JP5595961B2 - Cu-Ni-Si based copper alloy for electronic materials and method for producing the same - Google Patents

Description

  The present invention relates to a precipitation hardening type copper alloy, and more particularly to a Cu—Ni—Si based copper alloy suitable for use in various electronic components.

  Copper alloys for electronic materials used in various electronic parts such as connectors, switches, relays, pins, terminals, and lead frames are required to have both high strength and high conductivity (or thermal conductivity) as basic characteristics. Is done. In recent years, high integration and miniaturization / thinning of electronic components have been rapidly progressing, and the level of demand for copper alloys used in electronic device components has been increased accordingly.

  From the viewpoint of high strength and high conductivity, the amount of precipitation hardening type copper alloys is increasing instead of conventional solid solution strengthened copper alloys such as phosphor bronze and brass as copper alloys for electronic materials. . In precipitation-hardened copper alloys, by aging the solution-treated supersaturated solid solution, fine precipitates are uniformly dispersed, increasing the strength of the alloy, and at the same time reducing the amount of solid solution elements in copper. Electrical conductivity is improved. For this reason, a material excellent in mechanical properties such as strength and spring property and having good electrical conductivity and thermal conductivity can be obtained.

  Among precipitation hardening copper alloys, Cu-Ni-Si copper alloys, commonly called Corson alloys, are representative copper alloys that have relatively high electrical conductivity, strength, and bending workability, and are currently active in the industry. It is one of the alloys being developed. In this copper alloy, strength and electrical conductivity are improved by precipitating fine Ni—Si intermetallic compound particles in a copper matrix.

  In Japanese translations of PCT publication No. 2005-532477 (patent document 1), each annealing in the manufacturing process of a Cu-Ni-Si-Co-based alloy can be a staged annealing process, and typically in staged annealing. It is described that the first step is at a higher temperature than the second step, and stepped annealing can result in a better combination of strength and conductivity than annealing at a constant temperature.

JP 2006-283059 A (Patent Document 2) describes a Corson (Cu—Ni—Si) copper alloy having a yield strength of 700 N / mm ² or more, an electrical conductivity of 35% IACS or more, and excellent bending workability. For the purpose of obtaining a plate, the copper alloy ingot is hot-rolled and rapidly cooled as necessary, then cold-rolled and continuously annealed to obtain a solution recrystallized structure, and then the processing rate Cold rolling at 20% or less and aging treatment at 400 to 600 ° C. for 1 to 8 hours, followed by short annealing at 400 to 550 ° C. for 30 seconds or less after final cold rolling at a processing rate of 1 to 20% A method for producing a high-strength copper alloy sheet is described.

  Moreover, various efforts have been made to improve the strength, conductivity, and spring limit value of the Corson (Cu—Ni—Si based) copper alloy plate (Patent Documents 3 to 6).

JP 2005-532477 A JP 2006-283059 A Japanese Patent Application Laid-Open No. 2004-269962 JP-A-6-212374 JP 2006-283059 A JP-A-11-256256

  In this way, efforts have been made to improve the strength, conductivity, and spring limit value, but there is still room for improvement. Therefore, an object of the present invention is to provide a Cu—Ni—Si alloy having an improved balance of strength, conductivity, and spring limit value. Another object of the present invention is to provide a method for producing such a Cu—Ni—Si alloy.

  The present inventor conducted extensive research to solve the above problems. As a result, when the aging treatment after the solution treatment was performed in three stages under specific temperature and time conditions, in addition to strength and conductivity, We found that the spring limit value improved significantly. Thus, when the cause was investigated, the crystal orientation of the rolled surface obtained by the X-ray diffraction method was in a positional relationship of 55 ° (α = 35 ° on measurement conditions) with respect to the {200} Cu surface of the rolled surface. It has been found that the peak height at the β angle of 90 ° in the diffraction peak of the {111} Cu surface has a specificity of 2.5 times or more that of the copper powder. The reason why such a diffraction peak was obtained is unknown, but it is considered that the fine distribution state of the second phase particles has an influence.

  The present invention completed on the basis of the above knowledge includes, in one aspect, Ni: 1.0 to 4.0 mass%, Si: 0.2 to 1.0 mass%, with the balance being Cu and inevitable impurities. Diffraction peak intensity of {111} Cu surface with respect to {200} Cu surface by β scanning at α = 35 ° as a result of X-ray diffraction pole figure measurement based on rolled surface, which is a copper alloy for electronic materials Among them, a copper alloy having a peak height at a β angle of 90 ° is 2.5 times or more that of standard copper powder.

  In yet another embodiment of the copper alloy according to the present invention, the ratio i / Si of the mass concentration of Ni to the mass concentration of Si satisfies 3.5 ≦ Ni / Si ≦ 5.5.

  In yet another embodiment, the copper alloy according to the present invention is further selected from the group consisting of Cr, Mg, P, As, Sb, Be, B, Mn, Sn, Ti, Zr, Al, Fe, Zn, and Ag. At least one kind is contained in a maximum of 2.0% by mass in total.

In another aspect of the present invention,
-Step 1 of melting and casting an ingot of a copper alloy having any of the above compositions;
Step 2 of performing hot rolling after heating at −900 ° C. or higher and 1000 ° C. or lower for 1 hour or longer,
-Cold rolling process 3;
Step 4 of performing solution treatment at −700 ° C. or more and 900 ° C. or less, and cooling at an average cooling rate up to 400 ° C. at 10 ° C. or more per second;
-The first stage of heating at a material temperature of 400-500 ° C for 1-12 hours, the second stage of heating at a material temperature of 350-450 ° C for 1-12 hours, and then the material temperature of 260-340 ° C It has a third stage that is heated for 4 to 30 hours, and the cooling rate from the first stage to the second stage and the cooling rate from the second stage to the third stage are 0.1 to 8 ° C./min. A first aging treatment step 5 in which the second stage temperature difference is set to 20 to 60 ° C., and the second stage and third stage temperature difference is set to 20 to 180 ° C. to perform multi-stage aging;
-Cold rolling process 6;
A second aging treatment step 7 carried out at -100 ° C or higher and lower than 350 ° C for 1 to 48 hours;
It is a manufacturing method of the said copper alloy including performing these in order.

  In yet another aspect, the present invention is a copper drawn product made of the copper alloy according to the present invention.

  In still another aspect, the present invention is an electronic component including the copper alloy according to the present invention.

  The present invention provides a Cu—Ni—Si based alloy for electronic materials that is excellent in strength, conductivity, and spring limit value.

Addition amounts of Ni and Si Ni and Si form an intermetallic compound by performing an appropriate heat treatment, and can increase the strength without deteriorating conductivity.
If the addition amounts of Ni and Si are less than Ni: 1.0% by mass and Si: less than 0.2% by mass, the desired strength cannot be obtained. Conversely, Ni: more than 4.0% by mass, Si: 1 If it exceeds 0.0 mass%, the strength can be increased, but the electrical conductivity is remarkably lowered, and the hot workability is further deteriorated. Therefore, the addition amounts of Ni and Si were set to Ni: 1.0 to 4.0% by mass and Si: 0.2 to 1.0% by mass. The addition amounts of Ni and Si are preferably Ni: 1.5 to 3.0% by mass and Si: 0.3 to 0.8% by mass.

Moreover, if the ratio Ni / Si of the mass concentration with Ni with respect to the mass concentration of Si is too low, that is, if the ratio of Si with respect to Ni is too high, the solute Si may decrease the conductivity or the annealing process. In this case, an oxide film of SiO ₂ is formed on the material surface layer and solderability is deteriorated. On the other hand, if the ratio of Ni to Si is too high, Si required for silicide formation is insufficient and high strength is difficult to obtain.
Therefore, the Ni / Si ratio in the alloy composition is preferably controlled in the range of 3.5 ≦ Ni / Si ≦ 5.5, and more preferably in the range of 4.0 ≦ Ni / Si ≦ 5.0. preferable.

The added amount Cr of Cr preferentially precipitates at the grain boundaries in the cooling process during melt casting, so that the grain boundaries can be strengthened, cracks during hot working are less likely to occur, and yield reduction can be suppressed. That is, Cr that has precipitated at the grain boundaries during melt casting is re-dissolved by solution treatment or the like, but during subsequent aging precipitation, precipitated particles having a bcc structure mainly composed of Cr or a compound with Si are generated. In a normal Cu—Ni—Si based alloy, Si that does not contribute to aging precipitation suppresses the increase in conductivity while being dissolved in the matrix, but the silicide forming element Cr is not added. By adding and further depositing silicide, the amount of dissolved Si can be reduced, and the conductivity can be increased without impairing the strength. However, if the Cr concentration exceeds 0.5% by mass, especially 2.0% by mass, coarse second-phase particles are easily formed, which impairs product characteristics. Therefore, Cr can be added up to 2.0% by mass to the Cu—Ni—Si based alloy according to the present invention. However, since the effect is small if it is less than 0.03 mass%, it is preferable to add 0.03-0.5 mass%, more preferably 0.09-0.3 mass%.

Addition amounts of Mg, Mn, Ag and P Mg, Mn, Ag and P improve the product properties such as strength and stress relaxation characteristics without adding a small amount of addition by adding a small amount. The effect of addition is exhibited mainly by solid solution in the matrix phase, but further effects can be exhibited by inclusion in the second phase particles. However, if the total concentration of Mg, Mn, Ag, and P exceeds 0.5% by mass, particularly 2.0% by mass, the effect of improving characteristics is saturated and manufacturability is impaired. Therefore, in the Cu—Ni—Si based alloy according to the present invention, one or two or more selected from Mg, Mn, Ag and P in total is a maximum of 2.0 mass%, preferably a maximum of 1.5 mass. % Can be added. However, since the effect is small if it is less than 0.01% by mass, it is preferable to add 0.01 to 1.0% by mass in total, more preferably 0.04 to 0.5% by mass in total.

Even in the addition amounts Sn and Zn of Sn and Zn, the addition of a small amount improves product properties such as strength, stress relaxation properties, and plating properties without impairing electrical conductivity. The effect of addition is exhibited mainly by solid solution in the matrix. However, if the total amount of Sn and Zn exceeds 2.0% by mass, the effect of improving characteristics is saturated and manufacturability is impaired. Therefore, one or two selected from Sn and Zn can be added to the Cu—Ni—Si based alloy according to the present invention in a maximum of 2.0 mass% in total. However, since the effect is small if it is less than 0.05% by mass, it is preferable to add 0.05 to 2.0% by mass in total, and more preferably 0.5 to 1.0% by mass in total.

Addition amounts of As, Sb, Be, B, Ti, Zr, Al, and Fe As, Sb, Be, B, Ti, Zr, Al, and Fe are also adjusted according to required product characteristics. This improves product properties such as conductivity, strength, stress relaxation properties, and plating properties. The effect of addition is exhibited mainly by solid solution in the parent phase, but it can also be exhibited by forming the second phase particles having a new composition or contained in the second phase particles. However, if the total amount of these elements exceeds 2.0% by mass, the effect of improving characteristics is saturated and manufacturability is impaired. Therefore, in the Cu—Ni—Si based alloy according to the present invention, a total of one or more selected from As, Sb, Be, B, Ti, Zr, Al and Fe is up to 2.0 mass% in total. Can be added. However, since the effect is small if it is less than 0.001% by mass, it is preferable to add 0.001-2.0% by mass in total, more preferably 0.05-1.0% by mass in total.

  Manufacturability is liable to be impaired when the total amount of Cr, Mg, Mn, Ag, P, Sn, Zn, As, Sb, Be, B, Ti, Zr, Al, and Fe exceeds 2.0% by mass. Therefore, preferably the total of these is 2.0% by mass or less, more preferably 1.5% by mass or less.

Crystal orientation The copper alloy according to the present invention is a result obtained by X-ray diffraction pole figure measurement based on the rolled surface, and the diffraction peak of the {111} Cu surface relative to the {200} Cu surface by β scanning at α = 35 ° Among the intensities, the ratio of the peak height at the β angle of 90 ° to that of the standard copper powder (hereinafter referred to as “peak height ratio at the β angle of 90 °”) is 2.5 times or more. The reason why the spring limit value is improved by controlling the peak height at the β angle of 90 ° at the diffraction peak of the {111} Cu surface is not necessarily clear and is only an estimate, but the first aging treatment is performed in three stages. By aging, the growth of the second phase particles precipitated in the first stage and the second stage and the second phase particles precipitated in the third stage make it easy to accumulate work strains in the next rolling process and accumulate them. It is considered that the texture develops by the second aging treatment using the processing strain as a driving force.
The peak height ratio at a β angle of 90 ° is preferably 2.8 times or more, more preferably 3.0 times or more. The pure copper standard powder is defined as a copper powder having a purity of 99.5% with a 325 mesh (JIS Z8801).

  The peak height at the β angle of 90 ° at the diffraction peak of the {111} Cu plane is measured by the following procedure. Focusing on a certain diffractive surface {hkl} Cu, with respect to the 2θ value of the focused {hkl} Cu surface (fixing the scanning angle 2θ of the detector), α-axis scanning is performed in steps to obtain the angle α value. On the other hand, a measurement method in which the sample is scanned on the β axis (in-plane rotation (rotation) from 0 to 360 °) is called pole figure measurement. In the XRD pole figure measurement of the present invention, the direction perpendicular to the sample surface is defined as α = 90 °, which is used as a measurement reference. In addition, the pole figure measurement is performed by a reflection method (α: −15 ° to 90 °). In the present invention, the intensity with respect to the β angle of α = 35 ° is plotted, and the highest intensity in the range of β = 85 ° to 95 ° is read as the peak value of 90 °.

Manufacturing Method In a general manufacturing process of a Corson copper alloy, first, an atmospheric melting furnace is used to melt raw materials such as electrolytic copper, Ni, Si, etc., and a molten metal having a desired composition is obtained. Then, this molten metal is cast into an ingot. Thereafter, hot rolling is performed, and cold rolling and heat treatment are repeated to finish a strip or foil having a desired thickness and characteristics. Heat treatment includes solution treatment and aging treatment. In the solution treatment, heating is performed at a high temperature of about 700 to about 900 ° C., so that the second phase particles are dissolved in the Cu matrix, and at the same time, the Cu matrix is recrystallized. The solution treatment may be combined with hot rolling. In the aging treatment, the second phase particles heated in a temperature range of about 350 to about 550 ° C. for 1 hour or more and solid-dissolved by the solution treatment are precipitated as fine particles of nanometer order. This aging treatment increases strength and conductivity. In order to obtain higher strength, cold rolling may be performed before and / or after aging. Moreover, when performing cold rolling after aging, strain relief annealing (low temperature annealing) may be performed after cold rolling.
Between the above steps, grinding, polishing, shot blast pickling and the like for removing oxide scale on the surface are appropriately performed.

  The copper alloy according to the present invention also undergoes the manufacturing process described above, but in order for the properties of the finally obtained copper alloy to be in the range specified by the present invention, hot rolling, solution treatment and aging treatment are performed. It is important that the conditions are strictly controlled.

  First, coarse crystallized products are inevitably generated during the solidification process during casting, and coarse precipitates are inevitably generated during the cooling process, so it is necessary to dissolve these second-phase particles in the matrix during the subsequent steps. There is. If hot rolling is performed after holding at 900 ° C. to 1000 ° C. for 1 hour or longer, it can be dissolved in the matrix. Moreover, it is desirable to cool rapidly after completion | finish of hot rolling.

  The purpose of the solution treatment is to increase the age-hardening ability after the solution treatment by solidifying the crystallized particles at the time of dissolution casting and the precipitated particles after hot rolling. At this time, the holding temperature and time during the solution treatment and the cooling rate after holding are important. In the case where the holding time is constant, if the holding temperature is increased, the crystallized particles at the time of melting and casting and the precipitated particles after hot rolling can be dissolved.

  The faster the cooling rate after solution treatment, the more the precipitation during cooling can be suppressed. If the cooling rate is too slow, the second phase particles become coarse during cooling and the Ni and Si contents in the second phase particles increase, so that sufficient solution cannot be achieved by solution treatment, and aging is not possible. Curing ability is reduced. Therefore, the cooling after the solution treatment is preferably rapid cooling. Specifically, after solution treatment at 700 ° C. to 900 ° C., it is effective to cool to 400 ° C. at an average cooling rate of 10 ° C. or more, preferably 15 ° C. or more, more preferably 20 ° C. or more per second. . The upper limit is not particularly defined, but is 100 ° C. or less per second due to equipment specifications. Here, the “average cooling rate” is a value (° C./second) obtained by measuring the cooling time from the solution temperature to 400 ° C. and calculating “(solution temperature−400) (° C.) / Cooling time (second)”. ).

  In producing the Cu—Ni—Si based alloy according to the present invention, it is effective to perform a mild aging treatment in two stages after the solution treatment and perform cold rolling between the two aging treatments. is there. Thereby, coarsening of the precipitate is suppressed, and a good distribution state of the second phase particles can be obtained. This is considered to ultimately lead to the crystal orientation unique to the copper alloy according to the present invention.

  However, the present inventor has found that the spring limit value is remarkably improved when the first aging treatment immediately after the solution treatment is aged in three stages under the following specific conditions. Although there was literature that improved the balance between strength and conductivity by performing multi-stage aging, it is said that by strictly controlling the number of stages, temperature, time, and cooling rate of multi-stage aging, the spring limit value is significantly improved. It was a surprise. According to the inventor's experiment, such an effect could not be obtained by one-stage aging or two-stage aging, and sufficient effects could not be obtained even if only the second aging treatment was aged three stages. It was.

  Although it is not intended that the present invention be limited by theory, the reason why the spring limit value is remarkably improved by adopting the three-stage aging is considered as follows. By setting the first aging treatment to three-stage aging, the second-phase particles precipitated in the first and second stages grow and the second-phase particles precipitate in the third stage. It is thought that the organization becomes difficult to develop.

  In the three-stage aging, the material temperature is first set to 400 to 500 ° C. and heated for 1 to 12 hours. In the first stage, the purpose is to increase the strength and conductivity by nucleation and growth of the second phase particles.

  If the material temperature in the first stage is less than 400 ° C. or the heating time is less than 1 hour, the volume fraction of the second phase particles is small, and it is difficult to obtain desired strength and conductivity. On the other hand, when it is heated until the material temperature exceeds 500 ° C. or when the heating time exceeds 12 hours, the volume fraction of the second phase particles increases, but it tends to coarsen and the strength decreases. Becomes stronger.

  After completion of the first stage, the cooling rate is set to 0.1 to 8 ° C./min, and the aging temperature of the second stage is shifted. The cooling rate here is measured by ((first stage aging temperature−second stage aging temperature) (° C.) / (Cooling time (minutes) from first stage aging temperature to reaching second stage aging temperature).

  Subsequently, it heats for 1 to 12 hours by setting material temperature as 350-450 degreeC. In the second stage, the second phase particles precipitated in the first stage are grown in a range that contributes to strength, and the second phase particles are newly precipitated in the second stage (deposited in the first stage). The purpose is to increase strength and electrical conductivity by being smaller than the second phase particles.

  If the material temperature in the second stage is less than 350 ° C. or if the heating time is less than 1 hour, the second phase particles precipitated in the first stage cannot grow, making it difficult to increase the conductivity, and in the second stage Since the second phase particles cannot be precipitated, the strength and conductivity cannot be increased. On the other hand, when heated until the material temperature exceeds 450 ° C., or when the heating time exceeds 12 hours, the second phase particles precipitated in the first stage grow too much and become coarse, and the strength decreases. .

  If the temperature difference between the first stage and the second stage is too small, the second phase particles precipitated in the first stage become coarse and cause a decrease in strength, while if too large, the second phase particles precipitated in the first stage almost grow. Therefore, the conductivity cannot be increased. Moreover, since it becomes difficult to precipitate the second phase particles in the second stage, the strength and conductivity cannot be increased. Therefore, the temperature difference between the first stage and the second stage should be 20 to 60 ° C.

  After completion of the second stage, for the same reason as described above, the cooling rate is set to 0.1 to 8 ° C./min and the aging temperature of the third stage is shifted to. The cooling rate here is measured by (second stage aging temperature−third stage aging temperature) (° C.) / (Cooling time from second stage aging temperature to third stage aging temperature (minutes)). The

  Subsequently, it heats for 4 to 30 hours by setting material temperature as 260-340 degreeC. The purpose of the third stage is to slightly grow the second phase particles precipitated in the first and second stages and to newly generate second phase particles.

  If the material temperature in the third stage is less than 260 ° C. or the heating time is less than 4 hours, the second phase particles precipitated in the first and second stages cannot be grown. Since the second phase particles cannot be generated, it is difficult to obtain desired strength, conductivity, and spring limit value. On the other hand, when heated until the material temperature exceeds 340 ° C. or when the heating time exceeds 30 hours, the second phase particles precipitated in the first and second stages grow too much and become coarse. It is difficult to obtain desired strength and spring limit value.

  If the temperature difference between the second stage and the third stage is too small, the second phase particles precipitated in the first stage and the second stage are coarsened, leading to a decrease in strength and spring limit value. The second phase particles precipitated in the second stage hardly grow and the electrical conductivity cannot be increased. In addition, since the second phase particles are difficult to precipitate in the third stage, the strength, spring limit value, and conductivity cannot be increased. Therefore, the temperature difference between the second stage and the third stage should be 20 to 180 ° C.

  In the aging treatment in one stage, since the distribution of the second phase particles changes, the temperature should be constant in principle. However, there may be a fluctuation of about ± 5 ° C with respect to the set temperature. Absent. Therefore, each step is performed within a temperature fluctuation range of 10 ° C. or less.

  Cold rolling is performed after the first aging treatment. In this cold rolling, insufficient age hardening in the first aging treatment can be supplemented by work hardening. The degree of processing at this time is 10 to 80%, preferably 20 to 60% in order to reach a desired strength level. However, the spring limit value decreases.

  After cold rolling, it is important to increase the spring limit and conductivity in the second aging treatment. If the second aging temperature is set high, the spring limit value and the conductivity increase, but if the temperature condition is too high, the particles that have already precipitated become coarse and become over-aged, reducing the strength. To do. Therefore, it should be noted that the second aging treatment is held for a long period of time at a temperature lower than the conditions normally performed in order to restore the conductivity and the spring limit value. This is because both the suppression of the precipitation rate and the effect of rearrangement of dislocations are enhanced. An example of the conditions for the second aging treatment is 1 to 48 hours in a temperature range of 100 ° C. or more and less than 350 ° C., and more preferably 1 to 12 hours in a temperature range of 200 ° C. or more and 300 ° C. or less.

  Immediately after the second aging treatment, even when the aging treatment is performed in an inert gas atmosphere, the surface is slightly oxidized and the solder wettability is poor. Therefore, when solder wettability is required, pickling and / or polishing can be performed.

  The Cu—Ni—Si based alloy of the present invention can be processed into various copper products, such as plates, strips, tubes, bars and wires, and the Cu—Ni—Si based copper alloy according to the present invention is a lead. It can be used for electronic parts such as frames, connectors, pins, terminals, relays, switches, and foil materials for secondary batteries.

  Examples of the present invention will be described below together with comparative examples, but these examples are provided for better understanding of the present invention and its advantages, and are not intended to limit the invention.

Effect of first aging condition on alloy characteristics A copper alloy containing each additive element shown in Table 1 and the balance consisting of copper and impurities is melted at 1300 ° C. in a high-frequency melting furnace, and an ingot having a thickness of 30 mm Cast into. Next, this ingot was heated at 1000 ° C. for 3 hours, and then hot-rolled to a plate thickness of 10 mm, and cooled rapidly after the hot rolling was completed. Next, the surface was chamfered to a thickness of 9 mm to remove the scale, and then a plate having a thickness of 0.115 mm was formed by cold rolling. Next, solution treatment was performed at 700 ° C. or higher and 900 ° C. or lower for 120 seconds, and then cooled. The solution temperature was set higher when the concentration of the additive element was high. Water cooling was performed with an average cooling rate from the solution temperature to 400 ° C. at 20 ° C./s. Thereafter, it was allowed to cool in the air. Next, the first aging treatment was performed under the conditions described in Table 1 in an inert atmosphere. The material temperature in each stage was maintained within the set temperature ± 3 ° C. described in Table 1. Thereafter, it was cold-rolled to 0.08 mm, and finally subjected to a second aging treatment at 300 ° C. for 3 hours in an inert atmosphere to produce each test piece.

  With respect to each test piece thus obtained, the alloy characteristics were measured as follows.

  Regarding the strength, a tensile test in the rolling parallel direction was performed in accordance with JIS Z2241, and a 0.2% yield strength (YS: MPa) was measured.

  The conductivity (EC;% IACS) was determined by volume resistivity measurement using a double bridge.

  As for the spring limit value, in accordance with JIS H3130, a repetitive deflection test was performed, and the surface maximum stress was measured from the bending moment in which permanent strain remained.

  The peak height ratio at a β angle of 90 ° was determined by using the X-ray diffractometer of model RINT-2500V manufactured by Rigaku Corporation according to the measurement method described above.

  Regarding bending workability, as a W-bending test of Badway (the bending axis is the same direction as the rolling direction), a 90-degree bending process is performed using a W-shaped mold and the ratio of the sample plate thickness to the bending radius is 2. Went. Subsequently, the surface of the bent portion was observed with an optical microscope, and when no crack was observed, it was judged that there was no problem in practical use.

  The test results of each test piece are shown in Table 2.

Example No. Nos. 1 to 46 have a peak height ratio of β angle 90 ° of 2.5 or more, indicating that the balance of strength, conductivity and spring limit value is excellent.
Comparative Example No. 8, Comparative Example No. 19-23, Comparative Example No. 25 to 35 are examples in which the first aging was performed by two-stage aging.
Comparative Example No. 7 is an example in which the first aging is performed by one-step aging.
Comparative Example No. 2 and 9 are examples in which the aging time of the third stage was short.
Comparative Example No. 4 is an example in which the aging temperature in the third stage was low.
Comparative Example No. 13 is an example in which the aging temperature in the third stage was high.
Comparative Example No. 12 is an example in which the aging time of the third stage is long.
Comparative Example No. 1 is an example in which the aging temperature in the first stage was low.
Comparative Example No. 3 is an example in which the temperature difference between the first and second stages is large.
Comparative Example No. 5 is an example in which the first stage aging time was short.
Comparative Example No. 6 is an example in which the second stage aging time was short.
Comparative Example No. 10 is an example in which the aging time of the second stage is long.
Comparative Example No. 11 is an example in which the aging time of the first stage was long.
Comparative Example No. 14 is an example in which the temperature of the second stage was high.
Comparative Example No. 15 is an example in which the temperature of the first and second stages was high.
Comparative Example No. 16 is an example in which the cooling from the second stage to the third stage was slow.
Comparative Example No. 17 is an example in which the cooling from the first stage to the second stage was slow.
Comparative Example No. 18 is an example in which the Ni concentration was low.
Comparative Example No. 24 is an example in which the Ni concentration and the Si concentration were high.
In all of the comparative examples, the peak height ratio at the β angle of 90 ° is less than 2.5, and it can be seen that the balance of strength, conductivity, and spring limit value is inferior to the examples.

Claims (5)

Ni: 1.0 to 4.0% by mass, Si: 0.2 to 1.0% by mass, and the ratio of the total mass concentration of Ni to the mass concentration of Si is Ni ≦ Si 3.5 ≦ Ni / Si ≦ 5.5, the balance is a copper alloy for electronic materials consisting of Cu and inevitable impurities, and obtained by X-ray diffraction pole figure measurement based on the rolling surface, and by β scanning at α = 35 ° Among the diffraction peak intensities of the {111} Cu surface relative to the {200} Cu surface, a copper alloy having a peak height at a β angle of 90 ° is 2.5 times or more that of a standard copper powder. Furthermore, at least one selected from the group consisting of Cr, Mg, P, As, Sb, Be, B, Mn, Sn, Ti, Zr, Al, Fe, Zn, and Ag is contained in a total of up to 2.0% by mass. claim 1 Symbol placement of the copper alloy. -Melting and casting a copper alloy ingot having the composition according to claim 1 or 2 ;
Step 2 of performing hot rolling after heating at −900 ° C. or higher and 1000 ° C. or lower for 1 hour or longer;
Step 4 of performing solution treatment at −700 ° C. or more and 900 ° C. or less, and cooling at an average cooling rate up to 400 ° C. at 10 ° C. or more per second;
-The first stage of heating at a material temperature of 400-500 ° C for 1-12 hours, the second stage of heating at a material temperature of 350-450 ° C for 1-12 hours, and then the material temperature of 260-340 ° C It has a third stage that is heated for 4 to 30 hours, and the cooling rate from the first stage to the second stage and the cooling rate from the second stage to the third stage are 0.1 to 8 ° C./min. A first aging treatment step 5 in which the second stage temperature difference is set to 20 to 60 ° C., and the second stage and third stage temperature difference is set to 20 to 180 ° C. to perform multi-stage aging;
-Cold rolling process 6;
A second aging treatment step 7 carried out at -100 ° C or higher and lower than 350 ° C for 1 to 48 hours;
The manufacturing method of the copper alloy including performing sequentially. Claim 1 or 2 copper products made of a copper alloy according. An electronic component of claim 1 or 2, wherein the copper alloy.