WO2023127851A1 - Copper alloy irregular-shape strip, component for electronic/electrical devices, terminal, busbar, lead frame, and heat dissipation substrate - Google Patents

Abstract

Provided is a copper alloy irregular-shape strip having, in a cross-sectional view orthogonal to the longitudinal direction, portions with different thicknesses, i.e., a thick section and a thin section. The copper alloy irregular-shape strip has: a composition in which the Mg content is in the range from greater than 10 mass ppm to less than 1.2 mass% and the P content is in the range of 0 mass ppm to 200 mass ppm, with the remainder being Cu and unavoidable impurities; and an electroconductivity of 48% IACS or more. The thick section has a heat resistance temperature T1 of 260°C or more, and the thin section has a heat resistance temperature T2 of 240°C, where 0.9<T1/T2<1.25 is satisfied; the thick section has a low angle grain boundary ratio B1 of 80% or less, and the thin section has a low angle grain boundary ratio B2 of 80% or less, where 0.8<B1/B2<1.2 is satisfied. The surface area ratio of crystals having a crystallite orientation of no more than 10° with respect to a Goss orientation { 011 } <100> is 1% or more in both the thick section and the thin section. The copper alloy irregular-shape strip has high electroconductivity and excellent heat resistance.

Description

Copper alloy profile strips, parts for electronic and electrical equipment, terminals, bus bars, lead frames, heat dissipation substrates

The present invention relates to a copper alloy profile strip suitable for electronic and electrical device parts such as terminals, bus bars, lead frames, and heat dissipation substrates, and electronic and electrical device parts, terminals, bus bars and leads made of this copper alloy profile strip. It relates to the frame and the heat dissipation board.
This application claims priority based on Japanese Patent Application No. 2021-214036 filed in Japan on December 28, 2021, the content of which is incorporated herein.

2. Description of the Related Art Conventionally, copper or copper alloys with high conductivity are used for parts for electronic and electric devices such as terminals, bus bars, lead frames, and heat dissipation substrates.
Here, with the increase in current in electronic and electrical equipment, etc., due to the reduction of current density and the diffusion of heat due to Joule heat generation, large-sized parts for electronic and electrical equipment used in these electronic and electrical equipment, etc. It is also designed to be thinner and thicker.

Here, in order to cope with a large current, a pure copper material such as oxygen-free copper having excellent electrical conductivity is applied to the above electronic/electrical device parts. However, due to the heat generated when energized and the temperature of the usage environment, there is a demand for copper materials with excellent heat resistance, which means that the hardness does not decrease at high temperatures. There was a problem that it was inferior in characteristics and could not be used in a high temperature environment.
Therefore, Patent Document 1 discloses a rolled copper sheet containing Mg in the range of 0.005 mass% or more and less than 0.1 mass%.

The copper rolled sheet described in Patent Document 1 contains Mg in the range of 0.005 mass% or more and less than 0.1 mass%, and the balance is Cu and inevitable impurities. By making a solid solution in the mother phase, it was possible to improve the strength and heat resistance without significantly lowering the electrical conductivity.

Further, as a material for the electronic/electrical device parts described above, for example, as disclosed in Patent Documents 2 and 3, copper having a thick portion and a thin portion having different thicknesses in a cross section orthogonal to the longitudinal direction Alloy profile strips are used.

Japanese Patent Application Laid-Open No. 2016-056414 (A) Japanese Patent Application Laid-Open No. 2007-039735 (A) Japanese Patent Application Laid-Open No. 2009-009887 (A)

Here, the heat resistance of these materials is improved by adding a solute element. The structure tends to be different between the thick and thin portions, and the thick and thin portions tend to have different properties such as strength and heat resistance.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to stably use the thick part and the thin part in a high temperature environment without causing a difference in properties such as strength and heat resistance. It is an object of the present invention to provide a copper alloy profile strip, and electronic/electronic equipment components, terminals, bus bars, lead frames, and heat dissipation substrates made of this copper alloy profile strip.

In order to solve this problem, a copper alloy profile strip according to the present invention is a copper alloy profile strip having a thick portion and a thin portion having different thicknesses in a cross section perpendicular to the longitudinal direction, and containing Mg. The content is in the range of more than 10 massppm and less than 1.2 mass%, the content of P is in the range of 0 massppm to 200 massppm, and the balance is Cu and unavoidable impurities. The heat resistant temperature T1 of the thick portion is 260° C. or higher, the heat resistant temperature T2 of the thin portion is 240° C. or higher, and 0.9<T1/T2<1.25, and the rolled surface, that is, the ND surface, is formed by the EBSD method. The measurement area of 10000 μm ² or more in (Normal direction) is analyzed for each crystal grain, except for the measurement points where the CI value is 0.1 or less at a measurement interval step of 0.25 μm, and the adjacent The grain boundary between the measurement points where the orientation difference between the measurement points is 15 ° or more, the average grain size A is obtained by Area Fraction, and the measurement is performed in steps with a measurement interval that is 1/10 or less of the average grain size A. In order to include a total of 1000 or more crystal grains, the measurement area is 10000 μm ² or more in multiple fields of view, and the CI value analyzed by the data analysis software OIM is 0.1 or less. L _LB is the length of the low-angle grain boundary and subgrain boundary between the measurement points where the orientation difference between the adjacent measurement points is 2° or more and 15° or less, and the orientation difference between the adjacent measurement points is 15°. When the length of the high-angle grain boundary between the measurement points exceeding ° is defined as _LHB , and the low-angle grain boundary ratio B= _LLB /( _LLB + _LHB ), the low-angle grain boundary ratio B1 in the thick portion is 80% or less, the low angle grain boundary ratio B2 in the thin portion is 80% or less, and 0.8<B1/B2<1.2, and within 10° with respect to the Goss orientation {011} <100> The area ratio of crystals having a crystal orientation of is 1% or more in each of the thick portion and the thin portion.

According to the copper alloy profile strip having this configuration, the Mg content is in the range of more than 10 massppm and less than 1.2 mass%, and the P content is in the range of 0 massppm to 200 massppm. By forming a solid solution in the mother phase, the heat resistance can be sufficiently improved.
In addition, since the electrical conductivity is 48% IACS or higher, heat generation during energization can be suppressed, making it suitable as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates.
Furthermore, the heat resistant temperature T1 of the thick portion is 260° C. or higher, the heat resistant temperature T2 of the thin portion is 240° C. or higher, and 0.9<T1/T2<1.25. In addition, the difference in heat resistance between the thick portion and the thin portion is small, and the heat resistance of the entire copper alloy profile strip is stably improved.
Since the crystal structure is controlled so that the low-angle grain boundary ratio and the area ratio of Goss-oriented crystals in the thick portion and the thin portion are within the above-described ranges, recovery and recrystallization by movement of dislocations are achieved. is unlikely to occur, and the heat resistance can be sufficiently improved in the thick portion and the thin portion.

Here, in the copper alloy profile strip of the present invention, among the inevitable impurities, the S 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, and the Sb content is 5 mass ppm. Hereinafter, it is preferable that the content of Bi is 5 mass ppm or less, the content of As is 5 mass ppm or less, and the total content of S, Se, Te, Sb, Bi, and As is 24 mass ppm or less.
In this case, since the contents of S, Se, Te, Sb, Bi, and As, which are elements that form compounds with Mg, are specified as described above, Mg can be reliably dissolved, and heat resistance can be further reliably improved.

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

In the copper alloy profile strip of the present invention, the Vickers hardness H1 of the thick portion is 70 Hv or more, the Vickers hardness H2 of the thin portion is 75 Hv or more, and 0.7<H1/H2<1.2. It is preferable that
In this case, the Vickers hardness H1 of the thick portion is 70 Hv or more, the Vickers hardness H2 of the thin portion is 75 Hv or more, and the Vickers hardness ratio H1/H2 is 0.7<H1/H2<1. 2, the strength is excellent, and the difference in strength between the thick portion 11 and the thin portion 12 is small, so that it can be used stably.

Moreover, the copper alloy profile strip of the present invention preferably has a metal plating layer on its surface.
In this case, since it has a metal 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 substrates.

A component for an electronic/electrical device according to the present invention is characterized by being made of the copper alloy profile strip described above. In addition, the parts for electronic/electrical equipment in the present invention include terminals, bus bars, lead frames, heat-dissipating substrates, and the like.
Since the component for electronic/electrical equipment having this configuration is manufactured using the above-described copper alloy profile strip, it can exhibit excellent properties even in a high-temperature environment.

A terminal of the present invention is characterized by being made of the copper alloy profile strip described above.
Since the terminal having this configuration is manufactured using the above-described copper alloy profile strip, it can exhibit excellent characteristics even in a high-temperature environment.

A bus bar according to the present invention is characterized by being made of the copper alloy profile strip described above.
Since the bus bar having this configuration is manufactured using the above-described copper alloy profile strip, it can exhibit excellent characteristics even in a high-temperature environment.

A lead frame according to the present invention is characterized by being made of the above copper alloy profile strip.
Since the lead frame having this configuration is manufactured using the above-described copper alloy profile strip, it can exhibit excellent characteristics even in a high-temperature environment.

A heat dissipating substrate according to the present invention is characterized by being made of the copper alloy profile strip described above.
Since the heat dissipating substrate having this configuration is manufactured using the above-described copper alloy profile strip, it can exhibit excellent characteristics even in a high-temperature environment.

According to the present invention, there is little difference in properties such as strength and heat resistance between the thick portion and the thin portion, and a copper alloy profile strip that can be stably used in a high-temperature environment, and the copper alloy. It becomes possible to provide electronic and electronic device parts, terminals, bus bars, lead frames, and heat dissipation substrates made of dual-gauge strips.

1 is a cross-sectional explanatory view of a copper alloy dual-gauge strip according to the present embodiment; FIG. 1 is a flowchart of a method for manufacturing a copper alloy dual-gauge strip according to the present embodiment; FIG.

A copper alloy profile strip according to one embodiment of the present invention will be described below with reference to the accompanying drawings.
The copper alloy profile strip of this embodiment is optimally used as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates.

As shown in FIG. 1, a copper alloy profile strip 10 of this embodiment has a thick portion 11 and a thin portion 12 having different thicknesses in a cross section orthogonal to the longitudinal direction.
Also, the ratio t1/t2 between the thickness t1 of the thick portion 11 and the thickness t2 of the thin portion 12 is preferably 8 or less, preferably 6 or less.

In the copper alloy profile strip 10 of the present embodiment, the Mg content is in the range of more than 10 mass ppm and less than 1.2 mass%, the P content is in the range of 0 mass ppm to 200 mass ppm, and the balance is Cu and unavoidable impurities. It has a composition
In the copper alloy profile strip 10 of the present embodiment, among the inevitable impurities, the S 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, and the Sb content is 5 mass ppm. Hereinafter, it is preferable that the content of Bi is 5 mass ppm or less, the content of As is 5 mass ppm or less, and the total content of S, Se, Te, Sb, Bi, and As is 24 mass ppm or less.
Further, in the copper alloy profile strip 10 of the present embodiment, the Ag content may be in the range of 5 massppm or more and 20 massppm or less.

Further, in the copper alloy profile strip 10 of the present embodiment, the electrical conductivity is set to 48%IACS or more.
Furthermore, in the copper alloy deformed strip 10 of the present embodiment, the heat resistant temperature T1 of the thick portion 11 is 260° C. or higher, the heat resistant temperature T2 of the thin portion 12 is 240° C. or higher, and 0.9<T1/T2< 1.25.

Then, in the copper alloy deformed strip 10 of the present embodiment, a measured area of 10000 μm ² or more on the rolled surface, that is, the ND surface (Normal direction) is measured by the EBSD method, and the CI value is measured at a step of 0.25 μm measurement interval. Except for the measurement points where is 0.1 or less, the orientation difference of each crystal grain is analyzed. Obtain the average grain size A, measure at steps with a measurement interval that is 1/10 or less of the average grain size A, and measure 10000 μm ² or more in multiple fields so that the total number of crystal grains is 1000 or more. The area is analyzed except for the measurement points where the CI value analyzed by the data analysis software OIM is 0.1 or less, and the orientation difference between adjacent measurement points is 2 ° or more and 15 ° or less. L _LB is the length of the low-angle grain boundary and the subgrain boundary, L HB is the length of the high-angle grain boundary between measurement points where the orientation difference between adjacent measurement points exceeds 15°, and L _HB is the length of the low-angle grain boundary. When the ratio B=L _LB /(L _LB +L _HB ), the low-angle grain boundary ratio B1 in the thick portion 11 is 80% or less, the low-angle grain boundary ratio B2 in the thin portion 12 is 80% or less, and 0.5%. 8<B1/B2<1.2.
In addition, in the copper alloy profile strip 10 of the present embodiment, the area ratio of crystals having a crystal orientation within 10° with respect to the Goss orientation {011} <100> is 1% or more.

Furthermore, in the copper alloy profile strip 10 of the present embodiment, the Vickers hardness H1 of the thick portion 11 is 70 Hv or more, the Vickers hardness H2 of the thin portion 12 is 75 Hv or more, and 0.7<H1/H2< 1.2 is preferred.

Here, in the copper alloy deformed strip 10 of the present embodiment, the reasons why the composition, various properties, and crystal structure are defined as described above will be described below.

(Mg)
Mg is an element that has the function and effect of improving the strength and heat-resistant temperature resistance without significantly lowering the electrical conductivity by forming a solid solution in the matrix of copper.
Here, if the content of Mg is 10 ppm by mass or less, there is a possibility that the action and effect cannot be sufficiently exhibited. On the other hand, when the content of Mg is 1.2 mass % or more, the electrical conductivity becomes low, and there is a possibility that it cannot be used stably as a material for electronic/electrical device parts.
From the above, in the present embodiment, the content of Mg is set within a range of more than 10 mass ppm and less than 1.2 mass %.

Here, in order to further improve the heat resistance temperature, the lower limit of the Mg content is preferably 20 mass ppm or more, more preferably 30 mass ppm or more, and more preferably 40 mass ppm or more.
In order to further suppress the decrease in conductivity, the upper limit of the Mg content is preferably 1.0 mass% or less, more preferably 0.8 mass% or less, and 0.6 mass% or less. It is more preferable to set the content to 0.4 mass% or less.

(P)
P is an element that has an effect of improving castability, and may be added to improve productivity. On the other hand, when it is added excessively, it reacts with Mg to form a compound, which may reduce the effect of Mg solid solution.
From the above, in the present embodiment, the P content is set within the range of 0 mass ppm or more and 200 mass ppm or less.
Here, in order to further ensure the effect of Mg solid solution, the upper limit of the P content is preferably 160 mass ppm or less, more preferably 120 mass ppm or less, and more preferably 80 mass ppm or less. , 60 ppm by mass or less.

(S, Se, Te, Sb, Bi, As)
Elements such as S, Se, Te, Sb, Bi, and As described above are elements that are generally likely to be mixed into copper alloys. These elements are likely to react with Mg to form a compound, and may reduce the solid-solution effect of Mg added in a small amount. Therefore, the content of these elements must be strictly controlled.
Therefore, in the present embodiment, the S 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, and the As content is 5 mass ppm or less. It is preferable to limit the content to 5 mass ppm or less.
Furthermore, it is preferable to limit the total content of S, Se, Te, Sb, Bi and As to 24 ppm by mass or less.

The S content is more preferably 9 ppm by mass or less, and even more preferably 8 ppm by mass or less.
The Se content is more preferably 4 ppm by mass or less, and even more preferably 2 ppm by mass or less.
The Te content is more preferably 4 ppm by mass or less, and even more preferably 2 ppm by mass or less.
The Sb content is more preferably 4 ppm by mass or less, and even more preferably 2 ppm by mass or less.
The Bi content is more preferably 4 ppm by mass or less, and even more preferably 2 ppm by mass or less.
The As content is more preferably 4 ppm by mass or less, and even more preferably 2 ppm by mass or less.
Furthermore, the total content of S, Se, Te, Sb, Bi and As is more preferably 20 ppm by mass or less, and even more preferably 16 ppm by mass or less.

(Ag: 5 mass ppm or more and 20 mass ppm or less)
Ag hardly dissolves in the parent phase of Cu in the normal operating temperature range of 250° C. or less for electronic and electrical equipment. Therefore, a trace amount of Ag added to copper segregates in the vicinity of grain boundaries. As a result, movement of atoms at grain boundaries is prevented, grain boundary diffusion is suppressed, and heat resistance is improved.
Here, when the content of Ag is 5 ppm by mass or more, it is possible to sufficiently exhibit its effects. On the other hand, when the Ag content is 20 ppm by mass or less, the electrical conductivity can be ensured and an increase in manufacturing cost can be suppressed.
From the above, in the present embodiment, the Ag content is set within the range of 5 ppm by mass or more and 20 ppm by mass or less.

Here, 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 even more preferably 8 mass ppm or more. Further, in order to reliably suppress a decrease in conductivity and an 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 further preferably 14 mass ppm or less. preferable.
In addition, when Ag is not intentionally added, the content of Ag may be less than 5 mass%.

(Other unavoidable impurities)
Other unavoidable impurities other than the above elements include Al, B, Ba, Be, Ca, Cd, Cr, Sc, rare earth elements, V, Nb, Ta, Mo, Ni, W, Mn, Re, Ru, 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 as long as they do not affect the properties.
Here, since these unavoidable impurities may reduce 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. is more preferably 0.01 mass % or less.
The upper limit of the content of each of these inevitable impurities is preferably 10 mass ppm or less, more preferably 5 mass ppm or less, and even more preferably 2 mass ppm or less.

(Low angle grain boundary ratio)
In the grain boundary, since the low-angle grain boundaries and subgrain boundaries are regions with a high density of dislocations introduced during processing, the low-angle grain boundary ratio B= If L _LB /(L _LB +L _HB ) is too high, high-speed diffusion of atoms via dislocations is likely to occur, and recrystallization in a high-temperature environment and accompanying softening are likely to occur, thereby impairing heat resistance. There is a risk. Moreover, since the thick portion 11 and the thin portion 12 are used in the same temperature environment, it is required that there is no large difference in heat resistance between the thick portion 11 and the thin portion 12 .
Therefore, in the present embodiment, the low-angle grain boundary ratio B1 of the thick portion 11 is set to 80% or less, and the low-angle grain boundary ratio B2 of the thin portion 12 is set to 80% or less.
Also, the ratio B1/B2 between the low-angle grain boundary ratio B1 of the thick portion 11 and the low-angle grain boundary ratio B2 of the thin portion 12 is set to 0.8<B1/B2<1.2.

Here, the low-angle grain boundary ratio B1 of the thick portion 11 is more preferably 76% or less, and even more preferably 72% or less.
Further, the low-angle grain boundary ratio B1 of the thin portion 12 is more preferably 76% or less, and even more preferably 72% or less.
Furthermore, the ratio B1/B2 of the low-angle grain boundary ratio is preferably within the range of 0.85<T1/T2<1.15, and is within the range of 0.90<T1/T2<1.10. is more preferable.

(Area ratio of crystals having a crystal orientation within 10° with respect to the Goss orientation {011} <100>)
Crystals having a Goss orientation of {011}<100> are relatively resistant to accumulation of dislocations, so it is possible to suppress the diffusion of atoms caused by the movement of dislocations in a high-temperature environment and the recovery caused thereby, thereby improving the heat resistance. . Moreover, since the thick portion 11 and the thin portion 12 are used in the same temperature environment, it is required that there is no large difference in heat resistance between the thick portion 11 and the thin portion 12 .
Note that the above-mentioned Goss orientation {011}<100> does not occur in copper materials by general rolling or heat treatment, and can be formed by deformation processing followed by processing and heat treatment.

In this embodiment, the area ratio of crystals having a crystal orientation within 10° with respect to the Goss orientation {011}<100> is set to be 1% or more in each of the thick portion 11 and the thin portion 12. .
The area ratio of crystals having a crystal orientation within 10° with respect to the Goss orientation {011}<100> in the thick portion 11 and the thin portion 12 is preferably 1.4% or more, and 1.8%. It is more preferable to make it 2.2% or more, and more preferably 2.2% or more.

(conductivity)
In the copper alloy profile strip 10 of this embodiment, the electrical conductivity is set to 48%IACS or more. By setting the electrical conductivity to 48% IACS or more, heat generation during energization can be suppressed, and it becomes possible to use it favorably as parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates.
Here, the electrical conductivity is preferably 53%IACS or higher, more preferably 58%IACS or higher, even more preferably 63%IACS or higher, and even more preferably 75%IACS or higher.
Although not particularly limited, the conductivity may be 102.5% IACS or less, 102% IACS or less, or 101.5% IACS or less.

(Heatproof temperature)
In the copper alloy deformed strip 10 of this embodiment, it is preferable that the heat resistant temperature T1 of the thick portion 11 is 260° C. or higher and the heat resistant temperature T2 of the thin portion 12 is 240° C. or higher. By configuring the heat resistance temperature as described above, heat resistance can be sufficiently ensured.
Moreover, in the copper alloy profile strip 10, both the thick portion 11 and the thin portion 12 are often used in the same temperature environment. Therefore, the heat resistant temperature T1 of the thick portion 11 and the heat resistant temperature T2 of the thin portion 12 are preferably close to each other, and the ratio T1/T2 between the heat resistant temperature T1 of the thick portion 11 and the heat resistant temperature T2 of the thin portion 12 is 0. .9<T1/T2<1.25.
Here, the heat resistant temperature T1 of the thick portion 11 is more preferably 280° C. or higher, even more preferably 300° C. or higher, and even more preferably 320° C. or higher.
The heat resistance temperature T2 of the thin portion 12 is more preferably 260° C. or higher, even more preferably 280° C. or higher, and even more preferably 300° C. or higher.
Furthermore, the heat resistant temperature ratio T1/T2 is more preferably within the range of 0.92<T1/T2<1.20.

(Vickers hardness)
In the copper alloy profile strip 10 of the present embodiment, when the Vickers hardness H1 of the thick portion 11 is 70 Hv or more and the Vickers hardness H2 of the thin portion 12 is 75 Hv or more, the strength is ensured, Especially suitable as a material for electrical and electronic parts.
Also, if the difference in hardness between the thick part 11 and the thin part 12 is large, there is a possibility that the material will be distorted during press working when manufacturing parts for electronic and electrical equipment, especially terminals, bus bars, lead frames, and heat dissipation boards. There is Therefore, it is preferable that the hardness H1 of the thick portion 11 and the hardness H2 of the thin portion 12 are close to each other. .7<H1/H2<1.2.
Here, the Vickers hardness H1 of the thick portion 11 is more preferably 72 Hv or higher, more preferably 74 Hv or higher.
Further, the Vickers hardness H2 of the thin portion 12 is more preferably 77 Hv or higher, more preferably 79 Hv or higher.
Furthermore, the Vickers hardness ratio H1/H2 is more preferably in the range of 0.8<H1/H2<1.1.

Next, a method for manufacturing the copper alloy profile strip 10 having such a configuration according to the present embodiment will be described with reference to the flowchart shown in FIG.

(Melting/casting step S01)
First, the above elements are added to the molten copper obtained by melting the copper raw material to adjust the composition, thereby producing the molten copper alloy. For addition of various elements, simple elements, master alloys, or the like can be used. Also, a raw material containing the above elements may be melted together with the copper raw material. Recycled materials and scrap materials of the present alloy may also be used.
Here, the copper raw material is preferably so-called 4NCu with a purity of 99.99 mass% or higher, or so-called 5NCu with a purity of 99.999 mass% or higher.
At the time of melting, in order to suppress the oxidation of Mg and to reduce the hydrogen concentration, atmosphere melting is performed in an inert gas atmosphere (for example, Ar gas) with a low vapor pressure of H ₂ O, and the holding time during melting is minimized. It is preferable to limit
Then, an ingot is produced by injecting the molten copper alloy with the adjusted composition into the mold. In addition, when considering mass production, it is preferable to use a continuous casting method or a semi-continuous casting method.

(Homogenization/Solution Step S02)
Next, the obtained ingot is subjected to heat treatment for homogenization and solutionization. Inside the ingot, an intermetallic compound or the like containing Cu and Mg as main components may be present as the Mg is concentrated by segregation during the solidification process. Therefore, in order to eliminate or reduce these segregations and intermetallic compounds, etc., heat treatment is performed to heat the ingot to 300 ° C. or higher and 1080 ° C. or lower, so that Mg is uniformly diffused in the ingot. , and Mg are dissolved in the matrix. The homogenization/solution treatment step S02 is preferably performed in a non-oxidizing or reducing atmosphere.

Here, if the heating temperature is less than 300° C., the solutionization 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., part of the copper material becomes a liquid phase, and the texture and surface state may become uneven. Therefore, the heating temperature is set in the range of 300° C. or higher and 1080° C. or lower.
Note that hot working may be performed after the homogenization/solution treatment step S02 described above in order to improve the efficiency of rough rolling and homogenize the structure, which will be described later. In this case, the working method is not particularly limited, and for example, rolling, drawing, extrusion, groove rolling, forging, pressing, etc. can be employed. Also, the hot working temperature is preferably in the range of 300° C. or higher and 1080° C. or lower.

(Rough processing step S03)
Rough processing is performed in order to process into a predetermined shape. The temperature conditions in this rough processing step S03 are not particularly limited, but in order to suppress recrystallization or to improve dimensional accuracy, cold or warm rolling is performed within the range of -200 ° C. to 200 ° C. It is preferable to set it as, and especially normal temperature is preferable. The processing rate is preferably 20% or more, more preferably 30% or more. Moreover, the processing method is not particularly limited, and for example, rolling, drawing, extrusion, groove rolling, forging, pressing, etc. can be employed.
Note that the rough processing step S03 and the intermediate heat treatment step S04, which will be described later, may be repeated.

(Intermediate heat treatment step S04)
After the rough working step S03, a heat treatment is performed to soften for improving workability or to obtain a recrystallized structure.
At this time, a short-time heat treatment in a continuous annealing furnace is preferable, and when Ag is added, localization of Ag segregation to grain boundaries can be prevented.
Although the conditions for this heat treatment are not particularly limited, the heat treatment is generally carried out in the range of 200°C to 1000°C.

(Mechanical surface treatment step S05)
After the intermediate heat treatment step S04, mechanical surface treatment is performed. The mechanical surface treatment is a treatment that applies compressive stress to the vicinity of the surface, and when combined with the above-mentioned pre-heat treatment step S07 described later, the Goss orientation {011}<100> is increased, and heat resistance can be improved.
Mechanical surface treatments include shot peening, blasting, lapping, polishing, buffing, grinder polishing, sandpaper polishing, tension leveler treatment, light rolling with low rolling reduction per pass (rolling reduction per pass 1% or more and 10% or less and repeated three times or more), various commonly used methods can be used.

(Irregular shape rolling step S06)
In the profile rolling process, the material after the mechanical surface treatment step S05 is cooled by a flat die having an uneven surface and rolling rolls that reciprocate along the forming surface facing the forming surface of the die. A rough and deformed strip in which a rough and thick portion and a rough and thin portion are arranged in the width direction is obtained by deforming rolling.
It should be noted that the Goss orientation is likely to be formed in the pre-upper heat treatment step S07 by setting the area reduction rate of the working within the range of 5% or more and 90% or less. The area reduction rate of processing is more preferably in the range of 10% or more and 85% or less, and more preferably in the range of 15% or more and 80% or less.
Further, by setting the ratio of the thickness of the rough and thick portion to the thickness of the rough and thin portion to be 6 or less, in the pre-upper heat treatment step S07, the low angle grain boundary ratio B=L _LB /( L _LB +L _HB ) ratio B1/B2 can be 0.8<B1/B2<1.2, and Vickers hardness ratio H1/H2 in the thick portion 11 and the thin portion 12 can be 0.7<H1 /H2<1.2. In addition, it is more preferable that the ratio of the thickness of the rough and thick portion to the thickness of the rough and thin portion is 5 or less.

(Upper front heat treatment step S07)
Next, heat treatment is performed after the profile rolling step S06 to form a recrystallized structure and form a Goss orientation. In addition, the low-angle grain boundary ratio B is reduced by recrystallization. Furthermore, the structures of the thick portion 11 and the thin portion 12 are similar.
In this pre-heat treatment step S07, in order to eliminate the strain difference between the thick portion and the thin portion introduced in the deformed rolling step S06, and to form a uniform structure by recrystallization and subsequent grain growth, the temperature rises below a certain level. A temperature rate and a sufficiently long heat treatment time are required. Therefore, heat treatment by batch annealing is preferable. The heat treatment conditions are preferably such that the heat treatment temperature is in the range of 250° C. or more and 650° C. or less, the temperature increase rate is 500° C./h or less, and the heat treatment time is 1 hour or more and 100 hours or less.

(Finishing process S08)
After the pre-upper heat treatment step S07, cold working is performed. Cold working is carried out by rolling rolls consisting of stepped rolls and flat rolls.
In order to set the Vickers hardness H1 of the thick portion 11 to 70 Hv and the H2 of the thin portion 12 to 75 Hv or more, the processing rate is preferably 5% or more, more preferably 8% or more.
On the other hand, if the working rate is too high, the low-angle grain boundary ratios B1 and B2 will increase, and the area ratio of the Goss orientation, which is the recrystallized structure, will also decrease. More preferably:

(Low temperature annealing step S09)
After the finishing step S08, low-temperature annealing is performed as necessary. This low-temperature annealing step S09 has the effect of reducing the proportion of low-angle grain boundaries due to the removal and recovery of residual stress.
In this low-temperature annealing step S09, it is preferable to set the annealing temperature within the range of 100° C. or more and 600° C. or less and the holding time at the annealing temperature within the range of 0.1 second or more and 24 hours or less. When the heat treatment temperature is low, the heat treatment may be performed for a long time, and when the heat treatment temperature is high, the heat treatment may be performed for a short time.
If the annealing temperature in the low-temperature annealing step S09 is less than 100°C, or the holding time at the annealing temperature is less than 0.1 seconds, there is a risk that a sufficient strain relief effect will not be obtained. If it exceeds, there is a risk of recrystallization, and if the holding time at the annealing temperature exceeds 24 hours, the cost only increases.

In this embodiment, a straightening process using a tension leveler or the like may be added after the low-temperature annealing process S09.
Furthermore, in the copper alloy profile strip 10 of the present embodiment, a metal plating layer may be formed on the surface. In addition, as a metal plating layer, Sn plating, Ag plating, Ni plating, Au plating, Pd plating, Rh plating, etc. can be applied, for example.

Through the above steps, the copper alloy profile strip 10 of the present embodiment is manufactured.

In the copper alloy profile strip 10 of the present embodiment configured as described above, the Mg content is in the range of more than 10 mass ppm and less than 1.2 mass%, and the P content is in the range of 0 mass ppm to 200 mass ppm. Therefore, the heat resistance can be sufficiently improved by dissolving Mg in the matrix of copper.
In addition, since the electrical conductivity is 48% IACS or higher, heat generation during energization can be suppressed, making it suitable as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates.
Furthermore, the heat resistant temperature T1 of the thick portion 11 is 260° C. or higher, and the heat resistant temperature T2 of the thin portion 12 is 240° C. or higher, and 0.9<T1/T2<1.25. In addition, the difference in heat resistance between the thick portion 11 and the thin portion 12 is small, so that it can be used stably even in a high temperature environment.

The low-angle grain boundary ratios B1 and B2 of the thick portion 11 and the thin portion 12 are respectively 80% or less, and the low-angle grain boundary ratio B1/B2 is 0.8<B1/B2<1.2. , the crystal structure is controlled so that the area ratio of crystals having a crystal orientation within 10° with respect to the Goss orientation {011} <100> is 1% or more in each of the thick portion and the thin portion. , recovery and recrystallization due to movement of dislocations are unlikely to occur, and the heat resistance of the thick portion 11 and the thin portion 12 can be sufficiently improved.

In the copper alloy profile strip 10 of the present embodiment, among the inevitable impurities, the S 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 When the content of is 5 mass ppm or less, the content of As is 5 mass ppm or less, and the total content of S, Se, Te, Sb, Bi, and As is 24 mass ppm or less, Mg and a compound are generated Since the contents of S, Se, Te, Sb, Bi, and As, which are elements that .

Furthermore, in the copper alloy profile strip 10 of the present embodiment, when the Ag content is in the range of 5 ppm by mass or more and 20 ppm by mass or less, Ag segregates in the vicinity of grain boundaries. Field diffusion is suppressed, and the heat resistant temperature can be further improved.

Further, in the copper alloy profile strip 10 of the present embodiment, the Vickers hardness H1 of the thick portion 11 is 70 Hv or more, the Vickers hardness H2 of the thin portion 12 is 75 Hv or more, and 0.7<H1/H2<1. In the case of 2, the strength is excellent, and the difference in strength between the thick portion 11 and the thin portion 12 is small, so that it can be used stably.

Furthermore, when a metal plating layer is formed on the surface of the copper alloy profile strip 10 of the present embodiment, various characteristics can be imparted to the surface, and it can be applied to electronic and electrical applications such as terminals, bus bars, and heat dissipation substrates. It is particularly suitable as a material for equipment parts.

Furthermore, since the electronic/electrical device parts (terminals, bus bars, lead frames, heat dissipation substrates, etc.) of the present embodiment are made of the copper alloy profile strip 10 described above, they are excellent even in a high-temperature environment. characteristics can be exhibited.

Although the copper alloy profile strip 10 and the parts for electronic/electrical equipment (terminals, bus bars, lead frames, heat dissipation substrates, etc.) that are embodiments of the present invention have been described above, the present invention is not limited thereto. , can be changed as appropriate without departing from the technical idea of the invention.
For example, in the above-described embodiment, an example of the method for manufacturing the copper alloy deformed strip 10 has been described, but the method for manufacturing the copper alloy deformed strip 10 is not limited to the method described in the embodiment, and the existing You may manufacture by selecting the manufacturing method of suitably.
Further, in the present embodiment, the dual-gauge strip having the shape shown in FIG. 1 has been described as an example, but the multi-gauge strip is not limited to this, and may be a multi-gauge strip having another cross-sectional shape.

The results of confirmatory experiments conducted to confirm the effects of the present invention will be described below.
A raw material made of pure copper with a purity of 99.999 mass% or more was charged into a high-purity graphite crucible by a zone melting refining method, and high-frequency melting was performed in an atmosphere furnace in an Ar gas atmosphere.
In the obtained molten copper, various 0.1 mass% master alloys made using high-purity copper of 6N (purity 99.9999 mass%) or higher and pure metals having a purity of 2N (purity 99 mass%) or higher are used. The composition was prepared as shown in Tables 1 and 2, and poured into a heat insulating material (isowool) mold to produce an ingot. The size of the ingot was about 30 mm thick×about 60 mm wide×about 150 to 200 mm long.

The obtained ingot was heated under various temperature conditions for 1 hour in an Ar gas atmosphere, subjected to surface grinding to remove the oxide film, and cut into a predetermined size.
After that, the thickness was appropriately adjusted so as to obtain the final thickness, and cutting was performed. Each of the cut samples was subjected to rough rolling at room temperature at the reduction rates shown in Tables 3 and 4, and then subjected to intermediate heat treatment under the heat treatment conditions shown in Tables 3 and 4.

Next, these samples were subjected to a mechanical surface treatment process by the method described in Tables 3 and 4.
Buffing was performed using #1000 abrasive paper.
A tension leveler equipped with a plurality of φ16 mm rolls was used, and the line tension was 100 N/mm ² .
Light rolling (rolling with a low rolling reduction per pass) was performed with a rolling reduction of 4% per pass for the final three passes.

Then, the plate-shaped die is reciprocated along the molding surface facing the molding surface of the die so that the thicknesses of the thick portion and the thin portion become the values shown in Tables 3 and 4, respectively. Stepped deformation processing was carried out with rolling rolls.
Then, the upper pre-heat treatment was performed under the conditions described in Tables 3 and 4.
After that, finishing was performed under the conditions shown in Tables 3 and 4, and low-temperature annealing was performed with the exception of some samples. produced.

The obtained strips for characteristic evaluation were evaluated as follows.

(composition analysis)
A measurement sample was taken from the obtained ingot, Mg was measured by inductively coupled plasma atomic emission spectrometry, and other elements were measured by glow discharge mass spectrometry (GD-MS).
In addition, the measurement was performed at two points, the central portion and the end portion in the width direction of the sample, and the larger 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.

(Low angle grain boundary ratio)
Using the rolled surface, that is, the ND surface (Normal direction) as an observation surface, the low angle grain boundary ratios B1 and B2 in the thick and thin portions were obtained as follows using an EBSD measuring device and OIM analysis software.
After performing mechanical polishing using waterproof abrasive paper and diamond abrasive grains, final polishing was performed using a colloidal silica solution. Then, an EBSD measurement device (Quanta FEG 450 manufactured by FEI, OIM Data Collection manufactured by EDAX/TSL (currently AMETEK)) and analysis software (manufactured by EDAX/TSL (currently AMETEK) OIM Data Analysis ver.7.3 .1), an electron beam acceleration voltage of 15 kV, a measurement area of 10000 μm ² or more, except for the measurement points where the CI value is 0.1 or less at a measurement interval step of 0.25 μm, the misorientation of each crystal grain , and the grain boundaries between the measurement points where the orientation difference between the adjacent measurement points is 15° or more, and the average grain size A was obtained by Area Fraction using the data analysis software OIM. After that, the data is analyzed with a measurement area of 10000 μm ² or more in multiple fields of view so that a total of 1000 or more crystal grains are included by measuring in steps with a measurement interval of 1/10 or less of the average grain size A. Analysis was performed excluding measurement points where the CI value analyzed by soft OIM was 0.1 or less. L _LB is the length of the grain boundary, and L _HB is the length of the large angle grain boundary between the measurement points exceeding 15 °. A low-angle grain boundary ratio B=L _LB /(L _LB +L _HB ) was obtained as the thickness ratio.

(Goss orientation)
When measuring the above small angle grain boundary and subgrain boundary length ratio, the orientation of each crystal grain is also analyzed to determine whether each analysis point is the target Goss orientation (within 10 ° from the ideal orientation). was determined, and the Goss orientation ratio (area ratio of crystal orientation) in the measurement region was determined.

(Heatproof temperature)
The heat resistance temperature conforms to JCBA T325:2013 of the Japan Copper and Brass Association, acquires an isochronous softening curve by Vickers hardness in heat treatment for 1 hour, and obtains the heating temperature at which the hardness becomes 80% of the hardness before heat treatment. evaluated. The rolled surface was used as the surface for Vickers hardness measurement. Tables 5 and 6 show the evaluation results.

(Vickers hardness)
According to the micro Vickers hardness test method specified in JIS-Z2244, the Vickers hardness was measured with a test load of 0.98N on the surface of the strip for characteristic evaluation, that is, the ND surface (Normal Direction). Tables 3 and 4 show the evaluation results.

(conductivity)
A test piece having a width of 10 mm and a length of 60 mm was taken from the strip material for characteristic evaluation, and the electrical resistance was determined by the four-probe method. Also, the dimensions of the test piece were measured using a micrometer, and the volume of the test piece was calculated. Then, the electrical conductivity was calculated from the measured electrical resistance value and volume. The test piece was taken so that its longitudinal direction was parallel to the rolling direction of the strip for characteristic evaluation. Tables 5 and 6 show the evaluation results.

In Comparative Example 1, since the Mg content was less than the range of the present invention, the heat resistance temperature was low and the heat resistance was insufficient.
In Comparative Example 2, the content of Mg exceeded the range of the present invention, and the electrical conductivity was low.
In Comparative Example 3, the P content exceeded 200 ppm by mass, the heat resistance temperature was low, and the heat resistance was insufficient.
In Comparative Example 4, the low-angle grain boundary ratio exceeded 80%, the heat resistance temperature was low, and the heat resistance was insufficient.
In Comparative Example 5, the area ratio of Goss orientation was less than 1%, the heat resistance temperature was low, and the heat resistance was insufficient.
In Comparative Example 6, the ratio B1/B2 between the low-angle grain boundary ratio B1 in the thick portion and the low-angle grain boundary ratio B2 in the thin portion is outside the range of the present invention, and the heat-resistant temperature T1 of the thick portion and the heat-resistant temperature of the thin portion The ratio T1/T2 to T2 was out of the range of the present invention, resulting in variations in heat resistance.

On the other hand, in Examples 1 to 30 of the present invention, it was confirmed that the heat resistance was improved in a well-balanced manner between the thick portion and the thin portion.
From the above, according to the example of the present invention, there is little difference in properties such as strength and heat resistance between the thick part and the thin part, and the copper alloy profile strip can be stably used in a high temperature environment. It was confirmed that it is possible to provide

A copper alloy profile strip that can be stably used in a high-temperature environment with little difference in properties such as strength and heat resistance between the thick part and the thin part, and an electronic device made of this copper alloy profile strip.・It becomes possible to provide electronic device parts, terminals, bus bars, lead frames, and heat dissipation boards.

Code description

REFERENCE SIGNS LIST 10 Copper alloy plastic work material 11 Thick part 12 Thin part t1 Thickness of thick part 11 t2 Thickness of thin part 12

Claims (10)

1. A copper alloy profile strip having a thick portion and a thin portion having different thicknesses in a cross section orthogonal to the longitudinal direction,
   The composition has a Mg content of more than 10 massppm and less than 1.2 mass%, a P content of 0 massppm or more and 200 massppm or less, and the balance being Cu and unavoidable impurities,
   Conductivity is set to 48% IACS or more,
   The heat resistant temperature T1 of the thick portion is 260° C. or higher, the heat resistant temperature T2 of the thin portion is 240° C. or higher, and 0.9<T1/T2<1.25,
   By the EBSD method, the measurement area of 10000 μm ² or more on the rolled surface, except for the measurement points where the CI value is 0.1 or less at the measurement interval step of 0.25 μm, analyze the misorientation of each grain, The grain boundaries between the measurement points where the orientation difference between adjacent measurement points is 15° or more, and the average grain size A is obtained by Area Fraction, and the step of the measurement interval is 1/10 or less of the average grain size A. Excluding measurement points where the CI value analyzed by the data analysis software OIM is 0.1 or less with a measurement area of 10000 μm ² or more in multiple fields of view so that a total of 1000 or more crystal grains are included. L _LB is the length of the low angle grain boundary and subgrain boundary between the measurement points where the orientation difference between the adjacent measurement points is 2° or more and 15° or less, and the orientation difference between the adjacent measurement points is L _HB is the length of the high-angle grain boundary between the measurement points where the angle exceeds 15°, and the low-angle grain boundary ratio B=L _LB /(L _LB +L _HB ), the low-angle grain boundary in the thick part The ratio B1 is 80% or less, the low-angle grain boundary ratio B2 in the thin portion is 80% or less, and 0.8<B1/B2<1.2,
   A copper alloy profile strip, wherein the area ratio of crystals having a crystal orientation within 10° with respect to the Goss orientation {011}<100> is 1% or more in each of the thick portion and the thin portion.
2. Among the inevitable impurities, the S 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, and the As content. is 5 mass ppm or less, and the total content of S, Se, Te, Sb, Bi and As is 24 mass ppm or less.
3. The copper alloy profile strip according to claim 1 or 2, characterized in that the Ag content is in the range of 5 ppm by mass or more and 20 ppm by mass or less.
4. The Vickers hardness H1 of the thick portion is 70 Hv or more, the Vickers hardness H2 of the thin portion is 75 Hv or more, and 0.7<H1/H2<1.2. The copper alloy profile strip according to claim 3.
5. The copper alloy dual-shaped strip according to any one of claims 1 to 4, characterized by having a metal plating layer on the surface.
6. A component for electronic/electrical equipment, comprising the copper alloy profile strip according to any one of claims 1 to 5.
7. A terminal characterized by being made of the copper alloy profile strip according to any one of claims 1 to 5.
8. A bus bar characterized by being made of the copper alloy profile strip according to any one of claims 1 to 5.
9. A lead frame comprising the copper alloy profile strip according to any one of claims 1 to 5.
10. A heat dissipation board comprising the copper alloy profile strip according to any one of claims 1 to 5.

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