METHOD FOR PRODUCING Cu-Ag ALLOY WIRE AND Cu-Ag ALLOY WIRE PRODUCED ACCORDING TO THE PRODUCING METHOD, AND PROBE PIN FOR ELECTRIC / ELECTRONIC COMPONENT INSPECTION OBTAINED WITH Cu-Ag ALLOY WIRE

Abstract

To provide a metal wire for inspecting an electric / electronic component having both high electric conductivity and strength.SOLUTION: In order to achieve this purpose, the invention related to this application adopts a method for producing Cu-Ag alloy wire which is characterized by comprising the following steps in sequence and a Cu-Ag alloy wire produced by the producing method. Step 1: Melt metal raw materials blended to contain 10.0 wt% to 30.0 wt% of Ag while the remainder is Cu, excluding unavoidable impurities, to obtain a metal rod. Steps 2 to 4: Repeat cold wire drawing and heat treatment three times while gradually increasing the cross-sectional reduction rate before and after processing. Steps 5 to 7: Repeat cold wire drawing and heat treatment three times so that the cross-sectional reduction rate before and after processing is larger than that in Steps 2 to 4. Step 8: Perform cold wire drawing so that the cross-sectional reduction rate of the metal rod becomes 99.0% to 99.9999% and obtain Cu-Ag alloy wire with a diameter of 0.1 mm or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The invention of the present application relates to a method for manufacturing a Cu-Ag alloy wire, a Cu-Ag alloy wire manufactured by this manufacturing method, and a probe pin for inspecting electric / electronic devices obtained by using this Cu-Ag alloy wire. [Background technology]

[0002] In recent years, semiconductor devices have been increasing in number of pins and narrowing in pitch to meet market needs for higher functionality and performance. Accordingly, there is a demand for ultra-thin probe pins used in probe cards and contact probes for testing these devices. However, if conventional probe pins are made ultra-thin, they tend to lack strength and cannot be used repeatedly.

[0003] Here, one method for improving the strength of the probe pin while maintaining high electrical conductivity is to adjust the type and content of the metal that constitutes the wire for the probe pin. Patent Document 1 discloses a "high strength and high electrical conductivity copper alloy characterized by containing 4 to 32 at% Ag in Cu." According to Table 1 in the same document, the copper alloy in Patent Document 1 has a tensile strength of 85.1 kg / mm 2 ~99kg / mm 2 (834MPa~970MPa), and electrical conductivity is 78.4IACS%~84.8IACS%.

[0004] As another method, a technique is conceivable in which, after adopting the composition of the copper alloy of Patent Document 1, further improvements are made to the manufacturing process of the wire for probe pins. Patent Document 2 discloses a method for manufacturing a Cu-Ag alloy wire, which is characterized by "repeatably performing at least twice a step of cold working with an area reduction of 95% or more on a cast rod obtained by continuously casting a Cu-based alloy containing 10-20 atomic % of Ag and the balance being Cu and unavoidable impurities, and a step of performing a heat treatment at a temperature of 450-550°C for 1-20 hours, and then performing cold working with an area reduction of 90% or more." The tensile strength of the Cu-Ag alloy wire manufactured by the manufacturing method of Patent Document 2 is 95 kgf / mm 2 ~102kgf / mm 2 (931MPa~1000MPa), and electrical conductivity is 80IACS%~85IACS%.

[0005] Furthermore, Patent Document 3 discloses a method for producing a Cu-Ag alloy conductor, which is characterized in that "a cast rod containing 10-20 atomic % Ag, with the remainder being Cu and unavoidable impurities, is subjected to a heat treatment at a temperature of 450-500°C for 10-20 hours, and then subjected to cold working with an area reduction rate of 95% or more, after being continuously cast from a Cu-based alloy. The tensile strength of the Cu-Ag alloy conductor produced by the method of Patent Document 3 is 110 kgf / mm 2 ~126kgf / mm 2 (1078MPa~1235MPa), and electrical conductivity is 65IACS%~72IACS%. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 4-120227 [Patent Document 2] Japanese Patent Application Publication No. 6-103809 [Patent Document 3] Japanese Patent Application Publication No. 6-93399 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the copper alloy of Patent Document 1, the Cu-Ag alloy wire of Patent Document 2, and the Cu-Ag alloy conductor of Patent Document 3 still lack strength to be used as a wire for a probe pin, for example, an ultrafine wire with a diameter of 0.1 mm or less. Therefore, the market continues to demand a metal wire for inspecting electric and electronic components that has both high conductivity and strength. [Means for solving the problem]

[0008] As a result of intensive research, the inventors of the present application have achieved the above-mentioned object by adopting the following means.

[0009] A. Manufacturing method of Cu-Ag alloy wire The method for producing a Cu—Ag alloy wire according to the present application is characterized by comprising the following steps 1 to 8 in order.

[0010] Step 1: A metal rod is obtained by melting a metal raw material that is mixed so that the composition is 10.0 wt% to 30.0 wt% Ag, excluding inevitable impurities, and the remainder is Cu. Step 2: After cold drawing so that the cross-sectional area reduction rate before and after processing is 15% to 25%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 3: After cold drawing is performed so that the cross-sectional area reduction rate before and after processing is 25% to 35%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 4: After cold drawing is performed so that the cross-sectional area reduction rate before and after processing is 30% to 40%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 5: After cold wire drawing or cold wire drawing and shaving, the wire is heat treated in a slightly reducing gas or inert gas atmosphere so that the cross-sectional area reduction rate before and after processing is 80% to 90%. Step 6: After cold wire drawing or cold wire drawing and shaving, the wire is heat treated in a slightly reducing gas or inert gas atmosphere so that the cross-sectional area reduction rate before and after processing is 85% to 95%. Step 7: After cold wire drawing or cold wire drawing and shaving, the wire is heat treated in a slightly reducing gas or inert gas atmosphere so that the cross-sectional area reduction rate before and after processing is 80% to 90%. Step 8: The metal rod is cold drawn so that the cross-sectional area reduction rate is 99.0% to 99.9999%, to obtain a Cu-Ag alloy wire having a diameter of 0.1 mm or less, containing 10.0 wt% to 30.0 wt% Ag, with the remainder being Cu and unavoidable impurities.

[0011] In the method for producing a Cu-Ag alloy wire according to the present application, the heat treatments in steps 2 and 3 are preferably performed at 400°C to 500°C for 0.5 to 3 hours, the heat treatment in step 4 at 350°C to 450°C for 0.5 to 3 hours, the heat treatment in step 5 at 300°C to 400°C for 0.5 to 3 hours, the heat treatment in step 6 at 250°C to 350°C for 0.5 to 3 hours, and the heat treatment in step 7 at 230°C to 330°C for 0.5 to 3 hours.

[0012] B.Cu-Ag alloy wire The Cu-Ag alloy wire according to the present application is manufactured by the above-mentioned manufacturing method for a Cu-Ag alloy wire according to the present application, and is characterized by having a tensile strength of 1600 MPa or more.

[0013] The Cu-Ag alloy wire according to the present application preferably has an electrical conductivity of 46.0 IACS% or more, a resistivity of 4.0 μΩ·cm or less, and a Vickers hardness of 360 HV or more.

[0014] C. Probe pins for electrical and electronic component inspection The probe pin for inspecting electric / electronic devices according to the present application is characterized in that it is obtained using the Cu-Ag alloy wire according to the present application. Effect of the Invention

[0015] According to the invention of the present application, it is possible to provide a manufacturing method for a Cu-Ag alloy wire having both high electrical conductivity and strength and suitable for use as a wire for a probe pin having a diameter of 0.1 mm or less, and a Cu-Ag alloy wire manufactured by this manufacturing method. Furthermore, according to the invention of the present application, it is possible to provide a probe pin for inspecting electric / electronic components, suitable for use in a continuity inspection of a semiconductor device having a large number of pins and a narrow pitch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] A. Manufacturing method of Cu-Ag alloy wire The manufacturing method of the Cu-Ag alloy wire according to the present application is characterized by comprising the following steps 1 to 8 in order. The manufacturing method of the Cu-Ag alloy wire according to the present application satisfies the requirements, and can manufacture a Cu-Ag alloy wire having high strength suitable for use as a wire for a probe pin with a diameter of 0.1 mm or less while maintaining high conductivity required for a probe pin for inspecting electric and electronic components. In consideration of market demands and various test results during development, the specific value of "high conductivity required for a probe pin for inspecting electric and electronic components" is assumed to be 46.0 IACS% or more, and the specific value of "high strength suitable for use as a wire for a probe pin with a diameter of 0.1 mm or less" is assumed to be tensile strength of 1600 MPa or more. The contents of each step will be described below.

[0017] Step 1: A metal rod is obtained by melting a metal raw material that is mixed so that the composition is 10.0 wt% to 30.0 wt% Ag, excluding inevitable impurities, and the remainder is Cu.

[0018] The object to be produced by the method for producing a Cu-Ag alloy wire according to the present application is a Cu-Ag alloy wire having a diameter of 0.1 mm or less, containing 10.0 wt% to 30.0 wt% Ag, with the remainder consisting of Cu and inevitable impurities, as described in step 8. Therefore, the same composition is adopted for the metal raw material used in step 1. Here, if the Ag content in the metal raw material in step 1 is less than 10.0 wt%, the electrical conductivity of the Cu-Ag alloy wire obtained in step 8 decreases, which is undesirable because it tends to be difficult to use as a probe pin for inspecting electric and electronic components. On the other hand, even if the Ag content in the metal raw material in step 1 exceeds 30.0 wt%, the workability of the Cu-Ag alloy decreases, and defects such as breakage occur during steps 2 to 8, which is undesirable because it tends to be difficult to process the Cu-Ag alloy until it becomes an ultra-fine wire having a diameter of 0.1 mm or less.

[0019] In step 1, a metal raw material having the above composition is melted to obtain a metal rod. The melting method and conditions in step 1 may be any known method and are not particularly limited, but the diameter of the metal rod obtained after melting (the length and width in the case of a rectangular shape) is preferably 10 mm to 30 mm. If the diameter of the metal rod is less than 10 mm, the degree of processing (i.e., "processing degree η=ln(A 0 / A 1 ), but A 0 is the cross-sectional area of ​​the metal rod in step 1, A 1is calculated as "cross-sectional area of ​​Cu-Ag alloy wire in step 8") is insufficient, and a Cu-Ag alloy wire having a target strength (tensile strength of 1600 MPa or more) tends not to be obtained, which is not preferable. On the other hand, even if the diameter of the metal rod exceeds 30 mm, it is necessary to change the conditions and increase the number of cold wire drawing and heat treatment (or cold wire drawing, shaving and heat treatment) performed in the next step and thereafter, which is not preferable because the productivity tends to decrease. In addition, as a method for melting the metal raw material, continuous casting, melting in a vacuum or in an inert gas, etc. can be mentioned. When melting in a vacuum or in an inert gas is adopted, it is also preferable to perform a facing process after melting in order to remove impurities present near the surface. In that case, the preferable numerical range of the diameter of the metal rod mentioned above (10 mm to 30 mm) is a numerical value including the facing process (i.e., "preferable numerical range of the diameter of the metal rod obtained after melting and facing process").

[0020] Step 2: After cold drawing so that the cross-sectional area reduction rate before and after processing is 15% to 25%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 3: After cold drawing is performed so that the cross-sectional area reduction rate before and after processing is 25% to 35%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 4: After cold drawing is performed so that the cross-sectional area reduction rate before and after processing is 30% to 40%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere.

[0021] In these steps 2 to 4, the cold wire drawing and heat treatment are repeated multiple times while gradually increasing the cross-sectional reduction rate before and after processing (i.e., (cross-sectional area of ​​Cu-Ag alloy before processing-cross-sectional area of ​​Cu-Ag alloy after processing)÷cross-sectional area of ​​Cu-Ag alloy before processing×100). By adopting a method of sequentially performing these steps 2 to 4 and steps 5 to 7 described below, in step 8, a Cu-Ag alloy wire having a tensile strength of 1600 MPa or more, which is an indicator of "high strength suitable for use as a wire for a probe pin with a diameter of 0.1 mm or less", can be obtained.

[0022] The cold wire drawing and heat treatment methods and conditions in steps 2 to 4 may be conventionally known and are not particularly limited, but it is preferable that the heat treatments in steps 2 and 3 are carried out at 400°C to 500°C for 0.5 to 3 hours, and the heat treatment in step 4 is carried out at 350°C to 450°C for 0.5 to 3 hours. The types of atmospheric gases for carrying out the heat treatments in steps 2 to 4 include slightly reducing gases such as 95% nitrogen and 5% hydrogen, and inert gases such as helium and argon.

[0023] Here, the heat treatments performed in steps 2 to 4 are stress relief annealing operations performed to relieve stress. Therefore, considering the composition of the metal raw material and the diameter of the metal rod after each cold wire drawing (the length in both directions when cold wire drawing is performed in a rectangular shape), if the heat treatment temperature in steps 2 and 3 is less than 400°C, the effect of stress relief is insufficient, and the Cu-Ag alloy wire obtained in step 8 tends to have defects such as cracks, which is not preferable. Similarly, if the heat treatment temperature in step 4 is less than 350°C, the effect of stress relief is insufficient, and the Cu-Ag alloy wire obtained in step 8 tends to have defects such as cracks, which is not preferable. On the other hand, if the heat treatment temperature in steps 2 and 3 exceeds 500°C, the size of the crystal grains of the Cu-Ag alloy increases excessively, and the hardness of the Cu-Ag alloy wire obtained in step 8 tends to decrease, which is not preferable. Similarly, if the temperature of the heat treatment in step 4 exceeds 450°C, the size of the crystal grains of the Cu-Ag alloy will increase excessively, and the hardness of the Cu-Ag alloy wire obtained in step 8 will tend to decrease, which is undesirable.

[0024] Furthermore, if the heat treatment time in steps 2 to 4 is less than 0.5 hours, the effect of stress relief is insufficient, and defects such as cracks tend to occur in the Cu-Ag alloy wire obtained in step 8, which is not preferable. On the other hand, if the heat treatment time in steps 2 to 4 exceeds 3 hours, the effect of stress relief is not significantly improved, and the productivity simply decreases, which is not preferable.

[0025] Step 5: After cold wire drawing or cold wire drawing and shaving, the wire is heat treated in a slightly reducing gas or inert gas atmosphere so that the cross-sectional area reduction rate before and after processing is 80% to 90%. Step 6: After cold wire drawing or cold wire drawing and shaving, the wire is heat treated in a slightly reducing gas or inert gas atmosphere so that the cross-sectional area reduction rate before and after processing is 85% to 95%. Step 7: After cold wire drawing or cold wire drawing and shaving, the wire is heat treated in a slightly reducing gas or inert gas atmosphere so that the cross-sectional area reduction rate before and after processing is 80% to 90%.

[0026] In these steps 5 to 7, the cold wire drawing and heat treatment (or the cold wire drawing, shaving and heat treatment) are repeated multiple times so that the area reduction rate before and after the processing is 80% to 95%, which is higher than that of the above-mentioned steps 2 to 4. By adopting a method of sequentially performing the above-mentioned steps 2 to 4 and these steps 5 to 7, a Cu-Ag alloy wire having a tensile strength of 1600 MPa or more, which is a guideline for "high strength suitable for use as a wire for a probe pin with a diameter of 0.1 mm or less", can be obtained in step 8. After the cold wire drawing, it is also preferable to perform a shaving (peeling) process in one or more of steps 5 to 7 in order to remove impurities present near the surface. Note that, when a shaving process is performed after the cold wire drawing, the area reduction rate before and after the processing in steps 5 to 7 is a numerical value including the shaving process (i.e., "a numerical value of the area reduction rate before and after the processing, calculated by considering the cold wire drawing and shaving processes as a series of processing operations").

[0027] The methods and conditions of the cold wire drawing, shaving and heat treatment in steps 5 to 7 may be conventionally known and are not particularly limited, but it is preferable that the heat treatment in step 5 is performed at 300°C to 400°C for 0.5 to 3 hours, the heat treatment in step 6 is performed at 250°C to 350°C for 0.5 to 3 hours, and the heat treatment in step 7 is performed at 230°C to 330°C for 0.5 to 3 hours. The types of atmospheric gases for the heat treatment in steps 5 to 7 include slightly reducing gases such as 95% nitrogen and 5% hydrogen, and inert gases such as helium and argon.

[0028] Here, the heat treatment performed in steps 5 to 7 is a stress relief annealing process performed for stress relief, similar to steps 2 to 4 described above. Therefore, considering the composition of the metal raw material and the diameter of the metal rod after each cold wire drawing (or after cold wire drawing and shaving) (the length in both directions when cold wire drawing is performed in a rectangular shape), if the temperature of the heat treatment in step 5 is less than 300°C, the effect of stress relief is insufficient, and the Cu-Ag alloy wire obtained in step 8 tends to have defects such as cracks, which is not preferable. Similarly, if the temperature of the heat treatment in step 6 is less than 250°C, the effect of stress relief is insufficient, and the Cu-Ag alloy wire obtained in step 8 tends to have defects such as cracks, which is not preferable. Even if the temperature of the heat treatment in step 7 is less than 230°C, the effect of stress relief is insufficient, and the Cu-Ag alloy wire obtained in step 8 tends to have defects such as cracks, which is not preferable.

[0029] On the other hand, if the temperature of the heat treatment in step 5 exceeds 400°C, the size of the crystal grains of the Cu-Ag alloy will increase excessively, and the hardness of the Cu-Ag alloy wire obtained in step 8 will tend to decrease, which is not preferable. Similarly, if the temperature of the heat treatment in step 6 exceeds 350°C, the size of the crystal grains of the Cu-Ag alloy will increase excessively, and the hardness of the Cu-Ag alloy wire obtained in step 8 will tend to decrease, which is not preferable. If the temperature of the heat treatment in step 7 exceeds 330°C, the size of the crystal grains of the Cu-Ag alloy will increase excessively, and the hardness of the Cu-Ag alloy wire obtained in step 8 will tend to decrease, which is not preferable.

[0030] Furthermore, if the heat treatment time in steps 5 to 7 is less than 0.5 hours, the effect of stress relief is insufficient, and defects such as cracks tend to occur in the Cu-Ag alloy wire obtained in step 8, which is not preferable. On the other hand, if the heat treatment time in steps 5 to 7 exceeds 3 hours, the effect of stress relief is not significantly improved, and the productivity simply decreases, which is not preferable.

[0031] Step 8: Cold drawing is performed so that the cross-sectional area reduction rate relative to the metal rod in step 1 is 99.0% to 99.9999%, to obtain a Cu-Ag alloy wire having a diameter of 0.1 mm or less, containing 10.0 wt% to 30.0 wt% Ag, with the remainder being Cu and unavoidable impurities.

[0032] In this step 8, cold wire drawing is performed so that the area reduction ratio of the metal rod obtained in the above-mentioned step 1 (i.e., (cross-sectional area of ​​the metal rod in step 1-cross-sectional area of ​​the Cu-Ag alloy wire in this step 8)÷cross-sectional area of ​​the metal rod in step 1×100) is 99.0% to 99.9999%. From an experimental point of view, if the area reduction ratio in this step 8 is within this numerical range, the Vickers hardness of the Cu-Ag alloy subjected to the cold wire drawing and heat treatment (or the cold wire drawing, shaving and heat treatment) in the above-mentioned steps 2 to 7 tends to be improved by work hardening. Here, if the area reduction ratio of the metal rod obtained in the above-mentioned step 1 is less than 99.0%, the effect of improving the Vickers hardness of the Cu-Ag alloy tends not to be sufficiently obtained, which is not preferable. On the other hand, even if the reduction in area of ​​the metal rod obtained in the above-mentioned step 1 exceeds 99.9999%, it is not preferable because the toughness of the Cu-Ag alloy wire is reduced due to excessive work hardening, and the durability and reliability of the product tend to be impaired.

[0033] The preferred diameter of the Cu-Ag alloy wire obtained in step 8 (in the case of a rectangular shape, the length and width of each wire) is 0.1 mm or less. If the diameter of the Cu-Ag alloy wire exceeds 0.1 mm, it is not preferred because when it is processed into a probe pin, it tends not to be applicable to the continuity test of semiconductor devices with multiple pins and narrow pitches. On the other hand, there is no particular limit to the lower limit of the diameter of the Cu-Ag alloy wire, but the diameter of the Cu-Ag alloy wire is preferably 0.01 mm or more. Even if the diameter of the Cu-Ag alloy wire is less than 0.01 mm, the market value as a probe pin for inspecting electric and electronic components is not dramatically improved, and the manufacturing cost tends to increase.

[0034] B.Cu-Ag alloy wire The Cu-Ag alloy wire according to the present application is manufactured by the manufacturing method of the Cu-Ag alloy wire according to the present application described above. The Cu-Ag alloy wire according to the present application is characterized by having an extremely excellent property of tensile strength of 1600 MPa or more by satisfying the requirements, particularly by repeating "cold wire drawing and heat treatment multiple times while gradually increasing the area reduction rate before and after processing in steps 2 to 4, and then repeating cold wire drawing and heat treatment (or cold wire drawing, shaving, and heat treatment) multiple times so that the area reduction rate before and after processing is 80% to 95%, which is larger than steps 2 to 4" in the manufacturing method of the Cu-Ag alloy wire according to the present application. Due to this property, the Cu-Ag alloy wire according to the present application can be suitably used as a probe pin of an ultra-fine wire with a diameter of 0.1 mm or less.

[0035] Here, if the tensile strength of the Cu-Ag alloy wire is less than 1600 MPa, when it is used as a probe pin of an ultra-fine wire with a diameter of 0.1 mm or less, the strength is insufficient, and defects such as bending or bending occur, and the durability and reliability of the product tend to be insufficient, which is not preferable. On the other hand, although there is no particular limit on the upper limit of the tensile strength of the Cu-Ag alloy wire, the tensile strength of the Cu-Ag alloy wire is preferably 1900 MPa or less. Even if the tensile strength of the Cu-Ag alloy wire exceeds 1900 MPa, the function as a probe pin is not significantly improved, and rather the flexibility is reduced, and the durability of repeated bending tends to deteriorate.

[0036] In addition, the Cu-Ag alloy wire according to the present application preferably has a conductivity of 46.0IACS% or more, a resistivity of 4.0μΩ·cm or less, and a Vickers hardness of 360HV or more. Here, if the conductivity of the Cu-Ag alloy wire is less than 46.0IACS%, it is not preferable because when it is used as a probe pin, it tends not to be possible to accurately detect minute currents in an electric circuit formed on a substrate material such as a semiconductor device. On the other hand, although there is no particular limit to the upper limit of the conductivity of the Cu-Ag alloy wire, it is preferable that the conductivity of the Cu-Ag alloy wire is 80.0IACS% or less. This is because if the conductivity of the Cu-Ag alloy wire exceeds 80.0IACS%, it tends to be difficult to achieve both high conductivity and high hardness.

[0037] In addition, if the resistivity of the Cu-Ag alloy wire exceeds 4.0 μΩ·cm, the electrical resistance of the Cu-Ag alloy wire is too high, and when it is used as a probe pin, it tends not to be possible to accurately detect minute currents in an electric circuit formed on a substrate material such as a semiconductor device, which is not preferable. On the other hand, although there is no particular limit to the lower limit of the resistivity of the Cu-Ag alloy wire, the resistivity of the Cu-Ag alloy wire is preferably 2.0 μΩ·cm or more. If the resistivity of the Cu-Ag alloy wire is less than 2.0 μΩ·cm, it tends to be difficult to achieve both low resistivity and high hardness. And, if the Vickers hardness of the Cu-Ag alloy wire is less than 360HV, it is not preferable because when it is used as a probe pin to repeatedly perform a continuity test of an electric or electronic component, defects such as bending or bending occur, and the durability and reliability of the product tend to be insufficient. On the other hand, although there is no particular upper limit on the Vickers hardness of the Cu-Ag alloy wire, the Vickers hardness of the Cu-Ag alloy wire is preferably 450HV or less. Even if the Vickers hardness of the Cu-Ag alloy wire exceeds 450HV, the function as a probe pin is not significantly improved, and rather the processability is reduced, making it more time-consuming to process the wire into a desired probe pin shape, and the productivity tends to decrease.

[0038] C. Probe pins for electrical and electronic component inspection The probe pin for inspecting electric / electronic components according to the present application is characterized in that it is obtained by using the Cu-Ag alloy wire according to the present application. The probe pin for inspecting electric / electronic components according to the present application satisfies the requirements and can be suitably used as a probe pin for inspecting electric / electronic components used for inspecting semiconductor integrated circuits and semiconductor devices having narrow-pitch electrodes, and therefore has high market value and is excellent in durability and reliability.

[0039] The invention according to the present application will be described in more detail below with reference to examples, but the invention according to the present application is not limited to these examples. EXAMPLES

[0040] A metal rod with a diameter of 15 mm was obtained by continuous casting using a metal raw material mixed to have a composition of 18.8 wt% Ag, the remainder Cu, excluding unavoidable impurities. This metal rod was cold drawn using a groove rolling machine so that the area reduction rate before and after processing was 18.47%, then heat treated at 450°C for 1 hour in a slightly reducing gas atmosphere of 95% nitrogen and 5% hydrogen, and water-cooled. Next, cold drawn so that the area reduction rate before and after processing was 30.56%, then heat treated at 450°C for 1 hour in a slightly reducing gas atmosphere of 95% nitrogen and 5% hydrogen, and water-cooled. Next, cold drawn so that the area reduction rate before and after processing was 36.00%, then heat treated at 400°C for 1 hour in a slightly reducing gas atmosphere of 95% nitrogen and 5% hydrogen, and water-cooled. Furthermore, after cold wire drawing and shaving to a thickness of 25 μm were performed so that the reduction in area before and after processing was 85.94% (more specifically, after cold wire drawing and subsequent shaving to a thickness of 25 μm), heat treatment was performed at 350°C for 1 hour in a slightly reducing gas atmosphere of 95% nitrogen and 5% hydrogen, and water quenching was performed. In addition, cold wire drawing was performed so that the reduction in area before and after processing was 91.28%, heat treatment was performed at 300°C for 1 hour in a slightly reducing gas atmosphere of 95% nitrogen and 5% hydrogen, and water quenching was performed. Finally, cold wire drawing was performed so that the reduction in area before and after processing was 84.00%, heat treatment was performed at 275°C for 1 hour in a slightly reducing gas atmosphere of 95% nitrogen and 5% hydrogen, and water quenching was performed. Finally, the metal rod (the metal rod with a diameter of 15 mm described above) was subjected to cold wire drawing so that the cross-sectional area reduction rate was 99.9998%, thereby obtaining a Cu-Ag alloy wire with a diameter of 0.02 mm containing 18.8 wt% Ag and the remainder being Cu and unavoidable impurities.

[0041] A part of the Cu-Ag alloy wire obtained by the method of this embodiment was cut to a length of 500 mm to prepare a test piece, and the tensile strength was measured using a tensile strength tester. Next, a part of the Cu-Ag alloy wire obtained by the method of this embodiment was separately cut to a length of 1000 mm to prepare a sample piece, and the resistivity was measured using a resistance meter. Next, the electrical conductivity (IACS%) was calculated from the resistivity value obtained by the measurement (more specifically, when the resistivity, i.e., the resistivity, was 1.7241×10-8 The electrical conductivity of the test piece was calculated from the measured resistivity, with the electrical conductivity of the international standard soft copper in Ω·m taken as 100%. ) Furthermore, a part of the Cu-Ag alloy wire obtained by the method of this embodiment was cut to a length of 10 mm, and the cross section was polished to make a smooth specimen, and the Vickers hardness was measured with a micro Vickers hardness tester at a test load of HV0.005. These measurement results are shown in Table 1. Table 1 also shows the manufacturing conditions of this embodiment, namely, "the cross-sectional reduction rate (%) of the Cu-Ag alloy before and after each processing, i.e., (cross-sectional area of ​​the Cu-Ag alloy before processing-cross-sectional area of ​​the Cu-Ag alloy after processing)÷cross-sectional area of ​​the Cu-Ag alloy before processing×100)" and "the cross-sectional reduction rate (%) of the Cu-Ag alloy with respect to the metal rod after continuous casting, i.e., (cross-sectional area of ​​the metal rod after continuous casting-cross-sectional area of ​​the Cu-Ag alloy after each processing)÷cross-sectional area of ​​the metal rod after continuous casting×100)".

[0042] [Table 1]

[0043] As can be understood from the above examples, "a metal raw material containing 10.0wt% to 30.0wt% Ag, excluding unavoidable impurities, and the remainder Cu is melted to obtain a metal rod, and then cold wire drawing and heat treatment are repeated multiple times while gradually increasing the area reduction rate before and after processing, and cold wire drawing and heat treatment, and cold wire drawing, shaving and heat treatment are further performed multiple times so that the area reduction rate before and after processing is larger than that of the cold wire drawing, and finally cold wire drawing is performed so that the area reduction rate of the metal rod is 99.0% to 99.9999%." This makes it possible to obtain a Cu-Ag alloy wire containing 10.0wt% to 30.0wt% Ag, with the remainder being Cu and unavoidable impurities, having a diameter of 0.1mm or less, and a tensile strength of 1600MPa or more. The probe pin for inspecting electrical and electronic components obtained by using the Cu-Ag alloy wire obtained in this embodiment has the excellent properties shown in Table 1, and therefore it can be determined that it is suitable as a probe pin for use in inspecting semiconductor integrated circuits and semiconductor devices having narrow-pitch electrodes. [Industrial Applicability]

[0044] The manufacturing method of the Cu-Ag alloy wire according to the present application and the Cu-Ag alloy wire manufactured by this manufacturing method can be used for a probe pin for inspecting electric / electronic components and for manufacturing the same. In particular, the manufacturing method of the Cu-Ag alloy wire according to the present application and the Cu-Ag alloy wire manufactured by this manufacturing method can be suitably used for a probe pin for inspecting electric / electronic components such as semiconductor integrated circuits and semiconductor devices having narrow-pitch electrodes and for manufacturing the same.

Claims

1. A method for producing a Cu—Ag alloy wire, comprising the following steps 1 to 8 in order: Step 1: A metal rod is obtained by melting a metal raw material having a composition of 10.0 wt % to 30.0 wt % Ag, excluding inevitable impurities, and the remainder Cu. Step 2: After cold drawing is performed so that the cross-sectional area reduction rate before and after processing is 15% to 25%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 3: After cold drawing is performed so that the cross-sectional area reduction rate before and after the processing is 25% to 35%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 4: After cold drawing is performed so that the cross-sectional area reduction rate before and after the processing is 30% to 40%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 5: After cold wire drawing or cold wire drawing and shaving are performed so that the cross-sectional area reduction rate before and after processing is 80% to 90%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 6: After cold wire drawing or cold wire drawing and shaving are performed so that the cross-sectional area reduction rate before and after processing is 85% to 95%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 7: After cold wire drawing or cold wire drawing and shaving are performed so that the cross-sectional area reduction rate before and after processing is 80% to 90%, heat treatment is performed in a slightly reducing gas or inert gas atmosphere. Step 8: The metal rod is subjected to cold wire drawing so that the cross-sectional area reduction rate is 99.0% to 99.9999%, to obtain a Cu-Ag alloy wire having a diameter of 0.1 mm or less, containing 10.0 wt% to 30.0 wt% Ag, with the balance being Cu and unavoidable impurities.

2. The manufacturing method of Cu-Ag alloy wire according to claim 1, wherein the heat treatment of step 2 and step 3 is performed at 400°C to 500°C for 0.5 hours to 3 hours, the heat treatment of step 4 is performed at 350°C to 450°C for 0.5 hours to 3 hours, the heat treatment of step 5 is performed at 300°C to 400°C for 0.5 hours to 3 hours, the heat treatment of step 6 is performed at 250°C to 350°C for 0.5 hours to 3 hours, and the heat treatment of step 7 is performed at 230°C to 330°C for 0.5 hours to 3 hours.

3. A Cu-Ag alloy wire manufactured by the method for manufacturing a Cu-Ag alloy wire according to claim 1 or 2, A Cu-Ag alloy wire having a tensile strength of 1600 MPa or more.

4. 4. The Cu-Ag alloy wire according to claim 3, having an electrical conductivity of 46.0 IACS% or more, a resistivity of 4.0 μΩ·cm or less, and a Vickers hardness of 360 HV or more.

5. A probe pin for inspecting electric / electronic devices, obtained by using the Cu-Ag alloy wire according to claim 3.

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