JP2022072356A - Copper alloy, copper alloy plastic working material, component for electronic/electric apparatus, terminal, bus bar, lead frame and heat dissipation substrate - Google Patents

Abstract

To provide a copper alloy having high conductivity, excellent heat resistance and a small anisotropy of heat resistance.SOLUTION: There is provided a copper alloy in which a content of Mg is more than 10 mass ppm and less than 100 ppm, a content of S is set to 10 mass ppm or less, a content of P is set to 10 mass ppm or less, a content of Se is set to 5 mass ppm or less, a content of Te is set to 5 mass ppm or less, a content of Sb is set to 5 mass ppm or less, a content of Bi is set to 5 mass ppm or less and a content of As is set to 5 mass ppm or less and the total content of S, P, Se, Te, Sb, Bi and As is set to 30 mass ppm or less, wherein the mass ratio, [Mg]/[S+P+Se+Te+Sb+Bi+As] is 0.6 or more and 50 or less, the conductivity is 97%IACS or more and the ratio TLD/TTD between the semi-softening temperature TLD in the parallel direction to the rolling direction and the semi-softening temperature TTD in the orthogonal direction to the rolling direction is in the range of more than 0.95 and less than 1.108 and the semi-softening temperature TLD is 210°C or more.SELECTED DRAWING: None

Description

The present invention relates to a copper alloy suitable for electronic / electrical equipment parts such as terminals, bus bars, lead frames, and heat dissipation substrates, copper alloy plastic processed materials made of this copper alloy, electronic / electrical equipment parts, terminals, bus bars, and leads. It is related to the frame and heat dissipation board.

Conventionally, highly conductive copper or copper alloy has been used for electronic / electrical equipment parts such as terminals, bus bars, lead frames, and heat dissipation boards.
Here, in order to reduce the current density and dissipate heat due to Joule heat generation due to the increase in current of electronic devices and electric devices, the electronic and electric device parts used in these electronic devices and electric devices are used. , Pure copper material such as oxygen-free copper having excellent conductivity is applied.

In recent years, with the increase in the amount of current used for electrical and electronic parts, the copper material used has become thicker. With the heat generation during energization and the high temperature of the usage environment, there is a demand for a copper material having excellent heat resistance, which indicates that the hardness does not easily decrease at high temperatures. Further, in a large terminal, a bus bar, and a lead frame to which a large current is loaded, it is necessary to use a rolled material having less anisotropy. However, the pure copper material has a problem that it cannot be used in a high temperature environment due to insufficient heat resistance, which indicates that the hardness does not easily decrease at a high temperature.
Therefore, Patent Document 1 discloses a rolled copper plate containing Mg in a range of 0.005 mass% or more and less than 0.1 mass%.

In the copper rolled plate described in Patent Document 1, Mg is contained in the range of 0.005 mass% or more and less than 0.1 mass%, and the balance is composed of Cu and unavoidable impurities. By solid-dissolving in the matrix, it was possible to improve the stress relaxation resistance without significantly reducing the conductivity.

Japanese Unexamined Patent Publication No. 2016-056414

By the way, recently, in the copper material constituting the above-mentioned electronic / electrical equipment parts, it is used in order to sufficiently suppress heat generation when a large current is passed, and also in applications where pure copper material is used. It is required to further improve the conductivity so as to be possible. In the copper alloy described in Patent Document 1, since the stress relaxation resistance is improved by adding a solute element, the conductivity is inferior to that of pure copper. Therefore, it has been desired to develop a material having high heat resistance, which has higher conductivity and can cope with heat generation due to an increase in current.
In addition, the above-mentioned electronic / electrical equipment parts are often used in high-temperature environments such as engine rooms, and the copper materials that make up the electronic / electrical equipment parts have improved heat resistance more than ever before. I need to let you.
Further, in order to stably use parts for electronic and electrical equipment having various shapes, a copper alloy having a small anisotropy of heat resistance is required.

The present invention has been made in view of the above-mentioned circumstances, and is a copper alloy having high conductivity and excellent heat resistance and having a small anisotropy of heat resistance, a copper alloy plastically processed material, and electronic / electrical equipment. It is an object of the present invention to provide components, terminals, bus bars, lead frames, and heat dissipation boards.

As a result of diligent studies by the present inventors in order to solve this problem, in order to achieve both high conductivity and excellent heat resistance in a well-balanced manner, a small amount of Mg is added and the element that forms the compound with Mg is added. It became clear that it was necessary to regulate the content. That is, by regulating the content of Mg and the element that forms the compound and allowing a trace amount of Mg to be present in the copper alloy in an appropriate form, the conductivity and heat resistance are well-balanced at a higher level than before. We obtained the knowledge that it is possible to improve it.

The present invention has been made based on the above findings, and the copper alloy of the present invention has a composition in which the Mg content is in the range of more than 10 mass ppm and less than 100 mass ppm, and the balance is Cu and unavoidable impurities. Among the unavoidable impurities, the S content is 10 mass ppm or less, the P content is 10 mass ppm or less, the Se content is 5 mass ppm or less, the Te content is 5 mass ppm or less, the Sb content is 5 mass ppm or less, and the Bi content. Is 5 mass ppm or less, the As content is 5 mass ppm or less, and the total content of S, P, Se, Te, Sb, Bi and As is 30 mass ppm or less, and the Mg content is [Mg]. When the total content of S, P, Se, Te, Sb, Bi, and As is [S + P + Te + Sb + Bi + As], these mass ratios [Mg] / [S + P + Te + Sb + Bi + As] are within the range of 0.6 or more and 50 or less. The conductivity was 97% IACS or higher, and the semi-softening temperature _TLD obtained by conducting a tensile test in the direction parallel to the rolling direction and the tensile test obtained in the direction orthogonal to the rolling direction were obtained. The semi-softening temperature ratio T _LD / T _TD calculated from the semi-softening temperature T _TD is in the range of more than 0.95 and less than 1.08, and a tensile test is performed in the direction parallel to the rolling direction. The obtained semi-softening temperature _TLD is 210 ° C. or higher.
In the present invention, the semi-softening temperature ratio T _LD / T _TD is the temperature ratio in Kelvin.

According to the copper alloy having this configuration, the contents of Mg and the elements S, P, Se, Te, Sb, Bi, and As that form a compound with Mg are defined as described above, so a small amount is added. By solidifying the resulting Mg in the copper matrix, heat resistance can be improved without significantly reducing the conductivity. Specifically, the conductivity is 97% IACS or higher, and the conductivity is relative to the rolling direction. The semi-softening temperature _TLD obtained by conducting a tensile test in the parallel direction can be set to 210 ° C. or higher.
Then, the semi-softening calculated from the semi- _softening temperature T _LD obtained by performing the tensile test in the direction parallel to the rolling direction and the semi-softening temperature T T D obtained by performing the tensile test in the direction orthogonal to the rolling direction. Since the temperature ratio T _LD / T _TD exceeds 0.95 and is within the range of less than 1.08, the anisotropy of heat resistance is small, for example, in the rolling direction, such as terminals and bus bars for large currents. Sufficient strength in a high temperature environment is ensured even when heat resistance is required in both the direction parallel to the rolling direction and the direction orthogonal to the rolling direction.

Here, in the copper alloy of the present invention, it is preferable that the Ag content is in the range of 5 mass ppm or more and 20 mass ppm or less.
In this case, since Ag is contained in the above range, Ag segregates in the vicinity of the grain boundaries, diffusion of grain boundaries is suppressed, and heat resistance can be improved.

Further, in the copper alloy of the present invention, it is preferable that the area ratio of crystals having a crystal orientation within 10 ° with respect to the Brass orientation {110} <112> is 30% or less.
In this case, since the area ratio of the crystal having a crystal orientation within 10 ° with respect to the Brass orientation {110} <112> is limited to 30% or less, it is possible to suppress the anisotropy of heat resistance. Become. In addition, it is possible to prevent the strength in the direction orthogonal to the rolling direction from increasing preferentially, and to prevent the anisotropy of the strength from occurring.

Further, in the copper alloy of the present invention, the tensile strength TS _TD when the tensile test is conducted in the direction orthogonal to the rolling direction and the tensile strength TS _LD when the tensile test is conducted in the direction parallel to the rolling direction. The strength ratio TS _TD / TS _LD calculated from The _LD is preferably 200 MPa or more.
In this case, the strength calculated from the tensile strength TS _TD when the tensile test is performed in the direction orthogonal to the rolling direction and the tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction. Since the ratio TS _TD / TS _LD exceeds 0.93 and is within the range of less than 1.10, the strength anisotropy is small and the strength is small with respect to the rolling direction like terminals and bus bars for large currents. Sufficient strength is ensured when strength is required in both the parallel direction and the direction orthogonal to the rolling direction.
Further, since the tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction is 200 MPa or more, the strength is sufficiently excellent.

The copper alloy plastically processed material of the present invention is characterized by being made of the above-mentioned copper alloy.
According to the copper alloy plastic working material having this configuration, since it is composed of the above-mentioned copper alloy, it has excellent conductivity and heat resistance, has a small heat resistance anisotropy, and is used in high current applications and high temperature environments. It is particularly suitable as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation boards.

Here, in the copper alloy plastic working material of the present invention, a rolled plate having a thickness in the range of 0.1 mm or more and 10 mm or less may be used.
In this case, since the rolled plate has a thickness of 0.1 mm or more and 10 mm or less, the terminal, bus bar, and the like can be obtained by punching or bending the copper alloy plastically processed material (rolled plate). It is possible to mold parts for electronic and electrical equipment such as lead frames and heat dissipation boards.

Further, in the copper alloy plastic working material of the present invention, it is preferable to have a Sn plating layer or an Ag plating layer on the surface.
In this case, since it has a Sn plating layer or an Ag plating layer on the surface, it is particularly suitable as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation boards. In the present invention, "Sn plating" includes pure Sn plating or Sn alloy plating, and "Ag plating" includes pure Ag plating or Ag alloy plating.

The parts for electronic and electrical equipment of the present invention are characterized by being made of the above-mentioned copper alloy plastically processed material. The parts for electronic / electrical equipment in the present invention include terminals, bus bars, lead frames, heat dissipation boards, and the like.
Since the parts for electronic and electrical equipment having this configuration are manufactured using the above-mentioned copper alloy plastic working material, they can exhibit excellent characteristics even in high current applications and high temperature environments.

The terminal of the present invention is characterized by being made of the above-mentioned copper alloy plastically worked material.
Since the terminal having this configuration is manufactured by using the above-mentioned copper alloy plastic working material, it can exhibit excellent characteristics even in a large current application and a high temperature environment.

The bus bar of the present invention is characterized by being made of the above-mentioned copper alloy plastically worked material.
Since the bus bar having this configuration is manufactured by using the above-mentioned copper alloy plastic working material, it can exhibit excellent characteristics even in a large current application and a high temperature environment.

The lead frame of the present invention is characterized by being made of the above-mentioned copper alloy plastically worked material.
Since the lead frame having this configuration is manufactured by using the above-mentioned copper alloy plastic working material, it can exhibit excellent characteristics even in a large current application and a high temperature environment.

The heat radiating substrate of the present invention is characterized in that it is manufactured by using the above-mentioned copper alloy.
Since the heat dissipation substrate having this configuration is manufactured by using the above-mentioned copper alloy, it can exhibit excellent characteristics even in a large current application and a high temperature environment.

According to the present invention, copper alloys, copper alloy plastic processed materials, electronic / electrical equipment parts, terminals, bus bars, lead frames, heat dissipation, which have high conductivity and excellent heat resistance and low heat resistance anisotropy. It becomes possible to provide a substrate.

It is a flow chart of the manufacturing method of the copper alloy which is this embodiment.

Hereinafter, a copper alloy according to an embodiment of the present invention will be described.
The copper alloy of the present embodiment has a composition in which the Mg content is in the range of more than 10 mass ppm and less than 100 mass ppm, and the balance is Cu and unavoidable impurities. Among the unavoidable impurities, the S content is 10 mass ppm or less, P. The content of is 10 mass ppm or less, the content of Se is 5 mass ppm or less, the content of Te is 5 mass ppm or less, the content of Sb is 5 mass ppm or less, the content of Bi is 5 mass ppm or less, and the content of As is 5 mass ppm or less. , S, P, Se, Te, Sb, Bi, and As have a total content of 30 mass ppm or less.

When the content of Mg is [Mg] and the total content of S, P, Se, Te, Sb, Bi and As is [S + P + Se + Te + Sb + Bi + As], the mass ratios [Mg] / [S + P + Se + Te + Sb + Bi + As] are It is within the range of 0.6 or more and 50 or less.
In the copper alloy of this embodiment, the Ag content may be in the range of 5 mass ppm or more and 20 mass ppm or less.

Further, in the copper alloy of this embodiment, the conductivity is 97% IACS or more.
Further, in the copper alloy of the present embodiment, the semi-softening temperature _TLD obtained by conducting a tensile test in a direction parallel to the rolling direction is 210 ° C. or higher.
Then, in the copper alloy of the present embodiment, the semi-softening temperature _TLD obtained by performing a tensile test in the direction parallel to the rolling direction and the tensile test obtained by performing a tensile test in the direction orthogonal to the rolling direction. The semi-softening temperature ratio T _LD / T _TD calculated from the semi-softening temperature T _TD exceeds 0.95 and is within the range of less than 1.08.
The semi-softening temperature ratio T _LD / T _TD in this embodiment is a temperature ratio in Kelvin.

Further, in the copper alloy of the present embodiment, it is preferable that the area ratio of crystals having a crystal orientation within 10 ° with respect to the Brass orientation {110} <112> is 30% or less.
Further, in the copper alloy of the present embodiment, the tensile strength _TSTD when the tensile test is performed in the direction orthogonal to the rolling direction and the tensile strength when the tensile test is performed in the direction parallel to the rolling direction. It is preferable that the intensity ratio TS _TD / TS _LD calculated from TS _LD is in the range of more than 0.93 and less than 1.10.
Further, in the copper alloy of the present embodiment, it is preferable that the tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction is 200 MPa or more.

Here, in the copper alloy of the present embodiment, the reasons for defining the component composition, structure, and various characteristics as described above will be described below.

(Mg)
Mg is an element having an action effect of improving strength and heat resistance without significantly lowering the conductivity by being dissolved in the parent phase of copper.
Here, when the Mg content is 10 mass ppm or less, there is a possibility that the action and effect cannot be fully exerted. On the other hand, if the Mg content exceeds 100 mass ppm, the conductivity may decrease.
From the above, in the present embodiment, the Mg content is set within the range of more than 10 mass ppm and less than 100 mass ppm.

In order to further improve the heat resistance, the lower limit of the Mg content is preferably 20 mass ppm or more, more preferably 30 mass ppm or more, and even more preferably 40 mass ppm or more.
Further, in order to further suppress the decrease in conductivity, the upper limit of the Mg content is preferably less than 90 mass ppm, more preferably less than 80 mass ppm, and even more preferably less than 70 mass ppm.

(S, P, Se, Te, Sb, Bi, As)
The above-mentioned elements such as S, P, Se, Te, Sb, Bi, and As are generally elements that are easily mixed in the copper alloy. Then, these elements easily react with Mg to form a compound, and there is a possibility that the solid solution effect of Mg added in a small amount may be reduced. Therefore, it is necessary to strictly control the content of these elements.
Therefore, in the present embodiment, the S content is 10 mass ppm or less, the P content is 10 mass ppm or less, the Se content is 5 mass ppm or less, the Te content is 5 mass ppm or less, the Sb content is 5 mass ppm or less, and Bi. The content is limited to 5 mass ppm or less, and the content of As is limited to 5 mass ppm or less.
Further, the total content of S, P, Se, Te, Sb, Bi and As is limited to 30 mass ppm or less.

The content of S is preferably 9 mass ppm or less, and more preferably 8 mass ppm or less.
The content of P is preferably 6 mass ppm or less, and more preferably 3 mass ppm or less.
The content of Se is preferably 4 mass ppm or less, and more preferably 2 mass ppm or less.
The content of Te is preferably 4 mass ppm or less, and more preferably 2 mass ppm or less.
The content of Sb is preferably 4 mass ppm or less, and more preferably 2 mass ppm or less.
The Bi content is preferably 4 mass ppm or less, and more preferably 2 mass ppm or less.
The content of As is preferably 4 mass ppm or less, and more preferably 2 mass ppm or less.
Further, the total content of S, P, Se, Te, Sb, Bi and As is preferably 24 mass ppm or less, and more preferably 18 mass ppm or less.

([Mg] / [S + P + Se + Te + Sb + Bi + As])
As described above, elements such as S, P, Se, Te, Sb, Bi, and As easily react with Mg to form a compound. Therefore, in the present embodiment, the Mg content and S and P are used. By defining the ratio of Se, Te, Sb, Bi, and the total content of As, the existence form of Mg is controlled.
When the content of Mg is [Mg] and the total content of S, P, Se, Te, Sb, Bi and As is [S + P + Se + Te + Sb + Bi + As], these mass ratios [Mg] / [S + P + Se + Te + Sb + Bi + As] are 50. If it exceeds, Mg is present in the copper in an excessively solid-dissolved state, and the conductivity may decrease. On the other hand, if the mass ratio [Mg] / [S + P + Se + Te + Sb + Bi + As] is less than 0.6, Mg is not sufficiently solid-solved and the heat resistance may not be sufficiently improved.
Therefore, in the present embodiment, the mass ratio [Mg] / [S + P + Se + Te + Sb + Bi + As] is set within the range of 0.6 or more and 50 or less.

In order to further suppress the decrease in conductivity, the upper limit of the mass ratio [Mg] / [S + P + Se + Te + Sb + Bi + As] is preferably 35 or less, and more preferably 25 or less.
Further, in order to further improve the heat resistance, the lower limit of the mass ratio [Mg] / [S + P + Se + Te + Sb + Bi + As] is preferably 0.8 or more, and more preferably 1.0 or more.

(Ag: 5 mass ppm or more and 20 mass ppm or less)
Ag can hardly be dissolved in the matrix of Cu in the operating temperature range of ordinary electronic / electrical equipment of 250 ° C. or lower. Therefore, Ag added in a small amount to copper will segregate in the vicinity of the grain boundaries. As a result, the movement of atoms at the grain boundaries is hindered and the diffusion of the grain boundaries is suppressed, so that the heat resistance is improved.
Here, when the content of Ag is 5 mass ppm or more, the action and effect can be fully exerted. On the other hand, when the Ag content is 20 mass ppm or less, the conductivity can be ensured and the increase in manufacturing cost can be suppressed.
From the above, in the present embodiment, the Ag content is set within the range of 5 mass ppm or more and 20 mass ppm or less.

In order to further improve the heat resistance, the lower limit of the Ag content is preferably 6 mass ppm or more, more preferably 7 mass ppm or more, and further preferably 8 mass ppm or more. Further, in order to surely suppress the decrease in conductivity and the increase in cost, the upper limit of the Ag content is preferably 18 mass ppm or less, more preferably 16 mass ppm or less, and more preferably 14 mass ppm or less. preferable.
Further, when Ag is not intentionally contained but contained as an impurity, the content of Ag may be less than 5 mass ppm.

(Other unavoidable impurities)
Other unavoidable impurities other than the above-mentioned elements include Al, B, Ba, Be, Ca, Cd, Cr, Sc, rare earth elements, V, Nb, Ta, Mo, Ni, W, Mn, Re, Ru, Examples thereof include Sr, Ti, Os, Co, Rh, Ir, Pb, Pd, Pt, Au, Zn, Zr, Hf, Hg, Ga, In, Ge, Y, Tl, N, Si, Sn, Li and the like. These unavoidable impurities may be contained within a range that does not affect the characteristics.
Here, since these unavoidable impurities may lower the conductivity, the total amount is preferably 0.1 mass% or less, more preferably 0.05 mass% or less, and 0.03 mass% or less. It is more preferable to set it to 0.01 mass% or less.
The upper limit of the content of each of these unavoidable impurities is preferably 10 mass ppm or less, more preferably 5 mass ppm or less, and even more preferably 2 mass ppm or less.

(Semi-softening temperature ratio T _LD / T _TD : more than 0.95 and less than 1.08)
In this embodiment, it is calculated from the semi-softening temperature T _LD obtained by performing a tensile test in the direction parallel to the rolling direction and the semi-softening temperature T _TD obtained by performing a tensile test in the direction perpendicular to the rolling direction. The semi-softening temperature ratio T _LD / T T D is more than _0.95 and within the range of less than 1.08, the anisotropy of heat resistance is small, and it is parallel to the rolling direction and in the rolling direction. On the other hand, sufficient strength in a high temperature environment is ensured in any of the orthogonal directions.
Here, in order to ensure that the above-mentioned effects are effective, the lower limit of the semi-softening temperature ratio T _LD / T _TDD is preferably 0.97 or more, and more preferably 0.98 or more. On the other hand, the upper limit of the semi-softening temperature ratio T _LD / T _TD is preferably 1.06 or less, and more preferably 1.04 or less.

(Conductivity: 97% IACS or higher)
In the copper alloy of this embodiment, the conductivity is 97% IACS or more. By setting the conductivity to 97% IACS or higher, it is possible to suppress heat generation during energization and use it as a substitute for pure copper materials as parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation boards. It becomes.
The conductivity is preferably 97.5% IACS or higher, more preferably 98.0% IACS or higher, more preferably 98.5% IACS or higher, and 99.0% IACS or higher. It is even more preferable to have.

(Semi-softening temperature T _LD obtained by conducting a tensile test in the direction parallel to the rolling direction: 210 ° C or higher)
In the copper alloy of the present embodiment, when the semi-softening temperature _TLD obtained by performing a tensile test in the direction parallel to the rolling direction is high, the copper material recovers and softens due to recrystallization occurs even at a high temperature. Since it is difficult, it can be applied to an energizing member used in a high temperature environment.
Therefore, in the present embodiment, the semi-softening temperature _TLD obtained by performing a tensile test in the direction parallel to the rolling direction is 210 ° C. or higher.
The semi-softening temperature T _LD obtained by conducting a tensile test in a direction parallel to the rolling direction is more preferably 225 ° C. or higher, more preferably 250 ° C. or higher, and 275 ° C. or higher. Is even more preferable.

(Intensity ratio TS _TD / TS _LD : Exceeds 0.93 and less than 1.10)
The strength ratio TS _TD calculated from the tensile strength TS _TD when the tensile test is performed in the direction orthogonal to the rolling direction and the tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction. When / TS _LD exceeds 0.93 and is within the range of less than 1.10, the strength anisotropy is small, and strength is required in both the LD direction and TD direction like terminals for large currents and bus bars. Sufficient strength is ensured even in such cases.
Here, in order to ensure that the above-mentioned effects are effective, the lower limit of the intensity ratio _TSTD / _TSLD is more preferably 0.95 or more, and further preferably 0.98 or more. Further, the upper limit of the intensity ratio TS _TD / TS _LD is more preferably 1.08 or less, and further preferably 1.06 or less.

(Tensile strength TS _LD in the direction parallel to the rolling direction: 200 MPa or more)
In the copper alloy of the present embodiment, when the tensile strength TS _LD in the direction parallel to the rolling direction is 200 MPa or more, it is particularly suitable as a material for electronic / electrical equipment parts such as terminals, bus bars, and lead frames. Become. Although the upper limit of the tensile strength TS _LD in the direction parallel to the rolling direction is not set, the tensile strength TS _LD is 500 MPa in order to avoid a decrease in productivity due to the winding habit of the coil when using a coil-wound strip. The following is preferable.
The lower limit of the tensile strength TS _LD in the direction parallel to the rolling direction is more preferably 275 MPa or more, further preferably 300 MPa or more.

(Brass direction {110} <112>: 30% or less)
As the Brass direction increases, the strength in the direction orthogonal to the rolling direction increases. Therefore, in order to suppress the anisotropy of the strength, it is preferable that the area ratio of the crystal having the crystal orientation within 10 ° with respect to the Brass orientation {110} <112> is 30% or less.
In order to further suppress the anisotropy of the strength, the area ratio of the crystal having the crystal orientation within 10 ° with respect to the Brass orientation {110} <112> is preferably 20% or less, preferably 10% or less. Is more preferable.
On the other hand, if the ratio of the Brass direction is too low, the strength in the direction orthogonal to the rolling direction may become too low and the required strength may not be secured. Therefore, 10 ° with respect to the Brass direction {110} <112>. The lower limit of the area ratio of the crystal having a crystal orientation within is preferably 0.5% or more, more preferably 1% or more, and most preferably 1.5% or more.

Next, a method for manufacturing a copper alloy according to the present embodiment having such a configuration will be described with reference to the flow chart shown in FIG.

(Melting / Casting Step S01)
First, the above-mentioned elements are added to the molten copper obtained by melting the copper raw material to adjust the components to produce a molten copper alloy. In addition, a simple substance of an element, a mother alloy, or the like can be used for adding various elements. Further, the raw material containing the above-mentioned elements may be dissolved together with the copper raw material. Further, the recycled material and the scrap material of the present alloy may be used.
Here, the copper raw material is preferably a so-called 4NCu having a purity of 99.99 mass% or more, or a so-called 5 NCu having a purity of 99.999 mass% or more.

At the time of dissolution, in order to suppress the oxidation of Mg and to reduce the hydrogen concentration, the atmosphere is dissolved in an inert gas atmosphere (for example, Ar gas) having a low vapor pressure of _H2O , and the holding time at the time of dissolution is the minimum. It is preferable to keep it to the limit.
Then, a molten copper alloy whose composition has been adjusted is injected into a mold to produce an ingot. When mass production is considered, it is preferable to use a continuous casting method or a semi-continuous casting method.

(Homogenization / solutionization step S02)
Next, heat treatment is performed for homogenization and solution formation of the obtained ingot. Inside the ingot, there may be an intermetallic compound containing Cu and Mg as main components, which is generated by the concentration of Mg by segregation in the process of solidification. Therefore, in order to eliminate or reduce these segregation and intermetallic compounds, Mg is uniformly diffused in the ingot by performing a heat treatment in which the ingot is heated to 300 ° C. or higher and 1080 ° C. or lower. , Mg is dissolved in the matrix. The homogenization / solution step S02 is preferably carried out in a non-oxidizing or reducing atmosphere.

Here, if the heating temperature is less than 300 ° C., solution formation may be incomplete, and a large amount of intermetallic compounds containing Cu and Mg as main components may remain in the matrix phase. On the other hand, if the heating temperature exceeds 1080 ° C., a part of the copper material becomes a liquid phase, and the structure and surface condition may become non-uniform. Therefore, the heating temperature is set in the range of 300 ° C. or higher and 1080 ° C. or lower.
In order to improve the efficiency of rough rolling and to make the structure uniform, which will be described later, hot working may be performed after the above-mentioned homogenization / solutionization step S02. In this case, the processing method is not particularly limited, and for example, rolling, drawing, extrusion, groove rolling, forging, pressing, or the like can be adopted. The hot working temperature is preferably in the range of 300 ° C. or higher and 1080 ° C. or lower.

(Roughing process S03)
Roughing is performed in order to process into a predetermined shape. The temperature conditions in this roughing step S03 are not particularly limited, but are within the range of −200 ° C. to 200 ° C. for cold or warm rolling in order to suppress recrystallization or improve dimensional accuracy. Is preferable, and room temperature is particularly preferable. The processing rate is preferably 20% or more, more preferably 30% or more. The processing method is not particularly limited, and for example, rolling, drawing, extrusion, groove rolling, forging, pressing, or the like can be adopted.

(Intermediate heat treatment step S04)
After the roughing step S03, a heat treatment is performed to soften or recrystallize the workability. The intermediate heat treatment step S04 and the upper preprocessing step S05, which will be described later, may be repeated.
Here, since this intermediate heat treatment step S04 is substantially the final recrystallization heat treatment, the crystal grain size of the recrystallized structure obtained in this step is substantially equal to the final crystal grain size. Therefore, in this intermediate heat treatment step S04, it is preferable to appropriately select the heat treatment conditions so that the average crystal grain size is 5 μm or more. For example, at 700 ° C., it is preferably held for about 1 to 120 seconds.

(Upper pre-processing process S05)
In order to process the copper material after the intermediate heat treatment step S04 into a predetermined shape, upper preprocessing is performed. The temperature conditions in the pre-processing step S05 are not particularly limited, but cold or warm processing is performed in order to suppress recrystallization during processing or to suppress softening, and the temperature is −200 ° C. to 200 ° C. It is preferable that the temperature is within the above range, and room temperature is particularly preferable.
Further, the machining ratio is appropriately selected so as to be close to the final shape, but in order to increase the work hardening or the brass orientation ratio which is the rolled texture in the upper pre-machining step S05 and improve the strength. The processing rate is preferably 5% or more. Also. When further improving the strength, the processing rate is more preferably 10% or more, and the processing rate is more preferably 15% or more.
On the other hand, in order to suppress excessive orientation of the Brass orientation, the processing rate is preferably 75% or less, and more preferably 70% or less.
The processing method is not particularly limited, and for example, rolling, drawing, extrusion, groove rolling, forging, pressing, or the like can be adopted.

(Mechanical surface treatment step S06)
After the upper pre-processing step S05, a mechanical surface treatment is performed. The mechanical surface treatment is a treatment in which compressive stress is applied isotropically to the vicinity of the surface after the desired shape is almost obtained, and has the effect of reducing the anisotropy of heat resistance and strength.
Mechanical surface treatment includes shot peening treatment, blasting treatment, lapping treatment, polishing treatment, buffing, grinder polishing, sandpaper polishing, tension leveler treatment, and light rolling with low reduction rate per pass (reduction rate per pass). Various commonly used methods such as 1 to 10% and repeated 3 times or more can be used.
By adding this mechanical surface treatment to the copper alloy to which Mg is added, the heat resistance is greatly improved.

(Finishing heat treatment step S07)
Next, the plastic processed material obtained in the mechanical surface treatment step S06 may be subjected to a finish heat treatment in order to segregate the contained elements into the grain boundaries and remove residual strain.
The heat treatment temperature is preferably in the range of 100 ° C. or higher and 500 ° C. or lower. In this finish heat treatment step S07, it is necessary to set the heat treatment conditions so as to avoid a significant decrease in strength due to recrystallization. For example, it is preferably held at 450 ° C. for about 0.1 to 10 seconds, and at 250 ° C. for 1 minute to 100 hours. This heat treatment is preferably performed in a non-oxidizing atmosphere or a reducing atmosphere. The heat treatment method is not particularly limited, but a short-time heat treatment using a continuous annealing furnace is preferable from the viewpoint of reducing the manufacturing cost.
Further, the above-mentioned upper pre-processing step S05, mechanical surface treatment step S06, and finish heat treatment step S07 may be repeatedly performed.

In this way, the copper alloy (copper alloy plastically processed material) according to the present embodiment is produced. The copper alloy plastically processed material produced by rolling is called a copper alloy rolled plate.
Here, when the plate thickness of the copper alloy plastic working material is 0.1 mm or more, it is suitable for use as a conductor in a large current application. Further, by setting the plate thickness of the copper alloy plastic working material to 10.0 mm or less, it is possible to suppress an increase in the load of the press machine, secure productivity per unit time, and suppress manufacturing costs. ..
Therefore, the plate thickness of the plastically processed copper alloy material (rolled copper alloy material) is preferably in the range of 0.1 mm or more and 10.0 mm or less.
The lower limit of the plate thickness of the copper alloy plastically worked material (copper alloy rolled material) is preferably 0.5 mm or more, and more preferably 1.0 mm or more. On the other hand, the upper limit of the plate thickness of the copper alloy plastically worked material (copper alloy rolled material) is preferably less than 9.0 mm, more preferably less than 8.0 mm.

In the copper alloy of the present embodiment having the above-mentioned structure, the Mg content is in the range of more than 10 mass ppm and less than 100 mass ppm, and the content of S, which is an element that forms a compound with Mg, is 10 mass ppm or less. The P content is 10 mass ppm or less, the Se content is 5 mass ppm or less, the Te content is 5 mass ppm or less, the Sb content is 5 mass ppm or less, the Bi content is 5 mass ppm or less, the As content is 5 mass ppm or less, and further. Since the total content of S, P, Se, Te, Sb, Bi and As is limited to 30 mass ppm or less, Mg added in a small amount can be dissolved in the copper matrix, and the conductivity is greatly reduced. It is possible to improve the heat resistance without causing it.

When the content of Mg is [Mg] and the total content of S, P, Se, Te, Sb, Bi and As is [S + P + Se + Te + Sb + Bi + As], the mass ratios [Mg] / [S + P + Se + Te + Sb + Bi + As] are Since it is set in the range of 0.6 or more and 50 or less, it is possible to sufficiently improve the heat resistance without excessively dissolving Mg and lowering the conductivity.
Therefore, according to the copper alloy of the present embodiment, the conductivity is 97% IACS or more, and the semi-softening temperature _TLD obtained by conducting a tensile test in the direction parallel to the rolling direction is 210 ° C. or more. It is possible to achieve both high conductivity and excellent heat resistance.

Then, the semi-softening calculated from the semi- _softening temperature T _LD obtained by performing the tensile test in the direction parallel to the rolling direction and the semi-softening temperature T T D obtained by performing the tensile test in the direction orthogonal to the rolling direction. Since the temperature ratio T _LD / T _TD exceeds 0.95 and is within the range of less than 1.08, the anisotropy of heat resistance is small, for example, rolling like terminals and bus bars for large currents. Sufficient strength in a high temperature environment is ensured even when heat resistance is required in both the direction parallel to the direction and the direction orthogonal to the rolling direction.

In the present embodiment, when the Ag content is in the range of 5 mass ppm or more and 20 mass ppm or less, Ag segregates in the vicinity of the grain boundaries, the grain boundary diffusion is suppressed, and the heat resistance can be improved. Become.

Further, in the present embodiment, when the area ratio of the crystal having a crystal orientation within 10 ° with respect to the Brass orientation {110} <112> is limited to 30% or less, it is orthogonal to the rolling direction. It is possible to suppress the preferential increase in the strength in the direction, and it is possible to surely suppress the anisotropy of the strength.

Further, in the present embodiment, the tensile strength TS _TD when the tensile test is performed in the direction orthogonal to the rolling direction and the tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction are obtained. When the calculated intensity ratio TS _TD / TS _LD exceeds 0.93 and is within the range of less than 1.10, the intensity anisotropy is small, such as a terminal for large current or a bus bar. , Sufficient strength is ensured when strength is required in both the direction parallel to the rolling direction and the direction orthogonal to the rolling direction.

Further, in the present embodiment, when the tensile strength TS _TD in the direction parallel to the rolling direction is 200 MPa or more, the tensile strength TS _TD in the direction parallel to the rolling direction is sufficiently high, and the terminal, bus bar, lead frame, and the like. It is particularly suitable as a material for parts for electronic and electrical equipment such as heat dissipation boards.

Since the copper alloy plastically processed material of the present embodiment is composed of the above-mentioned copper alloy, it is excellent in conductivity and heat resistance, and has a small heat resistance anisotropy. It is particularly suitable as a material for parts for electronic and electrical equipment such as heat dissipation boards.
Further, when the copper alloy plastically processed material of the present embodiment is a rolled plate having a thickness of 0.1 mm or more and 10 mm or less, the copper alloy plastically processed material (rolled plate) is punched or punched. By bending, parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation boards can be molded relatively easily.
When a Sn plating layer or an Ag plating layer is formed on the surface of the plastically processed copper alloy material of the present embodiment, it is particularly used as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates. Is suitable.

Further, since the electronic / electrical equipment parts (terminals, bus bars, lead frames, heat dissipation boards, etc.) of the present embodiment are made of the above-mentioned copper alloy plastically processed material, they can be used in high currents and in high temperature environments. , Can exhibit excellent characteristics.

Although the copper alloy, the copper alloy plastic processed material, and the parts for electronic / electrical equipment (terminals, bus bars, lead frames, heat dissipation boards, etc.) which are the embodiments of the present invention have been described above, the present invention is limited thereto. However, it can be changed as appropriate without departing from the technical idea of the invention.
For example, in the above-described embodiment, an example of a method for manufacturing a copper alloy (copper alloy plastic processed material) has been described, but the method for manufacturing a copper alloy is not limited to that described in the embodiment, and is not limited to the existing method. The production method may be appropriately selected for production.

The results of the confirmation experiment conducted to confirm the effect of the present invention will be described below.
By the band melting purification method, a raw material made of pure copper having a purity of 99.999 mass% or more was charged into a high-purity graphite crucible and melted at high frequency in an atmosphere furnace having an Ar gas atmosphere.

Various 0.1 mass% mother alloys prepared using high-purity copper having a purity of 6N (purity 99.9999 mass%) or more and a pure metal having a purity of 2N (purity 99 mass%) or more are added to the obtained molten copper. The components were adjusted and poured into a heat insulating material (isowool) mold to produce ingots having the component compositions shown in Tables 1 and 2. The size of the ingot was about 30 mm in thickness × about 60 mm in width × about 150 to 200 mm in length.

The obtained ingot was heated at 900 ° C. for 1 hour in an Ar gas atmosphere to dissolve Mg, and surface grinding was performed to remove the oxide film to a predetermined size. I made a disconnection.
Then, the thickness was adjusted so as to be the final thickness as appropriate, and cutting was performed. Each of the cut samples was roughly rolled under the conditions shown in Tables 3 and 4, and then subjected to an intermediate heat treatment under the condition that the crystal grain size was about 30 μm by recrystallization.

Next, the upper pre-rolling (upper pre-machining step) was carried out under the conditions shown in Tables 3 and 4.
Then, these samples were subjected to a mechanical surface treatment step by the methods shown in Tables 3 and 4.
The sandpaper polishing was performed using # 180 polishing paper.
For grinding, a bearing foil with a count of # 400 was used, and polishing was performed at a speed of 4500 rotations per minute.
The shot peening treatment was carried out using a stainless steel shot having a diameter of 0.3 mm at a projection speed of 10 m / sec and a projection time of 10 seconds.
Then, the finish heat treatment was performed under the conditions shown in Tables 3 and 4, and the strips having a thickness × width of about 60 mm shown in Tables 3 and 4, respectively, were produced.

The following items were evaluated for the obtained strips.

(Composition analysis)
A measurement sample was taken from the obtained ingot, Mg was measured by inductively coupled plasma emission spectroscopy, and other elements were measured using a glow discharge mass spectrometer (GD-MS). The measurement was performed at two points, the center of the sample and the end in the width direction, and the one with the higher content was taken as the content of the sample. As a result, it was confirmed that the composition was as shown in Tables 1 and 2.

(Brass direction ratio)
With the plane perpendicular to the width direction of rolling, that is, the TD plane (Transverse direction) as the observation plane, the Brass directional ratio was measured as follows by an EBSD measuring device and OIM analysis software.
After mechanical polishing using water-resistant abrasive paper and diamond abrasive grains, finish polishing was performed using a colloidal silica solution. Then, the EBSD measuring device (Quanta FEG 450 manufactured by FEI, OIM Data Collection manufactured by EDAX / TSL (currently AMETEK)) and the analysis software (EDAX / TSL (currently AMETEK) OIM Data Analysis ver.7.3). According to 1), the orientation of each crystal grain was analyzed except for the measurement points where the electron beam acceleration voltage was 20 kV, the measurement interval was 3 μm, the measurement area was 1 mm ² or more, and the CI value was 0.1 or less. It was determined whether or not each analysis point was the target Brass orientation (within 10 ° from the ideal orientation), and the Brass orientation ratio (area ratio of the crystal orientation) in the measurement region was obtained.

(conductivity)
A test piece having a width of 10 mm and a length of 60 mm was sampled from a strip for character evaluation, and the electrical resistance was determined by the 4-terminal method. In addition, the dimensions of the test piece were measured using a micrometer, and the volume of the test piece was calculated. Then, the conductivity was calculated from the measured electric resistance value and volume. The test pieces were collected so that the longitudinal direction thereof was parallel to the rolling direction of the strip material for character evaluation. The evaluation results are shown in Tables 3 and 4.

(Strength ratio)
No. 13B test pieces specified in JIS Z 2241 were collected from the strips for characteristic evaluation in the direction parallel to the rolling direction and in the direction orthogonal to the rolling direction, and the tensile strength was determined by the offset method of JIS Z 2241. It was measured. Tensile strength TS _TD when the tensile test is performed in the direction perpendicular to the rolling direction, and tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction, and the strength ratio TS _TD / TS _LD . Was calculated.
Tables 3 and 4 show the strength ratio TS _TD / TS _LD and the tensile strength TS _LD when the tensile test was performed in the direction parallel to the rolling direction.

(Semi-softening temperature ratio)
The semi-softening temperature was evaluated in accordance with JCBA T325: 2013 of the Japan Copper and Brass Association by obtaining an isochronous softening curve based on the tensile strength after 1 hour of heat treatment. As for the tensile strength, the 13B test piece specified in JIS Z 2241 is sampled and the direction parallel to the rolling direction and orthogonal to the rolling direction are orthogonal to each other by the offset method of JIS Z 2241, as in the above-mentioned mechanical properties. Measured in each direction.
Then, the semi-softening temperature obtained above is converted into Kelvin, and a tensile test can be performed in a direction orthogonal to the rolling direction and the semi-softening temperature T _LD obtained by performing a tensile test in the direction parallel to the rolling direction. The semi-softening temperature ratio T _LD / T _TD calculated from the obtained semi-softening temperature T _TD was calculated.
Tables 3 and 4 show the semi-softening temperature ratio T _LD / T _TD and the semi-softening temperature T _LD obtained by performing a tensile test in the direction parallel to the rolling direction.

In Comparative Example 1, since the Mg content was lower than the range of the present invention, the semi-softening temperature was low and the heat resistance was insufficient.
In Comparative Example 2, the Mg content was beyond the range of the present invention, and the conductivity was low.
In Comparative Example 3, the total content of S, P, Se, Te, Sb, Bi and As exceeded 30 mass ppm, the semi-softening temperature was low, and the heat resistance was insufficient.
In Comparative Example 4, the mass ratio [Mg] / [S + P + Se + Te + Sb + Bi + As] was less than 0.6, the semi-softening temperature was low, and the heat resistance was insufficient.
In Comparative Example 5, the mechanical surface treatment step was not carried out, the semi-softening temperature ratio TL _D / T _TD was out of the scope of the present invention, and the anisotropy of heat resistance became large. In addition, the strength ratio TS _TD / TS _LD was also large, and the anisotropy of the strength was also large.

On the other hand, in Examples 1 to 24 of the present invention, it was confirmed that the conductivity and the heat resistance were improved in a well-balanced manner, and the anisotropy of the heat resistance and the strength was small.
From the above, it was confirmed that according to the example of the present invention, it is possible to provide a copper alloy having high conductivity and excellent heat resistance and having a small anisotropy of heat resistance.

Claims (12)

The composition has a composition in which the Mg content is in the range of more than 10 mass ppm and less than 100 mass ppm, and the balance is Cu and unavoidable impurities. Among the unavoidable impurities, the S content is 10 mass ppm or less, the P content is 10 mass ppm or less, and Se. The content is 5 mass ppm or less, the Te content is 5 mass ppm or less, the Sb content is 5 mass ppm or less, the Bi content is 5 mass ppm or less, the As content is 5 mass ppm or less, and S, P, Se, and Te. The total content of Sb, Bi and As is 30 mass ppm or less.
When the content of Mg is [Mg] and the total content of S, P, Se, Te, Sb, Bi and As is [S + P + Te + Sb + Bi + As], the mass ratios [Mg] / [S + P + Te + Sb + Bi + As] are 0. It is said to be within the range of 6 or more and 50 or less.
Conductivity is 97% IACS or higher,
Semi-softening temperature ratio calculated from the semi-softening temperature _TD obtained by conducting a tensile test in the direction parallel to the rolling direction and the semi-softening temperature _TTD obtained by performing a tensile test in the direction orthogonal to the rolling direction. T _LD / T _TD exceeds 0.95 and is within the range of less than 1.08.
A copper alloy characterized in that the semi-softening temperature _TLD obtained by conducting a tensile test in a direction parallel to the rolling direction is 210 ° C. or higher. The copper alloy according to claim 1, wherein the Ag content is in the range of 5 mass ppm or more and 20 mass ppm or less. The copper alloy according to claim 1 or 2, wherein the proportion of crystals having a crystal orientation within 10 ° with respect to the Brass orientation {110} <112> is 30% or less. The strength ratio TS _TD calculated from the tensile strength TS _TD when the tensile test is performed in the direction orthogonal to the rolling direction and the tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction. / TS _LD exceeds 0.93 and is within the range of less than 1.10.
The copper alloy according to any one of claims 1 to 3, wherein the tensile strength TS _LD when the tensile test is performed in the direction parallel to the rolling direction is 200 MPa or more. A copper alloy plastically worked material comprising the copper alloy according to any one of claims 1 to 4. The copper alloy plastically worked material according to claim 5, wherein the rolled plate has a thickness of 0.1 mm or more and 10 mm or less. The copper alloy plastic working material according to claim 5 or 6, wherein the surface thereof has a Sn plating layer or an Ag plating layer. A component for electronic / electrical equipment, which comprises the copper alloy plastic working material according to any one of claims 5 to 7. A terminal made of the copper alloy plastically worked material according to any one of claims 5 to 7. A bus bar made of the copper alloy plastically worked material according to any one of claims 5 to 7. A lead frame made of the copper alloy plastically worked material according to any one of claims 5 to 7. A heat-dissipating substrate made by using the copper alloy according to any one of claims 1 to 4.

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