JP6994195B2 - Manufacturing method of resistor - Google Patents

Description

The present invention relates to a method for manufacturing a resistor used for a current detection resistor, and more particularly to a method for manufacturing a resistor using a Cu—Mn—Ni alloy.

Cu-Mn-Ni alloy (manganin (registered trademark)) is a resistor material for current detection resistors, and since it has a small intrinsic resistance value and a small temperature coefficient of resistance, a resistor with a low resistance value can be obtained. So it is widely used. In order to manufacture resistors for detecting currents with various resistance values, it is necessary to plastically process Cu-Mn-Ni based alloys into various shapes, and adjust the thickness by rolling or press the shape. The required resistance value is obtained by processing.

In particular, in order to manufacture a resistor for current detection with a relatively high resistance value of 10 mΩ or more, it is necessary to thinly process a Cu-Mn-Ni alloy plate into a foil shape, and in order to obtain a higher resistance value. It is necessary to cut a plate thinly processed into a foil shape into a long pattern shape.

By the way, according to the following Patent Document 1, a fine powder substance (for example, a metal powder) is arranged between a parallel first surface and a second surface, and the powder is pressed by a predetermined pressing force on the first surface and the second surface. Described is a solidification molding method by compression shearing in which the fine powder substance is made into an integrally molded product (for example, a metal plate) by moving the first surface and the second surface in a direction orthogonal to the opposite direction while sandwiching the powder material.

Japanese Patent Application Laid-Open No. 2003-221603

Alloys used as resistors generally require high temperature heat treatment at the production stage and are supplied to the market as plates or wires. However, as a resistor for a current detection resistor, it is easy to thinly process a resistance alloy from a plate or wire into a foil shape and process it to a required pattern shape and dimensions in order to obtain the required resistance value. It's not that.

The present invention has been made based on the above circumstances, and is a resistor for a current detection resistor capable of producing a Cu—Mn-based alloy foil having an arbitrary pattern shape and thinly formed from powder. The purpose is to provide a manufacturing method.

The method for producing a resistor of the present invention has a first surface and a second surface arranged so as to be parallel to the first surface, and between the first surface and the second surface. A Cu—Mn-based metal powder material is arranged, and the first surface and the second surface are moved in a direction orthogonal to the opposite direction while sandwiching the metal powder material between the first surface and the second surface with a predetermined pressing force. The metal powder material is made into an integrally molded product (metal plate), and the average particle size of the metal powder material is 1 μm to 12 μm .

According to the present invention, since the metal powder material constituting the resistor of the resistor is powder, a Cu—Mn system having an arbitrary pattern shape and an arbitrary thickness can be used by using a metal mask, screen printing, or the like. Alloy foils can be made. Further, unlike the sintering method of a metal resistance material, a high temperature is not required, and plastic deformation processing and cutting processing are not required.

It is a figure which shows the manufacturing method of the Cu—Mn—Ni system resistor of one Example of this invention. It is an image of a Cu—Mn—Ni based alloy powder having an average particle size of 12.9 μm. It is an image of a Cu—Mn—Ni alloy powder having an average particle size of 3.5 μm. It is a surface image by SEM of the moving distance L = 0 mm of compression shear. It is a surface image by SEM of the moving distance L = 0.1 mm of compression shear. It is a surface image by SEM of the moving distance L = 0.2mm of compression shear. It is a surface image by SEM of the moving distance L = 0.5mm of compression shear. It is a surface image by SEM of the moving distance L = 1.0mm of compression shear. It is a graph of the relationship between the moving distance of compressive shear and Vickers hardness. It is a graph of the relationship between the moving distance of compressive shear and the volume resistance. It is a graph of the relationship between the measured temperature and the volume resistance of the resistor formed by compression shear. It is a figure which applied the screen printing to the formation of a powder filler.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 7. In each figure, the same or corresponding members or elements will be described with the same reference numerals.

FIG. 1 shows a method for manufacturing a Cu—Mn—Ni-based resistor according to an embodiment of the present invention. The outline of the manufacturing method is that a Cu—Mn—Ni-based metal powder material is filled in a required shape using a metal mask or the like to form a filler of the metal powder material. Then, a metal powder material is placed between the first surface and the second surface, which are arranged so as to be parallel to each other, and one surface is applied to the other surface while applying a compressive load. A metal foil of a Cu—Mn—Ni-based alloy is obtained by compression shearing in which a shearing force is applied to a filler made of a metal powder material by moving the metal powder material.

FIG. 1A shows a stage in which the metal mask 11 is placed on the lower plate 12. By providing the metal mask 11 with an opening O, it is possible to form a resistor pattern having a required shape according to the shape of the mask opening O filled with the metal powder material.

FIG. 1B shows a stage in which the opening O of the metal mask 11 is filled with a Cu—Mn—Ni-based metal powder material to form the powder filler 13. The powder used is a Cu-Mn-Ni-based metal powder material. The average particle size Φ is preferably 1 to 12 μm. In particular, the average particle size Φ of the Cu—Mn—Ni-based metal powder material used is preferably about 3.5 μm, as will be described later. If the average particle size Φ is larger than about 12.5 μm, molding becomes difficult. Further, as will be described later, if the average particle size is larger than this, there is a problem that there is no metallic luster and it is difficult to form a metal foil. There is a problem that it is difficult to form fine particles having an average particle size Φ smaller than 1 μm by the water atomization method.

The metal powder used is preferably non-spherical. This is because if it is a true sphere, the powder may not be crushed well due to rolling during compressive shear movement. In this example, a moderately distorted tear-drop-shaped powder having an average particle size of about 3.5 μm, which is produced by using a water atomizing method or the like, is used (see FIG. 2B). ).

On the other hand, for example, the metal powder material obtained by the gas atomizing method has a spherical shape, and it is difficult to obtain a small average particle size of Φ12.5 μm or less. Further, if the shape is a true sphere, the metal powder material is less likely to be deformed due to compressive shear movement, and it is difficult to form an integrally molded product (metal plate). Therefore, it is preferable that the metal powder material is prepared by the water atomizing method.

FIG. 2A shows a Cu—Mn—Ni based alloy powder having an average particle size Φ of 12.9 μm produced by the water atomization method. The atomizing method is a method for producing powder. When a molten metal or alloy is discharged from a small hole at the bottom of a tundish to form a trickle, and high-speed air, nitrogen, argon, water, etc. is blown onto the molten metal, the molten metal is formed. Scatters and quenches and solidifies into powder.

FIG. 1C shows a stage in which the metal mask 11 is removed. At this stage, a filler 13 made of a Cu—Mn—Ni-based metal powder material having the size of the opening O of the metal mask 11 is arranged on the first surface 12a of the lower plate 12.

FIG. 1D shows a stage in which the filler 13 made of a metal powder material is sandwiched between the second surface 14a of the upper plate 14 and the first surface 12a of the lower plate 12 by the pressing force of the compressive load F1. The second surface 14a is arranged so as to face the first surface 12a so that the first surface 12a and the first surface 12a are parallel to each other.

As for the compressive load, if the sample size is changed and the load per unit area is changed in the test, the strength of the obtained foil is sufficiently secured if the load is 1.7 kN / mm ² (30 mm × 10 mm) or more. However, with a load of 1.2 kN / mm ² (40 mm × 10 mm) or less, sufficient strength could not be obtained, resulting in cracking of the metal foil. Therefore, it is desirable to apply a compressive load of 1.7 kN / mm ² or more.

Then, as shown in FIG. 1 (E), a Cu—Mn—Ni-based metal powder material is formed between the second surface 14a on the lower surface of the upper plate 14 and the first surface 12a on the upper surface of the lower plate 12. The filler 13 is arranged, and while the metal powder material is sandwiched between the second surface 14a and the first surface 12a by a predetermined pressing force F1, the second surface 14a and the first surface 12a are predetermined in a direction orthogonal to the facing direction. By moving the distance between the two, the shearing force F2 can be applied to the filler 13 made of the metal powder material, and the filler 13 can be made into a metal foil (resistor) 13A which is an integrally molded product.

While sandwiching the metal powder material filler 13 with a predetermined pressing force, one surface is moved laterally to form a metal foil as an integrally molded product, and the compression shear transfer distance is relative to the film thickness of the filler 13. It is necessary to be 1 times or more. That is, when the film thickness of the filler 13 is 0.5 mm, the compression shear movement distance needs to be 0.5 mm or more.

That is, when shear strain = (moving distance / thickness of metal powder material), it is necessary to set the shear strain to 1 or more.

3A-3E use Cu—Mn—Ni alloy powder having an average particle size of Φ = 3.5 μm, the filling thickness is 0.5 mm, and the compression shear transfer distance L = 0 mm (FIG. 3A), L. It is a surface image by SEM when = 0.1 mm (FIG. 3B), L = 0.2 mm (FIG. 3C), L = 0.5 mm (FIG. 3D), L = 1.0 mm (FIG. 3E).

According to the above image, it can be seen that when the shearing movement is performed by L = 0.5 mm or more, the particle shape is not confirmed, the material has a metallic luster, and the Cu—Mn—Ni alloy foil is formed. On the other hand, in the shear movement of L = 0.2 mm or less, the shape of the powder particles is maintained, and the Cu—Mn—Ni based alloy foil is not formed.

When a Cu—Mn—Ni alloy powder having an average particle size of Φ = 12.9 μm was used, none of the samples having the shear transfer distance had metallic luster, were dull, and no metal foil was formed.

FIG. 4 is a graph showing the relationship between the compression shear movement distance and the Vickers hardness of the sample. ● Marks are for Cu—Mn—Ni alloy powder (average particle size Φ = 3.5 μm). When the thickness is 0.5 mm, the obtained hardness is low at a shearing distance shorter than 0.5 mm, and there is no hardness as a metal.

On the other hand, with a compression shear movement distance of 0.5 mm or more, hardness as a metal foil can be obtained. That is, when the shearing distance is 0.5 mm or more, the Vickers hardness of the sample increases and shows a value of 300 or more, confirming that a Cu—Mn—Ni alloy foil is formed.

On the other hand, the marks (1) are for Cu—Mn—Ni alloy powder (average particle size Φ = 12.9 μm). The obtained Vickers hardness is 100 or less, there is no hardness as a metal, and a metal foil which is an integrally molded product is not formed.

FIG. 5 shows the relationship between the shear movement distance and the volume resistance value. A metal foil having a shear transfer distance L of 1 mm or more showed a volume resistance value equivalent to that of a normal Cu—Mn—Ni based alloy. That is, the values in the vicinity of 45 × ^10-8 Ω · m are shown. On the other hand, at a shear distance smaller than L = 1 mm, the value of volume resistance changed significantly.

That is, the metal foil having L = 0.5 mm had a volume resistance value about 10 times higher than that of a normal Cu—Mn—Ni based alloy. Therefore, when it is desired to obtain a relatively high resistance value, a Cu—Mn—Ni alloy resistance foil having a high resistance value can be obtained by shearing with L = 0.5 mm.

FIG. 6 shows the temperature characteristics of the volume resistance values of the metal leaf of L = 0.5 mm and the metal leaf of L = 1.0 mm in FIG. The volume resistance value of the metal leaf with L = 0.5 mm (indicated by ◯ in the figure) at 25 ° C. was 510 μΩ · cm, and the temperature coefficient of resistance was 137 ppm / ° C. The volume resistance value of the metal leaf with L = 1.0 mm (indicated by ■ in the figure) at 25 ° C. is 47 μΩ · cm, and the temperature coefficient of resistance is + 25 ppm / ° C., which is equivalent to that of a normal Cu—Mn—Ni alloy. The characteristics of were obtained.

FIG. 1 (F) shows a stage in which a metal foil (resistor) 13A formed from a metal powder material is completed, and FIG. 1 (G) shows electrodes (Cu plates) 15 at both ends of the metal foil (resistor) 13A. Is welded to show the stage where the current detection resistor 16 is completed. Therefore, the step of forming the metal foil (resistor) 13A from the metal powder material can be carried out in a normal temperature environment without heating.

Then, by filling the fixed mold with the metal powder in a pattern shape by using a metal mask or a screen printing method, it is possible to obtain a metal foil of a Cu—Mn—Ni based alloy having various arbitrary shapes. Although the above description has been made using a Cu—Mn—Ni alloy as an example, the same results as above can be obtained even when a Cu—Mn—Sn alloy is used, and the present invention is a Cu—Mn based alloy. It can be applied when an alloy is used as a resistor.

FIG. 7 shows an example of forming an N-shaped resistance metal foil by using a screen printing method. First, as shown in (A), an N-shaped screen mask 31 is set. Next, as shown in (B), the metal powder 32 is placed on the screen mask and screen-printed. Then, as shown in (C), an N-shaped powder filler 33 is formed. Then, as shown in FIG. 1 (E), the powder filler 33 is subjected to compression shearing to form an N-shaped metal leaf resistor.

Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment and may be implemented in various different forms within the scope of the technical idea.

INDUSTRIAL APPLICABILITY The present invention can be particularly suitably used for manufacturing a resistor for a current detection resistor using a Cu—Mn based alloy.

Claims (4)

It has a first surface and a second surface arranged so as to be parallel to the first surface.
A Cu—Mn-based metal powder material is placed between the first surface and the second surface.
By sandwiching the metal powder material between the first surface and the second surface with a predetermined pressing force and moving the first surface and the second surface in a direction orthogonal to the facing direction, the metal powder material is integrally molded. death,
A method for producing a resistor , wherein the metal powder material has an average particle size of 1 μm to 12 μm . The method for manufacturing a resistor according to claim 1, wherein the shear strain is 1 or more when the shear strain = (movement distance / thickness of the metal powder material). The method for manufacturing a resistor according to claim 1, wherein the moving distance is 0.5 mm to 10 mm. It has a first surface and a second surface arranged so as to be parallel to the first surface.
A Cu—Mn-based metal powder material is placed between the first surface and the second surface.
By sandwiching the metal powder material between the first surface and the second surface with a predetermined pressing force and moving the first surface and the second surface in a direction orthogonal to the opposite direction, the metal powder material is made into an integrally molded product. ,
The metal powder material is a method for producing a resistor , which is produced by a water atomizing method.

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