TW201704490A - Copper alloy material and method for producing same - Google Patents

Abstract

The present invention provides: a copper alloy material which exhibits good heat resistance in addition to high strength, high electrical conductivity and good bending workability; and a method for producing same. This copper alloy material is characterized by having an alloy composition that contains 0.05-1.2 mass % of Ni, 0.01-0.15 mass % of P and 0.05-2.5 mass % of Sn, with the remainder comprising Cu and unavoidable impurities, and is characterized in that when a surface of the material is observed using an FE-SEM after electrolytic polishing, the number of compound particles having particle diameters of 5-30 nm is 20 particles/[mu]m2 or more and the number of compound particles having particle diameters of greater than 30 nm is 1 particle/[mu]m2 or less in a field of view having an area measuring 1[mu]m x 1[mu]m.

Description

Copper alloy material and method of manufacturing same

The present invention relates to a copper alloy material and a method of manufacturing the same, and more particularly to a copper alloy material for an electric and electronic component such as a lead frame usable for a semiconductor device, and a method of manufacturing the same.

The lead frame used in a semiconductor device such as an IC or an LSI is formed by press working a copper alloy material, and at this time, processing distortion remains in the material. When the processing deformation remains, the bending of the material occurs when the etching of the back end step is performed, and the dimensional accuracy of the wire spacing of the lead frame is lowered. Therefore, the wire frame after press working is usually subjected to a heat treatment at 400 to 450 ° C to remove the processing deformation. However, it is known that the crystal structure of the copper alloy is recrystallized during the heat treatment, and the strength of the copper alloy material is lowered. trend. Therefore, the copper alloy material for an electronic device used for the lead frame needs to have a property (heat resistance) that does not deteriorate in strength even when the heat treatment is performed.

In addition, the lead frame copper alloy material is required to have high strength for use in miniaturization of components, and high electrical conductivity for suppressing heat generation of the element, and also requires good bending workability for improving the degree of freedom in element molding. .

Cu-Ni-Sn-P alloys are widely available for satisfying such requirements. The Cu-Ni-Sn-P alloy can have high strength, high electrical conductivity, and good bending workability by precipitating a Ni-P-based compound.

Patent Literatures 1 to 9 discuss the combination of the size and distribution of precipitates, tensile strength, electrical conductivity, and bending workability, as well as elasticity, stress relaxation resistance, press workability, corrosion resistance, and plating. Various properties such as properties, solder wettability, migration resistance, and hot workability.

[Advanced technical literature]

[Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 4-145942

Patent Document 2: Japanese Laid-Open Patent Publication No. Hei-4-236736

Patent Document 3: Japanese Laid-Open Patent Publication No. Hei 10-226835

Patent Document 4: Japanese Laid-Open Patent Publication No. 2000-129377

Patent Document 5: Japanese Laid-Open Patent Publication No. 2000-256814

Patent Document 6: JP-A-2001-262255

Patent Document 7: JP-A-2001-262297

Patent Document 8: Japanese Laid-Open Patent Publication No. 2006-291356

Patent Document 9: JP-A-2007-100111

The Cu-Ni-Sn-P alloy is an excellent alloy system with high strength, high electrical conductivity and good bending workability, but is heat treated at 400 to 450 ° C for the lead frame after press working. Heat resistance cannot be said to be sufficient.

In Patent Documents 1 to 9, attempts have been made to improve various material properties, but there is no way to focus on the improvement of heat resistance.

In view of the above circumstances, the object of the present invention is to provide A copper alloy material having high strength, high electrical conductivity, good bending workability, and good heat resistance, and a method for producing the same.

The inventors of the present invention have studied Cu-Ni-Sn-P alloys for electric and electronic components including lead frames, and have found that Ni contains 0.05 to 1.2% by mass, P is 0.01 to 0.15% by mass, and Sn The composition of the alloy is 0.05 to 2.5% by mass, and the surface of the material after electrolytic polishing is observed by FE-SEM. In the field of view of 1 μm × 1 μm, the ratio of the number of compound particles having a particle diameter of 5 to 30 nm is 20 / μm. ^{In the case of 2} or more, the ratio of the number of the compound particles having a particle diameter of more than 30 nm is 1 piece/μm ² or less, and copper having high strength, high electrical conductivity, and good bending workability, and having better heat resistance can be obtained. The alloy material is completed to complete the present invention.

That is, the main points of the present invention are as follows.

(1) A copper alloy material comprising: Ni containing 0.05 to 1.2% by mass, P being 0.01 to 0.15% by mass, and Sn being 0.05 to 2.5% by mass, and the balance being composed of Cu and unavoidable impurities The alloy composition was observed by FE-SEM on the surface of the material after electrolytic polishing. In the field of view of 1 μm × 1 μm, the ratio of the number of compound particles having a particle diameter of 5 to 30 nm was 20 / μm ² or more, and the particle diameter exceeded The number ratio of the compound particles of 30 nm is 1 / μm ² or less.

(2) A copper alloy material comprising: Ni to 0.05 to 1.2% by mass, P of 0.01 to 0.15% by mass, and Sn of 0.05 to 2.5% by mass, further containing Fe, Zn, Pb, Si, Mg selected from the group consisting of Fe, Zn, Pb, Si, and Mg At least one component of Zr, Cr, Ti, Mn, and Co, Fe is 0.001 to 0.1% by mass, Zn is 0.001 to 0.5% by mass, Pb is 0.001 to 0.05% by mass, Si is 0.001 to 0.1% by mass, and Mg is 0.001. ~0.3 mass%, Zr is 0.001 to 0.15 mass%, Cr is 0.001 to 0.3 mass%, Ti is 0.001 to 0.05 mass%, Mn is 0.001 to 0.2 mass%, and Co is 0.001 to 0.2 mass%, and Mg, When Zr, Cr, Ti, Mn, and Co are contained in an amount of 2 or more, the total content is 0.001 to 0.5% by mass, and the remainder is composed of an alloy composed of Cu and unavoidable impurities, and the surface of the material after electrolytic polishing is FE-SEM. In the field of view of 1 μm × 1 μm, the ratio of the number of the compound particles having a particle diameter of 5 to 30 nm is 20 / μm ² or more, and the ratio of the number of the compound particles having a particle diameter of more than 30 nm is 1 / μm ² or less. .

(3) The copper alloy material according to the above (1) or (2), which contains Sn in an amount of 0.05 to 0.5% by mass, a tensile strength of 400 MPa or more, and a conductivity of 50% IACS or more.

(4) The copper alloy material according to the above (1) or (2), which contains Sn in an amount of more than 0.5% by mass and 2.5% by mass or less, a tensile strength of 500 MPa or more, and a conductivity of 25% IACS or more.

(5) A method for producing a copper alloy material, which is the method for producing the copper alloy material according to any one of the above (1) to (4), characterized by comprising the following (a) to (e) A step of:

(a) A melting casting step at a cooling rate of up to 300 ° C of 30 ° C / min or more.

(b) A homogenization heat treatment step of raising the temperature at 5 ° C / min or more and maintaining at 600 to 1000 ° C for 30 minutes to 10 hours.

(c) A heat-to-heat rolling step of a cooling rate of up to 300 ° C of 30 ° C / min or more.

(d) A cold rolling step in which the working ratio is 80% or more.

(e) An annealing step of maintaining a temperature of 350 to 600 ° C for 5 seconds to 10 hours.

According to the present invention, the electrolysis is composed of an alloy containing 0.05 to 1.2 mass% of Ni, 0.01 to 0.15 mass% of P, and 0.05 to 2.5% by mass of Sn, and the balance being composed of Cu and unavoidable impurities. The surface of the material after the polishing was observed by FE-SEM. In the field of view of 1 μm × 1 μm, the ratio of the number of compound particles having a particle diameter of 5 to 30 nm was 20 / μm ² or more, and the number of compound particles having a particle diameter of more than 30 nm was observed. The number ratio is one piece/μm ² or less, and a copper alloy material having high strength, high electrical conductivity, and good bending workability and having better heat resistance can be obtained.

Fig. 1 is a SEM photograph of the surface of the copper alloy material of the present invention (Example 14) after electrolytic polishing, observed at a magnification of FE-SEM: 50,000 times.

Fig. 2 is a SEM photograph of the surface after electrolytic polishing of Comparative Example 22, observed at an FE-SEM magnification: 50,000 times.

Hereinafter, preferred embodiments of the copper alloy material of the present invention will be described in detail.

(Component composition of copper alloy materials)

The basic composition of the copper alloy material of the present invention contains Ni in an amount of 0.05 to 1.2% by mass, P in an amount of 0.01 to 0.15% by mass, and Sn in an amount of 0.05 to 2.5% by mass, and the balance being Cu and unavoidable impurities.

[must contain ingredients]

(Ni: 0.05 to 1.2% by mass)

Ni is solid-solubilized in the parent phase and increases strength by forming a compound with P. element. Further, the Ni-based and P-forming compounds have an effect of improving the heat resistance while precipitating the product by increasing the conductivity. However, when the Ni content is less than 0.05% by mass, the effect cannot be sufficiently exhibited, and if it exceeds 1.2% by mass, the electrical conductivity is remarkably lowered. Therefore, the Ni content is 0.05 to 1.2% by mass, preferably 0.10 to 1.00% by mass, more preferably 0.10 to 0.40% by mass.

(P: 0.01 to 0.15 mass%)

P is an element that increases the strength, the electrical conductivity, and the heat resistance by forming a compound with Ni. However, when the content of P is less than 0.01% by mass, the effect cannot be sufficiently obtained, and when it exceeds 0.15 mass%, the electrical conductivity is lowered, and coarse (for example, a particle diameter of more than 30 nm) compound particles are formed to be bent. The workability is lowered, and the formation ratio of a fine (for example, a particle diameter of 5 to 30 nm) is reduced to lower the heat resistance and to lower the workability. Therefore, the content of P is 0.01 to 0.15 mass%, preferably 0.01 to 0.10 mass%, more preferably 0.05 to 0.10 mass%.

(Sn: 0.05~2.5% by mass)

Sn is a solid solution in the mother phase and contributes to an element that increases strength and improves heat resistance. However, when the content of Sn is less than 0.05% by mass, the effect cannot be sufficiently obtained, and when it exceeds 2.5% by mass, the electrical conductivity is lowered and the hot workability is deteriorated. Therefore, the content of Sn is 0.05 to 2.5% by mass. Further, among the tensile strength and the electrical conductivity, when the conductivity is particularly limited, the content of Sn is limited to 0.05 to 0.5% by mass, and the tensile strength may be 400 MPa or more, and the high electrical conductivity of 50% IACS or more is obtained. In addition, when the tensile strength is particularly limited to 0.5% by mass or more and 2.5% by mass or less, the electrical conductivity of 25% IACS or more can be obtained, and the high tensile strength of 500 MPa or more can be obtained. The point is better.

[optional addition]

In the present invention, it is necessary to contain the above-mentioned Ni, P, and Sn as a basic composition, and further contain at least one component selected from the group consisting of Fe, Zn, Pb, Si, Mg, Zr, Cr, Ti, Mn, and Co.

(Fe: 0.001 to 0.1% by mass)

In order to exhibit the effect, the content of Fe is preferably 0.001% by mass or more in order to exhibit an effect by forming a compound with P and contributing to an element which increases strength and improves heat resistance. However, when the content of Fe is more than 0.1% by mass, the material tends to be magnetic, and if the material is magnetic, the transmission characteristics of the lead frame transmission signal are deteriorated. Therefore, the content of Fe is preferably 0.001 to 0.1% by mass, more preferably 0.001 to 0.05% by mass, still more preferably 0.001 to 0.01% by mass.

(Zn: 0.001 to 0.5% by mass)

Zn is an element which contributes to increase strength, improve solder wettability, and improve plating property by being dissolved in the mother phase. In order to exhibit this effect, the content of Zn is preferably 0.001% by mass or more. However, when the content of Zn is more than 0.5% by mass, there is a tendency to lower the electrical conductivity. Therefore, the content of Zn is preferably 0.001 to 0.5% by mass, more preferably 0.01 to 0.5% by mass, still more preferably 0.1 to 0.5% by mass.

(Pb: 0.001 to 0.05% by mass)

Pb contributes to an element which improves press workability, and in order to exhibit this effect, it is preferable that the content of Pb is 0.001% by mass or more. However, even when the content of Pb is more than 0.05% by mass, it is not possible to confirm that the effect can be further improved. Further, from the viewpoint of environmental protection in recent years, it is preferable to suppress the Pb content as much as possible. Therefore, the content of Pb is preferably 0.001 to 0.05% by mass, more preferably 0.001 to 0.01% by mass.

(Si: 0.001 to 0.1% by mass)

The Si system contributes to an element which increases the strength, and in order to exhibit this effect, the content of Si is preferably 0.001% by mass or more. However, when the content of Si is more than 0.1% by mass, the electrical conductivity is lowered, or a coarse compound is formed to deteriorate the bending workability. Therefore, the content of Si is preferably 0.001 to 0.1% by mass, more preferably 0.01 to 0.1% by mass.

(Mg: 0.001 to 0.3% by mass)

The Mg system contributes to an element that increases strength and improves heat resistance. Further, for example, the spring contact of the electronic component or the like contributes to the improvement of the stress relaxation resistance. In order to exert such effects, the content of Mg is preferably 0.001% by mass or more. However, when the content of Mg is more than 0.3% by mass, the electrical conductivity may be lowered or an impurity may be formed during casting. Therefore, the content of Mg is preferably 0.001 to 0.3% by mass, more preferably 0.01 to 0.3% by mass.

(Zr: 0.001 to 0.15 mass%)

The Zr system contributes to elements that increase strength and improve heat resistance. Further, for example, the spring contact of the electronic component or the like contributes to the improvement of the stress relaxation resistance. In order to exert such effects, the content of Zr is preferably 0.001% by mass or more. However, when the content of Zr is more than 0.15% by mass, there is a possibility that the conductivity is lowered or cracked during hot processing. Therefore, the content of Zr is preferably 0.001 to 0.15 mass%, more preferably 0.01 to 0.1 mass%.

(Cr: 0.001 to 0.3% by mass)

The Cr-based element contributes to an element which increases strength and improves heat resistance, and in order to exhibit this effect, the Cr content is preferably 0.001% by mass or more. However, when the content of Cr is more than 0.3% by mass, there is a decrease in bending workability due to occurrence of crystal grains during casting. After that. Therefore, the content of Cr is preferably 0.001 to 0.3% by mass, more preferably 0.01 to 0.3% by mass.

(Ti: 0.001 to 0.05% by mass)

The Ti system contributes to elements that increase strength and improve heat resistance. Further, for example, the spring contact of the electronic component or the like contributes to the improvement of the stress relaxation resistance. In order to exert such effects, the content of Ti is preferably 0.001% by mass or more. However, when the content of Ti is more than 0.05% by mass, the electrical conductivity may be lowered or the cast muscle on the surface of the ingot may be abnormal. Therefore, the content of Ti is preferably 0.001 to 0.05% by mass, more preferably 0.01 to 0.05% by mass.

(Mn: 0.001 to 0.2% by mass)

Mn is an element which contributes to the increase in strength, the heat resistance, and the heat-intermediate workability. In order to exhibit this effect, the content of Mn is preferably 0.001% by mass or more. However, when the content of Mn is more than 0.2% by mass, the electrical conductivity is lowered. Therefore, the content of Mn is preferably 0.001 to 0.2% by mass, more preferably 0.01 to 0.2% by mass.

(Co: 0.001 to 0.2% by mass)

Co is contributed to an element which increases strength or improves inter-heat processability, and in order to exhibit this effect, the content of Co is preferably 0.001% by mass or more. However, when the content of Co is more than 0.2% by mass, the electrical conductivity is lowered. Therefore, the content of Co is preferably 0.001 to 2% by mass, more preferably 0.01 to 0.2% by mass.

(Total content when two or more types of Mg, Zr, Cr, Ti, Mn, and Co are contained: 0.001 to 0.5% by mass)

Mg, Zr, Cr, Ti, Mn, and Co contribute to increase strength and improve heat resistance by forming a compound with P. The amount of the elements added is preferably 0.001 to 0.5% by mass, more preferably 0.01 to 0.5% by mass, further preferably 0.1 to 0.5% by mass. Better. When it is larger than 0.5% by mass, the electrical conductivity is lowered to form a coarse compound, and the bending workability is deteriorated.

(compound particles)

In the present invention, the surface ratio of the material after electrolytic polishing is observed by FE-SEM, and the ratio of the number of compound particles having a particle diameter of 5 to 30 nm is 20 / μm ² or more in a field of view of 1 μm × 1 μm. When the ratio of the number of the compound particles having a diameter of more than 30 nm is one piece/μm ² or less, a copper alloy material having high strength, high electrical conductivity, and good bending workability and excellent heat resistance can be obtained. The term "compound particles" as used herein refers to a general term for precipitates formed after solidification by casting, which are impurities or crystals formed during casting. Further, the particle diameter of the compound particles means the length of the long side. In the field of view of 1 μm × 1 μm, when the number ratio of the fine compound particles having a particle diameter of 5 to 30 nm is 20 pieces/μm ² or more, recrystallization can be suppressed by obtaining a sufficient magnetic lock effect of the fine compound particles. Good heat resistance. On the other hand, when the ratio of the number of fine compound particles is less than 20 / μm ² , good heat resistance cannot be obtained. In addition, by setting the ratio of the number of coarse compound particles having a particle diameter of more than 30 nm to 1 / μm ² or less, good bending workability can be obtained. When the ratio of the number of the coarse compound particles exceeds 1 / μm ² , the coarse compound particles become a fracture origin, and the bending workability is remarkably deteriorated. In addition, in this case, when a large number of coarse compound particles are formed, the ratio of the number of fine compound particles tends to decrease, so that heat resistance is deteriorated. Previously, the dispersion state of the compound particles was mostly observed by a transmission electron microscope (TEM), and the number of fields and the area ratio were expressed, but the values depended on the thickness of the test piece. However, it is difficult to prepare the test piece for TEM to have the same thickness, and even if it is measured by the same test piece, there is a possibility that a slightly different result is obtained by measuring the number of times. Therefore, in the present invention, the number ratio of the compound particles was evaluated using a field emission scanning electron microscope (FE-SEM) which did not depend on the thickness of the test piece.

(Manufacturing method of copper alloy material)

Next, a method of producing the tin alloy material of the present invention will be described.

The copper alloy material of the present invention is usually produced by performing melt casting-homogenization heat treatment-heat-calendering-cold rolling-annealing-modification calendering. Between each step, face cutting, buffing, pickling, degreasing, and the like may be appropriately performed as needed. In addition, the cold rolling and annealing may be repeated several times, or may be further subjected to low temperature annealing after the modified calendering. In the production method of the present invention, in the melt casting, the homogenization heat treatment, and the heat-to-heat rolling, coarse compound particles are not generated as much as possible, and a large number of fine precipitates are formed in the subsequent cold rolling and annealing. Although the manufacturing method of the present invention is equivalent to the number of previous steps, the material properties can be improved by appropriately adjusting the respective step conditions.

<melt casting>

In the present invention, at the time of casting, cooling to 300 ° C is performed at a cooling rate of 30 ° C /min or more to suppress crystallization and precipitation during cooling, thereby suppressing formation of a coarse compound. The idea of particles is good. When the cooling rate is less than 30 ° C / min, crystals and precipitation during cooling cannot be sufficiently suppressed, and coarse compound particles tend to be formed.

<Homogenization heat treatment>

The homogenization heat treatment is carried out by solid-dissolving the coarse compound particles produced by the melt casting in the mother phase and in a solid solution state. Homogenization heat treatment, 600~1000 It is better to keep °C for 30 minutes to 10 hours. Conventionally, the temperature increase rate of the homogenization heat treatment has not been emphasized. However, in the present invention, in order to obtain a predetermined material structure, it is particularly preferable to control the temperature increase rate to 5 ° C /min or more, preferably 10 ° C / min or more. When the temperature rise rate is lower than 5 ° C / min, the coarse compound particles formed during the melt casting are grown at the time of temperature rise, and after the homogenization heat treatment, the coarse compound particles are not sufficiently dissolved in the matrix phase, and it is easy to remain. The bending workability of the final characteristics deteriorates. Further, since the ratio of the number of fine compound particles is also reduced, heat resistance is also deteriorated. When at least one of the retention temperature of less than 600 ° C and the retention time of less than 30 minutes is satisfied, it is easy to remain coarse compound particles which are insoluble in the matrix phase, and the bending property of the final properties is deteriorated, and the temperature is maintained. When it exceeds 1000 ° C, in the continuous hot-rolling step, there is a possibility that the inter-heat processing is broken. Further, the upper limit of the holding time is preferably 10 hours from the viewpoint of the effect of solid solution or from the viewpoint of actual production time limitation.

<Thermal calendering>

The heat is calendered and is preferably carried out at 550 to 950 °C. In the present invention, in particular, it is required to be cooled to 300 ° C at a cooling rate of 30 ° C / min or more. When the cooling rate up to 300 ° C is 30 ° C / min, it is easy to precipitate coarse compound particles during cooling, which adversely affects the final properties.

<cold rolling>

The inter-column rolling after hot rolling is preferably carried out at a processing rate of 80% or more. When the working ratio is 80% or less, the deformation cannot be uniformly introduced into the material, and when the fine compound particles are precipitated and precipitated later, a difference in precipitation state occurs in the material.

<annealing>

Annealing is preferably carried out at 350 to 600 ° C for 5 seconds to 10 hours. When the temperature is lower than the above range and the time is short, the fine compound particles are not sufficiently precipitated, and the strength and the electrical conductivity are lowered. Further, when the temperature is higher than the above range and the time is long, coarse compound particles are precipitated. There is a problem in that the bending workability is deteriorated and the heat resistance is deteriorated.

<modified calendering>

The processing rate of the modified rolling is not particularly limited, and is preferably 60% or less in order to obtain good bending workability.

<Low temperature annealing>

After calendering, low temperature annealing for 2 seconds to 5 hours can also be carried out at 250 to 400 °C. By low temperature annealing, the elasticity and stress relaxation properties of the material can be improved. When the temperature is lower than the above range and the time is short, the effect of low-temperature annealing cannot be obtained. Further, when the temperature is higher than the above range and the time is long, the fine compound particles are coarsely grown, and the bending workability and heat resistance are obtained. The cause of adverse effects. In addition, the material undergoes recrystallization, and there is a fear that the desired strength cannot be obtained.

The copper alloy material of the present invention, in addition to obtaining high strength, high electrical conductivity and good bending workability, by controlling the size and number of compound particles in a Cu-Ni-Sn-P based copper alloy having a predetermined alloy composition, And it can have both heat resistance. Therefore, the copper alloy material of the present invention is suitable for use in electrical and electronic components including lead frames.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention should not be limited thereto.

(Examples 1 to 26 and Comparative Examples 1 to 22)

Hereinafter, the present invention will be described in more detail based on examples, but the present invention should not be limited thereto.

The alloy component is dissolved, and is cast at a cooling rate of 30 ° C /min or more to 300 ° C to be cast, and an ingot having the composition shown in the first table is produced, and then heated at a temperature increase rate shown in Table 2 to 600 to 1000 ° C. The homogenization heat treatment is carried out for 30 minutes to 10 hours, and then, the inter-heat rolling is performed. After the inter-heat rolling, the film was cooled to 300 ° C at a cooling rate shown in Table 2, and then the surface oxide layer was removed by surface cutting, and cold rolling was performed at a processing ratio of 80% or more. Thereafter, the annealing is further performed at 350 to 600 ° C for 5 seconds to 10 hours, and then, the modified rolling is performed at a processing rate of 60% or less, and finally, the low temperature annealing is performed at 250 to 400 ° C for 2 seconds to 5 hours to produce a plate thickness of 0.5 mm. Copper alloy material.

The following evaluation was carried out on the test materials thus produced.

(Organizational observation)

20 μm of the surface of the test piece (size: 20 mm × 20 mm) taken from each of the produced copper alloy materials (test materials), and electrolytically polished with a phosphate aqueous solution, and the surface of the material was 10,000 to 100,000 by FE-SEM. Double observation. In the observation, the range of 1 μm × 1 μm was observed, and the three fields of view were observed, and the number of fine compound particles having a particle diameter of 5 to 30 nm and the number of coarse compound particles having a particle diameter of more than 30 nm were measured in the field of view. Thereafter, the number of measurements was converted into a ratio of the number of fields of view of 1 μm × 1 μm (1 μm ² ). The ratio of the number of conversions is rounded off, the fine compound particles are represented by integers, and the coarse compound particles are displayed to the second digit of the decimal point.

(Measurement of tensile strength)

Tensile strength, from each test material, will be attached to JIS Z2241:2011 The test piece No. 5 which was prescribed was cut out in the parallel direction of the rolling, and three pieces were taken, and three pieces were measured in accordance with the "Metal material tensile test method" prescribed in JIS Z2241:2011. The average value of these tensile strengths is shown in the second table.

(Measurement of conductivity)

The specific resistance was measured by a four-point probe method while maintaining a constant temperature of 20 ° C (± 0.5 ° C), and the conductivity was calculated from the measured specific resistance value. Furthermore, the probe pitch is 100 mm.

(bending workability)

The bending test was carried out based on JCBA T307:2007. The test piece having a plate width of 10 mm was bent in a direction perpendicular to the rolling direction (G.W. direction) and a parallel direction (B.W. direction) with a bending radius of 0.5 mm on the inner side and a bending angle of 90°. In the electric and electronic component including the lead frame, since the bending process in both the GW direction and the BW direction is assumed, the surface of the curved apex of the curved portion is observed by an optical microscope, and the GW direction and the BW direction are used. Those who did not have rupture on one side were evaluated as having good workability (A), and those who were found to have poor workability (D). The evaluation results are shown in the second table.

(heat resistance)

In the heat resistance, the test piece was placed in a salt bath heated to 450 ° C, and after 5 minutes, it was taken out and subjected to water-cooling heat treatment, and the hardness after the heat treatment was evaluated as good (A) except that the value of the hardness before the heat treatment was 0.8 or more. Those who are less than 0.8 are evaluated as poor heat resistance (D). The evaluation results are shown in the second table. In addition, the hardness is measured based on the test method of the Vickers hardness test prescribed by JIS Z2244:2009. Further, since the material after the heat treatment formed a film on the surface in contact with the salt bath, the hardness was measured after pickling and removing.

From the results shown in the first table and the second table, it is understood that any of Examples 1 to 13 having a Sn concentration of 0.05 to 0.5% by mass has a tensile strength of 432 to 492 MPa and both of them are 400 MPa or more, and the electrical conductivity is 50 to 77% IACS and both of them are 50% IACS or more, and good bending workability (A) and good heat resistance (A) are obtained. On the other hand, in Comparative Examples 1 to 9 in which the component compositions shown in Table 1 are outside the range of the present invention, and Comparative Examples 10 and 11 in which the production conditions shown in the second table are outside the range of the present invention, At least one of tensile strength, electrical conductivity, bending workability, heat resistance, and manufacturability is inferior.

Further, in any of Examples 14 to 26 in which the Sn concentration is in a range of more than 0.5% by mass and 2.5% by mass or less, the tensile strength is 512 to 593 MPa and 500 MPa or more, and the electrical conductivity is 27 to 38% IACS. 25% IACS or more, good bending workability (A) and good heat resistance (A) were obtained. On the other hand, in Comparative Examples 12 to 20 in which the component compositions shown in the first table are outside the range of the present invention, and the comparative examples 21 and 22 in which the manufacturing conditions shown in the second table are outside the range of the present invention, At least one of tensile strength, electrical conductivity, bending workability, heat resistance, and manufacturability is inferior.

In addition, FIG. 1 and FIG. 2 are SEM photographs of the surface after electrolytic polishing of the copper alloy materials of Example 14 and Comparative Example 22, respectively, observed by FE-SEM. With respect to the fine compound particles dispersed in the copper alloy material of Example 14 shown in Fig. 1, it was found that the copper alloy material of Comparative Example 22 shown in Fig. 2 had coarser compound particles.

[Industrial availability]

According to the present invention, it is possible to provide a copper alloy material which has better heat resistance than high strength, high electrical conductivity, and good bending workability. this invention The copper alloy material, in particular, is suitable for electrical and electronic components such as lead frames used in semiconductor devices.

Claims (5)

A copper alloy material characterized by having an alloy containing Ni to 0.05 to 1.2% by mass, P of 0.01 to 0.15% by mass, and Sn of 0.05 to 2.5% by mass, and the balance being formed of Cu and unavoidable impurities. In the composition, the surface of the material after electrolytic polishing was observed by FE-SEM. In the field of view of 1 μm × 1 μm, the ratio of the number of compound particles having a particle diameter of 5 to 30 nm was 20 / μm ² or more, and the particle diameter was over 30 nm. The number ratio of the compound particles is 1 / μm ² or less. A copper alloy material characterized by comprising: Ni-containing 0.05 to 1.2% by mass, P being 0.01 to 0.15% by mass, and Sn being 0.05 to 2.5% by mass, further containing Fe, Zn, Pb, Si, Mg, At least one component of Zr, Cr, Ti, Mn, and Co, Fe is 0.001 to 0.1% by mass, Zn is 0.001 to 0.5% by mass, Pb is 0.001 to 0.05% by mass, Si is 0.001 to 0.1% by mass, and Mg is 0.001. 0.3% by mass, Zr is 0.001 to 0.15% by mass, Cr is 0.001 to 0.3% by mass, Ti is 0.001 to 0.05% by mass, Mn is 0.001 to 0.2% by mass, and Co is 0.001 to 0.2% by mass, and two or more kinds thereof are contained. When Mg, Zr, Cr, Ti, Mn and Co are present, the total content thereof is 0.001 to 0.5% by mass, and the remainder is composed of an alloy formed of Cu and unavoidable impurities, and the surface of the material after electrolytic polishing is FE- SEM observation showed that the ratio of the number of compound particles having a particle diameter of 5 to 30 nm was 20 / μm ² or more, and the ratio of the number of compound particles having a particle diameter of more than 30 nm was 1 / μm ^{2 in} a field of view of 1 μm × 1 μm. the following. The copper alloy material according to claim 1 or 2, wherein the Sn content is 0.05 to 0.5% by mass, the tensile strength is 400 MPa or more, and the electrical conductivity is It is 50% IACS or more. The copper alloy material according to claim 1 or 2, which contains Sn in an amount of more than 0.5% by mass and 2.5% by mass or less, a tensile strength of 500 MPa or more, and a conductivity of 25% IACS or more. A method for producing a copper alloy material, which is a method for producing a copper alloy material according to any one of claims 1 to 4, characterized in that it comprises the following steps (a) to (e): a) a cooling casting step at a cooling rate of 300 ° C or higher of 30 ° C / min or more; (b) a homogenization heat treatment step of raising the temperature at 5 ° C / min or more and maintaining at 600 to 1000 ° C for 30 minutes to 10 hours; a cooling rate of 300 ° C / min or more to the inter-heat rolling step; (d) a cold rolling step of 80% or more; and (e) holding at 350 to 600 ° C for 5 seconds to 10 hours Annealing step.