KR100689687B1 - Cu-Ni-Si-Mg SYSTEM COPPER ALLOY STRIP - Google Patents

Abstract

(Problem) Provided is a Cu-Ni-Si-Mg-based alloy having excellent strength, conductivity, stress relaxation resistance, bending workability, etching property, wettability, and plating property and which can be stably manufactured.

(Measures) 1.0-4.0 mass% of Ni is contained, 1/6-1/4 concentration of Si is contained with respect to the mass% of Ni, 0.05%-0.3 mass% of Mg, and remainder is Cu And a copper-based alloy made of unavoidable impurities, wherein the Ni-Si-based compound particles have a distribution state of the following (1) and (2) in a cross section parallel to the rolling direction. Mg based copper alloy strip.

(1) Ni-Si type compound particle whose particle diameter is 10 micrometers or more and 20 micrometers or less is 2 pieces / mm <2> or less,

(2) Of the Ni-Si-based particle groups composed of Ni-Si-based compound particles having a particle diameter of 2 µm or more and 20 µm or less, the number of Ni-Si-based particle groups having a length of 0.05 mm or more and 1.0 mm or less is 2 pieces / mm 2 or less. being.

Description

Cu-Ni-Si-Mg-based copper alloy strip {Cu-Ni-Si-Mg SYSTEM COPPER ALLOY STRIP}

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the typical form of the aggregate of Ni-Si-type coarse particle.

It is a schematic diagram which shows the typical form of the Ni-Si type particle group observed in a rolling parallel cross section.

3 is a view showing a mold shape.

4 is an explanatory diagram of a cyclic bending test method.

5 is an explanatory diagram of a stress relaxation test method.

It is explanatory drawing about the permanent deformation amount of a stress relaxation test method.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a copper alloy strip, and more particularly to a copper alloy strip used in a lead frame member of a semiconductor device such as an integrated circuit (IC) or a conductive spring member such as a connector, terminal, relay, or switch. will be.

Copper alloy strips for electronic materials used in lead frames, terminals, connectors, and the like are required to have both high strength and high electrical conductivity (thermal conductivity) as basic properties of the alloy. In addition to these properties, bending workability, stress relaxation resistance, heat resistance, adhesion to plating, solder wettability, etching workability, press punching resistance, corrosion resistance, and the like are required.

On the other hand, in response to the miniaturization and high integration of electronic components in recent years, lead frames, terminals, and connectors have increased in lead number and narrower pitch, and component shapes have become complicated. At the same time, the demand for improved reliability at the time of assembly and after mounting is increasing. Against this background, the demand level for the characteristics of the above-described copper alloy material is becoming more and more advanced.

In view of high strength and high electrical conductivity, the amount of the age hardening type copper alloy is increasing as a copper alloy for electronic materials in place of the solid solution type copper alloy represented by conventional phosphor bronze, brass and the like. In the age hardening type copper alloy, by aging the solution-treated supersaturated solid solution, fine precipitates are uniformly dispersed to increase the strength of the alloy, and the amount of solid solution in copper is reduced to improve electrical conductivity. For this reason, the material which is excellent in mechanical properties, such as strength and a spring property, and is excellent in electrical conductivity and thermal conductivity is obtained.

Among the aging hardening copper alloys, Cu-Ni-Si-based copper alloys are representative copper alloys having high strength and high electrical conductivity, and have been put into practical use as materials for electronic devices. In this copper alloy, fine Ni-Si-based intermetallic compound particles are precipitated in the copper matrix to increase strength and electrical conductivity.

To Cu-Ni-Si-based copper alloys, elements other than Ni and Si are often added in order to improve mechanical properties and the like. In particular, Mg is a representative element added to the Cu-Ni-Si-based copper alloy. As an effect of the addition of Mg,

(1) The strength and stress relaxation resistance are improved (Japanese Patent Laid-Open No. 61-250134),

(2) hot workability is improved (Japanese Patent Laid-Open No. 05-345941),

(3) By forming Mg into an oxide and trapping oxygen, generation or coarsening of Si oxide during heat treatment can be prevented (Japanese Patent Laid-Open No. 09-209062),

And the like have been reported.

However, when Mg is added to the Cu-Ni-Si-based alloy, strength and stress relaxation resistance are improved, but coarse inclusions are easily generated in the alloy, resulting in a decrease in bending workability, etching property, plating property, and the like. The presence of inclusions in the alloy is known to adversely affect bending workability, etching properties, plating properties, and the like.

Inclusions of Cu-Ni-Si-based copper alloys include two kinds of non-metallic inclusions such as oxides and sulfides and coarse Ni-Si-based compounds. In the case of Cu-Ni-Si-Mg-based copper alloys, since Mg is more easily oxidized than Si, the composition of the oxide is MgO, and the sulfide is MgS. However, it is clearly shown in Japanese Laid-Open Patent Publication No. 05-059468 that lowering the O and S concentrations to 15 ppm or less can suppress the production of MgO and MgS.

On the other hand, according to Mizuno et al., When Mg is added to a Cu-Ni-Si-based copper alloy, coarse Ni-Si-based precipitates containing about 15 at% Mg in the grain boundary are coarsely grown (Mizuno Masataka, Henmi Yoshio, Kokura Tetsuzo, Hama). Takamoto: The Journal of the Shindong Institute of Technology, vol. 38 (1999), p291-297.). That is, when Mg is added to the Cu-Ni-Si-based copper alloy, the coarse Ni-Si-based compound significantly increases.

Increasing the coarse Ni-Si-based compound increases the amount of smut generated during etching and decreases the plating property and the bending workability. Thus, Japanese Laid-Open Patent Publication No. 2001-49369 discloses that Cu- Ni-Si-based inclusions such as Ni-Si-based compounds with respect to the Ni-Si-based copper alloy were adjusted to 10 µm or less, and the number of inclusions of 5 to 10 µm was adjusted to 50 / mm 2 or less in the cross section parallel to the rolling direction. The influence of system inclusions can be suppressed.

[Patent Document 1] Japanese Unexamined Patent Publication No. 61-250134

[Patent Document 2] Japanese Patent Application Laid-Open No. 05-345941

[Patent Document 3] Japanese Patent Application Laid-Open No. 09-209062

[Patent Document 4] Japanese Patent Application Laid-Open No. 05-059468

[Patent Document 5] Japanese Unexamined Patent Publication No. 2001-49369

[Non-Patent Document 1] Mizuno Masataka, Henmi Yoshio, Kokura Detsuzo, Hamamoto Takashi: Shindong Technology Research Society, vol.38 (1999), p291-297.

Although Japanese Unexamined Patent Publication No. 2001-49369 includes Cu-Ni-Si-Mg-based copper alloys, the present invention can also be applied to Cu-Ni-Si-based alloys containing other metal components such as Zn, Sn, Fe, etc. It only describes the comprehensive case which exists, and does not disclose the conditions of the specific case of an individual Cu-Ni-Si-Mg type alloy. The focus of attention on the Ni-Si coarse particles was only the size and average number of each particle. In order to manufacture an alloy having the size and number of inclusions within the range required by the invention, hot rolling and solution treatment at a high temperature and a long time must be performed to reduce the manufacturing cost of the Cu-Ni-Si-Mg-based copper alloy strip. There was a problem with raising. In addition, high temperature and long time hot rolling and solution treatment may result in coarsening of grains of the Cu—Ni—Si—Mg based copper alloy strip, thereby stably producing products having desired characteristics (strength and bending workability). There was also a problem that can not be obtained.

Therefore, an object of this invention is to solve the said subject. More specifically, it can be produced without high temperature and long time hot rolling and solution treatment, which causes manufacturing cost, and has excellent strength, conductivity, stress relaxation resistance, bending workability, etching property, wettability and plating property. Another object is to provide a Cu-Ni-Si-Mg-based copper alloy strip that can be stably manufactured.

In order to achieve the above object, the present inventors have intensively studied to identify Ni-Si-based coarse particles from a viewpoint different from the prior art, and the focus on the conventional Ni-Si-based coarse particles is the size of each particle. By paying attention to only the number of particles and the average number, and paying attention to the distribution state of Ni-Si-based coarse particles by newly obtaining the concept of "particle group" described below, the effect of Ni-Si-based coarse particle groups on the characteristics is investigated. It was.

Here, referring to FIG. 1, FIG. 1 shows a typical form of an aggregate of Ni-Si coarse particles which can be observed at a magnification of 1000 times using FE-SEM (electrolytic radial scanning electron microscope: manufactured by PHILIPS). When the cross section parallel to the rolling direction or the cross section perpendicular to the rolling direction is observed, it is observed as an aggregate of Ni-Si-based coarse particles aligned in the direction orthogonal to the thickness direction. Hereinafter, this aggregate can form the Ni-Si type particle group defined later.

The Ni-Si-based particle group caused the following adverse effects on the properties.

(1) When soldering, the solder aggregates on the particle group.

(2) During the etching process, the particles melted, leaving the smoothness of the etching surface.

(3) When plating with Ag, Ni, etc. was performed, the pinhole of plating generate | occur | produced on the particle group. Moreover, sufficient plating adhesion strength was not obtained on a particle group, and peeling of a plating and swelling of plating generate | occur | produced in this part.

(4) During bending, the particle group became a starting point of cracking, and the bending workability was deteriorated.

(5) When cold rolling, it became the cause of damage and the surface appearance was damaged.

On the other hand, the present inventors also obtained the following knowledge.

(1) For particles having a particle diameter of 10 µm or more and 20 µm or less, they adversely affect properties even if they are dispersed and distributed, but if they are 2 / mm 2 or less, the adverse effects can be ignored.

(2) For particles having a particle size of 2 µm or more and less than 10 µm, the effect on the properties is small when they are dispersed and distributed, but when they aggregate and exist as a particle group, they adversely affect the properties,

(3) It was found out that the particle size was less than 2 µm and the effect on the properties was small even though the particles existed as a particle group.

This invention is completed based on the said knowledge, It contains 1.0-4.0 mass% of Ni, It contains Si of 1/6-1/4 concentration with respect to the mass% of Ni, 0.05-0.3 mass% Is a copper-based alloy containing Mg and the balance of Cu and inevitable impurities, wherein the Ni-Si-based compound particles have a distribution state of the following (1) and (2) in a cross section parallel to the rolling direction Cu-Ni-Si-Mg based copper alloy strip.

(1) Ni-Si type compound particle whose particle diameter is 10 micrometers or more and 20 micrometers or less is 2 pieces / mm <2> or less,

(2) Of the Ni-Si-based particle groups composed of Ni-Si-based compound particles having a particle diameter of 2 µm or more and 20 µm or less, the number of Ni-Si-based particle groups having a length of 0.05 mm or more and 1.0 mm or less is 2 pieces / mm 2 or less. being.

The present invention further provides a Cu-Ni-Si-Mg-based copper alloy strip comprising 0.01 to 2.0 mass% of at least one of Sn, Zn and Ag in total amount.

In another embodiment, the present invention is a component for an electronic device such as a lead frame of a semiconductor device obtained by processing the alloy strip, or a conductive spring such as a connector, a terminal, a relay, or a switch.

Best Mode for Carrying Out the Invention

(1) Ni and Si

Ni and Si form fine particles of an intermetallic compound mainly containing Ni ₂ Si by aging treatment. As a result, the strength of the alloy is significantly increased, and at the same time, the electrical conductivity is also increased. The addition concentration (mass%) of Si is made into the range of 1/6-1/4 of the addition concentration (mass%) of Ni. If the amount of Si added is out of this range, the electrical conductivity is lowered. Ni is added in the range of 1.0-4.0 mass%. If Ni is less than 1.0 mass%, sufficient strength will not be obtained. When Ni exceeds 4.0 mass%, a crack will arise in hot rolling.

(2) Mg

Addition of 0.05 mass% or more of Mg to Cu-Ni-Si alloy raises tensile strength and proof strength, and also improves heat resistance and stress relaxation characteristics. On the other hand, when Mg addition amount exceeds 0.3 mass%, productivity will deteriorate and electrical conductivity will fall large.

(3) Ni-Si particles having a particle diameter of 10 µm or more and 20 µm or less

Particles having a particle size of 10 μm or more adversely affect solder wettability, plating property, and bendability even if they are dispersed and distributed.However, if the number of particles having a particle size of 10 μm or more is 2 / mm 2 or less in a cross section parallel to the rolling direction, I found out that I could ignore the adverse effects on the system. Here, Ni-Si type particle | grains are defined as particle | grains containing 50at% or more of Ni and 20at% or more of Si. In addition, the particle diameter of Ni-Si type particle | grains is defined as the diameter of the minimum circle | round | yen which surrounds a particle | grains (it is the same below). Moreover, although the particle | grains whose particle diameter exceeds 20 micrometers adversely affect a characteristic regardless of the number, particle | grains larger than 20 micrometers do not exist in a normal Cu-Ni-Si alloy.

(4) Ni-Si type particle group

When Ni-Si type particle | grains with a particle diameter of 2 micrometers or more gather and form a particle group, it will have a bad influence on solder wettability, plating property, bending workability, etc. The typical form of the Ni-Si type particle group observed in the rolling parallel cross section is shown in FIG. 2 (It can observe by 1000 times the magnification using FE-SEM [electrolytic radial scanning electron microscope: PHILIPS make).). Here, an aggregate of Ni-Si-based particles having a particle size of 2 µm or more and 20 µm or less in which the distance (d) to Ni-Si-based particles having an adjacent particle diameter of 2 µm or more and 20 µm or less is 10 µm or less is selected from the group of Ni-Si particles. It is defined as If the Ni-Si-based particles are dispersed at intervals exceeding 10 μm, the adverse effects on the properties can be neglected if the particle size is 10 μm or less, but if the particles are collected at a distance of 10 μm or less, the particle size may be 10 μm or less. Unless it is less than 2 micrometers, it has a bad influence on a characteristic as a particle group. Although "particle length L" is defined here as the diameter of the minimum circle surrounding one particle group, the larger the particle group and the larger the number of particle groups, the greater the adverse effect on the characteristics. However, according to the experimental result by the present inventors, even if 2 micrometers or more of Ni-Si type particle | grains aggregate and form a particle group, when the length L of particle group is shorter than 0.05 mm in the cross section parallel to a rolling direction, the number Regardless of whether the particle group length L is 0.05 mm or more and 1.0 mm or less without adversely affecting the properties such as solder wettability, plating property and bending workability, the number of particle groups is 2 / mm2 or less. It could be seen that it does not adversely affect. Moreover, although the particle group whose length L exceeds 1.0 mm adversely affects a characteristic regardless of the number, the particle group exceeding 1.0 mm does not exist in a normal Cu-Ni-Si alloy.

(5) Additional elements other than Mg

When an element which chemically reacts with Ni or Si is added to the Cu—Ni—Si—Mg system copper alloy strip, the form and distribution of the Ni—Si system particles change, so that the effect of the present invention is not obtained. On the other hand, in the case of adding elements that do not chemically react with Ni and Si, such as Sn, Zn, and Ag, for the purpose of increasing the strength, the effects of the present invention are obtained in the same manner as in the case where these elements are not added. Lose. However, since electrical conductivity falls, it is preferable to make the addition amount into 2.0 mass% or less in total, but in order to acquire a desired effect, it is preferable to set it as 0.01 mass% or more.

In the general manufacturing process of Cu-Ni-Si-Mg type copper alloy strip, an atmospheric melting furnace is first used, and raw materials, such as electric copper, Ni, Si, Mg, are melt | dissolved under charcoal coating, and the molten metal of a desired composition is obtained. And this molten metal is cast into an ingot. Thereafter, hot rolling is performed, and cold rolling and heat treatment are repeated to finish with a bath or foil having a desired thickness and characteristic. Heat treatment includes a solution treatment and an aging treatment. In the solution treatment, it heats at high temperature of 700-1000 degreeC, makes a Ni-Si type compound solid-solution in Cu base material, and simultaneously recrystallizes Cu base material. The solution treatment may also serve as hot rolling. In the aging treatment, heating is carried out for at least 1 hour in a temperature range of 350 to 550 ° C, and Ni and Si dissolved in the solution treatment are precipitated as fine particles mainly containing Ni ₂ Si. This aging treatment increases strength and electrical conductivity. In order to obtain higher strength, cold rolling may be performed before and / or after aging. In addition, when cold rolling after aging, strain removal annealing (low temperature annealing) may be carried out after cold rolling.

In this process, the most important process in the production of Ni-Si coarse particles is casting. The site of generation of the Ni-Si coarse particles at the time of casting is a grain boundary of the solidification structure, and the cause is that Si and Mg are concentrated (segregated) at the grain boundary. In the solidification process of molten metal, Ni-Si-based coarse particles are formed (crystallized) at grain boundaries. In the cooling process after solidification, the coarse Ni-Si particles grow and become larger, and generation (precipitation) of new Ni-Si-based coarse particles also occurs. By the presence of Mg, generation and growth of Ni-Si coarse particles at grain boundaries are significantly promoted. Since Ni-Si-based coarse particles are produced at grain boundaries, the distribution of Ni-Si-based coarse particles becomes coarse when the cast structure is made finer to increase the grain boundary area. On the contrary, when the cast structure is coarsened, the grain boundary area decreases, the distribution of Ni-Si coarse particles becomes dense, and the frequency of occurrence of the Ni-Si-based particle group shown in FIG. 1 increases.

In the Cu-Ni-Si-Mg-based copper alloy strip of the present invention, even if the temperature of the hot rolling and / or solution treatment is not increased to increase the coarseness of Ni-Si-based particles, casting structure such as raising the cooling rate at the time of casting It is a copper alloy strip that can obtain the desired properties just by controlling.

(Example)

EMBODIMENT OF THE INVENTION Hereinafter, in order to make clear the characteristic of this invention and the best form for implementing this invention, it demonstrates concretely using an Example.

Using a high frequency induction furnace, 3 kg of electric copper was dissolved in a graphite crucible having an internal diameter of 60 mm, Ni, Si, and Mg were added, and the molten component was added to 2.5 mass% Ni-0.5 mass% Si (mass% of Ni). (Concentration of 1/5) -0.15 mass% Mg. After adjusting the molten metal to predetermined temperature, it injected into the mold of the shape of FIG. In order to change the size of the cast structure, the mold injection temperature and the material of the mold were changed as follows.

(1) Mold injection temperature: It injected | poured on two types of conditions, 1150 degreeC and 1250 degreeC. By lowering the mold injection temperature, the cast structure was made fine and the Ni-Si-based particles were expected to be dispersed.

(2) Mold material: It carried out on four types of conditions, which were fire brick, graphite, cast iron, and pure copper. The cooling rate increases in the order of refractory bricks, graphite, cast iron, and pure copper. By increasing the cooling rate, the cast structure was made fine and the Ni-Si particles were expected to be dispersed.

Moreover, the alloy which did not add Mg was also produced as a comparison, and the influence of Mg on Ni-Si type | system | group interference | inclusion generation, etc. were also investigated.

Next, this ingot was processed and heat-treated in the following order, and the sample of thickness 0.15mm was obtained.

(1) After heating an ingot for 3 hours at 780 degreeC, it hot-rolled to thickness 8mm. Hot rolling finish temperature was 620 degreeC.

(2) The scale of oxidation of the surface of the hot rolled material was removed with a grinder.

(3) Cold rolling was carried out to the plate thickness of 2 mm.

(4) As a solution treatment, it heated at 780 degreeC for 20 second, and quenched in water.

(5) The surface oxide film was removed by chemical polishing.

(6) Cold rolling was performed to plate thickness 0.5mm.

(7) It heated at 430 degreeC in hydrogen for 3 hours as an aging treatment.

(8) The surface oxide film was removed by chemical polishing.

(9) Cold rolling was carried out to 0.15 mm of plate | board thickness.

(10) As strain removal annealing (low temperature annealing), heating was performed at 400 ° C. for 1 minute in hydrogen.

The following evaluation was performed about the sample produced in this way. Moreover, all the samples had the O concentration of 5-10 mass ppm, and the S concentration of 10-15 mass ppm.

(1) Number of Ni-Si-based particles and particle groups

The cross section parallel to the rolling direction was mirror-finished by mechanical polishing using diamond abrasive grains having a diameter of 1 µm, and then immersed for 2 minutes while stirring in an aqueous ferric chloride solution at 20 ° C. and 47 ° Be (Bome). By this etching treatment, the Cu base was dissolved, and the Ni-Si-based particles melted and remained. This cross section was observed by 1000 times the magnification using FE-SEM (electrolytic radial scanning electron microscope: PHILIPS Corporation make), and the number of particle | grains and the number of particle | grain groups of 10 micrometers or more were measured. Here, the number of particles and particle groups were randomly selected and observed from a plurality of observation fields so that the observation area was 2 mm 2 from a cross section parallel to the rolling direction of the sample. Moreover, the particle | grains exceeding 20 micrometers were not observed. Moreover, the particle group whose length exceeds 1.0 mm was not observed. It was confirmed by analyzing that the particle | grains and the component of a particle group are Ni-Si type | system | group particle | grains using the EDS [energy dispersion type X-ray analysis] of FE-SEM.

(2) bending workability

As shown in FIG. 4, the number of times until the bending shaft is broken by a method of counting one round trip in one direction with a bending radius of 0.15 mm in the direction (Bad Way) so as to be parallel to the rolling direction. Counted. The test was carried out five times and an average of five times was obtained.

(3) solder wettability

The elongate test piece of width 10mm was extract | collected, the surface was acetone degreased, and it was pickled with 10vol% sulfuric acid aqueous solution. The sample was then immersed in 25% rosin-ethanol for 5 seconds and then immersed in the solder bath for 10 seconds. The composition of the solder was 60 mass% Sn-40 mass% Pb, the temperature of the solder was 230 degreeC, and the immersion depth of the sample was 10 mm. When the surface of the sample after solder immersion was observed with a stereoscopic microscope, a point-like site where solder was agglomerated was observed depending on the sample. The number of solder agglomerates was determined for an area of 1000 mm 2 (front and back of five test pieces).

(4) stress relaxation characteristics

Fig. 5 shows a test piece with a thickness t = 0.15 mm and a bending stress of a mark distance l = 50 mm and a height y ₀ = 20 mm, loaded at a width of 10 mm X length 100 mm as shown in Fig. 5 and heating at 150 ° C. for 1000 hours. The permanent deformation amount (height: y) shown in 6 was measured, and the stress relaxation rate {(yy ₁ ) (mm) / (y ₀ -y ₁ ) (mm)] × 100 (%)} was calculated. Moreover, y ₁ is the height of the initial curvature before loading a stress.

As can be seen from Table 1, according to the present invention, a Cu-Ni-Si-Mg-based copper alloy strip having good bending workability and solder wettability equivalent to or greater than N0.9 and 10 of the comparative example without Mg added is obtained. It was obtained [Examples N0.1 to 5].

On the other hand, N0.6-8 of the comparative example are alloys of the same components as the present invention, but the ingot structure is not sufficiently small under the influence of the mold material and the mold injection temperature, and the number of particles having a particle diameter of 10 µm or more and the Ni-Si-based particle group is 2 It exceeded piece / mm <2>, and solder wettability and bending workability fell.

Comparative examples N0.9 and N0.10 are Cu-Ni-Si alloys without adding Mg, and particles of 10 µm or more having a particle diameter of 10 µm or more by adding Mg producing ingots under the same conditions as N0.5 and N0.7, respectively, and It can be seen that the number of Ni-Si-based particle groups increased. The bending workability and the solder wettability of Comparative Examples N0.9 and N0.10 were good because Mg was not added, and the number of particles having a particle size of 10 µm or more and the Ni-Si-based particle group was suppressed to 2 / mm 2 or less, but was good. Since it did not add, it was inferior to an Example from the viewpoint of the stress relaxation resistance.

In addition, Japanese Patent Laid-Open No. 2000-49369 defines the size of all particles to be 10 µm or less, and the number of inclusions having a size of 5 to 10 µm is 50 pieces / mm 2. And in order to acquire this state, hot-rolling heating temperature is prescribed | regulated as 800 degreeC or more and end temperature as 650 degreeC or more, and the solution treatment temperature is supposed to be 800 degreeC or more. Here, when the N0.5 of this invention was examined, the number of Ni-Si particles of 10 micrometers or more of particle diameters was 1.0 piece / mm <2>, and when the particle number of 5-10 micrometers was measured separately, it was 60 pieces / mm <2>. This is because the hot rolling temperature and the solution treatment temperature are low. However, by optimizing the casting conditions to adjust the distribution of the Ni-Si particles, good solder wettability and repeated bending workability are obtained despite the large number of Ni-Si particles.

The Cu-Ni-Si-Mg-based copper alloy strip of the present invention does not require high temperature and long time hot rolling to increase manufacturing costs, and has good strength, conductivity, stress relaxation resistance, bending workability, etching resistance, Since it has wettability and plating property, technical value and practicality are higher than the prior art, and it is suitable as a copper alloy used for lead frames, a terminal, a connector, etc.

Claims (3)

1.0 to 4.0% by mass of Ni, containing 1/6 to 1/4% of Si relative to the mass% of Ni, 0.05% to 0.3% by mass of Mg, and the remainder as Cu and unavoidable impurities A copper-based alloy made of Cu-Ni-Si-Mg-based copper alloy strip, wherein the Ni-Si-based compound particles have a distribution state of the following (1) and (2) in a cross section parallel to the rolling direction. (1) Ni-Si type compound particle whose particle diameter is 10 micrometers or more and 20 micrometers or less is 2 pieces / mm <2> or less, (2) Of the Ni-Si-based particle groups composed of Ni-Si-based compound particles having a particle diameter of 2 µm or more and 20 µm or less, the number of Ni-Si-based particle groups having a length of 0.05 mm or more and 1.0 mm or less is 2 pieces / mm 2 or less. being. The Cu-Ni-Si-Mg-based copper alloy strip according to claim 1, further comprising 0.01 to 2.0% by mass of at least one of Sn, Zn, and Ag in a total amount. The component for electronic devices obtained by processing the alloy strip of Claim 1 or 2.

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