plating, respectively.

In the practice of the present invention, a step of adhering the sheet-shaped substrate to the mounting surface of the sheet-shaped resistor is further provided.

In the practice of the present invention, preferably, in the step of adhering the sheet-shaped substrate, an adhesive made of an epoxy resin is applied, or an adhesive sheet made of a glass epoxy resin is placed on the mounting surface of the sheet-shaped resistor. As a result, the sheet-shaped substrate is adhered.

In the resistor according to the present invention, a plurality of grooves different from the trimming groove and which do not penetrate the resistor are formed on the surface of the resistor. The plurality of grooves can be formed by the existing manufacturing equipment. Therefore, according to the resistor according to the present invention and the manufacturing method thereof, it is possible to adjust the target resistance value for each resistor with higher accuracy while utilizing the existing manufacturing equipment.

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

It is a top view which shows the resistor which concerns on 1st Embodiment of this invention. It is a bottom view which shows the resistor of FIG. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 5 is an enlarged cross-sectional view of a main part schematically showing a resistor of the resistor of FIG. It is a top view which shows the process which concerns on the manufacturing method of the resistor of FIG. It is a perspective view which shows the process which concerns on the manufacturing method of the resistor of FIG. It is a top view which shows the process which concerns on the manufacturing method of the resistor of FIG. It is a top view which shows the manufacturing method of the resistor region (the resistor of the resistor of FIG. 1). (A) to (h) are plan views showing the manufacturing method of the resistor region of FIG. 8 along with each manufacturing step. It is an enlarged cross-sectional view of the main part which shows the manufacturing state of the resistor of FIG. It is a top view which shows the process which concerns on the manufacturing method of the resistor of FIG. It is a top view which shows the process which concerns on the manufacturing method of the resistor of FIG. It is a perspective view which shows the process which concerns on the manufacturing method of the resistor of FIG. It is a perspective view which shows the process which concerns on the manufacturing method of the resistor of FIG. It is a top view which shows the resistor which concerns on 2nd Embodiment of this invention. It is a bottom view which shows the resistor of FIG. FIG. 5 is a cross-sectional view taken along the line XVII-XVII of FIG. It is a top view which shows the manufacturing method of the resistor region (the resistor of the resistor of FIG. 15). It is a top view which shows the resistor which concerns on 3rd Embodiment of this invention. FIG. 5 is a cross-sectional view taken along the line XX-XX of FIG.

An embodiment of the resistor according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
The resistor A1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a plan view showing the resistor A1. FIG. 2 is a bottom view showing the resistor A1. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is an enlarged cross-sectional view of a main part schematically showing the resistor 1 described later of the resistor A1. In FIG. 1, for convenience of understanding, the substrate 2 and the adhesive layer 3 described later are omitted. Further, in FIG. 2, for convenience of understanding, the protective film 5 described later is seen through.

The resistor A1 shown in these figures is of a type that is surface-mounted on a circuit board of various electronic devices. The resistor A1 of the present embodiment includes a resistor 1, a substrate 2, an adhesive layer 3, an electrode 4, and a protective film 5. In the present embodiment, the resistor A1 has a rectangular shape in a plan view.

The resistor 1 is an element that functions to limit the current or detect the current. In the present embodiment, the thickness t of the resistor 1 shown in FIG. 4 is 50 to 150 μm. Further, in the present embodiment, the plan view shape of the resistor 1 is a rectangular shape having the long side in the direction X shown in FIGS. 1 and 2. The resistor 1 is made of, for example, an alloy containing Cu, Mn, and Ni (manganin), geranin, a Cu—Ni alloy, a Ni—Cr alloy, or an Fe—Cr alloy. The resistor 1 has a surface 11, a mounting surface 12, a first side surface 13, a second side surface 14, a trimming groove 15, and a plurality of grooves 16.

The surface 11 is the lower surface of the resistor 1 shown in FIG. 3, and is a surface covered with the electrode 4 and the protective film 5. The mounting surface 12 is the upper surface of the resistor 1 shown in FIG. 3, and is a surface used when the resistor 1 is mounted on the substrate 2. The surface 11 and the mounting surface 12 face each other. Further, the mounting surface 12 faces the substrate 2 side. The first side surface 13 is a pair of surfaces that are orthogonal to the surface 11 and the mounting surface 12 and face the long side direction (direction X shown in FIGS. 1 and 2) of the resistor 1. The second side surface 14 is a pair of surfaces that are orthogonal to the surface 11 and the mounting surface 12 and face the short side direction (direction Y shown in FIGS. 1 and 2) of the resistor 1. The first side surface 13 and the second side surface 14 are located between the surface 11 and the mounting surface 12. Further, the first side surface 13 and the second side surface 14 are orthogonal to each other.

The trimming groove 15 penetrates in the thickness direction of the resistor 1. The trimming groove 15 forms an opening on the side surface of the resistor 1 in the long side direction. In the present embodiment, two trimming grooves 15 are formed in the resistor 1.

The plurality of grooves 16 are formed on the surface 11 of the resistor 1 and do not penetrate in the thickness direction of the resistor 1. The width of the plurality of grooves 16 is relatively narrower than the width of the trimming groove 15. In the present embodiment, the directions of the plurality of grooves 16 are in directions orthogonal to the direction of the current flowing through the resistor 1 (direction X shown in FIGS. 1 and 2) (direction Y shown in FIGS. 1 and 2). be. Further, in the present embodiment, the distance Δl of the plurality of grooves 16 shown in FIG. 4 is 50 to 100 μm. As shown in FIGS. 1 and 2, in a plan view, a part of the region of the electrode 4 overlaps at least one of the plurality of grooves 16.

The substrate 2 is a member on which the resistor 1 is mounted. By integrating the substrate 2 with the resistor 1 via the adhesive layer 3, the substrate 2 functions to reinforce the resistor A1 against an external force or the like and to protect the resistor 1 from the outside. In this embodiment, the substrate 2 is an electrical insulator. Further, when the resistor A1 is used, the substrate 2 is preferably made of a material having high thermal conductivity in order to easily dissipate the heat generated from the resistor 1 to the outside. Therefore, in the present embodiment, the substrate 2 is made of, for example, alumina (Al2O3). The substrate 2 has a main surface 21 and a mounting surface 22. In the present embodiment, the substrate 2 has the same rectangular shape as the resistor 1 in a plan view.

The main surface 21 is the upper surface of the substrate 2 shown in FIG. 3, and is a surface exposed to the outside. The mounting surface 22 is the lower surface of the substrate 2 shown in FIG. 3, and is a surface used when the resistor 1 is mounted on the substrate 2. The main surface 21 and the mounting surface 22 face opposite to each other. Further, the mounting surface 22 faces the resistor 1 side. Therefore, the resistor 1 is mounted on the substrate 2 with the mounting surface 12 of the resistor 1 and the mounting surface 22 of the substrate 2 facing each other.

The adhesive layer 3 is a member made of an adhesive for mounting the resistor 1 on the substrate 2, which is interposed between the mounting surface 12 of the resistor 1 and the mounting surface 22 of the substrate 2. The adhesive layer 3 is an electrical insulator. In the present embodiment, the adhesive layer 3 is made of, for example, an epoxy resin or a glass epoxy resin which is a prepreg obtained by impregnating a glass fiber cloth with an epoxy resin. Further, in the present embodiment, the adhesive layer 3 covers the entire mounting surface 22 of the substrate 2, but the adhesive layer 3 may be arranged so as to cover a part of the mounting surface 22.

The electrode 4 is a pair of members that conduct with the resistor 1 and are separated from each other for interconnecting the resistor A1 and the wiring pattern of the circuit board of various electronic devices. The electrodes 4 are arranged on both sides of the resistor 1 in the direction X shown in FIGS. 1 and 2. The electrode 4 has an internal electrode 41, an intermediate electrode 42, and an external electrode 43.

The internal electrode 41 is a pair of portions that are electrically connected to the resistor 1 and that cover a part of the protective film 5 and are separated from each other. In this embodiment, the internal electrode 41 is made of, for example, a Ni—Cr alloy. The internal electrode 41 is electrically connected to the resistor 1 by covering a part of the surface 11 of the resistor 1.

The intermediate electrode 42 is a pair of portions that cover the internal electrode 41 and are separated from each other. In the present embodiment, the intermediate electrode 42 has a first intermediate electrode 42a and a second intermediate electrode 42b. The first intermediate electrode 42a is a pair of portions separated from each other that cover the internal electrode 41, the first side surface 13 of the resistor 1, and a part of the second side surface 14 of the resistor 1. In the present embodiment, the first intermediate electrode 42a is made of, for example, a Cu plating layer. The second intermediate electrode 42b is a pair of portions that cover the first intermediate electrode 42a and are separated from each other. In the present embodiment, the second intermediate electrode 42b is composed of, for example, a Ni plating layer. The second intermediate electrode 42b functions to protect the electrode 4 from heat and impact.

The external electrode 43 is a pair of portions that cover the intermediate electrode 42 and are separated from each other. More specifically, the external electrode 43 covers the second intermediate electrode 42b of the intermediate electrode 42. In the present embodiment, the external electrode 43 is, for example, a Sn plating layer. When the solder adheres to the external electrode 43 and the external electrode 43 is integrated with the solder, the resistor A1 and the wiring pattern of the circuit board of various electronic devices are interconnected. In the present embodiment, since the second intermediate electrode 42b is made of a Ni plating layer, it is difficult to directly attach the solder to the second intermediate electrode 42b. Therefore, an external electrode 43 made of a Sn plating layer is required.

The protective film 5 is a member that covers a part of the surface 11 of the resistor 1 and functions to protect the resistor 1 from the outside. As shown in FIG. 3, a part of the protective film 5 is interposed between the surface 11 of the resistor 1 and the internal electrode 41. The protective film 5 is an electrical insulator so that the resistance value of the resistor 1 does not fluctuate due to an influence from the outside or the like. Further, since the protective film 5 is significantly affected by the heat generated from the resistor 1 when the resistor A1 is used, the protective film 5 is made of a thermosetting resin in the present embodiment. Further, in order to easily dissipate the heat to the outside, the protective film 5 is preferably made of a material having a relatively high thermal conductivity. Therefore, in the present embodiment, the protective film 5 is made of, for example, a polyimide resin.

Next, a method for manufacturing the resistor A1 will be described with reference to FIGS. 5 to 14. 5, FIG. 7, FIG. 11 and FIG. 12 are plan views showing steps related to the method for manufacturing the resistor A1. FIG. 8 is a plan view showing a method of manufacturing a resistor region 811 (resistor 1 of the resistor A1) of the sheet-shaped resistor 81, which will be described later. 9 (a) to 9 (h) are plan views showing the manufacturing method of the resistor region 811 of FIG. 8 along with each manufacturing step. FIG. 10 is an enlarged cross-sectional view of a main part showing a manufacturing state of the resistor A1. 6, 13 and 14 are perspective views showing a process according to a method for manufacturing the resistor A1. Note that FIGS. 13 and 14 see through the protective film 5 for convenience of understanding. Further, FIG. 14 shows a cross section of the electrode 4 along the second side surface 14 of the resistor 1 for convenience of understanding.

First, as shown in FIG. 5, a sheet-shaped resistor 81 made of manganin, geranin, a Cu—Ni alloy or the like is prepared. The sheet-shaped resistor 81 is an assembly of a plurality of resistor regions 811. The resistor region 811 is a rectangular region in a plan view surrounded by the alternate long and short dash line shown in FIG. This region is the region that becomes the resistor 1 of the resistor A1. The sheet-shaped resistor 81 has a surface 812 and a mounting surface 813. The surface 812 and the mounting surface 813 face each other. Note that FIG. 5 shows the surface 812 of the sheet-shaped resistor 81.

Next, as shown in FIG. 6, the sheet-shaped substrate 82 is adhered to the mounting surface 813 of the sheet-shaped resistor 81. The sheet-shaped substrate 82 has a main surface 821 and a mounting surface 822. The main surface 821 and the mounting surface 822 face opposite to each other. The sheet-like substrate 82 is made of alumina. In the present embodiment, the adhesive sheet 83 made of glass epoxy resin is sandwiched between the sheet-shaped resistor 81 and the sheet-shaped substrate 82, and then the sheet-shaped substrate 82 is bonded by a high-pressure vacuum press. The adhesive sheet 83 is sandwiched in a state where the mounting surface 813 of the sheet-shaped resistor 81 and the mounting surface 822 of the sheet-shaped substrate 82 face each other. The sheet-shaped substrate 82 can also be adhered by applying an adhesive made of a fluid epoxy resin to the mounting surface 822 of the sheet-shaped substrate 82 instead of the adhesive sheet 83. At this time, the adhesive may be applied so as to partially cover each of the plurality of resistor regions 811 on the mounting surface 813 of the sheet-shaped resistor 81.

Next, as shown in FIG. 7, trimming grooves 815 penetrating the resistor region 811, which are two for one resistor region 811, are formed in the plurality of resistor regions 811. After forming the trimming groove 815, a plurality of grooves 816 that do not penetrate the resistor region 811 for adjusting the resistance value are formed on the surface 812 of the plurality of resistor regions 811. The trimming groove 815 and the plurality of grooves 816 are the same as the trimming groove 15 and the plurality of grooves 16 of the resistor 1 described above. In the present embodiment, the trimming groove 815 and the plurality of grooves 816 are both formed by a laser trimming device (not shown). The trimming groove 815 is formed so as to be orthogonal to the direction of the current flowing through the resistor region 811 from one side surface of the resistor region 811 in the long side direction toward the other side surface. At this time, the resistance value of the resistor region 811 is set to be approximately 85% or more of the target resistance value. Therefore, the trimming grooves 815 may form a number of grooves other than the two so as to be approximately 85% or more of the target resistance value, or the resistance value of the resistor region 811 has already reached the target resistance value. If the values are close to each other, the groove does not have to be formed.

After forming the trimming groove 815 in the plurality of resistor regions 811, a plurality of grooves 816 are subsequently formed on the surface 812 of the plurality of resistor regions 811. Here, the plurality of grooves 816 are formed for each of the plurality of compartments 814 (regions surrounded by the broken line shown in FIG. 8) set on the surface 812 of the resistor region 811 shown in FIG. At this time, the plurality of grooves 816 are formed in the order of compartments 814a, 814b, 814c, ..., 814f, 814g. Therefore, the plurality of grooves 816 are formed in order from the compartment 814 located outside the resistor region 811 toward the inside of the resistor region 811. Further, the plurality of grooves 816 are formed after the partition 814 located between the center of the resistor region 811 and the internal electrode 41 of one of the pair of internal electrodes 41 (formed by the conductive layer 841 described later), and then the resistor. The compartments 814 located between the center of the region 811 and the other internal electrode 41 are formed in this order and alternately.

The specific formation process of the plurality of grooves 816 is shown in FIG. FIG. 9A shows a case where the trimming groove 815 is formed in the resistor region 811. FIG. 9B shows a case where a plurality of grooves 816 are formed in the section 814a of the surface 812 of the resistor region 811. FIG. 9C shows a case where a plurality of grooves 816 are formed in the section 814b of the surface 812 of the resistor region 811. FIG. 9D shows a case where a plurality of grooves 816 are formed in the compartment 814c of the surface 812 of the resistor region 811. Hereinafter, a plurality of grooves 816 are formed as shown in the order of FIGS. 9 (e), (f), and (g), and when a plurality of grooves 816 are formed in the last remaining compartment 814 g, the plurality of grooves 816 are shown in FIG. 9 (h). It will be as follows.

The plurality of grooves 816 are formed under a state in which probes for measuring resistance values (not shown) are in contact with both ends of the resistor region 811 in the long side direction. In the present embodiment, the plurality of grooves 816 are formed by a laser irradiated from a laser trimming device after recognizing each of the compartments 814 as an image. Therefore, the laser is accurately irradiated in each compartment 814. The wavelength of the laser irradiated toward the compartment 814 is preferably as short as possible (less than 1 μm). The laser output is preferably 0.7 W to 1.0 W so as not to penetrate the resistor region 811. At this time, if the rate of increase in the resistance value of the resistor region 811 is relatively low, the laser is irradiated several times so as to trace the same position to form a plurality of grooves 816. Further, in the present embodiment, the plurality of grooves 816 are formed in the compartments 814a to 814 shown in FIG. 8 at equal intervals and orthogonal to the direction of the current flowing through the resistor region 811. The section 814g located at the center of the resistor region 811 shown in FIG. 8 is the final adjustment section for the resistance value, and when the resistance value of the resistor region 811 reaches the target resistance value in the section, a plurality of grooves The formation of 816 is completed.

FIG. 10 shows an enlarged cross-sectional view of a main part showing the manufacturing state of the resistor A1 after actually forming the plurality of grooves 816. The material of the resistor region 811 at this time is manganin. Along the plurality of grooves 816, minute protrusions (burrs) are formed on the surface 812 of the resistor region 811 (the upper surface of the resistor region 811 shown in FIG. 12).

Next, as shown in FIG. 11, a protective film body 85 covering the plurality of resistor regions 811 is formed on the surface 812 of the sheet-shaped resistor 81. At this time, both ends of the resistor region 811 in the long side direction are exposed. In the present embodiment, the protective film body 85 is formed in a plurality of bands extending along the short side of the resistor region 811 so as to straddle the long side of the resistor region 811. Here, the protective film 5 may be formed so as to be separated for each resistor region 811. Further, in the present embodiment, the protective film body 85 is formed by printing a fluid polyimide resin using a silk screen and curing it. In addition to the method using printing, it may be formed by coating.

Next, as shown in FIG. 12, the conductive layer 841 is formed on the surface 812 of the sheet-shaped resistor 81 in the exposed portion of the plurality of resistor regions 811 not covered by the protective film body 85. At this time, in addition to the exposed portion, a part of the protective film body 85 is covered with the conductive layer 841. In the present embodiment, the conductive layer 841 is formed in a plurality of strips extending along the short side of the resistor region 811 so as to straddle the long side of the resistor region 811. Here, the conductive layer 841 may be formed so as to be separated for each resistor region 811 in the same manner as the protective film body 85 described above. The conductive layer 841 is formed by a method using thin film deposition or printing. In the present embodiment, the conductive layer 841 is formed by depositing a Ni—Cr alloy by a sputtering method.

Next, as shown in FIG. 13, the region including the resistor region 811 of the sheet-shaped resistor 81 (the region surrounded by the alternate long and short dash line shown in FIG. 5) is punched to divide it into a plurality of individual pieces 87. .. At this time, the resistor region 811 becomes the same as the resistor 1. By dividing the sheet-shaped resistor 81 into a plurality of individual pieces 87, a pair of internal electrodes 41 conducting with the resistor region 811 are formed on both sides of the resistor region 811. The pair of internal electrodes 41 correspond to the above-mentioned conductive layer 841. Further, the substrate 2, the adhesive layer 3 and the protective film 5 correspond to the above-mentioned sheet-shaped substrate 82, the adhesive sheet 83, and the protective film body 85, respectively.

Next, as shown in FIG. 14, an intermediate electrode 42 covering the pair of internal electrodes 41 and an external electrode 43 covering the intermediate electrode 42 are formed on the individual piece 87, respectively. The step of forming the intermediate electrode 42 includes a step of forming a first intermediate electrode 42a covering the pair of internal electrodes 41 and a step of forming a second intermediate electrode 42b covering the first intermediate electrode 42a. At this time, the first side surface 13 of the resistor 1 and a part of the second side surface 14 of the resistor 1 are covered with the first intermediate electrode 42a. In the present embodiment, the first intermediate electrode 42a is formed by Cu plating, the second intermediate electrode 42b is formed by Ni plating, and the external electrode 43 is formed by Sn plating. By this step, a pair of electrodes 4 conducting with the resistor 1 are formed. By going through the above steps, the resistor A1 is manufactured.

Next, the action and effect of the resistor A1 will be described.

According to this embodiment, a plurality of grooves 16 that do not penetrate the resistor 1 are formed on the surface 11 of the resistor 1 of the resistor A1, which is different from the trimming groove 15. The laser trimming device used for forming the plurality of grooves 16 recognizes each of the plurality of compartments 814 set on the surface 812 (surface 11) of the resistor region 811 (resistor 1) and then lasers the laser. Since irradiation is performed, it is possible to efficiently form a plurality of equally spaced grooves 16 on the surface 812 of the resistor region 811. Therefore, it is possible to adjust the target resistance value for each resistor A1 with higher accuracy while utilizing the laser trimming device constituting the existing manufacturing equipment.

By setting the direction of the plurality of grooves 16 to be orthogonal to the direction of the current flowing through the resistor 1, the direction of the plurality of grooves 16 is not the same as the direction of the current flowing through the resistor 1. A cross section having a relatively small area is formed on the resistor 1. Therefore, it is possible to avoid a significant decrease in the rate of increase in the resistance value of the resistor 1 due to the formation of the plurality of grooves 16. Therefore, it is possible to prevent a decrease in the efficiency of adjusting the resistance value of the resistor A1 due to the formation of the plurality of grooves 16.

In the step of forming the plurality of grooves 16, the plurality of grooves 16 are formed for each section 814 set on the surface 812 of the resistor region 811. Further, the plurality of grooves 16 are formed in order from the compartment 814 located outside the resistor region 811 toward the inside of the resistor region 811. Further, the plurality of grooves 16 are formed in the center of the resistor region 811 and the inside of the other after the compartment 814 located between the center of the resistor region 811 and one of the internal electrodes 41 of the pair of internal electrodes 41. The compartments 814 located between the electrodes 41 are formed in this order and alternately. By forming the plurality of grooves 16 in this order, the heat concentration of the resistor region 811 due to the laser irradiation is reduced. Therefore, since the increase in the resistance value of the resistor 1 due to the temperature drift that occurs with the formation of the plurality of grooves 16 is reduced, it is possible to avoid a decrease in the accuracy of the resistance value of the resistor A1.

By configuring the internal electrode 41 to cover a part of the protective film 5, the surface area of the electrode 4 can be secured wider. Therefore, when the resistor A1 is used, the heat generated from the resistor 1 is more likely to be dissipated to the outside.

15 to 20 show other embodiments of the present invention. In these figures, the same or similar elements as the above-mentioned resistor A1 are designated by the same reference numerals, and duplicate description will be omitted.

[Second Embodiment]
The resistor A2 according to the second embodiment of the present invention will be described with reference to FIGS. 15 to 18. FIG. 15 is a plan view showing the resistor A2. FIG. 16 is a bottom view showing the resistor A2. FIG. 17 is a cross-sectional view taken along the line XVII-XVII of FIG. FIG. 20 is a plan view showing a method of manufacturing a resistor region 811 (resistor 1 of the resistor A2) of the sheet-shaped resistor 81. In FIG. 15, the substrate 2 and the adhesive layer 3 are omitted for convenience of understanding. Further, in FIG. 16, the protective film 5 is seen through for convenience of understanding. In the present embodiment, the resistor A2 has a rectangular shape in a plan view.

The resistor A2 of the present embodiment is different from the resistor A1 described above in the material of the substrate 2 and the plan view shape and arrangement form of the resistor 1. In the present embodiment, the substrate 2 is made of a glass epoxy resin. The sheet-shaped resistor 81 (resistor 1) excluding the adhesive sheet 83 shown in FIG. 6 and the sheet-shaped substrate 82 (board 2) made of glass epoxy resin are pressure-bonded by a high-pressure vacuum press to be shown in FIG. As shown, the resistor 1 is embedded in the substrate 2. In the crimping, the mounting surface 813 of the sheet-shaped resistor 81 and the mounting surface 822 of the sheet-shaped substrate 82 are crimped in a state of facing each other. By the crimping, as shown in FIG. 17, the resistor 1 is mounted on the mounting surface 22 of the substrate 2 so that the height of the surface 11 of the resistor 1 and the mounting surface 22 of the substrate 2 are substantially the same. Can be done. Therefore, the resistor A2 does not include the adhesive layer 3.

In the present embodiment, the plan view shape of the resistor 1 is a serpentine shape. The resistor 1 having the shape is formed by shaping the sheet-shaped resistor 81 by punching, photolithography, or the like.

In the present embodiment, the plurality of grooves 816 are formed for each of the plurality of compartments 814 (regions surrounded by the broken line shown in FIG. 18) set on the surface 812 of the resistor region 811 shown in FIG. At this time, the plurality of grooves 816 are formed in the order of compartments 814a, 814b, 814c, ..., 814n, 814o. The section 814o located in the center of the resistor region 811 is the final adjustment section for the resistance value, and when the resistance value of the resistor area 811 reaches the target resistance value in the section, the formation of the plurality of grooves 816 is completed. do. It should be noted that the formation of a plurality of grooves 816 in the compartments 814c, 814d, 814g, 814h, 814k and 814l can be omitted depending on the rate of increase in the resistance value of the resistor region 811.

Also in this embodiment, by adjusting the resistance value of the resistor 1 with the plurality of grooves 16, it is possible to adjust the target resistance value for each resistor A2 with higher accuracy while utilizing the existing manufacturing equipment. It becomes. Further, by mounting the resistor 1 on the mounting surface 22 of the substrate 2 in a state of being embedded in the substrate 2, the thickness of the resistor A2 can be made relatively thinner than that of the resistor A1. Further, by making the plan view shape of the resistor 1 a serpentine shape, the resistance value of the resistor A2 can be made relatively higher than that of the resistor A1. Therefore, it is possible to cope with higher power while reducing the thickness of the resistor A2.

[Third Embodiment]
The resistor A3 according to the third embodiment of the present invention will be described with reference to FIGS. 19 and 20. FIG. 19 is a plan view showing the resistor A3. FIG. 20 is a cross-sectional view taken along the line XX-XX of FIG. In FIG. 19, the protective film 5 is omitted for convenience of understanding. In the present embodiment, the resistor A3 has a rectangular shape in a plan view.

The resistor A3 of the present embodiment is different from the above-mentioned resistors A1 and A2 in the arrangement form of the resistor 1, the adhesive layer 3 and the protective film 5 and the configuration of the electrode 4. Further, unlike the resistors A1 and A2, the resistor A3 does not include the substrate 2 but newly includes the heat conductive portion 6.

In this embodiment, the surface 11 of the resistor 1 faces upward as shown in FIG. The plan view shape of the resistor 1 and the method of forming the plurality of grooves 16 are the same as those of the resistor A2. Further, in the present embodiment, the mounting surface 12 of the resistor 1 and the first intermediate electrode 42a of the electrode 4 are arranged so as to face each other. The adhesive layer 3 is interposed between the mounting surface 12 of the resistor 1 and the first intermediate electrode 42a. The surface of the protective film 5 faces upward as shown in FIG.

The internal electrode 41 is a pair of portions that are conductive with the resistor 1 and are separated from each other. In the present embodiment, the internal electrode 41 covers the first side surface 13 of the resistor 1 and a part of each of the surface 11 and the mounting surface 12 of the resistor 1. Further, in the present embodiment, the internal electrode 41 is composed of, for example, a Cu plating layer or an Au plating layer.

The first intermediate electrode 42a is a pair of portions that are conductive with the internal electrode 41 and are separated from each other. The upper surface of the first intermediate electrode 42a shown in FIG. 20 and the adhesive layer 3 and the internal electrode 41 are in contact with each other. In the present embodiment, the first intermediate electrode 42a functions to support the resistor 1 in addition to the function of conducting with the internal electrode 41. Further, in the present embodiment, the first intermediate electrode 42a is formed of, for example, a metal plate made of Cu. The size of the first intermediate electrode 42a is larger than that of the resistors A1 and A2.

The second intermediate electrode 42b is a pair of portions that are conductive with the internal electrode 41 and the first intermediate electrode 42a and are separated from each other. In the present embodiment, the second intermediate electrode 42b covers the internal electrode 41 and the first intermediate electrode 42a. The second intermediate electrode 42b is made of, for example, a Ni plating layer. The external electrode 43 is a pair of portions that cover the second intermediate electrode 42b and are separated from each other. The external electrode 43 is made of, for example, a Sn plating layer.

The heat conductive portion 6 is a member sandwiched between a pair of electrodes 4 in the direction X shown in FIG. The heat conductive portion 6 functions to dissipate heat generated from the resistor 1 to the outside when the resistor A3 is used. In the present embodiment, the upper surface of the heat conductive portion 6 shown in FIG. 20 and the adhesive layer 3 are in contact with each other. Further, the side surface of the heat conductive portion 6 facing the direction X shown in FIG. 19 and the first intermediate electrode 42a are in contact with each other. Therefore, in the present embodiment, the heat conductive portion 6 must be an electrical insulator. Further, the heat conductive portion 6 is preferably made of a material that is resistant to heat and has a relatively high thermal conductivity. Therefore, in the present embodiment, the heat conductive portion 6 is made of, for example, a polyimide resin.

Also in this embodiment, by adjusting the resistance value of the resistor 1 with the plurality of grooves 16, it is possible to adjust the target resistance value for each resistor A3 with higher accuracy while utilizing the existing manufacturing equipment. It becomes. Further, since the resistor A3 has a configuration in which the substrate 2 is omitted, the cost can be reduced. Further, the size of the electrode 4 of the resistor A3 is relatively larger than that of the resistors A1 and A2, and the resistor A3 includes the heat conductive portion 6. Therefore, the heat dissipation effect of the heat generated from the resistor 1 when the resistor A3 is used can be made relatively larger than that of the resistors A1 and A2.

The resistor according to the present invention is not limited to the above-described embodiment and the like. The specific configuration of each part of the resistor according to the present invention can be freely redesigned.

A1, A2, A3: Resistor 1: Resistor 11: Surface 12: Mounting surface 13: First side surface 14: Second side surface 15: Trimming groove 16: Groove 2: Substrate 21: Main surface 22: Mounting surface 3: Adhesion Layer 4: Electrode 41: Internal electrode 42: Intermediate electrode 42a: First intermediate electrode 42b: Second intermediate electrode 43: External electrode 5: Protective film 6: Heat conductive part 81: Sheet-like resistor 811: Resistor region 812: Surface 813: Mounting surface 814a to o: Section 815: Trimming groove 816: Groove 82: Sheet-like substrate 821: Main surface 822: Mounting surface 83: Adhesive sheet 841: Conductive layer 85: Protective film 87: Individual pieces X, Y : Direction Δl: Interval t: Thickness

Claims (12)

A resistor having a front surface and a first back surface facing each other in the thickness direction,
A pair of electrodes arranged with the resistor in the first direction orthogonal to the thickness direction and conducting with the resistor.
A protective film covering a part of the resistor is provided.
The resistor is formed with a first slit and a second slit that penetrate the resistor in the thickness direction and extend in the second direction orthogonal to the thickness direction and the first direction. ,
The first slit extends inward of the resistor from the peripheral edge of the resistor located on one side of the second direction.
The second slit extends inward from the peripheral edge of the resistor located next to the first slit in the first direction and on the other side of the second direction. ,
When viewed along the first direction, the second slit overlaps the first slit.
A first groove extending in the first direction and a second groove extending in the second direction are formed on the surface of the resistor.
The first groove is located next to either the first slit or the second slit in the first direction.
The second groove is a resistor located between any of the first slit and the second slit and the peripheral edge of the resistor in the second direction. The resistor according to claim 1, wherein the width of each of the first groove and the second groove is narrower than the width of each of the first slit and the second slit. The resistor according to claim 2, wherein the protective film includes a portion that enters the first slit and the second slit. The resistor according to claim 2 or 3, wherein one of the pair of electrodes overlaps the first groove and the second groove when viewed along the thickness direction. The resistor according to any one of claims 1 to 4, wherein the pair of electrodes covers a part of each of the resistor and the protective film. 5. The pair of electrodes have an internal electrode that conducts to the resistor and covers a part of the protective film, an intermediate electrode that covers the internal electrode, and an external electrode that covers the intermediate electrode. The resistor described in. The resistor according to claim 6, wherein the internal electrode is made of a Ni—Cr alloy. The resistor according to claim 6 or 7, wherein the intermediate electrode and the external electrode are made of a plating layer. The resistor according to claim 8, wherein the external electrode is made of a Sn-plated layer. The resistor according to claim 8 or 9, wherein the intermediate electrode includes a first intermediate electrode covering the internal electrode and a second intermediate electrode covering the first intermediate electrode. The first intermediate electrode is made of a Cu plating layer.
The resistor according to claim 10, wherein the second intermediate electrode is made of a Ni-plated layer. Further provided with a substrate on which the resistor is mounted,
The substrate has a main surface and a second back surface that face opposite to each other in the thickness direction.
The resistor according to any one of claims 1 to 11, wherein the second back surface faces the first back surface.

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