JP2012087363A - Electrode plate and method of producing electrode plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode plate high in productivity, and excellent in electric conductivity, softening temperature and surface quality, and a method of producing an electrode plate.SOLUTION: The electrode plate includes an additive element selected from the group consisting of Ti, Mg, Zr, Nb, Ca, V, Ni, Mn and Cr, and oxygen in an amount exceeding 2 mass ppm, with the remainder being copper and unavoidable impurities, and has an electric conductivity of 101.5% IACS or more.

Description

  The present invention relates to an electrode plate and a method for manufacturing the electrode plate.

  As a conventional technique, a plurality of bus bars made of long plate-like conductors have adjacent portions that are adjacent to each other via an insulator along the long side direction of the plate surface along the route, and are layered together with the insulator by a fixing means. There is known a layered bus bar which is fixed in a fixed manner (for example, see Patent Document 1).

  In this conventional layered bus bar, the bus bar is formed in layers, so that both miniaturization and heat dissipation can be achieved.

JP 2004-140933 A

  However, in order to further improve the heat dissipation, the conventional layered bus bar needs to increase the area of the bus bar, which causes an increase in weight and volume, resulting in an increase in manufacturing cost.

  Accordingly, an object of the present invention is to provide an electrode plate having high productivity, excellent conductivity, heat dissipation, softening temperature, and surface quality, and a method for manufacturing the electrode plate.

  In order to achieve the above object, the present invention includes an additive element selected from the group consisting of Ti, Mg, Zr, Nb, Ca, V, Ni, Mn and Cr, oxygen in an amount exceeding 2 mass ppm, and the balance Provides an electrode plate comprising copper and inevitable impurities and having a conductivity of 101.5% IACS or more.

  Further, in the above electrode plate, the additive element may be Ti, and may contain 2 mass ppm or more and 12 mass ppm or less of sulfur, 2 mass ppm or more and 30 mass ppm or less of oxygen, and 4 mass ppm or more and 55 mass ppm or less of Ti. preferable.

In the above electrode plate, sulfur (S) and Ti have a TiO, TiO ₂ , TiS, or a compound having a Ti—O—S bond, or a TiO, TiO ₂ , TiS, or Ti—O—S bond. It is preferable that it is contained as an aggregate of the compound, and the remaining Ti and S are contained as a solid solution.

In the above electrode plate, compounds or aggregates in the form of TiO, TiO ₂ , TiS, Ti—O—S are distributed in the crystal grains, TiO has a size of 200 nm or less, and TiO ₂ Has a size of 1000 nm or less, TiS has a size of 200 nm or less, a compound or agglomerate in the form of Ti-O-S has a size of 300 nm or less, and particles of 500 nm or less are 90% The above is preferable.

  In order to achieve the above object, the present invention includes an additive element selected from the group consisting of Ti, Mg, Zr, Nb, Ca, V, Ni, Mn and Cr, oxygen in an amount exceeding 2 mass ppm, and the balance Manufacturing a molten copper alloy material composed of copper and inevitable impurities at a molten copper temperature of 1100 ° C. or higher and 1320 ° C. or lower, a wire rod manufacturing step of manufacturing a wire rod from the molten metal, and heating the wire rod Hot rolling process for performing hot rolling, wire drawing process for performing wire drawing on a wire rod that has undergone hot rolling, and electrode for forming an electrode plate by rolling the wire rod that has been subjected to wire drawing And a plate forming step.

  In the above electrode plate manufacturing method, the temperature of the rolling roll in the hot rolling process is preferably 880 ° C. or lower and 550 ° C. or higher.

  Further, in the above electrode plate manufacturing method, the electrode plate has Ti as an additive element, sulfur of 2 mass ppm or more and 12 mass ppm or less, oxygen of 2 mass ppm or more and 30 mass ppm or less, 4 mass ppm or more, 55 mass ppm It is preferable to contain the following Ti.

  According to the electrode plate and the method for manufacturing the electrode plate according to the present invention, it is possible to provide an electrode plate and a method for manufacturing the electrode plate that are high in productivity and excellent in conductivity, heat dissipation, softening temperature, and surface quality.

FIG. 1 is a view showing an SEM image of TiS particles. FIG. 2 is a diagram showing the analysis result of FIG. FIG. 3 is a view showing an SEM image of TiO ₂ particles. FIG. 4 is a diagram showing the analysis result of FIG. FIG. 5 is a diagram showing an SEM image of Ti—O—S particles. FIG. 6 is a diagram showing the analysis result of FIG. FIG. 7 is a schematic diagram showing a state where the bus bar according to the present embodiment is connected to the power module.

[Summary of embodiment]
The electrode plate according to the embodiment includes an additive element selected from the group consisting of Ti, Mg, Zr, Nb, Ca, V, Ni, Mn, and Cr, and oxygen in an amount exceeding 2 mass ppm, with the balance being copper. And unavoidable impurities, and the conductivity is 101.5% IACS or more. The reason why the elements selected from the group consisting of Mg, Zr, Nb, Ca, V, Ni, Mn, Ti, and Cr are selected as the additive elements is that these elements are active elements that are easily combined with other elements. This is because S can be trapped because it is easily combined with S, and the copper base material (matrix) can be highly purified. One or more additive elements may be included. Also, other elements and impurities that do not adversely affect the properties of the alloy can be included in the alloy.
Further, in the preferred embodiment described below, it is described that the oxygen content is more than 2 and not more than 30 mass ppm, but depending on the addition amount of the additive element and the S content, In the range having the property of, it is possible to include more than 2 and 400 mass ppm.

[Embodiment]
(Configuration of electrode plate)
The electrode plate according to the present embodiment is more thermally conductive than aluminum (Al), for example, from the viewpoint of miniaturization of a power module used in an automobile or the like and / or increase in current density of current supplied to the power module. It is made of copper (Cu), which is a high-rate material. For example, the electrode is connected to supply a direct current from a power source to the power module and to output an alternating current converted from direct current to alternating current by the power module.

For example, the electrode plate according to the present embodiment has an electrical conductivity of 101.5% IACS (International Standard Copper Standard) or higher, and a resistivity of 1.7241 × 10 ⁻⁸ Ωm as 100%. ) It is configured using a soft dilute copper alloy material as a soft type copper material satisfying the above.

  In addition, the electrode plate according to the present embodiment uses an SCR (Southward Continuous Rod) continuous casting facility, has few scratches on the surface, has a wide manufacturing range, can be stably produced, and has a workability of 90% (for example, from φ8 mm) The material is made of a material having a softening temperature of 148 ° C. or lower in processing to a wire of φ2.6 mm.

The electrode plate according to the present embodiment includes sulfur (S) of 2 mass ppm to 12 mass ppm, oxygen (O) of 2 mass ppm to 30 mass ppm, and titanium (Ti) of 4 mass ppm to 55 mass ppm. including. Furthermore, sulfur (S) and titanium (Ti) is, _TiO, agglomeration of TiO 2, TiS, or a compound having a TiO-S bond or _TiO, TiO 2, TiS, or a compound having a TiO-S bond The remaining Ti and S are contained in the electrode plate as a solid solution.

Further, a compound or aggregate in the form of TiO, TiO ₂ , TiS, Ti—O—S is distributed inside the crystal grains constituting the electrode plate, and TiO has a size of 200 nm or less, and TiO ₂ Has a size of 1000 nm or less, TiS has a size of 200 nm or less, and compounds or aggregates in the form of Ti-O-S have a size of 300 nm or less. Furthermore, the electrode plate according to the present embodiment includes 90% or more of particles of 500 nm or less. A crystal grain means the crystal structure of copper.

(Method for manufacturing electrode plate)
The method for manufacturing the electrode plate according to the present embodiment is as follows. A soft diluted copper alloy material containing titanium (Ti) as a raw material for this electrode plate is prepared (raw material preparation step). Next, this soft dilute copper alloy material is made into a molten metal at a casting temperature of 1100 ° C. or higher and 1320 ° C. or lower (melt manufacturing process). Next, a wire rod is produced from the molten metal (wire rod production process). Subsequently, the wire rod is hot-rolled at a temperature of 880 ° C. or lower and 550 ° C. or higher (hot rolling step). Further, the wire rod that has undergone the hot rolling process is subjected to a drawing process (drawing process). Next, the wire rod subjected to wire drawing is subjected to rolling to form an electrode plate (electrode plate forming step). Thereby, the electrode plate which concerns on this Embodiment is manufactured.

  In addition, the production of the electrode plate includes sulfur (S) of 2 mass ppm or more and 12 mass ppm or less, oxygen (O) of more than 2 mass ppm and 30 mass ppm or less, and titanium (Ti) of 4 mass ppm or more and 55 mass ppm or less. Soft dilute copper alloy material is used. Specifically, a soft dilute copper alloy material having a softening temperature of 130 ° C. or more and 148 ° C. or less with a size of φ2.6 mm is used. In this embodiment, so-called low oxygen copper (LOC) is targeted because it contains oxygen exceeding 2 mass ppm and not more than 30 mass ppm.

  Hereinafter, the contents studied by the present inventors in the realization of the electrode plate according to the present embodiment will be described.

  First, high-purity copper having a purity of 6N (that is, 99.9999%) has a softening temperature of 130 ° C. at a workability of 90%. Accordingly, the inventor of the present invention is able to stably produce soft copper having a soft material having a conductivity of 101.5% IACS or more at a softening temperature of 130 ° C. or more and 148 ° C. or less that can be stably produced. A copper alloy material and a method for producing the soft diluted copper alloy material were studied.

  Here, high-purity copper (4N) having an oxygen concentration of 1 to 2 mass ppm was prepared, and a small continuous casting machine (small continuous casting machine) installed in a laboratory was used. ). And several mass ppm of titanium (Ti) was added to this molten metal. Subsequently, a φ8 mm wire rod was manufactured from the molten metal to which titanium (Ti) was added. Next, a φ8 mm wire rod was processed to φ2.6 mm (that is, the processing degree was 90%). The softening temperature of the φ2.6 mm wire rod was 160 ° C. to 168 ° C., and the softening temperature was not lower than this temperature. The conductivity of this φ2.6 mm wire wire rod was about 101.7% IACS. That is, even if the oxygen concentration contained in the wire rod is lowered and titanium (Ti) is added to the molten metal, the softening temperature of the wire rod cannot be lowered, and the conductivity of high purity copper (6N) is 102.8%. The inventor has found that the conductivity is lower than that of IACS.

  The reason why the softening temperature could not be lowered and the conductivity was lower than that of 6N high-purity copper was that sulfur (S) of several mass ppm or more as an inevitable impurity was contained during the production of the molten metal. I guessed that. That is, it was speculated that the softening temperature of the wire rod does not decrease due to insufficient formation of sulfides such as TiS between sulfur (S) and titanium (Ti) contained in the molten metal. .

  Therefore, the present inventor has studied the following two measures in order to realize a decrease in the softening temperature of the electrode plate and an improvement in the conductivity of the electrode plate. And the electrode plate which concerns on this Embodiment was obtained by using together the following two measures for manufacture of an electrode plate.

FIG. 1 is an SEM (Scanning Electron Microscope) image of TiS particles, and FIG. 2 shows the analysis result of FIG. FIG. 3 is an SEM image of TiO ₂ particles, and FIG. 4 shows the analysis result of FIG. 5 is an SEM image of Ti—O—S particles, and FIG. 6 shows the analysis result of FIG. In the SEM image, each particle is shown near the center of the figure. 1 to 6 are SEM observation and EDX analysis of a cross section of a φ8 mm copper wire (wire rod) having oxygen concentration, sulfur concentration, and Ti concentration shown in the third row from the top in Example 1 of Table 1. It has been evaluated. The observation conditions were an acceleration voltage of 15 KeV and an emission current of 10 μA.

First, the first policy is to prepare a molten copper (Cu) in a state where titanium (Ti) is added to copper (Cu) having an oxygen concentration exceeding 2 mass ppm. In this molten metal, it is considered that oxides of TiS and titanium (Ti) (for example, TiO ₂ ) and Ti—O—S particles are formed. This is a consideration from the SEM image of FIG. 1 and the analysis result of FIG. 2, and the SEM image of FIG. 3 and the analysis result of FIG. 2, 4, and 6, platinum (Pt) and palladium (Pd) are metal elements that are vapor-deposited on an observation object when SEM observation is performed.

Next, the second strategy is to introduce a dislocation into copper (Cu) to facilitate the precipitation of sulfur (S), and to set the temperature in the hot rolling step under the normal copper production conditions. It is to set temperature (880 degreeC-550 degreeC) lower than temperature (namely, 950 degreeC-600 degreeC). With such a temperature setting, sulfur (S) can be deposited on dislocations, or sulfur (S) can be deposited using titanium (Ti) oxide (for example, TiO ₂ ) as a nucleus. As an example, as shown in FIGS. 5 and 6, Ti—O—S particles and the like are formed together with molten copper.

  By the above first and second measures, sulfur (S) contained in copper (Cu) crystallizes and precipitates, so that a copper wire rod having a desired softening temperature and a desired conductivity is cooled. It can be obtained after wire drawing.

  In addition, the electrode plate according to the present embodiment is manufactured using an SCR continuous casting and rolling facility. Here, the following three conditions were provided as restrictions on the manufacturing conditions when using the SCR continuous casting and rolling equipment.

(1) About composition When obtaining a soft copper material having an electrical conductivity of 102% IACS or more, as pure copper (base material) containing inevitable impurities, 3 to 12 mass ppm of sulfur (S) and more than 2 to 30 mass ppm A soft dilute copper alloy material containing the following oxygen (O) and 4 to 25 mass ppm of titanium (Ti) is used.

  Usually, in the industrial production of pure copper, since sulfur (S) is taken into copper (Cu) when producing electrolytic copper, it is difficult to reduce sulfur (S) to 3 mass ppm or less. The upper limit of the sulfur concentration of general-purpose electrolytic copper is 12 mass ppm.

  When the oxygen concentration is low, the softening temperature of the electrode plate is unlikely to decrease, so the oxygen concentration is controlled to exceed 2 mass ppm. Further, when the oxygen concentration is high, the surface of the electrode plate is likely to be damaged in the hot rolling process, and therefore, the oxygen concentration is controlled to 30 mass ppm or less.

(2) Dispersed substance The size of the dispersed particles dispersed in the electrode plate is preferably small, and it is preferable that many dispersed particles are dispersed in the electrode plate. This is because the dispersed particles have a function as a precipitation site of sulfur (S), and the precipitation site is required to have a small size and a large number.

Sulfur (S) and titanium (Ti) contained in the electrode plate have a TiO, TiO ₂ , TiS, or a compound having a Ti—O—S bond or a TiO, TiO ₂ , TiS, or Ti—O—S bond. It is contained as an agglomerate of the compound, and the remaining Ti and S are contained as a solid solution. As a soft dilute copper alloy material that is a raw material of the electrode plate, TiO has a size of 200 nm or less, TiO ₂ has a size of 1000 nm or less, TiS has a size of 200 nm or less, Ti—O—S A soft dilute copper alloy material having a size of 300 nm or less and distributed in the crystal grains is used.

  In addition, since the particle size formed in a crystal grain changes according to the holding | maintenance time of molten copper at the time of casting, and cooling conditions, it is necessary to set casting conditions appropriately.

(3) Casting conditions By SCR continuous casting and rolling, wire rods are produced with an ingot rod working degree of 90% (30 mm) to 99.8% (5 mm). As an example, a condition for manufacturing a wire rod of φ8 mm with a processing degree of 99.3% is adopted. Hereinafter, casting conditions (a) to (b) will be described.

[Casting conditions (a)]
The molten copper temperature in the melting furnace is controlled to 1100 ° C. or higher and 1320 ° C. or lower. When the temperature of the molten copper is high, blowholes increase, and scratches are generated and the particle size tends to increase, so the temperature is controlled to 1320 ° C. or lower. The reason why the temperature is controlled to 1100 ° C. or higher is that copper (Cu) tends to harden and the production is not stable, but the molten copper temperature is preferably as low as possible.

[Casting conditions (b)]
As for the temperature of the hot rolling process, the temperature in the first rolling roll is controlled to 880 ° C. or lower, and the temperature in the final rolling roll is controlled to 550 ° C. or higher.

  Unlike normal pure copper production conditions, for the purpose of further reducing the solid solubility limit, which is the driving force for crystallization of sulfur (S) in molten copper and precipitation of sulfur (S) during hot rolling, It is preferable to set the molten copper temperature and the hot rolling temperature to the conditions described in “Casting Condition (a)” and “Casting Condition (b)”.

  Further, the temperature in the normal hot rolling process is 950 ° C. or less in the first rolling roll and 600 ° C. or more in the final rolling roll, but for the purpose of reducing the solid solution limit, The first rolling roll is set to 880 ° C. or lower, and the final rolling roll is set to 550 ° C. or higher.

  The reason why the temperature in the final rolling roll is set to 550 ° C. or higher is that the wire rod obtained at a temperature lower than 550 ° C. has many scratches, and the manufactured electrode plate cannot be handled as a product. The temperature in the hot rolling process is preferably as low as possible while controlling the temperature to 880 ° C. or lower in the first rolling roll and 550 ° C. or higher in the final rolling roll. By setting such a temperature, the softening temperature of the electrode plate (softening temperature after processing to φ8 to φ2.6 mm) is brought close to the softening temperature of 6N high-purity copper (Cu) (that is, 130 ° C.). be able to.

  The conductivity of oxygen-free copper is about 101.7% IACS, the conductivity of tough pitch copper is 101.2% IACS, and the conductivity of 6N copper (Cu) is 102.8% IACS. In the present embodiment, for example, the conductivity of a wire rod having a diameter of φ8 mm is 101.5% IACS or more. In the present embodiment, a soft dilute copper alloy in which the softening temperature of the wire rod of the wire rod (for example, φ2.6 mm) after cold drawing is 130 ° C. or higher and 148 ° C. is manufactured, and this soft dilute copper is manufactured. Alloys are used for the production of electrode plates.

  In order to use industrially, the electrical conductivity of 98% IACS or more is requested | required as electrical conductivity of the soft copper wire of the purity utilized industrially manufactured from electrolytic copper. Further, the softening temperature is 148 ° C. or less judging from industrial value. Since the softening temperature of 6N copper (Cu) is 127 ° C to 130 ° C, the upper limit value of the softening temperature is set to 130 ° C from the obtained data. This slight difference is due to the presence of inevitable impurities not contained in 6N copper (Cu).

  After the base material copper (Cu) is melted in the shaft furnace, it is preferably flowed in a reduced state in a trough. That is, in a reducing gas (for example, CO) atmosphere, the wire rod is stably manufactured by casting while controlling the sulfur concentration, titanium concentration, and oxygen concentration of the dilute alloy and rolling the material. It is preferable. In addition, that copper oxide mixes and / or a particle size is larger than predetermined size will reduce the quality of the electrode plate manufactured.

  Here, the reason for adding titanium (Ti) as an additive to the electrode plate is as follows. That is, (a) titanium (Ti) is likely to be a compound by combining with sulfur (S) in molten copper, and (b) easy to process and handle compared to other additive metals such as zirconium (Zr). This is because (c) it is cheaper than niobium (Nb) and the like, and (d) it is easy to deposit with oxide as a nucleus.

  As described above, a practical soft dilute copper alloy material having high productivity and excellent conductivity, softening temperature, and surface quality can be obtained as a raw material for the electrode plate according to the present embodiment. A plating layer can also be formed on the surface of the soft dilute copper alloy material. For the plating layer, for example, a material mainly containing tin (Sn), nickel (Ni), silver (Ag), or Pb-free plating can be used. Further, the shape of the soft dilute copper alloy material is not particularly limited, and can be a round cross-section, a rod shape, or a flat conductor.

  In the present embodiment, the wire rod is manufactured by the SCR continuous casting rolling method and the soft material is manufactured by hot rolling. However, the twin roll type continuous casting rolling method or the Properti type continuous casting rolling method is adopted. You can also. Below, the Example and comparative example of an electrode plate produced by said manufacturing method are demonstrated.

  Table 1 shows the experimental conditions and results.

  First, as an experimental material, a φ8 mm copper wire (wire rod, workability 99.3%) having the oxygen concentration, sulfur concentration, and titanium concentration shown in Table 1 was prepared. The φ8 mm copper wire is hot-rolled by SCR continuous casting and rolling. Ti flows the molten copper melted in the shaft furnace into the reed in the reducing gas atmosphere, guides the molten copper flowing in the reed to the casting pot of the same reducing gas atmosphere, and after adding Ti in this casting pot, An ingot rod was made with a mold formed between the cast ring and the endless belt through the nozzle. This ingot rod is hot-rolled to produce a φ8 mm copper wire. Next, cold drawing was applied to each experimental material. Thus, a copper wire having a size of φ2.6 mm was produced. And while measuring the semi-softening temperature and electrical conductivity of a copper wire of φ 2.6 mm size, the dispersed particle size in the copper wire of φ 8 mm was evaluated.

  The oxygen concentration was measured with an oxygen analyzer (Leco (registered trademark) oxygen analyzer), and the concentrations of sulfur and titanium were analyzed by ICP emission spectroscopic analysis.

  The measurement of the semi-softening temperature in the φ2.6 mm size was obtained from the result of quenching in water after holding each temperature at 400 ° C. or lower for 1 hour and conducting a tensile test. The value obtained by using the result of the tensile test at room temperature and the result of the tensile test of the soft copper wire heat-treated at 400 ° C. for 1 hour, and adding the tensile strengths of the two tensile tests and dividing by two. The temperature corresponding to the strength was determined as the semi-softening temperature.

As described above, the size of the dispersed particles dispersed in the electrode plate is preferably small, and it is preferable that many dispersed particles are dispersed in the electrode plate. Therefore, the case where the number of dispersed particles having a diameter of 500 nm or less is 90% or more was regarded as acceptable. Here, the “size” is the size of the compound and means the size of the major axis of the diameter and minor axis of the shape of the compound. The “particles” refer to the TiO, TiO ₂ , TiS, and Ti—O—S. “90%” indicates the ratio of the number of corresponding particles to the total number of particles.

  In Table 1, Comparative Example 1 is a result of trial production of a copper wire having a diameter of 8 mm in an argon (Ar) atmosphere in a laboratory, and 0 to 18 mass ppm of titanium (Ti) was added. While the semi-softening temperature of the copper wire not added with titanium (Ti) was 215 ° C., the softening temperature of the copper wire added with 13 mass ppm of titanium (Ti) decreased to 160 ° C. Is the minimum temperature.) As shown in Table 1, as the Ti concentration increased to 15 mass ppm and 18 mass ppm, the semi-softening temperature also increased, and the required softening temperature of 148 ° C. or lower could not be realized. Moreover, since electrical conductivity did not satisfy | fill 101.5% IACS or more, comprehensive evaluation was disqualified (henceforth, disqualified is represented as "x").

  Therefore, as Comparative Example 2, a Φ8 mm copper wire (wire rod) having an oxygen concentration adjusted to 7 to 8 mass ppm was prototyped using the SCR continuous casting and rolling method.

  In Comparative Example 2, it was a copper wire having a minimum Ti concentration (that is, 0 mass ppm, 2 mass ppm) among the prototype manufactured by the SCR continuous casting and rolling method, and the conductivity was 102% IACS or more, but the semi-softening temperature. Was 164 ° C. and 157 ° C., and was not less than the required 148 ° C., so the overall evaluation was “x”.

  In Example 1, the oxygen concentration and the sulfur concentration substantially coincide (that is, the oxygen concentration: 7 to 8 mass ppm, the sulfur concentration: 5 mass ppm), and different copper wires are used within the range of the Ti concentration of 4 to 55 mass ppm. Prototype.

  When the Ti concentration was in the range of 4 to 55 mass ppm, the softening temperature was 148 ° C. or less, 102% IACS or more, and the dispersed particle size was 90% or more for particles having a size of 500 nm or less. Moreover, since the surface of the wire rod was also clean (that is, the surface was smooth) and all satisfied the product performance, the comprehensive evaluation was a pass (hereinafter, the pass was expressed as “◯”).

  Here, the copper wire satisfying the conductivity of 102% IACS or more was a case where the Ti concentration was 4 to 25 mass ppm. When the Ti concentration was 13 mass ppm, the conductivity showed a maximum value of 102.4% IACS, and the conductivity was slightly lower around this concentration. This is because, when the Ti concentration is 13 mass ppm, by capturing the sulfur content in copper (Cu) as a compound, the conductivity is close to that of high-purity copper (6N).

  Therefore, both the semi-softening temperature and the conductivity can be satisfied by increasing the oxygen concentration and adding titanium (Ti).

  Comparative Example 3 is a prototype material having a Ti concentration exceeding 25 mass ppm. In Comparative Example 3, the semi-softening temperature satisfied the request, but the conductivity was lower than 101.5% IACS, so the overall evaluation was x.

  In Comparative Example 4, a copper wire having a Ti concentration of 60 mass ppm was made experimentally. Although the copper wire which concerns on the comparative example 3 satisfy | fills a request | requirement, semi-softening temperature is 148 degreeC or more, and did not satisfy | fill product performance. Furthermore, there are many scratches on the surface of the wire rod, making it difficult to adopt as a product. Therefore, it was shown that the addition amount of titanium (Ti) is preferably less than 60 mass ppm.

  In the copper wire which concerns on Example 2, while setting sulfur concentration to 5 mass ppm and controlling Ti concentration in the range of 13-10 mass ppm, the influence of oxygen concentration was examined by changing oxygen concentration.

  Regarding the oxygen concentration, copper wires having greatly different concentrations from 2 mass ppm to 30 mass ppm were prepared. However, since copper wires with an oxygen concentration of less than 2 mass ppm are difficult to produce and cannot be stably manufactured, the overall evaluation is “△” (“△” is an intermediate evaluation between “○” and “×”) .) Further, even when the oxygen concentration was 30 mass ppm, both the semi-softening temperature and the conductivity met the requirements.

  In Comparative Example 5, when the oxygen concentration was 40 mass ppm, there were many scratches on the surface of the wire rod, and the product could not be used as a product.

  Therefore, by setting the oxygen concentration in the range of more than 2 and 30 mass ppm or less, all the characteristics of the semi-softening temperature, the electrical conductivity of 102% IACS or more, and the dispersed particle size can be satisfied. It was shown to be clean and satisfy product performance.

  Example 3 is a copper wire in which the oxygen concentration and the Ti concentration are set close to each other and the sulfur concentration is changed within a range of 4 to 20 mass ppm. In Example 3, a copper wire having a sulfur concentration of less than 2 mass ppm could not be realized due to restrictions on raw materials. However, by controlling the Ti concentration and the sulfur concentration, the requirements for both the semi-softening temperature and the conductivity could be satisfied.

  In Comparative Example 6, when the sulfur concentration was 18 mass ppm and the Ti concentration was 13 mass ppm, the semi-softening temperature was as high as 162 ° C., and the required characteristics were not satisfied. In particular, the surface quality of the wire rod was poor and it was difficult to produce a product.

  From the above, when the sulfur concentration is in the range of 2 to 12 mass ppm, the semi-softening temperature, the conductivity of 102% IACS or more, and the dispersed particle size can be satisfied, and the surface of the wire rod is also clean. It was shown that the product performance can be satisfied.

  Comparative Example 7 is a copper wire using 6N Cu. In the copper wire according to Comparative Example 6, a particle having a semi-softening temperature of 127 ° C. to 130 ° C., a conductivity of 102.8% IACS, and a dispersed particle size of 500 μm or less was not observed at all.

  Table 2 shows the temperature of molten copper and the rolling temperature as production conditions.

  In Comparative Example 8, a wire rod having a molten copper temperature of 1330 ° C. to 1350 ° C. and a rolling temperature of 950 to 600 ° C. and a diameter of 8 mm was produced. The wire rod according to Comparative Example 8 satisfies the requirements for the semi-softening temperature and the electrical conductivity, but the dispersed particle size has a particle size of about 1000 nm, and the particle size of 500 nm or more also exceeds 10%. . Therefore, the wire rod according to Example 7 was determined to be inappropriate.

  In Example 4, the molten copper temperature was controlled in the temperature range of 1200 ° C. to 1320 ° C., and the rolling temperature was controlled in the temperature range of 880 ° C. to 550 ° C. to produce a φ8 mm wire rod. The wire rod according to Example 4 had good wire rod surface quality and dispersed particle size, and the overall evaluation was “◯”.

  In Comparative Example 9, the molten copper temperature was controlled to 1100 ° C., and the rolling temperature was controlled to a temperature range of 880 ° C. to 550 ° C. to produce a φ8 mm wire rod. The wire rod according to Comparative Example 8 was not suitable as a product because there were many scratches on the surface of the wire rod because the molten copper temperature was low. This is because, since the molten copper temperature is low, scratches are likely to occur during rolling.

  In Comparative Example 10, the molten copper temperature was controlled to 1300 ° C. and the rolling temperature was controlled to a temperature range of 950 ° C. to 600 ° C. to produce a φ8 mm wire rod. The wire rod according to Comparative Example 9 has a high quality in the surface of the wire rod because the temperature in the hot rolling process is high, but the dispersed particle size includes a large size, and the overall evaluation is “x”. It was.

  In Comparative Example 11, the molten copper temperature was controlled to 1350 ° C., and the rolling temperature was controlled to a temperature range of 880 ° C. to 550 ° C. to produce a φ8 mm wire rod. The wire rod according to Comparative Example 11 contained a large dispersed particle size due to the high molten copper temperature, and the overall evaluation was “x”.

(About bus bar)
FIG. 7 is a schematic diagram showing a state where the bus bar according to the present embodiment is connected to the power module. FIG. 7 illustrates a part of the periphery of the power module 2 to which, for example, the bus bars 1a to 1e as electrode plates are connected. Below, the case where the electrode plate of this Embodiment is applied to a bus bar is demonstrated.

  The bus bar 1a to the bus bar 1e are formed, for example, by bending the plate-shaped electrode plate described above into an L shape in a plane parallel to the surface having a large area, and one end portion of the bus bar 1a to the bus bar 1e is a power module. 2 is attached. Moreover, the hole by which the volt | bolt 3 is inserted is formed in the bus bar 1a-bus bar 1e, for example in one edge part. The other ends of the bus bar 1a to the bus bar 1e are processed according to the connection destination, for example.

  The power module 2 is mounted on an automobile and is configured to convert a direct current supplied from a power source of the automobile into an alternating current and output the alternating current to a motor of the automobile. The power module 2 includes, for example, a positive input terminal 2a and a negative input terminal 2b that receive a direct current supplied from a power source, and output terminals 2c to 2e that output a three-phase alternating current converted by an electronic circuit. Are generally configured.

  The bus bar 1a is fixed to the plus input terminal 2a using a bolt 3, and is electrically connected to an electronic circuit inside the power module 2 via the plus input terminal 2a. The bus bar 1b is fixed to the negative input terminal 2b using a bolt 3, and is electrically connected to an electronic circuit inside the power module 2 via the negative input terminal 2b. The bus bar 1c is fixed to the output terminal 2c using a bolt 3, and is electrically connected to an electronic circuit inside the power module 2 via the output terminal 2c. The bus bar 1d is fixed to the output terminal 2d using a bolt 3, and is electrically connected to an electronic circuit inside the power module 2 via the output terminal 2d. The bus bar 1e is fixed to the output terminal 2e using a bolt 3, and is electrically connected to an electronic circuit inside the power module 2 via the output terminal 2e.

  The bus bars 1a to 1e are formed using, for example, a material having the third highest conductivity from the top in Example 1 shown in Table 1. That is, the bus bars 1a to 1e formed from this material have higher electrical conductivity than any of the materials manufactured in Comparative Examples 1 to 10, and thus the copper wires manufactured in Comparative Examples 1 to 10 are used. Heat generation due to current is less than that of bus bars formed from

  In addition, the bus bar 1a to the bus bar 1e are manufactured by using a condition that the molten copper temperature is 1320 ° C. and the rolling temperature is 880 ° C. to 550 ° C. to produce a wire rod of φ8 mm from the material having the highest conductivity. The wire rod was drawn to produce a φ2.6 mm material, and then rolled to the material to produce a bus bar having a thickness of 1.0 mm and a width of 5.0 mm. Is.

(Effect of embodiment)
The electrode plate according to the present embodiment does not require copper purification (99.9999% by mass or more), and can achieve high conductivity by an inexpensive continuous casting and rolling method. Can do. Since the electrode plate is made of a material having a higher conductivity than that of tough pitch copper, the temperature increase of the semiconductor element can be suppressed by improving the heat dissipation, and the reliability is improved. Since the added titanium (Ti) traps sulfur (S), which is an impurity, the copper matrix (matrix) is highly purified, and the soft properties of the material are improved. In the manufacturing process of the electrode plate, the annealing process is unnecessary, and thus the productivity is high.

  In addition, since the bus bar according to the present embodiment has a rectangular cross section, the bus bar has a higher heat dissipation effect than a bus bar having a circular cross section, and has good soft characteristics. Is easy.

  In addition, although the bus bar 1a-bus bar 1e described above was plate-shaped, it is not limited to this, You may perform a bending process or a wise edge process according to a use.

  As mentioned above, although embodiment of this invention and its modification were demonstrated, embodiment and modification which were described above do not limit the invention which concerns on a claim. In addition, it should be noted that not all combinations of features described in the embodiments and the modifications are necessarily essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1a-1e ... Bus bar 2 ... Power module 2a ... Positive input terminal 2b ... Negative input terminal 2c ... Output terminal 2d ... Output terminal 2e ... Output terminal 3 ... Bolt

Claims (7)

  It contains an additive element selected from the group consisting of Ti, Mg, Zr, Nb, Ca, V, Ni, Mn and Cr, oxygen in an amount exceeding 2 mass ppm, and the balance is made of copper and inevitable impurities. An electrode plate having a rate of 101.5% IACS or more.   2. The electrode plate according to claim 1, wherein the additive element is Ti, and includes 2 mass ppm or more and 12 mass ppm or less of sulfur, 2 mass ppm or more and 30 mass ppm or less of oxygen, and 4 mass ppm or more and 55 mass ppm or less of Ti. The electrode plate as described. The sulfur (S) and the Ti are a compound having a TiO, TiO ₂ , TiS, or Ti—O—S bond, or the compound having the TiO, the TiO ₂ , the TiS, or the Ti—O—S bond. The electrode plate according to claim 2, wherein the electrode plate is contained as an aggregate and the remaining Ti and S are contained as a solid solution. The TiO, the TiO ₂ , the TiS, the compound of Ti—O—S or the aggregates are distributed in the crystal grains,
The TiO has a size of 200 nm or less;
The TiO ₂ has a size of 1000 nm or less;
The TiS has a size of 200 nm or less;
The compound or aggregate in the form of Ti-O-S has a size of 300 nm or less,
The electrode plate according to claim 2, wherein the particle size of 500 nm or less is 90% or more. Dilute copper containing an additive element selected from the group consisting of Ti, Mg, Zr, Nb, Ca, V, Ni, Mn and Cr, oxygen in an amount exceeding 2 mass ppm, and the balance consisting of copper and inevitable impurities A molten metal manufacturing process in which the alloy material is melted at a molten copper temperature of 1100 ° C. or higher and 1320 ° C. or lower;
A wire rod production step of producing a wire rod from the molten metal;
A hot rolling step of hot rolling the wire rod;
A wire drawing process for drawing the wire rod after the hot rolling;
An electrode plate forming step of forming an electrode plate by rolling the wire rod subjected to the wire drawing;
The manufacturing method of the electrode plate containing this.   The method for producing an electrode plate according to claim 5, wherein the hot rolling step is performed at a temperature of a rolling roll in a hot rolling process of 880 ° C or lower and 550 ° C or higher.   6. The electrode plate according to claim 5, wherein the additional element is Ti, and includes 2 mass ppm or more and 12 mass ppm or less of sulfur, 2 mass ppm or more and 30 mass ppm or less of oxygen, and 4 mass ppm or more and 55 mass ppm or less of Ti. 6. A method for producing an electrode plate according to 6.