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

Abstract

To provide a copper alloy deformed bar material having high conductivity and excellent heat resistance.SOLUTION: A copper alloy deformed bar material has a thick part and a thin part having different thicknesses in a cross section perpendicular to a longitudinal direction, has a composition having the content of Mg of more than 10 mass ppm and less than 1.2 mass%, the content of P of 0 mass ppm or more and 200 mass ppm or less, the balance Cu with inevitable impurities, and has conductivity of 48%IACS or more, wherein a heat-resistant temperature T1 of the thick part is 260°C or higher, a heat-resistant temperature T2 of the thin part is 240°C or higher, T1 and T2 satisfy 0.9<T1 / T2<1.25, a small tilt angle grain ratio B1 of the thick part is 80% or less, a small tilt angle grain ratio B2 of the thin part is 80% or less, B1 and B2 satisfy 0.8<B1 / B2<1.2, and each of area ratios of crystals having crystal orientation of 10° or less with respect to Goss orientation {011}<100> of the thick part and the thin part are 1% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a copper alloy profile strip suitable for electronic and electrical equipment components such as terminals, bus bars, lead frames, and heat dissipation substrates, and to electronic and electrical equipment components, terminals, bus bars, lead frames, and heat dissipation substrates made from this copper alloy profile strip. [Background technology]

[0002] Conventionally, highly conductive copper or copper alloys have been used for components of electronic and electrical devices such as terminals, bus bars, lead frames, and heat dissipation substrates. As the currents of electronic and electrical devices increase, efforts are being made to increase the size and thickness of the electronic and electrical device components used in these electronic and electrical devices in order to reduce current density and dissipate heat caused by Joule heating.

[0003] To cope with large currents, pure copper materials such as oxygen-free copper, which have excellent electrical conductivity, are used in the above-mentioned electronic and electrical equipment components. However, due to the heat generated when current is applied and the high temperatures in the operating environment, copper materials with excellent heat resistance, i.e., the ability to withstand high temperatures without losing hardness, are required. However, pure copper materials lack these properties, making them unsuitable for use in high-temperature environments. Therefore, Patent Document 1 discloses a copper rolled sheet containing Mg in the range of 0.005 mass % or more and less than 0.1 mass %.

[0004] The copper rolled sheet described in Patent Document 1 contains 0.005 mass% or more but less than 0.1 mass% of Mg, with the remainder consisting of Cu and unavoidable impurities. By dissolving Mg in the copper matrix, it was possible to improve the strength and heat resistance without significantly reducing the electrical conductivity.

[0005] In addition, as a material for the above-mentioned electronic and electrical equipment components, copper alloy deformed strip material having thick and thin portions with different thicknesses in a cross section perpendicular to the longitudinal direction, as disclosed in Patent Documents 2 and 3, for example, is used. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-056414 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-039735 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-009887 Summary of the Invention [Problem to be solved by the invention]

[0007] Here, the heat resistance characteristics of these materials are improved by adding solute elements, but in copper alloy deformed strip materials that have thick and thin portions of different thicknesses, the material structure is likely to be different between the thick and thin portions, and differences in properties such as strength and heat resistance are likely to occur between the thick and thin portions, which could make them unable to be used stably in high-temperature environments.

[0008] This invention has been made in consideration of the above-mentioned circumstances, and aims to provide a copper alloy shaped strip material that is less likely to have differences in properties such as strength and heat resistance between thick and thin portions and that can be used stably in high-temperature environments, as well as electronic and electronic equipment components, terminals, bus bars, lead frames, and heat dissipation substrates made from this copper alloy shaped strip material. [Means for solving the problem]

[0009] In order to solve this problem, the copper alloy profiled bar of the present invention is a copper alloy profiled bar having thick and thin portions with different thicknesses in a cross section orthogonal to the longitudinal direction, and has a composition in which the Mg content is in the range exceeding 10 mass ppm and less than 1.2 mass%, the P content is in the range of 0 mass ppm or more and 200 mass ppm or less, and the balance is Cu and inevitable impurities. The conductivity is 48% IACS or more, the heat-resistant temperature T1 of the thick portion is 260° C or more, the heat-resistant temperature T2 of the thin portion is 240° C or more, and 0.9 < T1 / T2 < 1.25. By the EBSD method, in the rolling plane, that is, the ND plane (Normal direction), for a measurement area of 10000 μm 2 or more, excluding measurement points with a CI value of less than or equal to 0.1 at a measurement interval step of 0.25 μm, the orientation difference between adjacent grains is analyzed. Measurement points with an orientation difference of 15° or more between adjacent measurement points are defined as grain boundaries, and the average grain size A is obtained by Area Fraction. Measured at a measurement interval step of 1 / 10 or less of the average grain size A, and in multiple fields so that a total of 1000 or more grains are included, for a measurement area of 10000 μm 2 or more, excluding measurement points with a CI value of less than or equal to 0.1 analyzed by data analysis software OIM, and the lengths of small-angle grain boundaries and sub-grain boundaries where the orientation difference between adjacent measurement points is 2° or more and 15° or less are L LB The length of the large-angle grain boundary where the orientation difference between adjacent measurement points exceeds 15° is L HB Let it be, and the small-angle grain boundary ratio B = L LB / (L LB +L HB ). When this is the case, the small-angle grain boundary ratio B1 of the thick portion is 80% or less, the small-angle grain boundary ratio B2 of the thin portion is 80% or less, and 0.8 < B1 / B2 < 1.2. 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.

[0010] According to the copper alloy shaped bar of this configuration, since the Mg content is in the range exceeding 10 mass ppm and less than 1.2 mass%, and the P content is in the range of 0 mass ppm or more and 200 mass ppm or less, Mg dissolves in the copper matrix phase, so that the heat resistance can be sufficiently improved. Also, since the conductivity is 48% IACS or more, heat generation during energization can be suppressed, and it is suitable as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates. Furthermore, since the heat resistance temperature T1 of the thick part is 260 °C or more, the heat resistance temperature T2 of the thin part is 240 °C or more, and 0.9 < T1 / T2 < 1.25, it is sufficiently excellent in heat resistance, and the difference in heat resistance between the thick part and the thin part is small, and the heat resistance of the entire copper alloy shaped bar is stably improved. And, since the crystal structure is controlled so that the small inclination grain boundary ratio and the area ratio of the Goss orientation crystals of the thick part and the thin part are within the above ranges, recovery and recrystallization due to the movement of dislocations are unlikely to occur, and in the thick part and the thin part, it is possible to sufficiently improve the heat resistance. <000,0083>

[0011] Here, in the copper alloy shaped bar 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, the Sb content is 5 mass ppm or less, the Bi content is 5 mas ppm or less, and the As content is 5 mass ppm or less, and it is preferable that 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 defined as above, Mg can be surely dissolved, and it is possible to further surely improve the heat resistance. [[ID=I4]]

[0012] Also, in the copper alloy shaped bar 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 within the above range, Ag segregates near the grain boundaries, grain boundary diffusion is suppressed, and heat resistance can be further improved.

[0013] In the copper alloy deformed strip material 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 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

[0014] In addition, the copper alloy deformed strip material of the present invention preferably has a metal plating layer on the surface. In this case, since the surface has a metal plating layer, it is particularly suitable as a material for parts of electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates.

[0015] The electronic / electrical device parts of the present invention are characterized by being made of the copper alloy deformed strip material described above. The electronic / electrical device parts in the present invention include terminals, bus bars, lead frames, heat dissipation substrates, etc. The electronic / electrical device component having this configuration is manufactured using the copper alloy deformed strip material described above, and therefore can exhibit excellent properties even in high-temperature environments.

[0016] The terminal of the present invention is characterized by being made of the copper alloy profile strip material described above. The terminal having this configuration is manufactured using the copper alloy strip material described above, and therefore can exhibit excellent characteristics even in a high-temperature environment.

[0017] The bus bar of the present invention is characterized by being made of the copper alloy profile strip material described above. ​​The bus bar having this configuration is manufactured using the copper alloy deformed strip material described above, and therefore can exhibit excellent characteristics even in a high-temperature environment.

[0018] The lead frame of the present invention is characterized by being made of the copper alloy profile strip material described above. The lead frame having this configuration is manufactured using the copper alloy profile strip material described above, and therefore can exhibit excellent characteristics even in a high temperature environment.

[0019] The heat dissipation substrate of the present invention is characterized by being made of the copper alloy profile strip material described above. The heat dissipation board of this configuration is manufactured using the copper alloy deformed strip material described above, and therefore can exhibit excellent characteristics even in a high-temperature environment. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a copper alloy shaped strip material that has little difference in properties such as strength and heat resistance between thick and thin portions and can be used stably in high-temperature environments, as well as electronic and electronic equipment components, terminals, bus bars, lead frames, and heat dissipation substrates made from this copper alloy shaped strip material. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional explanatory view of a copper alloy deformed strip material according to an embodiment of the present invention; [Figure 2] 1 is a flow diagram of a method for manufacturing a copper alloy irregular shaped strip material according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, a copper alloy deformed strip material according to one embodiment of the present invention will be described with reference to the accompanying drawings. The copper alloy deformed strip material of this embodiment is most suitable for use as a material for parts of electronic and electrical devices such as terminals, bus bars, lead frames, and heat dissipation substrates.

[0023] As shown in FIG. 1, the copper alloy deformed strip material 10 of this embodiment has a thick portion 11 and a thin portion 12 which are different in thickness in a cross section perpendicular to the longitudinal direction. Furthermore, the ratio t1 / t2 of the thickness t1 of the thick portion 11 to the thickness t2 of the thin portion 12 is preferably 8 or less, and more preferably 6 or less.

[0024] The copper alloy deformed strip material 10 of this embodiment has a composition in which the Mg content is in the range of more than 10 massppm and less than 1.2 mass%, the P content is in the range of 0 massppm to 200 massppm, and the balance is Cu and unavoidable impurities. In the copper alloy shaped strip material 10 of this embodiment, of the unavoidable impurities, it is preferable that the S content is 10 massppm or less, the Se content is 5 massppm or less, the Te content is 5 massppm or less, the Sb content is 5 massppm or less, the Bi content is 5 massppm or less, and the As content is 5 massppm or less, and the total content of S, Se, Te, Sb, Bi, and As is 24 massppm or less. In addition, in the copper alloy deformed strip material 10 of this embodiment, the Ag content may be in the range of 5 massppm to 20 massppm.

[0025] Furthermore, the copper alloy deformed strip material 10 of this embodiment has a conductivity of 48% IACS or more. Furthermore, in the copper alloy deformed strip material 10 of this 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 <T1 / T2<1.25とされている。

[0026] In the copper alloy deformed strip material 10 of this embodiment, a 10000 μm 2The above measurement area is analyzed for the misorientation of each crystal grain, excluding measurement points where the CI value is 0.1 or less at measurement intervals of 0.25 μm. Measurement points where the misorientation between adjacent measurement points is 15° or more are considered to be crystal grain boundaries. The average grain size A is calculated using Area Fraction, and measurements are made at measurement intervals of 1 / 10 or less of the average grain size A. A total of 1000 crystal grains are included in the area of ​​10,000 μm in multiple fields of view. 2 The measurement area is larger than or equal to 100°, and the analysis is performed excluding measurement points where the CI value analyzed by the data analysis software OIM is 0.1 or less. The length of the low-angle grain boundary and subgrain boundary between measurement points where the misorientation between adjacent measurement points is 2° or more and 15° or less is defined as L. LB The length of the high-angle grain boundary between adjacent measurement points where the misorientation between the measurement points exceeds 15° is defined as L. HB The small-angle grain boundary fraction B = L LB / (L LB +L HB ), the low-angle grain boundary ratio B1 of the thick portion 11 is 80% or less, the low-angle grain boundary ratio B2 of the thin portion 12 is 80% or less, and <B1 / B2<1.2とされている。 In addition, in the copper alloy deformed strip material 10 of this embodiment, the Goss orientation {011} <100> The area ratio of crystals having a crystal orientation within 10° with respect to the direction of the arrow is set to 1% or more in both the thick portion 11 and the thin portion 12.

[0027] Furthermore, in the copper alloy deformed strip material 10 of this 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

[0028] Here, the reasons for specifying the component composition, various properties, and crystalline structure of the copper alloy deformed strip material 10 of this embodiment as described above will be explained below.

[0029] (Mg) Mg is an element that has the effect of improving strength and heat resistance temperature without significantly reducing electrical conductivity by dissolving in the copper matrix. ​If the Mg content is 10 mass ppm or less, the effect of the magnesium may not be fully achieved, whereas if the Mg content is 1.2 mass % or more, the electrical conductivity may be low, making it difficult to stably use the material as a material for electronic and electrical equipment components. For the above reasons, in this embodiment, the Mg content is set within the range of more than 10 mass ppm and less than 1.2 mass %.

[0030] Here, in order to further improve the heat resistance temperature, the lower limit of the Mg content is preferably set to 20 massppm or more, more preferably 30 massppm or more, and even more preferably 40 massppm or more. In order to further suppress the decrease in electrical conductivity, the upper limit of the Mg content is preferably set to 1.0 mass% or less, more preferably to 0.8 mass% or less, even more preferably to 0.6 mass% or less, and even more preferably to 0.4 mass% or less.

[0031] (P) P is an element that has the effect of improving castability and may be added to improve productivity, but if added in excess, it may react with Mg to form a compound, which may reduce the effect of Mg solid solution. For the above reasons, in this embodiment, the P content is set within the range of 0 massppm to 200 massppm. Here, in order to ensure the effect of Mg solid solution, the upper limit of the P content is preferably set to 160 massppm or less, more preferably set to 120 massppm or less, even more preferably set to 80 massppm or less, and even more preferably set to 60 massppm or less.

[0032] (S, Se, Te, Sb, Bi, As) The elements S, Se, Te, Sb, Bi, and As mentioned above are generally elements that are easily mixed into copper alloys. These elements are likely to react with Mg to form compounds, which may reduce the solid solution effect of trace amounts of Mg added. For this reason, the content of these elements must be strictly controlled. Therefore, in this embodiment, it is preferable to limit the S content to 10 massppm or less, the Se content to 5 massppm or less, the Te content to 5 massppm or less, the Sb content to 5 massppm or less, the Bi content to 5 massppm or less, and the As content to 5 massppm or less. Furthermore, it is preferable to limit the total content of S, Se, Te, Sb, Bi, and As to 24 mass ppm or less.

[0033] The S content is more preferably 9 massppm or less, and even more preferably 8 massppm or less. The Se content is more preferably 4 massppm or less, and further preferably 2 massppm or less. The Te content is more preferably 4 massppm or less, and further preferably 2 massppm or less. The Sb content is more preferably 4 massppm or less, and further preferably 2 massppm or less. The Bi content is more preferably 4 massppm or less, and further preferably 2 massppm or less. The As content is more preferably 4 massppm or less, and further preferably 2 massppm or less. Furthermore, the total content of S, Se, Te, Sb, Bi, and As is more preferably 20 massppm or less, and even more preferably 16 massppm or less.

[0034] (Ag: 5 massppm or more and 20 massppm or less) Ag is hardly able to dissolve in the Cu matrix at temperatures below 250°C, the temperature range in which ordinary electronic and electrical equipment is used. Therefore, when a small amount of Ag is added to copper, it segregates near the grain boundaries. This prevents the movement of atoms at the grain boundaries, suppressing grain boundary diffusion and improving heat resistance. When the Ag content is 5 massppm or more, the effect can be fully achieved, whereas when the Ag content is 20 massppm or less, the electrical conductivity is ensured and the increase in manufacturing costs can be suppressed. For the above reasons, in this embodiment, the Ag content is set within the range of 5 massppm to 20 massppm.

[0035] In order to further improve the heat resistance, the lower limit of the Ag content is preferably 6 massppm or more, more preferably 7 massppm or more, and even more preferably 8 massppm or more. In order to reliably suppress a decrease in conductivity and an increase in cost, the upper limit of the Ag content is preferably 18 massppm or less, more preferably 16 massppm or less, and even more preferably 14 massppm or less. When Ag is not intentionally added, the Ag content may be less than 5 mass %.

[0036] (Other unavoidable impurities) Examples of inevitable 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, Sr, Ti, Os, Co, Rh, Ir, Pb, Pd, Pt, Au, Zn, Zr, Hf, Hg, Ga, In, Ge, Y, Tl, N, Si, Sn, Li, etc. These inevitable impurities may be contained to the extent that they do not affect the characteristics. Here, since these inevitable impurities may reduce the conductivity, it is preferable that the total amount is 0.1 mass% or less, more preferably 0.05 mass% or less, still more preferably 0.03 mass% or less, and even more preferably 0.01 mass% or less. In addition, 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 still more preferably 2 mass ppm or less.

[0037] (Small tilt grain boundary ratio) At grain boundaries, small tilt grain boundaries and sub-grain boundaries are regions with a high density of dislocations introduced during processing. Therefore, if the small tilt grain boundary ratio B = L LB / (L LB +L HB ) which is the ratio of the lengths of small tilt grain boundaries and sub-grain boundaries is too high, high-speed diffusion of atoms through dislocations is likely to occur, and recrystallization and accompanying softening under high-temperature environments are likely to occur, so the heat resistance may be impaired. Also, since the thick part 11 and the thin part 12 are used in the same temperature environment, it is required that there is no significant difference in heat resistance between the thick part 11 and the thin part 12. Therefore, in this embodiment, the small tilt grain boundary ratio B1 of the thick part 11 is set to 80% or less, and the small tilt grain boundary ratio B2 of the thin part 12 is set to 80% or less. Also, the ratio B1 / B2 of the small tilt grain boundary ratio B1 of the thick part 11 to the small tilt grain boundary ratio B2 of the thin part 12 is set to 0.8 < B1 / B2 < 1.2.

[0038] Here, the small tilt grain boundary ratio B1 of the thick part 11 is more preferably 76% or less, and still more preferably 72% or less. Also, the small tilt grain boundary ratio B1 of the thin part 12 is more preferably 76% or less, and still more preferably 72% or less. Furthermore, the ratio B1 / B2 of the small tilt grain boundary ratio is preferably within the range of 0.85 < T1 / T2 < 1.15, and more preferably within the range of 0.90 < T1 / T2 < 1.10.

[0039] (Goss direction {011} <100> (area ratio of crystals with a crystal orientation within 10° of the Since crystals with the Goss orientation {011}<100> are relatively resistant to dislocation accumulation, it is possible to suppress atomic diffusion and the resulting recovery caused by dislocation movement in high-temperature environments, thereby improving heat resistance. Furthermore, since the thick and thin parts 11 and 12 are used in similar temperature environments, it is required that there is no significant difference in heat resistance between the thick and thin parts 11 and 12. The Goss orientation {011}<100> mentioned above does not occur in copper materials through ordinary rolling or heat treatment, but can be formed through special forming and subsequent processing and heat treatment.

[0040] In this embodiment, the Goss orientation {011} <100> The area ratio of crystals having a crystal orientation within 10° to the direction of the arrow is set to be 1% or more in both the thick portion 11 and the thin portion 12. The thick portion 11 and the thin portion 12 have a Goss orientation of {011} <100> The area ratio of crystals having a crystal orientation within 10° to the above is preferably 1.4% or more, more preferably 1.8% or more, and even more preferably 2.2% or more.

[0041] (conductivity) The copper alloy shaped strip material 10 of this embodiment has an electrical conductivity of 48% IACS or more. By making the electrical conductivity 48% IACS or more, heat generation during electrical conduction is suppressed, and the material can be suitably used as a terminal, a bus bar, a lead frame, a heat dissipation substrate, or other electronic and electrical device component. Here, the conductivity is preferably 53% IACS or more, more preferably 58% IACS or more, even more preferably 63% IACS or more, and even more preferably 75% IACS or more.

[0042] (Heat-resistant temperature) In the copper alloy shaped bar 10 according to this embodiment, it is preferable that the heat resistance temperature T1 of the thick portion 11 is 260 °C or higher and the heat resistance temperature T2 of the thin portion 12 is 240 °C or higher. By configuring the heat resistance temperature as described above, sufficient heat resistance can be ensured. In addition, in the copper alloy shaped bar 10, the thick portion 11 and the thin portion 12 are often used in the same temperature environment. Therefore, it is preferable that the heat resistance temperature T1 of the thick portion 11 and the heat resistance temperature T2 of the thin portion 12 are close values, and it is preferable that the ratio T1 / T2 of the heat resistance temperature T1 of the thick portion 11 to the heat resistance temperature T2 of the thin portion 12 is 0.9 < T1 / T2 < 1.25. Here, the heat resistance temperature T1 of the thick portion 11 is more preferably 280 °C or higher, further preferably 300 °C or higher, and even more preferably 320 °C or higher. In addition, the heat resistance temperature T2 of the thin portion 12 is more preferably 260 °C or higher, further preferably 280 °C or higher, and even more preferably 300 °C or higher. Furthermore, it is more preferable that the ratio T1 / T2 of the heat resistance temperature is within the range of 0.92 < T1 / T2 < 1.20.

[0043] (Vickers hardness) In the copper alloy shaped bar 10 according to this embodiment, when the Vickers hardness H1 of the thick portion 11 is 70 Hv or higher and the Vickers hardness H2 of the thin portion 12 is 75 Hv or higher, the strength is ensured and it is particularly suitable as a material for electric and electronic components. In addition, when the hardness difference between the thick portion 11 and the thin portion 12 is large, deformation of the material may occur during press working when manufacturing parts for electric and electronic equipment, particularly terminals, bus bars, lead frames, and heat dissipation substrates. Therefore, it is preferable that the hardness H1 of the thick portion 11 and the hardness H2 of the thin portion 12 are close values, and it is preferable that the ratio H1 / H2 of the Vickers hardness H1 of the thick portion 11 to the Vickers hardness H2 of the thin portion 12 is 0.7 < H1 / H2 < 1.2. Here, the Vickers hardness H1 of the thick portion 11 is more preferably 72 Hv or higher, and further preferably 74 Hv or higher. Furthermore, the Vickers hardness H2 of the thin portion 12 is more preferably 77 Hv or more, and even more preferably 79 Hv or more. Furthermore, the Vickers hardness ratio H1 / H2 is 0.8

[0044] Next, a method for manufacturing the copper alloy deformed strip material 10 of this embodiment having the above-described configuration will be described with reference to the flow chart shown in FIG.

[0045] (Melting and casting process S01) First, the copper raw material is melted, and the above-mentioned elements are added to the resulting molten copper to adjust the composition, producing a molten copper alloy. The various elements can be added as simple elements or master alloys. Raw materials containing the above-mentioned elements may also be melted together with the copper raw material. Recycled or scrap materials of the alloy may also be used. Here, the copper raw material is preferably so-called 4NCu, which has a purity of 99.99 mass% or more, or so-called 5NCu, which has a purity of 99.999 mass% or more. During melting, in order to suppress oxidation of Mg and reduce the hydrogen concentration, it is preferable to carry out atmospheric melting in an inert gas atmosphere (e.g., Ar gas) with a low vapor pressure of HO, and to keep the holding time during melting to a minimum. The molten copper alloy with the adjusted composition is then poured into a mold to produce an ingot. When mass production is taken into consideration, it is preferable to use a continuous casting method or a semi-continuous casting method.

[0046] (Homogenization / solution treatment step S02) ​Next, the resulting ingot is subjected to a heat treatment for homogenization and solution treatment. The ingot may contain intermetallic compounds, primarily composed of Cu and Mg, that are formed as a result of Mg segregation and concentration during solidification. To eliminate or reduce these segregations and intermetallic compounds, the ingot is heated to a temperature of 300°C to 1080°C, thereby diffusing Mg homogeneously within the ingot and dissolving it in the matrix. This homogenization / solution treatment step S02 is preferably performed in a non-oxidizing or reducing atmosphere.

[0047] If the heating temperature is below 300°C, the solution treatment will be incomplete, and there is a risk that a large amount of intermetallic compounds, primarily composed of Cu and Mg, will remain in the matrix. On the other hand, if the heating temperature exceeds 1080°C, part of the copper material will become liquid, and there is a risk that the structure and surface condition will become non-uniform. Therefore, the heating temperature is set in the range of 300°C to 1080°C. In order to improve the efficiency of the rough rolling and to homogenize the structure, which will be described later, hot working may be performed after the homogenization / solution treatment step S02. In this case, the working method is not particularly limited, and for example, rolling, drawing, extrusion, groove rolling, forging, pressing, etc. can be used. In addition, the hot working temperature is preferably in the range of 300°C or higher and 1080°C or lower.

[0048] (Rough machining process S03) Rough processing is performed to process the material into a predetermined shape. The temperature conditions in this rough processing step S03 are not particularly limited, but in order to suppress recrystallization or improve dimensional accuracy, cold or warm rolling is preferably performed at a temperature in the range of -200°C to 200°C, with room temperature being particularly preferred. The processing rate is preferably 20% or more, and more preferably 30% or more. The processing method is not particularly limited, and examples of methods that can be used include rolling, drawing, extrusion, groove rolling, forging, and pressing. The rough processing step S03 and the intermediate heat treatment step S04 described below may be repeatedly performed.

[0049] (Intermediate heat treatment process S04) After the rough processing step S03, heat treatment is carried out to soften the material to improve workability or to create a recrystallized structure. In this case, a short-time heat treatment in a continuous annealing furnace is preferable, and when Ag is added, localized segregation of Ag at grain boundaries can be prevented. The conditions for this heat treatment are not particularly limited, but it is generally carried out in the range of 200°C to 1000°C.

[0050] (Mechanical surface treatment process S05) After the intermediate heat treatment step S04, a mechanical surface treatment is performed. This mechanical surface treatment applies compressive stress to the surface area, and by combining it with the upper pre-heat treatment step S07 described below, the Goss orientation {011}<100> is enhanced, thereby improving heat resistance. Mechanical surface treatment can be performed using a variety of commonly used methods, such as shot peening, blasting, lapping, polishing, buffing, grinder polishing, sandpaper polishing, tension leveler treatment, and light rolling with a low reduction per pass (a reduction per pass of 1% to 10%, repeated three or more times).

[0051] (Deformed shape rolling process S06) In the deformed rolling process, the material after the mechanical surface treatment step S05 is cold deformed using a flat die with an uneven surface and a rolling roll that faces the molding surface of the die and moves back and forth along the molding surface, to obtain a roughly deformed strip material in which coarse thick parts and coarse thin parts are aligned in the width direction. In addition, by setting the area reduction rate in the processing range from 5% to 90%, the Goss orientation is easily formed in the upper pre-heat treatment step S07. The area reduction rate in the processing is more preferably set in the range of 10% to 85%, and even more preferably set in the range of 15% to 80%. In addition, by setting the ratio of the thickness of the coarse thick portion to the thickness of the coarse thin portion to 6 or less, in the upper pre-heat treatment step S07, the ratio B of the small angle grain boundaries in the thick portion 11 and the thin portion 12 is set to L LB / (L LB +L HB) The ratio B1 / B2 can be set to 0.8 < B1 / B2 < 1.2, and the ratio H1 / H2 of the Vickers hardness in the thick portion 11 and the thin portion 12 can be set to 0.7 < H1 / H2 < 1.2. It is more preferable that the ratio of the thickness of the thick portion to the thickness of the thin portion is 5 or less.

[0052] (Pre - heat treatment step S07) Next, by performing heat treatment after the shape - rolling process step S06, a recrystallized structure is formed to form a Goss orientation. Also, the ratio B of small - angle grain boundaries is reduced by recrystallization. Furthermore, the structures of the thick portion 11 and the thin portion 12 are made similar. In this pre - heat treatment step S07, in order to eliminate the strain difference between the thick and thin portions introduced by the shape - rolling process step S06 and to perform uniform structure formation by recrystallization and subsequent grain growth, a heating rate below a certain level 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 within the range of not less than 250°C and not more than 650°C, the heating rate is not more than 500°C / h, and the heat treatment time is not less than 1 hour and not more than 100 hours.

[0053] (Finishing process step S08) After the pre - heat treatment step S07, cold working is performed. It is carried out by cold working using a rolling roll composed of a stepped roll and a flat roll. In order to make the Vickers hardness H1 of the thick portion 11 70 Hv and H2 of the thin portion 12 75 Hv or more, the working rate is preferably 5% or more, and more preferably 8% or more. On the other hand, if the working rate is too high, the ratios B1 and B2 of small - angle grain boundaries become high, and the area ratio of the Goss orientation, which is a recrystallized structure, also decreases. Therefore, the working rate is preferably 50% or less, and more preferably 45% or less.

[0054] (Low - temperature annealing step S09) After the finishing process step S08, low - temperature annealing is performed as necessary. By this low - temperature annealing step S09, the effects of removing residual stress and reducing the ratio of small - angle grain boundaries by recovery can be obtained. In this low-temperature annealing process S09, it is preferable that the annealing temperature is within the range of 100°C or higher and 600°C or lower, and the holding time at the annealing temperature is within the range of 0.1 seconds or longer and 24 hours or shorter. Note that when the heat treatment temperature is low, a long heat treatment time may be used, and when the heat treatment temperature is high, a short heat treatment time may be used. If the annealing temperature in the low-temperature annealing process 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 cannot be obtained. On the other hand, if the annealing temperature exceeds 600°C, there is a risk of recrystallization. Further, if the holding time at the annealing temperature exceeds 24 hours, it only causes an increase in cost.

[0055] Note that in this embodiment, a correction process using a tension leveler or the like may be added after the low-temperature annealing process S09. Furthermore, in the copper alloy shaped bar 10 of this embodiment, a metal plating layer may be formed on the surface. As the metal plating layer, for example, Sn plating, Ag plating, Ni plating, Au plating, Pd plating, Rh plating, etc. can be applied. [[ID=~]]

[0056] Through the above processes, the copper alloy shaped bar 10 of this embodiment is manufactured.

[0057] In the copper alloy shaped bar 10 of this embodiment configured as described above, since the Mg content is within the range exceeding 10 mass ppm and less than 1.2 mass%, and the P content is within the range of 0 mass ppm or higher and 200 mass ppm or lower, by dissolving Mg in the copper matrix phase, the heat resistance can be sufficiently improved. [[ID=1~]] Also, since the conductivity is 48% IACS or higher, heat generation during energization can be suppressed, and it is suitable as a material for parts for electronic and electrical equipment such as terminals, bus bars, lead frames, and heat dissipation substrates. Furthermore, since the heat resistance temperature T1 of the thick portion 11 is 260°C or higher, the heat resistance temperature T2 of the thin portion 12 is 240°C or higher, and 0.9 < T1 / T2 < 1.25, it is sufficiently excellent in heat resistance, and the difference in heat resistance between the thick portion 11 and the thin portion 12 is small, so it can be stably used even in a high-temperature environment.

[0058] And, the small-angle grain boundary ratios B1 and B2 of the thick portion 11 and the thin portion 12 are each 80% or less, and the ratio B1 / B2 of the small-angle grain boundary ratios is 0.8 < B1 / B2 < 1.2. The crystal grain boundary structure is controlled such 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 the thick portion and the thin portion, respectively. Therefore, recovery and recrystallization due to dislocation movement are less likely to occur, and in the thick portion 11 and the thin portion 12, it is possible to sufficiently improve the heat resistance.

[0059] In the copper alloy profiled bar 10 of the present embodiment, among inevitable impurities, the content of S 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 mas ppm or less, and the content of As is 5 mass ppm or less. When the total content of S, Se, Te, Sb, Bi, and As is 24 mass ppm or less, the contents of S, Se, Te, Sb, Bi, and As, which are elements that form compounds with Mg, are kept low. Therefore, Mg can be surely dissolved, and it is possible to further surely improve the heat resistance.

[0060] Furthermore, in the copper alloy profiled bar 10 of the present embodiment, when the content of Ag is within the range of 5 mass ppm or more and 20 mass ppm or less, Ag segregates near the grain boundaries. This Ag suppresses grain boundary diffusion, and it is possible to further surely improve the heat resistance temperature.

[0061] Also, in the copper alloy profiled bar 10 of the present embodiment, when 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, it has excellent strength, and the difference in strength between the thick portion 11 and the thin portion 12 is small, and it can be stably used.

[0062] Furthermore, when a metal plating layer is formed on the surface of the copper alloy shaped strip material 10 of this embodiment, various properties can be imparted to the surface, making it particularly suitable as a material for electronic and electrical equipment components such as terminals, bus bars, and heat dissipation substrates.

[0063] Furthermore, the electronic and electrical equipment components (terminals, bus bars, lead frames, heat dissipation substrates, etc.) of this embodiment are made of the above-mentioned copper alloy shaped strip material 10, and therefore can exhibit excellent properties even in high-temperature environments.

[0064] The above describes the copper alloy shaped strip material 10 and components for electronic and electrical equipment (terminals, bus bars, lead frames, heat dissipation substrates, etc.) that are embodiments of the present invention, but the present invention is not limited to this and can be modified as appropriate within the scope of the technical concept of the invention. For example, in the above embodiment, an example of a method for manufacturing the copper alloy irregular strip material 10 is described, but the method for manufacturing the copper alloy irregular strip material 10 is not limited to that described in the embodiment, and it may be manufactured by appropriately selecting an existing manufacturing method. In addition, in this embodiment, the description has been given taking the deformed strip having the shape shown in FIG. 1 as an example, but the present invention is not limited to this, and deformed strips having other cross-sectional shapes may also be used. [Example]

[0065] The results of confirmation experiments conducted to confirm the effects of the present invention will be described below. A raw material consisting of pure copper with a purity of 99.999 mass% or more was placed in a high-purity graphite crucible by the zone melting refining method, and was then high-frequency melted in an atmospheric furnace with an Ar gas atmosphere. The obtained molten copper was mixed with 0.1 mass% of various master alloys made from high-purity copper of 6N (purity 99.9999 mass%) or higher and pure metals with a purity of 2N (purity 99 mass%) or higher to adjust the composition shown in Tables 1 and 2, and poured into a mold made of insulating material (isowool) to produce an ingot. The size of the ingot was approximately 30 mm thick x 60 mm wide x 150 to 200 mm long.

[0066] The obtained ingots were heated for 1 hour under various temperature conditions in an Ar gas atmosphere, the surface was ground to remove the oxide film, and then cut to a predetermined size. The thickness was then adjusted appropriately to the final thickness and cut. Each cut sample was roughly rolled at room temperature at the working ratio shown in Tables 3 and 4, and then intermediate heat treatment was performed under the heat treatment conditions shown in Tables 3 and 4.

[0067] These samples were then subjected to a mechanical surface treatment process according to the methods described in Tables 3 and 4. The buffing was carried out using #1000 abrasive paper. The tension leveler is equipped with multiple φ16mm rolls, and the line tension is 100N / mm. 2 This was carried out at. Light rolling (rolling with a low reduction rate per pass) was performed with the final three passes having a reduction rate of 4% per pass.

[0068] Then, stepped profile processing was performed using a flat die and a rolling roll that faced the forming surface of the die and moved back and forth along the forming surface, so that the thicknesses of the thick and thin portions would be the values ​​shown in Tables 3 and 4, respectively. Then, pre-heat treatment was carried out under the conditions shown in Tables 3 and 4. Thereafter, finishing processing was carried out under the conditions shown in Tables 3 and 4, and low-temperature annealing was carried out on all samples except for a few, to produce strip materials for property evaluation with the thickness shown in Tables 3 and 4 and a width of approximately 60 mm.

[0069] The obtained strip material for property evaluation was evaluated as follows.

[0070] (composition analysis) Measurement samples were taken from the resulting ingot, and Mg was measured using inductively coupled plasma atomic emission spectrometry, and other elements were measured using a glow discharge mass spectrometer (GD-MS). The measurements were taken at two locations, the center and the widthwise edge of the sample, and the higher content was recorded as the content of that sample. As a result, it was confirmed that the component compositions were as shown in Tables 1 and 2.

[0071] (Small angle grain boundary ratio) The rolled surface, i.e., the ND (Normal direction) surface, was used as the observation surface, and the low-angle grain boundary proportions B1 and B2 in the thick and thin sections were determined as follows using an EBSD measurement device and OIM analysis software. After mechanical polishing using waterproof polishing paper and diamond abrasive grains, the specimen was polished using colloidal silica solution. EBSD measurement equipment (FEI Quanta FEG 450, EDAX / TSL (now AMETEK) OIM Data Collection) and analysis software (EDAX / TSL (now AMETEK) OIM Data Analysis ver.7.3.1) was used to measure the electron beam acceleration voltage of 15 kV and 10,000 μm 2 The above measurement area was analyzed for the misorientation of each crystal grain, excluding measurement points where the CI value was 0.1 or less at measurement intervals of 0.25 μm. Measurement points where the misorientation between adjacent measurement points was 15° or more were considered to be grain boundaries, and the average grain size A was calculated using the area fraction analysis software OIM. After that, measurements were made at measurement intervals of 1 / 10 or less of the average grain size A, and a 10,000 μm field was used in multiple fields of view to include a total of 1,000 or more crystal grains. 2 In the measurement area of ​​1000 or more, the analysis was performed excluding measurement points where the CI value analyzed by the data analysis software OIM was 0.1 or less, and the measurement points where the misorientation between adjacent measurement points was 2° or more and 15° or less were defined as low-angle grain boundaries and subgrain boundaries, and their length was defined as L LB The boundary between the measurement points exceeding 15° is defined as a high-angle grain boundary, and its length is L HB By setting the ratio of the length of low-angle grain boundaries and subgrain boundaries in all grain boundaries, the low-angle grain boundary ratio B = L LB / (L LB +L HB ) was sought.

[0072] (Goss direction) When measuring the length ratios of the low-angle grain boundaries and subgrain boundaries, the orientation of each crystal grain was also analyzed. Each analysis point was determined to determine whether it had the target Goss orientation (within 10° of the ideal orientation), and the Goss orientation ratio (area ratio of the crystal orientation) in the measurement region was calculated.

[0073] (Heat-resistant temperature) The heat resistance temperature was evaluated in accordance with JCBA T325:2013 of the Japan Copper and Brass Association, by obtaining an isochronous softening curve based on Vickers hardness after one hour of heat treatment and determining the heating temperature at which the hardness reached 80% of the hardness before heat treatment. The Vickers hardness was measured on the rolled surface. The evaluation results are shown in Tables 5 and 6.

[0074] (Vickers hardness) In accordance with the micro Vickers hardness testing method specified in JIS-Z2244, the Vickers hardness was measured on the surface of the strip material for property evaluation, i.e., the ND (Normal Direction) surface, with a test load of 0.98 N. The evaluation results are shown in Tables 3 and 4.

[0075] (conductivity) Test pieces measuring 10 mm wide and 60 mm long were taken from the strip material for property evaluation, and electrical resistance was measured using the four-terminal method. The dimensions of the test pieces were also measured using a micrometer, and the volume of the test pieces was calculated. The electrical conductivity was then calculated from the measured electrical resistance value and volume. The test pieces were taken so that their longitudinal direction was parallel to the rolling direction of the strip material for property evaluation. The evaluation results are shown in Tables 5 and 6.

[0076] [Table 1]

[0077] [Table 2]

[0078] [Table 3]

[0079] [Table 4]

[0080] [Table 5]

[0081] [Table 6]

[0082] In Comparative Example 1, the Mg content was lower than the range of the present invention, and therefore the heat-resistant temperature was low and the heat resistance was insufficient. In Comparative Example 2, the Mg content exceeded the range of the present invention, resulting in low electrical conductivity. In Comparative Example 3, the P content exceeded 200 mass ppm, the heat resistance temperature was low, and the heat resistance was insufficient. In Comparative Example 4, the proportion of low-angle tilt boundaries exceeded 80%, the heat-resistant 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 of the low-angle grain boundary fraction B1 in the thick portion to the low-angle grain boundary fraction B2 in the thin portion was outside the range of the present invention, and the ratio T1 / T2 of the heat resistance temperature T1 in the thick portion to the heat resistance temperature T2 in the thin portion was also outside the range of the present invention, resulting in variations in heat resistance.

[0083] In contrast, it was confirmed that in Examples 1 to 30 of the present invention, the heat resistance was improved in a well-balanced manner between the thick and thin portions. From the above, it has been confirmed that according to the present invention, it is possible to provide a copper alloy deformed strip material that is less likely to have differences in properties such as strength and heat resistance between the thick and thin portions and can be used stably in high-temperature environments.

Claims

1. A copper alloy deformed strip material having thick portions and thin portions having different thicknesses in a cross section perpendicular to the longitudinal direction, The composition includes a Mg content in the range of more than 10 mass ppm and less than 1.2 mass%, a P content in the range of 0 mass ppm or more and 200 mass ppm or less, and the balance being Cu and unavoidable impurities, The conductivity is 48% IACS or more, the heat resistance temperature T1 of the thick portion is 260°C or higher, the heat resistance temperature T2 of the thin portion is 240°C or higher, and 0.9<T1 / T2<1.25; 10,000 μm on the rolled surface by EBSD method ２ The above measurement area is analyzed for the misorientation of each crystal grain, excluding measurement points where the CI value is 0.1 or less at measurement intervals of 0.25 μm. Measurement points where the misorientation between adjacent measurement points is 15° or more are considered to be crystal grain boundaries. The average grain size A is calculated by area fraction, and measurements are made at measurement intervals of 1 / 10 or less of the average grain size A. A total of 1000 or more crystal grains are included in the measurement area of ​​10,000 μm in multiple fields of view. ２ In the measurement area of ​​100° or more, the analysis was performed excluding measurement points where the CI value analyzed by the data analysis software OIM was 0.1 or less, and the length of the low-angle grain boundary and subgrain boundary between measurement points where the misorientation between adjacent measurement points was 2° or more and 15° or less was defined as L ＬＢ The length of the high-angle grain boundary between adjacent measurement points where the misorientation between the measurement points exceeds 15° is defined as L ＨＢ and the small-angle grain boundary ratio B = L ＬＢ / (L ＬＢ +L ＨＢ ), the low-angle grain boundary ratio B1 of the thick portion is 80% or less, the low-angle grain boundary ratio B2 of the thin portion is 80% or less, and 0.8<B1 / B2<1.2; A copper alloy irregular strip material characterized in that the area ratio of crystals having a crystal orientation within 10° of the Goss orientation {011}<100> is 1% or more in each of the thick portion and the thin portion.

2. The copper alloy irregular strip material according to claim 1, characterized in that, among the unavoidable 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. 3. The copper alloy deformed strip material according to claim 1, wherein the Ag content is in the range of 5 ppm by mass to 20 ppm by mass.

4. A copper alloy irregular strip material as described in any one of claims 1 to 3, characterized in that 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.

5. 5. The copper alloy deformed strip material according to claim 1, further comprising a metal plating layer on the surface thereof.

6. A component for an electronic or electrical device, comprising the copper alloy deformed strip material according to any one of claims 1 to 5.

7. A terminal comprising the copper alloy profile strip material according to any one of claims 1 to 5.

8. A bus bar comprising the copper alloy deformed strip material according to any one of claims 1 to 5.

9. A lead frame comprising the copper alloy profile strip material according to any one of claims 1 to 5.

10. A heat dissipation substrate comprising the copper alloy profile strip material according to any one of claims 1 to 5.

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