Alloy, alloy wire obtained using said alloy, alloy wire for probe pin obtained using said alloy wire, and method for manufacturing alloy wire for probe pin

Abstract

The present invention aims to provide an alloy that combines the high hardness and workability required for probe pins, an alloy wire obtained using said alloy, an alloy wire for probe pins obtained using said alloy wire, and a method for manufacturing the same.To achieve this objective, the present invention employs an alloy characterized by 5.0 to 15.0 mass% Ag, 48.2 to 58.3 mass% Pd, 34.6 to 42.3 mass% Cu, 0.05 to 0.17 mass% B, 0.3 to 1.5 mass% Zn, 0.006 to 0.10 mass% Al, and the balance being unavoidable impurities, an alloy wire obtained using said alloy, an alloy wire for probe pins obtained using said alloy wire, and a method for manufacturing the same.

Description

[Technical Field]

[0001] The present invention relates to an alloy, an alloy wire obtained using the alloy, an alloy wire for a probe pin obtained using the alloy wire, and a method for manufacturing an alloy wire for a probe pin. [Background technology]

[0002] Probe cards and contact probes have been known as probes for electrical testing of semiconductor components, such as semiconductor integrated circuits and semiconductor packages, that have narrow-pitch electrodes. These testing probes use multiple probe pins formed using a small-diameter alloy wire (also referred to as a fine metal wire or a fine alloy wire). Small-diameter alloy wires such as those used for probe pins are also used as conductor materials in wires and cables used in electronic devices such as mobile devices and industrial robots, as well as in medical devices. Since the alloy wires used for such probe pins repeatedly come into contact with the electrodes of the components under test at an appropriate load when used as probe pins, they are required to have a well-balanced combination of properties, such as high hardness and bendability.

[0003] In response to these demands on probe pin materials, for example, Patent Document 1 discloses a probe pin material that has excellent resistance and hardness (wear resistance) and improved bending resistance, and is made of Ag, Pd, Cu, a first additional element B, at least one of Zn, Bi, and Sn as a second additional element, and inevitable impurities.The patent also discloses that the probe pin material has a Vickers hardness of 380 HV to 580 HV and can be bent at a 90° angle five or more times. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication "Patent No. 7072126" Summary of the Invention [Problem to be solved by the invention]

[0005] As in the above example, it has been reported that the hardness can be improved by adding various metal elements to an alloy containing Ag, Pd, and Cu as the main components (hereinafter referred to as an Ag-Pd-Cu alloy). However, depending on the alloy composition, the workability into alloy wire may be reduced. As a result, the inventors of the present invention have found that there is room for improvement in achieving both an improvement in the hardness of the alloy and the workability into alloy wire.

[0006] The present invention has been made in view of the above circumstances, and aims to provide an alloy that satisfies both the high hardness required for probe pins and the ease of workability into alloy wire, an alloy wire obtained using the alloy, an alloy wire for probe pins obtained using the alloy wire, and a method for manufacturing the alloy wire for probe pins. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, as a result of intensive research, the following alloy, an alloy wire obtained using the alloy, an alloy wire for a probe pin obtained using the alloy wire, and a method for manufacturing the alloy wire for a probe pin were conceived.

[0008] The first alloy according to the present invention is an alloy characterized by comprising 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.05 mass% to 0.17 mass% B, 0.3 mass% to 1.5 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the remainder being unavoidable impurities.

[0009] The second alloy according to the present invention is preferably the first alloy in which B is 0.05 mass % or more and 0.09 mass % or less.

[0010] The third alloy according to the present invention is preferably the first alloy in which B is 0.11 mass % or more and 0.16 mass % or less.

[0011] The fourth alloy according to the present invention is preferably the first alloy containing 0.09 mass% or more and 0.16 mass% or less of B and 1.0 mass% or more and 1.5 mass% or more of Zn.

[0012] The fifth alloy according to the present invention is an alloy characterized by comprising 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.08 mass% to 0.17 mass% B, 0.3 mass% to 1.3 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the remainder being unavoidable impurities.

[0013] The first alloy wire according to the present invention employs an alloy wire obtained using the first alloy.

[0014] The alloy wire according to the present invention preferably has a wire diameter of 1.0 mm or less.

[0015] The alloy wire according to the present invention preferably has a Vickers hardness of 490 HV or more and 600 HV or less.

[0016] The alloy wire according to the present invention preferably has a volume resistivity of 11.5 μΩ·cm or less.

[0017] The alloy wire for a probe pin according to the present invention is Either The alloy wire material for the probe pin was obtained using the alloy wire material. In addition to the first alloy, the second, third, and fourth alloys can also be used as the alloy wire material for the probe pin.

[0018] The second alloy wire according to the present invention is an alloy wire obtained using the fifth alloy, and is characterized by having a wire diameter of 0.1 mm or less.

[0019] The first method for producing an alloy wire for a probe pin according to the present invention employs a method for producing an alloy wire for a probe pin, which is characterized by comprising the following steps 1 to 3. Step 1: A metallic material containing Ag, Pd, Cu, B, Zn, and Al is heated and melted to obtain an ingot containing 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.05 mass% to 0.17 mass% B, 0.3 mass% to 1.5 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the remainder being unavoidable impurities. Step 2: The ingot is repeatedly subjected to cold working with a cross-sectional area reduction rate of 50% or more and heat treatment to obtain a pre-aging alloy wire having a wire diameter of 1.0 mm or less. Step 3: The unaged alloy wire is subjected to aging treatment to obtain an aged alloy wire for a probe pin.

[0020] The second method for producing an alloy wire for a probe pin according to the present invention employs a method for producing an alloy wire for a probe pin, which is characterized by comprising the following steps 1 to 3. Step 1: A metallic material containing Ag, Pd, Cu, B, Zn, and Al is heated and melted to obtain an ingot containing 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.08 mass% to 0.17 mass% B, 0.3 mass% to 1.3 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the remainder being unavoidable impurities. Step 2: The ingot is repeatedly subjected to cold working with a cross-sectional area reduction rate of 50% or more and heat treatment to obtain a pre-aging alloy wire having a wire diameter of 0.1 mm or less. Step 3: The unaged alloy wire is subjected to aging treatment to obtain an aged alloy wire for a probe pin. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide an alloy that combines the high hardness required for probe pins with the ease of processing into alloy wire, an alloy wire obtained using said alloy, an alloy wire for probe pins obtained using said alloy wire, and a method for manufacturing an alloy wire for probe pins. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, the alloy according to the present invention, the alloy wire obtained using the alloy, the alloy wire for probe pins obtained using the alloy wire, and the manufacturing method of the alloy wire for probe pins will be described. Note that the following description merely shows one embodiment, and should not be construed as being limited to the following description.

[0023] 1.Alloy The first alloy according to the present invention contains 5.0 to 15.0 mass% Ag, 48.2 to 58.3 mass% Pd, 34.6 to 42.3 mass% Cu, 0.05 to 0.17 mass% B, 0.3 to 1.5 mass% Zn, and 0.006 to 0.10 mass% Al. The sum of the above-mentioned components is 100 mass%. However, the first alloy according to the present invention may contain unavoidable impurities. If unavoidable impurities are contained, the sum of all the above-mentioned metal composition components and the unavoidable impurities is 100 mass%. The first alloy with this composition has both the high hardness and workability required for probe pins.

[0024] The main components of this alloy are Ag (silver), Pd (palladium), and Cu (copper). Cu has low electrical resistance, but its hardness is insufficient. Therefore, Ag and Pd are added to improve hardness, achieving both high hardness and low resistance. In this case, the preferred composition ranges for achieving high hardness and low resistance are 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, and 34.6 mass% to 42.3 mass% Cu.

[0025] The first component added to the above-mentioned Ag, Pd, and Cu is B (boron). Adding B to an Ag-Pd-Cu alloy can improve hardness. The B content is 0.05 mass% or more and 0.17 mass% or less. If the B content is less than 0.05 mass%, the above-mentioned effect cannot be obtained. On the other hand, if the B content exceeds 0.17 mass%, the plastic workability is significantly reduced and the precipitation of intermetallic compounds, which will be described later, is inhibited.

[0026] The second component added to the above-mentioned Ag, Pd, and Cu is Zn (zinc). Zn strengthens grain boundaries by forming intermetallic compounds with the PdCu ordered phase, which is a factor in age hardening in Ag-Pd-Cu alloys. This improves hardness and provides improved wear resistance. The Zn content is 0.3 mass% to 1.5 mass%. If the Zn content is less than 0.3 mass%, the above-mentioned effects cannot be achieved. Also, if the Zn content exceeds 1.5 mass%, workability decreases, making cold working during the manufacturing process difficult.

[0027] The third component added to the above-mentioned Ag, Pd, and Cu is Al (aluminum). Al has the effect of suppressing grain boundary reactions of precipitates in Ag-Pd-Cu alloys and promoting intragranular formation of precipitates. Adding Al in an appropriate range improves the workability of the alloy into an alloy wire and also improves hardness after aging treatment. The Al content is 0.006 mass% or more and 0.10 mass% or less. If the Al content is less than 0.006 mass%, the above-mentioned effects cannot be obtained. Furthermore, if the Al content exceeds 0.10 mass%, the precipitation of intermetallic compounds is inhibited, the effect of improving hardness cannot be obtained, and the melt flowability is reduced.

[0028] Thus, the first alloy according to the present invention is an Ag-Pd-Cu alloy containing B and Zn, and further containing Al in the above-mentioned content. The alloy of the above-mentioned composition has good workability when it is made into an alloy wire, and the alloy wire has improved hardness after aging treatment.

[0029] By using an alloy containing Ag, Pd, Cu, B, Zn, and Al in the above-mentioned ranges, with the remainder consisting of inevitable impurities, a good balance of high hardness and workability can be achieved. This results in excellent workability into probe pins and a long service life when used as probe pins. Here, the inevitable impurities are not particularly limited as long as they are unavoidably mixed in, and they may be included as inevitable impurities, but are not necessarily included. Here, when inevitable impurities are included, the sum of all of the above-mentioned metal composition components according to the present invention and the inevitable impurities is 100 mass%.

[0030] The second alloy according to the present invention is the first alloy except that the content of B is 0.05 mass% or more and 0.09 mass% or less. As shown in Table 3 below, by limiting the B content of the first alloy to the above range, good hardness and workability as well as good (lower) volume resistivity can be obtained.

[0031] The third alloy according to the present invention is the first alloy except that the content of B is 0.11 mass% or more and 0.16 mass% or less. As shown in Table 4 below, by limiting the B content to the above range compared to the first alloy, higher hardness can be obtained.

[0032] The fourth alloy according to the present invention is the first alloy, but with the B content being 0.09 to 0.16 mass% and the Zn content being 1.0 to 1.5 mass%. As shown in Table 5 below, by limiting the B and Zn contents to the above ranges, the fourth alloy provides a good balance of higher hardness and good volume resistivity.

[0033] The fifth alloy of the present invention contains 5.0 to 15.0 mass% Ag, 48.2 to 58.3 mass% Pd, 34.6 to 42.3 mass% Cu, 0.08 to 0.17 mass% B, 0.3 to 1.3 mass% Zn, and 0.006 to 0.10 mass% Al. The sum of the above-mentioned components is 100 mass%. However, the fifth alloy of the present invention may contain unavoidable impurities. If unavoidable impurities are contained, the sum of all the above-mentioned metal components and the unavoidable impurities is 100 mass%. The fifth alloy with this composition not only has the high hardness and workability required for probe pins, but also can be bent 20 or more times at a final working rate of 99% or more. This is because the addition of Al in an appropriate range improves the workability of the alloy into an alloy wire rod, and also improves the hardness and bending resistance after aging treatment at the same time.

[0034] [Method for measuring composition] The method for measuring the composition of the alloy is not particularly limited, and can be performed using an ICP (inductively coupled plasma) optical emission spectrometer, XRF (X-ray fluorescence) analysis, etc. Measurement can also be performed using analytical methods such as gravimetric analysis, EDX (energy dispersive X-ray) analysis, and WDX (wavelength dispersive X-ray) analysis.

[0035] 2.Alloy wire rod The alloy wire according to the present invention is obtained using the above-mentioned alloy, and therefore has the high hardness required for a probe pin and is easy to process into an alloy wire.

[0036] [Wire diameter] The wire diameter of the alloy wire according to the present invention is preferably 1.0 mm or less. A wire diameter exceeding 1.0 mm is undesirable because it severely limits the applications of the alloy wire as a probe pin for electrical testing, such as in probe cards and contact probes, and also tends to reduce the added value of the alloy wire. Furthermore, to achieve the number of 20 or more folds described below, the wire diameter is more preferably 0.1 mm or less. This is because a thinner wire diameter results in a finer alloy structure and improved bending resistance. A wire diameter of 0.1 mm can achieve a number of 20 or more folds (see Table 6 in the Examples section below). Similarly, if the wire diameter is 0.1 mm or less and the final processing rate is 99% or more, a number of 20 or more folds can also be achieved. While there is no particular lower limit for the wire diameter, a wire diameter of 0.020 mm or more is preferred in consideration of processing precision.

[0037] [Workability] The final working ratio of the alloy wire rod according to the present invention is preferably 90% or more. If the final working ratio is less than 90%, the hardness after aging treatment tends not to be sufficiently improved, and the volume resistivity after aging treatment tends to increase. On the other hand, although there is no particular upper limit to the final working ratio, a high final working ratio tends to make working difficult and does not allow for further improvement in hardness, so the final working ratio is preferably 99.99% or less. Here, the final working ratio is the area reduction ratio when working from the final heat treatment to the final wire diameter. The area reduction ratio is calculated by (cross-sectional area before working - cross-sectional area after working) / cross-sectional area before working × 100%.

[0038] [Vickers hardness] The Vickers hardness of the alloy wire according to the present invention is preferably 490 HV or more and 600 HV or less. A Vickers hardness of less than 490 HV makes it more susceptible to wear during a touchdown test, which involves repeated contact with the test object. It has been reported that a Vickers hardness of 476 HV breaks after approximately 110,000 repeated contacts, whereas a Vickers hardness of 490 HV does not break even after more than 200,000 contacts, and a Vickers hardness of 530 HV does not break even after more than 230,000 contacts. Furthermore, a Vickers hardness of more than 600 HV makes it difficult to achieve 90° bending more than 20 times. The touchdown test is a durability test in which a probe pin comes into contact with a chip on a semiconductor wafer.

[0039] [Volume resistivity] The volume resistivity of the alloy wire according to the present invention is preferably 11.5 μΩ·cm or less, more preferably 8.50 μΩ·cm or less, and even more preferably 7.80 μΩ·cm or less. As mentioned above, the alloy wire is used as a probe pin for electrical testing of semiconductor components, etc. If the volume resistivity exceeds 11.5 μΩ·cm, the voltage drop due to the current flowing through the probe pin during electrical testing increases, resulting in a large measurement error. While there is no particular lower limit for the volume resistivity, lowering the volume resistivity improves bendability but reduces hardness. Therefore, the volume resistivity of the alloy wire according to the present invention is preferably 5 μΩ·cm or more.

[0040] [Number of folds] An alloy wire obtained using the fifth alloy of the present invention has a wire diameter of 0.1 mm or less and a final working ratio of 99% or more, and can be bent 90° 20 times or more in a 90° bending test after aging treatment. Since the number of bending times before fracture can be increased by reducing the wire diameter of the alloy wire, it is preferable that the alloy wire has a wire diameter of 0.1 mm or less and a final working ratio of 99% or more. Furthermore, a large number of 90° bending times not only means excellent workability, but also makes the alloy suitable for use in cantilever-type probe pins, etc.

[0041] If the number of 90° bends is less than 20, not only will the workability be poor, but the durability will also be poor when used, for example, as a cantilever-type probe pin. On the other hand, although there is no particular upper limit on the number of 90° bends, increasing the number of 90° bends reduces hardness, so it is preferable that the number of 90° bends of the alloy wire according to the present invention be approximately 40 or less. The 90° bend test is a test in which a straightened alloy wire is subjected to a first step of bending it at an approximately 90° angle, and a second step of bending it back to the straight state from the approximately 90° bent state, alternating between these steps. Each of the first step and the second step counts as one bend, and the total number of bends until the wire breaks is defined as the number of 90° bends.

[0042] 3. Alloy wire for probe pins The alloy wire for a probe pin according to the present invention is obtained using the above-mentioned alloy wire. Therefore, it has the high hardness required for a probe pin. By forming a probe pin using this alloy wire for a probe pin, a probe pin with high hardness can be obtained. In other words, it can be suitably used as a probe for electrical testing of semiconductor components, etc.

[0043] 4. Manufacturing method of alloy wire for probe pins The first method for manufacturing the alloy wire for a probe pin according to the present invention is the method for manufacturing the alloy wire for a probe pin described above, and includes the following steps 1 to 3. Step 1: A metallic material containing Ag, Pd, Cu, B, Zn, and Al is heated and melted to obtain an ingot containing 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.05 mass% to 0.17 mass% B, 0.3 mass% to 1.5 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the remainder being unavoidable impurities. Step 2: The ingot obtained in step 1 is repeatedly subjected to cold working with a cross-sectional area reduction rate of 50% or more and heat treatment to obtain a pre-aging alloy wire having a wire diameter of 1.0 mm or less. Step 3: The pre-aging alloy wire obtained in step 2 is subjected to aging treatment to obtain an aged alloy wire for a probe pin.

[0044] By employing this manufacturing method, it is possible to manufacture an alloy wire for a probe pin that satisfies both the high hardness required for a probe pin and the ease of processing into an alloy wire.

[0045] [Process 1] Step 1 is a process for producing an ingot, which serves as the raw material for obtaining a probe pin alloy wire having a predetermined composition, using a casting technique. Specifically, a metallic material containing Ag, Pd, Cu, B, Zn, and Al is placed in a heat-resistant container and heated to melt. The atmosphere is not particularly limited, but the heating and melting can be performed in air, a vacuum, an inert gas atmosphere such as nitrogen or argon, or a slightly reducing atmosphere. Next, the molten metallic material is poured into a mold to obtain an ingot containing 5.0 to 15.0 mass% Ag, 48.2 to 58.3 mass% Pd, 34.6 to 42.3 mass% Cu, 0.05 to 0.17 mass% B, 0.3 to 1.5 mass% Zn, 0.006 to 0.10 mass% Al, and the remainder consisting of unavoidable impurities. As long as the ingot of step 1 can be obtained, the method is not limited to the above, and the ingot may be obtained by any melting and casting method, such as a continuous casting method.

[0046] Here, if the Al content exceeds 0.01 mass%, it is not preferable because the fluidity of the molten metal decreases. If the B content exceeds 0.17 mass%, it is not preferable because the workability decreases significantly and cold working becomes difficult. Also, if the Zn content exceeds 1.5 mass%, it is not preferable because the workability decreases and cold working becomes difficult.

[0047] The manufacturing conditions for heating and melting in step 1 may be conventionally known, such as a melting temperature of 1300°C and an inert gas atmosphere. However, as long as the metal material can be heated and melted, the conditions are not limited to those described above. Note that a slightly reducing atmosphere is a gas in which a trace amount of a reducing gas such as hydrogen or carbon monoxide is mixed with an inert gas; for example, a gas mixture of 95% nitrogen and 5% hydrogen can be used.

[0048] [Process 2] Step 2 is a process for producing a pre-aging alloy wire having a wire diameter of 1.0 mm or less by repeatedly cold working the ingot obtained in Step 1 to a cross-sectional area reduction rate of 50% or more and heat treating it in an inert gas atmosphere or a slightly reducing atmosphere. The cold working process is a process for forming the ingot into the desired shape and dimensions and for introducing a large compressive stress into the alloy to improve its strength and hardness. Specifically, the ingot obtained in Step 1 is worked using a rolling machine, wire drawing machine, or the like in an environment near room temperature so that the cross-sectional area reduction rate is 50% or more. A cross-sectional area reduction rate of less than 50% is undesirable because the improvement in hardness due to cold working tends to be insufficient. While there is no particular upper limit to the cross-sectional area reduction rate, a cross-sectional area reduction rate of 99.99% or less is preferred because it tends to make processing difficult and does not allow for further improvement in hardness. The final reduction ratio, which is the area reduction ratio when processed from the final heat treatment to the final wire diameter, is preferably 90% or more, more preferably 95% or more, and even more preferably 99% or more. The Ag-Pd-Cu alloy is hardened and its volume resistivity is reduced by aging treatment, and the aging phenomenon is generally accelerated as the final reduction ratio before aging treatment is higher.

[0049] Next, the heat treatment step involves heating and maintaining the alloy to an appropriate temperature, thereby dissolving the metal atoms in the alloy into a solid (forming a solid solution), and then rapidly cooling the alloy without forming precipitates. The heat treatment conditions may be those conventionally known in the art. For example, the alloy may be placed in a heat-resistant container, treated in an inert gas atmosphere such as nitrogen or argon, or in a slightly reducing atmosphere, at 600°C to 900°C for 30 minutes to 3 hours, and then rapidly cooled. The rapid cooling method is not particularly limited, and may include water cooling, oil cooling, and cooling using an inert gas.

[0050] By repeatedly performing the above-mentioned cold working and heat treatment on the ingot obtained in step 1, a pre-aging alloy wire having a wire diameter of 1.0 mm or less can be obtained.

[0051] [Step 3] Step 3 is a step of producing an aged alloy wire for a probe pin by subjecting the pre-aging alloy wire obtained in Step 2 to aging treatment in an inert gas atmosphere or a slightly reducing atmosphere. Aging refers to the change in mechanical properties such as hardness over time, and aging treatment refers to a treatment that accelerates time transformation by applying temperature. In Step 3, the pre-aging alloy wire obtained in Step 2 is subjected to aging treatment to precipitate a PdCu ordered phase or an intermetallic compound of a PdCu ordered phase and Zn in the matrix, thereby improving hardness. The aging treatment conditions may be conventionally known. For example, the pre-aging alloy wire obtained in Step 2 may be placed in a heat-resistant container and heat-treated at 300°C to 550°C for about 1 minute to 20 hours in an inert gas atmosphere such as nitrogen or argon, and then allowed to cool.

[0052] The second method for manufacturing the alloy wire for a probe pin according to the present invention is the method for manufacturing the alloy wire for a probe pin described above, and includes the following steps 1 to 3. Step 1: A metallic material containing Ag, Pd, Cu, B, Zn, and Al is heated and melted to obtain an ingot containing 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.08 mass% to 0.17 mass% B, 0.3 mass% to 1.3 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the remainder being unavoidable impurities. Step 2: The ingot obtained in step 1 is repeatedly subjected to cold working with a cross-sectional area reduction rate of 50% or more and heat treatment to obtain a pre-aging alloy wire with a final working rate of 99% or more and a wire diameter of 0.1 mm or less. Step 3: The pre-aging alloy wire obtained in step 2 is subjected to aging treatment to obtain an aged alloy wire for a probe pin.

[0053] By adopting this manufacturing method, it is possible to produce alloy wire for probe pins that not only has the high hardness and workability required for probe pins, but can also be bent more than 20 times at a final processing rate of more than 99%.

[0054] [Other steps] The method for manufacturing an alloy wire for a probe pin according to the present invention may include other steps in addition to the above-described steps 1 to 3, as long as it is possible to manufacture the above-described alloy wire for a probe pin. For example, it is preferable to use a shaper to cut and remove a predetermined amount from the surface of the ingot between steps 1 and 2. This is because it is possible to remove the oxide film on the surface of the ingot manufactured in step 1 and inclusions such as alumina and silica embedded in the ingot surface, thereby increasing the compositional purity of the ingot.

[0055] The embodiment of the present invention described above is one aspect of the present invention, and can be modified as appropriate without departing from the spirit of the present invention. In addition, the present invention will be described in more detail below using examples, but the present invention is not limited to the following examples. [Example]

[0056] The following process was carried out as step 1. A metal material containing Ag, Pd, Cu, B, Zn, and Al was placed in a carbon crucible and melted at 1300°C in an inert gas atmosphere. The melted metal material was then poured into a mold to obtain an ingot measuring 20 mm x 20 mm x 150 mm and having the composition shown in Table 1. In Table 1, the No. column indicates the example number, and the Ag, Pd, Cu, B, Zn, and Al columns indicate the composition (mass%) of each element. Furthermore, composition values marked with an asterisk (*) indicate the maximum or minimum value in Table 1. In the composition analysis of the ingot, Ag and Pd were measured using gravimetric analysis, B, Zn, and Al were measured using ICP, and the remainder was Cu. Furthermore, these compositions do not preclude the possibility of the inclusion of unavoidable impurities that may have been present due to measurement accuracy limitations.

[0057] Next, before step 2, a shaper was used to cut and remove the surface of the ingot obtained in step 1 to a thickness of 1 mm. This removed the oxide film on the surface of the ingot obtained in step 1 and inclusions such as alumina and silica embedded in the ingot surface.

[0058] Next, in step 2, the ingot was subjected to the following process, in which the surface was cut off to a thickness of 1 mm using a shaper. Cold working was performed at room temperature (25°C) using a grooved rolling mill and a wire drawing machine to achieve a cross-sectional area reduction rate of 50% or more, followed by heat treatment in which the ingot was held in a nitrogen atmosphere at 800°C for 1 hour and then quenched, thereby obtaining pre-aging alloy wire rods with the wire diameters shown in Table 1. In Table 1, the workability column indicates that a final working rate of 90% or more was considered good, the final working rate column indicates the final working rate (%), and the wire diameter column indicates the wire diameter (mm) after final working. In addition, the "φ" in the wire diameter column indicates that the cross section of the worked alloy wire rod was circular.

[0059] Next, in step 3, the pre-aging alloy wire obtained in step 2 was subjected to aging treatment by holding it for 1 hour in a slightly reducing atmosphere of 300 to 550°C containing a mixture of 95% nitrogen and 5% hydrogen, thereby obtaining an alloy wire of the example.

[0060] The following process was performed as step 1. A metal material containing Ag, Pd, Cu, B, Zn, and Al was placed in a carbon crucible and melted at 1300°C in an inert gas atmosphere. The melted metal material was then poured into a mold to obtain an ingot measuring 20 mm x 20 mm x 150 mm and having the composition shown in Table 2. In Table 2, the No. column indicates the comparative example number, and the Ag, Pd, Cu, B, Zn, and Al columns indicate the composition (mass%) of each element. In the composition analysis of the ingot, Ag and Pd were measured using gravimetric analysis, B, Zn, and Al were measured using ICP, and the remainder was Cu. Furthermore, these compositions do not preclude the possibility of the inclusion of unavoidable impurities that may have been present due to measurement accuracy limitations.

[0061] The subsequent steps were the same as those in the examples to obtain alloy wires of comparative examples. In Table 2, the workability column indicates that a final processing rate of 90% or more was Good, and that a final processing rate of less than 90% was Bad. Those with a final processing rate of less than 90% had poor workability and could not be processed to a wire diameter of 1.0 mm or less. The final processing rate column indicates the final processing rate (%), and the wire diameter column indicates the wire diameter (mm) after final processing. In addition, in the wire diameter column, "φ" indicates that the cross section of the processed alloy wire is circular, and "□" indicates that the cross section of the processed alloy wire is other than circular.

[0062] 〔evaluation〕 The alloy wires of each composition in the Examples and Comparative Examples were measured for Vickers hardness (HV), volume resistivity (μΩ·cm), and number of 90° bends (times). The measurement results are shown in Tables 1 and 2, respectively. In Tables 1 and 2, the hardness column indicates Vickers hardness (HV), the volume resistivity column indicates volume resistivity (μΩ·cm), and the number of bends column indicates the number of 90° bends (times). In addition, for samples with poor workability, measurements of Vickers hardness (HV), volume resistivity (μΩ·cm), and number of 90° bends (times) were not performed because they could not be processed into wires with a circular cross section.

[0063] [Table 1]

[0064] [Table 2]

[0065] As shown in Table 1, all alloy wires obtained using alloys within the composition range specified in the present invention had a Vickers hardness of 490 HV or more and 600 HV or less, and a volume resistivity of 11.5 μΩ·cm or less. As shown in Table 2, those with a final processing rate of less than 90% had poor processability and could not be processed to a wire diameter of 1.0 mm or less. Furthermore, even those that could be processed to a wire diameter of 1.0 mm or less had a Vickers hardness of less than 490 HV.

[0066] [Example of composition focusing on characteristics] Additionally, compositions that satisfy an even lower volume resistivity (7.80 μΩ·cm or less) are selected from Table 1 and shown in Table 3. Focusing on B, a volume resistivity of 7.80 μΩ·cm is obtained when the B content is between 0.05 mass% and 0.09 mass%. Composition values marked with an "*" indicate the maximum or minimum value of B in Table 3.

[0067] [Table 3]

[0068] Compositions that satisfy even higher hardness (530 HV or higher) are excerpted from Table 1 and shown in Table 4. Focusing on B, a hardness of 530 HV or higher is obtained when the B content is 0.11 mass% or more and 0.16 mass% or less. Composition values marked with an "*" indicate the maximum or minimum value of B in Table 4.

[0069] [Table 4]

[0070] Table 5 also shows compositions from Table 1 that offer a good balance between volume resistivity (8.50 μΩ·cm or less) and hardness (500 HV or more). Focusing on B and Zn, a volume resistivity of 8.50 μΩ·cm or less and a hardness of 500 HV or more are achieved when B is between 0.09 mass% and 0.16 mass% and Zn is between 1.0 mass% and 1.5 mass%. Composition values marked with an "*" indicate the maximum or minimum values for B and Zn in Table 5.

[0071] [Table 5]

[0072] Furthermore, compositions that satisfy the requirements of a final wire diameter of 0.1 mm, a final working rate of 99% or more, and a 90° bending count of 20 or more are excerpted from Table 1 and shown in Table 6. Here, focusing on B and Zn, a 90° bending count of 20 or more is achieved when B is 0.08 mass% or more and 0.17 mass% or less and Zn is 0.3 mass% or more and 1.3 mass% or less. Composition values marked with "*" indicate the maximum or minimum value in Table 6.

[0073] [Table 6] [Industrial Applicability]

[0074] The alloy according to the present invention satisfies both the high hardness required for probe pins and the workability into alloy wires, and therefore can be suitably used as alloy wires for electrical inspection probes and as alloy wires for probe pins obtained using the alloy wires. The method for manufacturing the alloy wire for probe pins according to the present invention is also suitable as a method for manufacturing the alloy wire for probe pins according to the present invention.

Claims

1. An alloy comprising 5.0 mass% or more and 15.0 mass% or less of Ag, 48.2 mass% or more and 58.3 mass% or less of Pd, 34.6 mass% or more and 42.3 mass% or less of Cu, 0.05 mass% or more and 0.17 mass% or less of B, 0.3 mass% or more and 1.5 mass% or less of Zn, 0.006 mass% or more and 0.10 mass% or less of Al, and the balance being inevitable impurities.

2. 2. The alloy according to claim 1, wherein B is 0.05 mass% or more and 0.09 mass% or less.

3. The alloy according to claim 1, wherein B is 0.11 mass% or more and 0.16 mass% or less.

4. 2. The alloy according to claim 1, wherein B is 0.09 mass% or more and 0.16 mass% or less, and Zn is 1.0 mass% or more and 1.5 mass% or less.

5. An alloy comprising 5.0 mass% or more and 15.0 mass% or less of Ag, 48.2 mass% or more and 58.3 mass% or less of Pd, 34.6 mass% or more and 42.3 mass% or less of Cu, 0.08 mass% or more and 0.17 mass% or less of B, 0.3 mass% or more and 1.3 mass% or less of Zn, 0.006 mass% or more and 0.10 mass% or less of Al, and the balance being inevitable impurities.

6. An alloy wire obtained using the alloy according to claim 1.

7. 7. The alloy wire according to claim 6, wherein the wire diameter is 1.0 mm or less.

8. 7. The alloy wire according to claim 6, having a Vickers hardness of 490 HV or more and 600 HV or less.

9. 7. The alloy wire according to claim 6, wherein the volume resistivity is 11.5 μΩ·cm or less.

10. An alloy wire for a probe pin, obtained by using the alloy wire according to any one of claims 6 to 9.

11. 6. An alloy wire obtained using the alloy according to claim 5, characterized in that the wire diameter is 0.1 mm or less.

12. A method for manufacturing an alloy wire for a probe pin, comprising: A method for manufacturing an alloy wire for a probe pin, comprising the following steps 1 to 3: Step 1: A metal material containing Ag, Pd, Cu, B, Zn, and Al is heated and melted to obtain an ingot containing 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.05 mass% to 0.17 mass% B, 0.3 mass% to 1.5 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the balance being unavoidable impurities. Step 2: The ingot is repeatedly subjected to cold working with a cross-sectional area reduction rate of 50% or more and heat treatment to obtain a pre-aging alloy wire having a wire diameter of 1.0 mm or less. Step 3: The unaged alloy wire is subjected to aging treatment to obtain an aged alloy wire for a probe pin.

13. A method for manufacturing an alloy wire for a probe pin, comprising: A method for manufacturing an alloy wire for a probe pin, comprising the following steps 1 to 3: Step 1: A metal material containing Ag, Pd, Cu, B, Zn, and Al is heated and melted to obtain an ingot containing 5.0 mass% to 15.0 mass% Ag, 48.2 mass% to 58.3 mass% Pd, 34.6 mass% to 42.3 mass% Cu, 0.08 mass% to 0.17 mass% B, 0.3 mass% to 1.3 mass% Zn, 0.006 mass% to 0.10 mass% Al, and the balance being unavoidable impurities. Step 2: The ingot is repeatedly subjected to cold working with a cross-sectional area reduction rate of 50% or more and heat treatment to obtain a pre-aging alloy wire having a wire diameter of 0.1 mm or less. Step 3: The unaged alloy wire is subjected to aging treatment to obtain an aged alloy wire for a probe pin.

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