JP4804266B2 - Cu-Zn-Sn alloy for electrical and electronic equipment and method for producing the same - Google Patents

Description

  The present invention relates to a copper alloy having excellent strength, electrical conductivity, bending workability and press punching workability, and suitable for electrical and electronic parts such as terminals, connectors, switches and relays.

Inexpensive brass is used for various terminals, connectors, relays, switches, and the like of electrical and electronic equipment in applications where production costs are important. Further, phosphor bronze is used in applications where springiness is important, and white is used in applications where spring properties and corrosion resistance are important. These copper alloys are solid solution strengthened alloys, and the strength and spring property are improved by the action of the alloy elements, but the conductivity and thermal conductivity are lowered.
In recent years, the amount of precipitation-strengthened copper alloys used has increased in place of solid solution strengthened alloys. The precipitation-strengthened alloy is characterized in that an alloy element is precipitated as fine compound particles in a Cu matrix. As the alloying elements precipitate, the strength increases and at the same time the conductivity increases. Therefore, the precipitation hardened alloy can obtain higher conductivity with the same strength as the solid solution strengthened alloy. Examples of the precipitation strengthening type copper alloy include a Cu—Ni—Si alloy, a Cu—Be alloy, a Cu—Ti alloy, a Cu—Zr alloy, and the like.
However, in precipitation-strengthened alloys, there are high-temperature and short-time heat treatment (solution treatment) for once dissolving the alloy elements in Cu and low-temperature and long-time heat treatment (aging treatment) for precipitating the alloy elements. It is necessary and its manufacturing process is complicated. Moreover, since an active element such as Si, Ti, Zr, or Be is contained as an alloy element, it is difficult to build ingot quality. Therefore, the manufacturing cost of the precipitation strengthening type alloy is very high compared with the manufacturing cost of the solid solution strengthening type alloy.

On the other hand, by improving a solid solution strengthened alloy, development of an inexpensive copper alloy having necessary and sufficient electrical conductivity and strength is in progress. A Cu—Zn-based alloy typified by brass is an alloy that can be manufactured at a particularly low cost because it is easy to manufacture and coupled with the fact that Zn is inexpensive. The present inventors previously adjusted the amount of Zn in the Cu-Zn alloy, added a small amount of Sn, and further adjusted the metal structure, so that the necessary and sufficient conductivity, strength and bending as materials for various terminals and the like were obtained. An alloy having workability was developed (Patent Document 1). In general, necessary and sufficient electrical conductivity, strength and bending workability are described below.
(A) Conductivity: 35% IACS or higher. This conductivity is comparable to the conductivity of a Cu—Ni—Si alloy (Corson alloy), which is a precipitation strengthening type alloy. The conductivity of brass (C2600) is 28% IACS, and the conductivity of phosphor bronze (C5210) is 13% IACS.
(B) Tensile strength: 410 MPa or more. This tensile strength corresponds to the tensile strength of grade H of brass (C2600) defined by the JIS standard (JIS 3100).
(C) Bendability: Under the condition of bending radius R / sheet thickness t = 0.1, both Good Way (direction in which the bending axis is perpendicular to the rolling direction) and Bad Way (direction in which the bending axis is parallel to the rolling direction) W bending is possible. If cracks do not occur in this bending test, the most severe level of bending applied to the connector is possible.

With recent miniaturization of electronic equipment components, terminals, connectors, switches, relays, and the like are also miniaturized. In response to this trend, there is a need for a copper alloy material that balances conductivity, strength, and bending workability at a higher level. The Cu-Zn-Sn alloy previously developed by the present inventors has the strength of brass, the electrical conductivity of the Corson alloy, and the bending workability equivalent to or better than that of brass and Corson alloy, and the balance of the characteristics is the same as that of the conventional Cu- Compared with Zn-Sn alloy (Patent Documents 2 to 4), it is remarkably superior. This alloy can be said to be a copper alloy that is suitable as a material for electronic device parts that are becoming smaller in size.
Japanese Patent Application No. 2005-207556 JP-A-1-162737 JP-A-2-170954 JP 7-258777 A

When processing a copper alloy strip into an electronic component, first, punching by a press is performed. With the miniaturization of terminals, connectors, switches, relays, etc., the demand for dimensional accuracy after press punching has become strict. That is, there is a demand for a copper alloy strip that is less likely to generate burrs and sagging during press punching. In the conventional Cu—Zn—Sn alloys disclosed in Patent Documents 2 to 4 and the like, the alloy design considering press punchability is not performed, and it is possible to cope with the press accuracy demanded recently. It was getting harder.
An object of the present invention is to provide a Cu—Zn—Sn alloy strip having improved press punching workability.

  The present inventor has intensively studied measures for improving the press punching workability of Cu—Zn—Sn alloy strips. As a result, it has been found that press punching processability is improved if compound particles such as precipitates and non-metallic inclusions are distributed in the alloy at an appropriate frequency according to the dimensions. And the optimal distribution state of the compound particle in a Cu-Zn-Sn type alloy was clarified, and the method for obtaining this distribution state was clarified.

The present invention has been made based on this discovery,
(1) It contains 2 to 12% by mass of Zn and 0.1 to 1.0% by mass of Sn, and includes the Sn mass% concentration ([% Sn]) and the Zn mass% concentration ([% Zn]). Relationship
0.5 ≦ [% Sn] +0.16 [% Zn] ≦ 2.0
The balance is a copper alloy composed of copper and its inevitable impurities, and the frequency of compound particles having a diameter of 0.1 μm or more and 5 μm or less is 500 to 50,000 / mm ^2. A copper alloy for electrical and electronic equipment, wherein the frequency of compound particles having a diameter of more than 5 μm is 10 / mm ² or less,
(2) 2 to 12% by mass of Zn, 0.1 to 1.0% by mass of Sn, Sn mass% concentration ([% Sn]) and Zn mass% concentration ([% Zn]) Relationship
0.5 ≦ [% Sn] +0.16 [% Zn] ≦ 2.0
Adjusted to the range of
Furthermore, it contains at least one selected from the group of Ni, Fe, Mn, Mg, Co, Ti, Cr, Zr, Al, P, Si and Ag in a range of 0.005 to 0.5% by mass, and the balance Is a copper alloy composed of copper and its inevitable impurities,
In a cross section parallel to the rolling surface, the frequency of compound particles having a diameter of 0.1 μm or more and 5 μm or less is 500 to 50000 pieces / mm ² , and the frequency of compound particles having a diameter of more than 5 μm is 10 pieces / mm ² or less. Features copper alloy for electrical and electronic equipment,
(3) The copper alloy for electrical and electronic equipment according to (1) or (2) above, which contains 15 to 60 ppm by mass of S and O in total.
(4) Ingot is manufactured by melt casting, this ingot is hot-rolled, then cold rolling and recrystallization annealing are repeated, and finally in the process of manufacturing in a process of finishing a predetermined product thickness by cold rolling, The method for producing a copper alloy for electrical and electronic equipment according to the above (1) to (3), wherein the hot rolling is performed under the following conditions:
(A) The ingot is heated at 800 to 900 ° C. for 1 to 5 hours.
(B) The material temperature at the end of hot rolling is 600 to 700 ° C.
(C) During hot rolling, a sheet having a processing degree of 30% or more is performed twice or more.
It is about.

(A) Zn and Sn concentrations The copper alloy of the present invention contains Zn and Sn as basic components, and creates mechanical properties and electrical conductivity by the action of both elements. The Zn concentration range is 2 to 12% by mass, preferably 5 to 10% by mass, and the Sn concentration range is 0.1 to 1.0% by mass, preferably 0.1 to 0.5% by mass. When Zn is less than 2% by mass, the strength is insufficient and good manufacturability that is characteristic of the Cu—Zn alloy is lost. When Zn exceeds 12% by mass, a conductivity of 35% IACS or more cannot be obtained even if the Sn concentration is adjusted. Sn has the effect | action which accelerates | stimulates the work hardening in the case of rolling, and intensity | strength will be insufficient when Sn is less than 0.1 mass%. On the other hand, when Sn exceeds 1.0 mass%, the productivity of an alloy will fall.
The total concentration (T) of Sn and Zn is adjusted as follows.
0.5 ≦ T ≦ 2.0
T = [% Sn] +0.16 [% Zn]
Here, [% Sn] and [% Zn] are the mass% concentrations of Sn and Zn, respectively. If T is 2.0 or less, a conductivity of 35% IACS or more can be obtained. Further, if T is 0.5 or more, a tensile strength of 410 MPa or more can be obtained by appropriately adjusting the metal structure. Therefore, T is specified to be 0.5 to 2.0, preferably 0.6 to 1.7. By adjusting to this range, a conductivity of 35% IACS or more and a tensile strength of 410 MPa or more can be obtained more stably.

(B) Ni, Fe, Mn, Mg, Co, Ti, Cr, Zr, Al, P, Si, and Ag
The alloy of the present invention includes a group of Ni, Fe, Mn, Mg, Co, Ti, Cr, Zr, Al, P, Si and Ag for the purpose of improving the strength, heat resistance and stress relaxation resistance of the alloy. 0.005 to 0.5 mass% in total can be added at least one selected from However, the addition of the alloy element may cause a decrease in conductivity, a decrease in manufacturability, an increase in raw material cost, and the like, and thus this point needs to be taken into consideration.
When the total amount of the above elements is less than 0.005% by mass, the effect of improving the characteristics is not exhibited. On the other hand, when the total amount of the above elements exceeds 0.5% by mass, the decrease in conductivity becomes significant. Therefore, the total amount is specified to be 0.005 to 0.5 mass%.

(C) Compound particles When compound particles having a diameter of 0.1 μm or more and 5 μm or less (hereinafter referred to as fine particles) are contained at a frequency of 500 particles / mm ² or more in a cross-section parallel to the rolling surface, burrs after press punching are processed. Becomes smaller. On the other hand, if the frequency of the compound particles of fine particles exceeds 50000 / mm ² , bending workability deteriorates. Therefore, the frequency of compound particles of fine particles is defined to be 500 to 50000 pieces / mm ² . A more preferable frequency is 1000 to 10,000 pieces / mm ² , and good punching workability and bending workability are more stably achieved. Constituent components of the compound particles are described in (d) below.
Compound particles having a diameter of more than 5 μm (hereinafter referred to as coarse particles) significantly deteriorate the bending workability. Therefore, the frequency of coarse particles is regulated to 10 particles / mm ² or less in a cross section parallel to the rolling surface. If it is 10 pieces / mm ² or less, the influence on bending workability can be ignored.
The compound particles having a diameter of less than 0.1 μm do not affect the punching workability and bending workability. Therefore, the frequency of compound particles having a diameter of less than 0.1 μm is not particularly specified.

(D) S concentration, O concentration As compound particles in the Cu—Zn—Sn alloy, there are ZnO, ZnS, Cu ₂ S, CaO, CaS, MgS, MgO, SiO _{2 and the} like. The compounds of Zn and Cu are derived from the alloy components, and the compounds of Ca, Mg and Si are derived from the furnace material components of the melting furnace.
Since compound particle components are mostly oxides and sulfides, the frequency of compound particles can be adjusted by adjusting the S concentration and the O concentration.
S and O are preferably adjusted to a total of 15 to 60 ppm by mass. If the total of S and O is less than 15 ppm by mass, it is difficult to adjust the frequency of fine particles to 500 particles / mm ² or more. On the other hand, when the total of S and O exceeds 60 mass ppm, the fine particles may exceed 50000 / mm ² or the frequency of coarse particles may exceed 10 / mm ² .

(E) Manufacturing method In the manufacture of the Cu-Zn-Sn alloy of the present invention, an ingot is first manufactured by melt casting, this ingot is hot-rolled, and then cold rolling and recrystallization annealing are repeated. Finish to a predetermined product thickness by cold rolling. For the purpose of improving the spring limit value, stress corrosion cracking susceptibility, stress relaxation resistance, etc., strain relief annealing may be performed after finish cold rolling. In addition, the surface of the product may be subjected to plating such as reflow tin plating. In these series of steps, an important step for adjusting the compound particles is hot rolling (hereinafter, hot rolling).
The metal structure of the ingot is composed of dendritic crystals, and compounds such as sulfides and oxides are distributed in the gaps between the dendritic crystals. The compound in the ingot is coarse, and in this form, the effect for improving the punching workability is small. Therefore, it is necessary to dissolve a coarse compound once in hot rolling and reprecipitate it as fine compound particles, and to crush and refine the coarse compound during hot rolling.
The ingot is heated at a temperature of 800 to 950 ° C. for 1 to 5 hours in order to dissolve the compound in the matrix. When the temperature is less than 800 ° C., the compound is not sufficiently dissolved. On the other hand, when the temperature exceeds 950 ° C., cracks occur due to hot rolling. When the heating time of the ingot is less than 1 hour, the compound is not sufficiently dissolved. On the other hand, even if heating is performed for more than 5 hours, the compound is not further dissolved, which increases costs and is uneconomical.
In order to reprecipitate the compound particles once dissolved in the matrix, the material temperature at the end of hot rolling is set to 600 to 700 ° C. Since the solubility of the compound in the matrix is lower as the temperature is lower, the compound particles are reprecipitated while the material temperature is lowered from the hot rolling start temperature (800 to 950 ° C.) to 600 to 700 ° C. When the material temperature at the end of hot rolling exceeds 700 ° C., reprecipitation of the compound particles becomes insufficient. If the material temperature at the end of hot rolling is less than 600 ° C., the workability is lowered and hot rolling cracks occur.
In the hot rolling process, the material is passed through a rolling mill a plurality of times and finished to a predetermined thickness. In order to effectively crush a coarse compound, it is necessary to perform a total of 2 or more passes during hot-rolling through a sheet having a degree of processing adjusted to 30% or more. Here, the processing degree R is defined by the following equation.
R = (t ₀ -t) / t ₀ (t ₀ : thickness before rolling, t: thickness after rolling)

Using a high frequency induction furnace, 2 kg of electrolytic copper was dissolved in a graphite crucible having an inner diameter of 60 mm and a depth of 200 mm. After covering the molten copper surface with charcoal pieces, Zn and Sn were added. Further, CuS was added as necessary for adjusting the S concentration, and CuO was added as necessary for adjusting the O concentration. After adjusting the molten copper temperature to 1200 ° C., it was cast into a mold to produce an ingot having a width of 60 mm and a thickness of 30 mm, and the following steps were taken as a standard process and processed to a thickness of 0.3 mm.
(Step 1) The thickness is reduced to 6 mm by hot rolling (hot rolling).
(Step 2) The oxidized scale on the surface of the hot rolled plate is ground and removed with a grinder.
(Step 3) Cold rolling (primary rolling) to a plate thickness of 1.5 mm.
(Process 4) As recrystallization annealing (intermediate annealing), it heats in air | atmosphere for 30 minutes at 400 degreeC, and adjusts a crystal grain diameter to about 3 micrometers.
(Step 5) Pickling with a 10% by mass sulfuric acid-1% by mass hydrogen peroxide solution and mechanical polishing with # 1200 emery paper are sequentially performed to remove the surface oxide film formed by annealing.
(Step 6) By cold rolling (intermediate rolling), the steel sheet is rolled to a thickness of 0.43 mm at a workability of 71%.
(Step 7) As recrystallization annealing (final annealing), heating is performed in the atmosphere at 400 ° C. for 30 minutes to adjust the crystal grain size to about 3 μm.
(Step 8) Pickling with 10% by mass sulfuric acid-1% by mass hydrogen peroxide solution and mechanical polishing with # 1200 emery paper are sequentially performed to remove the surface oxide film formed by annealing.
(Step 9) Cold rolling (finish rolling) is performed at a workability of 30% to 0.3 mm.
The following evaluation was performed about the obtained sample.

Compound particle measurement:
The rolled surface was finished to a mirror surface by mechanical polishing and electrolytic polishing. In the electrolytic polishing, a solution obtained by mixing 125 mL of phosphoric acid, 250 mL of distilled water, 125 mL of ethanol, 25 mL of propanol, and 2.5 g of uric acid was used as an electrolytic solution, and energization was performed using the sample as an anode.
The surface after electropolishing was observed using an FE-SEM (field emission scanning electron microscope), and the number of compound particles was measured. For compound particles having a diameter of 0.1 μm or more and 5 μm or less, an area of 0.01 mm ² was observed at a magnification of 10,000, and the number of particles obtained was converted to the number per 1 mm ² . For compound particles having a diameter of more than 5 μm, an area of 1 mm ² was observed at a magnification of 1,000 times, and the number of particles was measured.
In the case where the shape of the compound particles is elliptical, rod-like, linear, etc., the average value of the minor axis (L1) and the major axis (L2) is taken as the diameter, as shown in FIG. In addition, for a particle group composed of particles continuous in the rolling direction (for example, B-based inclusions in JISG0555), the diameter and number of the particle group are not measured, but the diameter of each particle constituting the particle group. And the number was measured.

Press punching workability:
A round hole was formed in the sample by press punching. The punch had a cylindrical shape with a diameter of 9.96 mm, and the hole diameter on the die side was 10.00 mm (clearance 0.02 mm). The punching speed was 10 mm / min, and no material pressing was performed.
The fracture surface of the round hole was observed from the cross section, and the height of the burr shown in FIG. 2 was measured. The measurement position was a fracture surface portion parallel to the rolling direction. Each sample was measured 10 times, and the average value was obtained. It was judged that good punching workability was obtained when the burr height was 10 μm or less.

Bending workability:
A W-bending test defined in JISH3110 was performed using a strip-shaped sample having a width of 10 mm. The bending direction was set to Good Way and Bad Way, and the bending radius was set to 0.03 mm (bending radius R / plate thickness t = 0.1).
For the sample after bending, the presence or absence of cracks was observed from the surface and cross section of the bent part. When no cracks occurred on Good Way and Bad Way, cracks occurred on both, Good Way and Bad Way, or on one side. The case was evaluated as x. A crack having a depth exceeding 10 μm was regarded as a crack.

conductivity:
According to JIS H 0505, the measurement was performed by the 4-terminal method.
Tensile strength:
A JIS No. 13B specimen was prepared using a press so that the tensile direction was parallel to the rolling direction. The tensile test of this test piece was performed according to JIS-Z2241, and the tensile strength was determined.

Example 1
Cu-Zn-Sn alloy ingots having the components shown in Table 2 were produced and processed to a thickness of 0.3 mm according to the standard process. In any sample, in the hot rolling, the ingot was heated at 850 ° C. for 3 hours. Thereafter, a plate having a degree of processing of 30% or more was passed twice according to pattern A in Table 1 showing a processing pattern in hot rolling, and the thickness was finished to 6 mm. The material temperature (hot rolling end temperature) immediately after finishing hot rolling was about 630 ° C.
Table 2 shows the influence of the Zn concentration and the Sn concentration and the compound particles on the press punchability.
In Invention Examples 1 to 21, as a result of adjusting the total concentration of S and O to 15 to 60 ppm by mass, the frequency of fine particles falls within 500 to 50000 particles / mm ² and coarse particles become 10 particles / mm ² or less. It was. For this reason, the burr height was 10 μm or less, and no crack was generated by the W bending of R / t = 0.1. Moreover, since the density | concentration of the alloy component was adjusted to the appropriate range, the electrical conductivity of 35% IACS or more and the tensile strength of 410 Mpa or more were obtained.
In Invention Examples 1 to 5 and Comparative Examples 22 to 24, the total concentration of S and O is changed with respect to the Cu-8 mass% Zn-0.3 mass% Sn alloy. It can be seen that as the total concentration of S and O increases, fine particles increase and burrs become smaller. Among these, in Comparative Example 22, since the total concentration of S and O was less than 15 ppm by mass, the fine particles were less than the specified range, and burrs exceeding 10 μm were generated. In Comparative Examples 23 and 24, the total concentration of S and O exceeded 60 mass ppm. For this reason, in Comparative Example 23, the fine particles exceeded the specified range, and cracking occurred in the W bending of R / t = 0.1. Similarly, in Comparative Example 24, fine particles and coarse particles exceeded the specified range, and cracking occurred in the W-bending with R / t = 0.1.
Comparative Examples 25 to 28 are examples in which the target conductivity or tensile strength was not obtained although the burrs were small and W-bending was possible because the concentration of the alloy component was inappropriate. Since Comparative Example 25 had a low Zn concentration, Comparative Example 26 had a low Sn concentration, so the tensile strength was less than 410 MPa. Since Comparative Example 27 had high Zn and Sn concentrations, Comparative Example 28 had high Al and Si concentrations, so the conductivity was less than 35% IACS.
In Comparative Example 29, since the Ni concentration was too high, the conductivity was low, and cracking occurred in W bending. Furthermore, since the total concentration of S and O was less than 15 ppm by mass, the burr height exceeded 10 μm.

(Example 2)
Table 3 shows the influence of the hot rolling conditions on the compound particles and press punchability.
An ingot having a Zn concentration of 8% by mass, an Sn concentration of 0.3% by mass, ([% Sn] +0.16 [% Zn]) of 1.58, an S concentration of 15 ppm by mass, and an O concentration of 20 ppm by mass. According to the standard process, the plate was processed to a thickness of 0.3 mm. In the hot rolling, the heating temperature and time of the ingot were changed, and the processing patterns were changed in seven types A to F in Table 1. Furthermore, the hot rolling end temperature was changed by, for example, air-cooling the material between the plates.
In Invention Examples 30 to 46, as a result of hot rolling under the conditions of the present invention, the frequency of fine particles was within 500 to 50000 particles / mm ² and the coarse particles were 10 particles / mm ² or less. For this reason, the burr height was 10 μm or less, and no crack was generated by the W bending of R / t = 0.1.
In Invention Examples 30 to 33 and Comparative Examples 47 to 49, the heating time of the ingot was 3 hours, the processing pattern was B (twice of the processing plate of 30% or more), the hot rolling end temperature was about 650 ° C., The heating temperature is changed. It can be seen that the higher the heating temperature, the smaller the coarse particles, the more fine particles, and the smaller the burrs. Of these, since Comparative Example 47 had a heating temperature lower than 800 ° C., coarse particles exceeded 10 particles / mm ² , and cracking occurred in W bending. In Comparative Example 48, since the heating temperature was further lower, the coarse particles exceeded 10 particles / mm ² and the fine particles were less than 500 particles / mm ² , cracks were generated by W bending, and burrs exceeding 10 μm were generated. In Comparative Example 49, since the heating temperature of the ingot exceeded 900 ° C., cracking occurred during hot rolling, and processing was not possible up to a plate thickness of 0.3 mm.
In invention examples 31, 34 to 38, and comparative example 50, the heating temperature of the ingot was 830 ° C., the processing pattern was B (twice through the processing degree 30% or more), the hot rolling end temperature was about 650 ° C., The heating time is changed. It can be seen that as the heating time is longer, coarse particles are reduced, fine particles are increased, and burrs are reduced. In Comparative Example 50, since the heating time was shorter than 1 hour, the coarse particles exceeded 10 particles / mm ² , and cracking occurred in W bending. Although the heating time of Invention Example 38 is 6 hours, which is longer than that of Invention Example 37 with a heating time of 5 hours, the number of fine particles and coarse particles is equal to that of Invention Example 34, and the effect of increasing the heating time is recognized. Absent.
In Invention Examples 35, 39 to 42, and Comparative Examples 51 to 53, the heating temperature of the ingot is 830 ° C., the heating time is 2 hours, the processing pattern is B (twice passing plate with a processing degree of 30% or more), and the hot rolling is finished. The material temperature at the time is changed. It can be seen that the lower the material temperature at the end of hot rolling, the more fine particles increase and the burr becomes smaller. In Comparative Examples 52 and 53, since the hot rolling end temperature exceeded 700 ° C., the reprecipitation of fine particles was insufficient, the number of fine particles was less than 500 particles / mm ² , and the burr height exceeded 10 μm. It was. In Comparative Example 51, when processing was performed at a temperature lower than 600 ° C. in the second half of hot rolling, the material was cracked and could not be processed to 0.3 mm.
In Invention Examples 40, 43 to 46, and Comparative Examples 54 to 56, the heating temperature of the ingot was 830 ° C., the heating time was 2 hours, the hot rolling end temperature was about 650 ° C., and the processing pattern in hot rolling was changed. . It can be seen that by increasing the number of passing plates with a processing degree of 30% or more, the coarse compound is crushed, the number of coarse particles is reduced, and the number of fine particles is increased. In Comparative Examples 54 to 56, the number of coarse particles exceeded 10 particles / mm ² because the number of pass plates having a workability of 30% or more was less than twice, and cracking occurred in W bending.

It is the schematic which shows the short axis (L1) and the long axis (L2) in the case where the shape of a compound particle is an ellipse shape, rod shape, a linear shape. It is the schematic which shows the height of the burr | flash of a press fracture surface cross section (a rolling direction is perpendicular | vertical to a figure) in press punching workability measurement.

Claims (4)

2 to 12% by mass of Zn, 0.1 to 1.0% by mass of Sn, and the relationship between the Sn mass% concentration ([% Sn]) and the Zn mass% concentration ([% Zn]) ,
0.5 ≦ [% Sn] +0.16 [% Zn] ≦ 2.0
The balance is a copper alloy composed of copper and its inevitable impurities, and the frequency of compound particles having a diameter of 0.1 μm or more and 5 μm or less is 500 to 50,000 / mm ^2. The frequency of compound particles having a diameter of more than 5 μm is 10 / mm ² or less. 2 to 12% by mass of Zn, 0.1 to 1.0% by mass of Sn, and the relationship between the Sn mass% concentration ([% Sn]) and the Zn mass% concentration ([% Zn]) ,
0.5 ≦ [% Sn] +0.16 [% Zn] ≦ 2.0
Adjusted to the range of
Furthermore, it contains at least one selected from the group of Ni, Fe, Mn, Mg, Co, Ti, Cr, Zr, Al, P, Si and Ag in a range of 0.005 to 0.5% by mass, and the balance Is a copper alloy composed of copper and its inevitable impurities,
In a cross section parallel to the rolling surface, the frequency of compound particles having a diameter of 0.1 μm or more and 5 μm or less is 500 to 50000 pieces / mm ² , and the frequency of compound particles having a diameter of more than 5 μm is 10 pieces / mm ² or less. A copper alloy for electrical and electronic equipment.   Furthermore, S and O are contained 15 to 60 mass ppm in total, The copper alloy for electrical and electronic equipment of Claim 1 or 2 characterized by the above-mentioned. Ingot is manufactured by melt casting, this ingot is hot-rolled, then cold rolling and recrystallization annealing are repeated, and finally, in the process of manufacturing in the process of finishing to a predetermined product thickness by cold rolling, hot rolling The method for producing a copper alloy for electrical and electronic equipment according to any one of claims 1 to 3, wherein:
(1) The ingot is heated at 800 to 900 ° C. for 1 to 5 hours.
(2) The material temperature at the end of hot rolling is 600 to 700 ° C.
(3) During hot rolling, a sheet having a processing degree of 30% or more is performed twice or more.

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