Method for manufacturing a sheet material made of a copper-silver alloy and method for manufacturing a sheet for an electrode of a probe card

Abstract

To obtain a sheet made of a copper-silver alloy excellent in hardness and an electrode sheet for a probe card using the sheet. 【Solution means】(a) A step of obtaining a base material having a thickness or diameter of 6 to 30 mm by continuous casting of a copper-silver alloy; (b) A step of performing at least one rolling treatment on the base material to obtain a sheet material having a thickness of 0.01 to 0.10 mm; and (c) A step of annealing the sheet material. At least these steps are included.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a sheet material made of a copper-silver alloy and a method for manufacturing a sheet for an electrode of a probe card. More specifically, the present invention relates to a method for manufacturing a sheet material made of a copper-silver alloy having excellent hardness and a method for manufacturing a sheet for an electrode of a probe card.

Background Art

[0002] As one of the methods for manufacturing various parts and members using a copper-silver alloy, Patent Document 1 below discloses a method for manufacturing an ultra-fine copper alloy wire having strength, high conductivity, and excellent heat resistance, with little decrease in strength even under a thermal load. Further, Patent Document 2 below discloses a method for manufacturing a copper alloy capable of obtaining high strength and high conductivity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The applicant focused on the characteristics of a copper-silver alloy having high conductivity and conceived of manufacturing a sheet for an electrode used in a semiconductor inspection probe card. However, the electrode sheet used in a semiconductor inspection probe card is required to have high hardness, and a sheet material made of a copper-silver alloy having satisfactory hardness has not yet been found.

[0005] Therefore, an object of the present invention is to obtain a sheet made of a copper-silver alloy having excellent hardness and a sheet for an electrode of a probe card.

Means for Solving the Problems

[0006] A preferred embodiment of the present invention made to solve the above problems is a method for manufacturing a sheet material made of a copper-silver alloy, comprising: (a) a step of obtaining a base material having a thickness or diameter of 6 to 30 mm by continuous casting of a copper-silver alloy; (b) a step of performing at least one or more rolling treatments on the base material to obtain a sheet material having a thickness of 0.01 to 0.10 mm; and (c) a step of annealing the sheet material. The sheet material after step (c) is characterized in that the Vickers hardness is 280 HV or more.

[0007] Another aspect of the present invention is a method for manufacturing a sheet for an electrode of a probe card, comprising: (a) a step of obtaining a base material having a thickness or diameter of 6 to 30 mm by continuous casting of a copper-silver alloy; (b) a step of performing at least one or more rolling treatments on the base material to obtain a sheet material having a thickness of 0.01 to 0.10 mm; and (c) a step of annealing the sheet material. The sheet for an electrode made of the sheet material after step (c) is characterized in that the Vickers hardness is 280 HV or more.

Advantages of the Invention

[0008] According to the present invention, it is possible to obtain a sheet made of a copper-silver alloy excellent in hardness and a sheet for an electrode of a probe card.

Brief Description of the Drawings

[0009]

Figure 1

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this specification, the "~" indicating a numerical range includes the upper limit value and the lower limit value within that range.

Examples

[0011] <1> Overall Structure (Figure 1) The manufacturing method of the sheet material made of copper-silver alloy according to the present invention mainly includes at least a base material forming step, a sheet material forming step, and an annealing step. Hereinafter, the details of each step will be described.

[0012] <2> Step (a): Base Material Forming Step (S100) The base material forming step is a step for forming a base material having a predetermined shape made of copper-silver alloy.

[0013] <2.1> Composition of Copper-Silver Alloy In the present invention, the composition of the copper-silver alloy to be melted is not particularly limited and can be appropriately designed according to the properties required according to the use of the sheet material after completion. For example, when the sheet material obtained by the manufacturing method according to the present invention is used as an electrode sheet for a prop card, the following compositions can be adopted from the viewpoint of obtaining high hardness. · Copper (Cu): 70 to 92% by mass, preferably 70 to 85% by mass · Silver (Ag): 8 to 30% by mass, preferably 15 to 30% by mass · Remainder (including inevitable impurities): 0 to 1% by mass

[0014] <2.2> Method for Forming Base Material In the present invention, it is preferable to use the continuous casting method for forming the base material. The continuous casting method is a method of taking out a long-connected casting by gradually withdrawing and solidifying the molten metal while cooling it with a mold. According to the continuous casting method, since the alloy constituent elements are easily uniformly dispersed, the solution treatment consisting of a high-temperature heat treatment + rapid cooling step can be omitted. In addition, according to the continuous casting method, since it is possible to easily control the structure of the base material during continuous casting (for example, crystal grain size in anticipation of the characteristics of the final shape of the sheet material, control of the precipitation layer remaining at the grain boundary, etc.), by appropriately managing this structure control, it is expected to maintain the crystal grain size made fine in advance until the final shape of the sheet material and improve the hardness and strength of the sheet material. In addition, if the crystal grain size of the sheet material can be reduced by appropriately managing the above-described organizational form, the generation of burrs can be suppressed even when the sheet material is cut, and an improvement in yield can also be expected.

[0015] <2.3> Cross-sectional shape of the base material In the present invention, the cross-sectional shape of the base material is not particularly limited, and a circular shape, a rectangular shape, etc. can be appropriately selected according to the use of the sheet material after completion.

[0016] For example, when the sheet material is used for bus bar applications with a low aspect ratio (ratio of thickness to width) and a thickness of 0.5 mm or more, the cross-sectional shape of the base material is preferably circular. This is beneficial in terms of processing a flat conductor for large current conduction.

[0017] In addition, when the sheet material is used for flat wire applications, the cross-sectional shape of the base material is preferably rectangular rather than circular. This is because a base material with a circular cross-sectional shape causes stress concentration at the center, and edge cracking and meandering are likely to occur during the rolling process for forming a thin sheet material, which may not improve the yield by removing the edge portion, etc., or the cross-sectional shape of the sheet material after the rolling process becomes a racetrack shape (the side surface has a curved shape), and the occupation ratio may not increase when used for winding applications as it is. Therefore, the sheet material according to the present invention is particularly advantageous for producing flat wires with a high aspect ratio.

[0018] <2.4> Casting thickness of the base material In the present invention, the casting thickness of the base material is not particularly limited, and can be appropriately designed according to the characteristics required for the sheet material after completion. For example, when the sheet material is used for electrode applications of a probe card and the thickness of the sheet material obtained in the sheet material forming process described later is assumed to be 0.025 to 0.050 mm, the thickness of the base material is preferably 15 to 20 mm. For example, when the casting thickness of the base material is made thinner than 15 mm, it is considered that the working degree (rolling reduction) cannot be achieved and the necessary hardness cannot be obtained. When the casting thickness of the base material is made thicker than 20 mm, the working limit is reached at a relatively thick stage, and particularly severe cracking occurs at the edge portion. Therefore, this leads to an increase in the heat treatment process and an increase in the manufacturing cost. Also, since it is considered that problems such as an increase in the difficulty of optimizing the heat treatment conditions and difficulty in achieving reproducibility will occur, these problems are to be avoided.

[0019] <2.5>Casting speed of the base material In the present invention, the casting speed of the base material is not particularly limited and can be appropriately designed according to the characteristics required for the sheet material after completion. For example, when the sheet material is used for the electrode of a probe card, assuming that the thickness of the sheet material obtained in the sheet material forming step described later is 15 to 20 mm, the casting speed is preferably set to 50 to 1000 mm / min, and more preferably 100 to 300 mm / min.

[0020] <3>Step (b): Sheet material forming step (S200) The sheet material forming step is a step for processing the base material to a predetermined thickness to form a sheet-like member (sheet material). This step shall include at least rolling treatment. In the present invention, the number of times of performing the rolling treatment in this step is not particularly limited, and it may be appropriately designed in consideration of the thickness and characteristics of the base material that is the starting point of this step and the thickness and characteristics of the sheet material that is the arrival point of this step.

[0021] <3.1>Rolling treatment The rolling treatment is a treatment for applying a continuous force to the target base material to thin the base material. As a general method for the rolling treatment, a pair of rolls arranged in parallel are rotated, and a member to be rolled is passed between this pair of rolls. In the present invention, the type of rolling process is not particularly limited, and for example, cold rolling can be used. Also, in the present invention, the thickness of the base material (intermediate or final product as a sheet material) after the rolling process may be appropriately designed.

[0022] <3.2>Heat treatment Also, in this step, when performing the rolling process again on the base material after the rolling process, it is preferable to perform heat treatment appropriately in advance. In the present invention, the conditions (heating temperature, heating time, etc.) in the heat treatment before performing the re-rolling are not particularly limited.

[0023] <4>Step (c): Annealing step (S300) The annealing step is a heating step for removing the residual stress from the sheet material formed to a predetermined thickness through the rolling process, and is a step called so-called annealing.

[0024] <4.1>Heating temperature The heating temperature in this step is preferably in the range of 200 to 500°C from the viewpoint of preventing recovery or avoiding abnormal grain growth.

[0025] <4.2>Heating time The heating time in this step is not particularly limited because the optimal time varies depending on the above-mentioned heating temperature. However, when the heating temperature is in the range of 200 to 500°C, it is preferably in the range of approximately 60 to 4500 minutes.

[0026] <4.2>Thickness of the sheet material In the present invention, the thickness of the sheet material after this step is not particularly limited. However, when the sheet material is used for the electrode of the probe card, it is preferably set to 0.025 to 0.050 mm.

[0027] <5>Other steps The sheet material that has passed through step (c) can be appropriately processed into a predetermined shape according to the final application. For example, by cutting a sheet material to a predetermined width (0.5 to 2 mm), an ultra-fine flat wire can be produced. Also, by processing the sheet material into an arbitrary shape, it can be used as a bus bar, a ribbon-type heater, or an electrode sheet for a probe card used in semiconductor inspection.

[0028] <6> Experimental Example Using the manufacturing method according to the present invention, a plurality of test specimens were produced, and the hardness (Vickers hardness) of each conductive wire for electrical property inspection was measured with a Vickers hardness tester in accordance with JIS Z 2244. The evaluation criteria are as follows.

[0029] [Evaluation Criteria] 〇: 280 HV or more ×: Less than 280 HV

[0030] In addition, using the double-bridge method, the electrical resistance of each test specimen was measured in a room controlled at 20 °C (±2 °C), and the average values of the conductivity (%IACS) were calculated. The distance between the voltage terminals was set to 500 mm. The calculation results are as shown in Table 2. The required conductivity for the electrode sheet of the probe card is 38%IACS or more.

[0031] <6.1> Manufacturing Conditions The manufacturing conditions of each test specimen were set as shown in Table 1 below. Also, the details of each process are as follows.

[0032] [Table 1] TIFF0007709624000002.tif54150

[0033] (a) Substrate formation step: The raw material was heated and melted at 1000 to 1400 °C to prepare a composition (molten metal) having the composition ratio shown in Table 1. The casting speed was set to 300 mm / min, the melt (molten metal) was poured into a mold, and cooled to room temperature within 10 minutes to cast a substrate A with a thickness or diameter of 6 to 14.3 mm.

[0034] (b) Sheet material forming process: The base material A was cold-rolled from a thickness or diameter of 6 to 14.3 mm to a thickness of 1.83 to 4.56 mm to produce the rolled base material B. Thereafter, the rolled base material B was heated at 370 to 450 °C for 2400 minutes in an N2 gas atmosphere. Thereafter, the rolled base material B was further cold-rolled from a thickness of 1.83 to 4.56 mm to a thickness of 0.05 to 0.6 mm to produce the sheet material C with the desired thickness.

[0035] (c) Annealing process: The sheet material C was annealed at 200 °C for 60 minutes in an N2 gas atmosphere to obtain test specimens 1 to 10.

[0036] <6.2> Measurement results The measurement results of each test specimen are shown in Table 2.

[0037] [Table 2] JPEG0007709624000003.jpg13150

[0038] <6.3> Verification results As shown in Table 2, the sheet materials related to test specimens 3 to 4 and test specimens 6 to 10 were able to obtain the Vickers hardness (280 HV or more) and conductivity (38% IACS or more) required for the electrode sheet of the probe card.

Explanation of symbols

[0039] S100: Base material forming process S200: Sheet material forming process S300: Annealing process A: Base material B: Rolled base material C: Sheet material

Claims

1. A method for manufacturing a sheet material made of a copper-silver alloy, comprising: the copper-silver alloy consists of 75 to 90% by mass of copper, 10 to 24% by mass of silver, and 0 to 1% by mass of the balance (including inevitable impurities); (a) obtaining a base material with a thickness or diameter of 6 to 14.3 mm by continuous casting of the copper-silver alloy; (b) performing a first rolling treatment, a heat treatment, and a second rolling treatment on the base material to obtain a sheet material with a thickness of 0.05 mm; (c) performing an annealing treatment on the sheet material; at least including, the casting speed in (a) is 300 mm / min; the heating temperature of the heat treatment in (b) is 370 °C, and the heating time is 2400 minutes; the heating temperature of the heat treatment in (c) is 200 °C, and the heating time is 60 minutes; for the sheet material after (c), the conductivity is 38% IACS or more, and the Vickers hardness is 280 HV or more, characterized in that, A method for manufacturing a sheet material made of a copper-silver alloy.

2. In (a), the cross-sectional shape of the base material is rectangular, and the thickness is 9 to 14.3 mm, characterized in that, The method for manufacturing a sheet material made of a copper-silver alloy according to Claim 1.

3. In (a), the cross-sectional shape of the base material is circular, and the diameter is 6 mm, characterized in that, The method for manufacturing a sheet material made of a copper-silver alloy according to Claim 1.

4. A method for manufacturing a sheet for an electrode of a probe card, comprising: the copper-silver alloy consists of 75 to 90% by mass of copper, 10 to 24% by mass of silver, and 0 to 1% by mass of the balance (including inevitable impurities); (a) obtaining a base material with a thickness or diameter of 6 to 14.3 mm by continuous casting of the copper-silver alloy; (b) performing a first rolling treatment, a heat treatment, and a second rolling treatment on the base material to obtain a sheet material with a thickness of 0.05 mm; (c) performing an annealing treatment on the sheet material; at least including, the silver content in the copper-silver alloy is 10 to 24% by mass; the casting speed in (a) is 300 mm / min; the heating temperature of the heat treatment in (b) is 370 °C, and the heating time is 2400 minutes; the heating temperature of the heat treatment in (c) is 200 °C, and the heating time is 60 minutes; For the electrode sheet made of the sheet material that has passed through the above (c), the conductivity is 38% IACS or more, and the Vickers hardness is 280 HV or more, characterized in that A method for manufacturing an electrode sheet for a probe card.

5. In the above (a), The cross-sectional shape of the base material is a rectangular shape, and the thickness is 9 to 14.3 mm, characterized in that The method for manufacturing an electrode sheet for a probe card according to claim 4.

6. In the above (a), The cross-sectional shape of the base material is a circular shape, and the diameter is 6 mm, characterized in that The method for manufacturing an electrode sheet for a probe card according to claim 4.

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