Copper alloy sheet, electronic component, and method for manufacturing copper alloy sheet

Abstract

Provided are a copper alloy sheet having excellent heat resistance and high hardness even after annealing, an electronic component, and a method for manufacturing a copper alloy sheet. The present invention is a copper alloy sheet containing 1.50 to 4.60 mass% of Ni, 0.10 to 0.80 mass% of Co, and 0.10 to 1.30 mass% of Si, with the remainder consisting of Cu and inevitable impurities, and having a Vickers hardness of 250 HV or more after annealing at 450°C for 5 minutes.

Description

Technical Field

[0001] This invention relates to copper alloy plates, electronic components, and methods for manufacturing copper alloy plates. Background Technology

[0002] Cosen alloys are alloys in which intermetallic compounds such as Ni-Si, Co-Si, and Ni-Co-Si are precipitated in a Cu matrix. Due to their combination of high strength and high conductivity, Cosen alloys are used in electronic components. For example, they can be used as lead frames to support and fix semiconductor components and form internal wiring in semiconductor packages (e.g., see Patent Document 1).

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2018-035437 Summary of the Invention

[0004] [The problem the invention aims to solve] Leadframes can be manufactured, for example, by pressing copper alloy plates. To reduce residual stress caused by pressing, short-term annealing is sometimes performed. However, this annealing can sometimes reduce the hardness of the copper alloy plate. The invention described in Patent Document 1 aims to improve strength and surface smoothness of the etched surface, but it has not adequately addressed the issue of reduced hardness due to decreased heat resistance after annealing.

[0005] In view of the above problems, the present invention provides: a copper alloy plate with excellent heat resistance and high hardness even after annealing, electronic components, and a method for manufacturing the copper alloy plate.

[0006] [Technical means to solve the problem] To solve the above problems, according to one embodiment of the present invention, a copper alloy plate can be provided, which contains 1.50 to 4.60% by mass of Ni, 0.10 to 0.80% by mass of Co, 0.10 to 1.30% by mass of Si, with the remainder consisting of Cu and unavoidable impurities. The Vickers hardness of the copper alloy plate after annealing at 450°C for 5 minutes is above 250 HV.

[0007] According to another embodiment of the present invention, an electronic component may be provided which includes the aforementioned copper alloy plate.

[0008] According to another embodiment of the present invention, a method for manufacturing a copper alloy plate can be provided, which includes the following steps in sequence: Hot rolling is performed on copper alloy ingots containing 1.50–4.60% by mass of Ni, 0.10–0.80% by mass of Co, 0.10–1.30% by mass of Si, with the remainder consisting of Cu and unavoidable impurities. The obtained copper alloy intermediate was subjected to solution treatment; Aging treatment of copper alloy intermediates; Precision cold rolling of copper alloy intermediates; and Stress-relief annealing is performed on copper alloy intermediates. The method for manufacturing the aforementioned copper alloy plate includes: manufacturing the aforementioned copper alloy intermediate such that the tensile strength A (MPa), 0.2% yield strength B (MPa), and conductivity C (%IACS) of the copper alloy intermediate before the solution treatment and aging treatment steps are such that the X value expressed by the following formula (1) is 582 or higher. X = (A × B) / C (1).

[0009] [The effects of the invention] According to the present invention, the present invention can provide: a copper alloy plate with excellent heat resistance and high hardness even after annealing, electronic components, and a method for manufacturing the copper alloy plate. Attached Figure Description

[0010] Figure 1 This is a graph showing the relationship between the tensile strength (A), 0.2% yield strength (B), and conductivity (C) of the intermediate copper alloy plate after solution treatment and before aging treatment, expressed by the relationship X = (A × B) / C, and the hardness HV of the copper alloy plate after annealing at 450°C for 5 minutes. Detailed Implementation

[0011] The embodiments of the present invention are described in detail below, but the present invention is not limited to the embodiments described below.

[0012] (Copper alloy plate) The copper alloy plate in this embodiment contains 1.50–4.60% by mass Ni, 0.10–0.80% by mass Co, and 0.10–1.30% by mass Si, with the remainder consisting of Cu and unavoidable impurities. That is, the copper alloy plate in this embodiment is a Cu-Ni-Co-Si alloy plate.

[0013] (Content of Ni, Co, and Si) Ni, Co, and Si can be precipitated to form Cu-Ni-Co-Si intermetallic compounds through appropriate heat treatment, thereby improving the conductivity, strength, and heat resistance of copper alloys.

[0014] The higher the amount of Ni added, the higher the strength, but the conductivity tends to decrease. When the Ni concentration is less than 1.50% by mass, the desired strength cannot be obtained. The Ni concentration is preferably 2.00% by mass or more, more preferably 2.30% by mass or more, and even more preferably 3.00% by mass or more, and even more preferably 3.50% by mass or more. On the other hand, when the Ni concentration exceeds 4.60% by mass, the desired conductivity cannot be obtained. The Ni concentration is preferably 4.50% by mass or less, more preferably 4.30% by mass or less, even more preferably 4.00% by mass or less, and even more preferably 3.70% by mass or less.

[0015] When the Si concentration is less than 0.10% by mass, the desired strength cannot be obtained. The Si concentration is preferably 0.30% by mass or more, more preferably 0.50% by mass or more, and even more preferably 0.70% by mass or more, and even more preferably 0.80% by mass or more. On the other hand, when the Si concentration exceeds 1.30% by mass, the desired conductivity cannot be obtained. The Si concentration is preferably 1.20% by mass or less, more preferably 1.10% by mass or less, even more preferably 1.00% by mass or less, and even more preferably 0.90% by mass or less.

[0016] Co can improve conductivity and strength, and by adding an appropriate amount, after the copper alloy sheet of this embodiment is pressed into the desired electronic components such as lead frames, the decrease in heat resistance of the copper alloy sheet caused by short-time annealing during the reduction of residual stress after pressing can be suppressed. In order to obtain a copper alloy sheet that has both high conductivity, high strength and improved heat resistance after short-time annealing, the Co concentration is set to 0.10% by mass or more. The Co concentration is preferably 0.15 to 0.80% by mass, more preferably 0.15 to 0.70% by mass, more preferably 0.20 to 0.50% by mass, and more preferably 0.20 to 0.40% by mass.

[0017] (Ni + Co) If the Ni+Co content is too low, the desired strength, conductivity, and heat resistance improvement effect after short-time annealing following heat treatment cannot be significantly obtained. On the other hand, if the Ni+Co content is too high, the processability deteriorates. The copper alloy plate of this embodiment preferably contains a total of 1.60% by mass or more of Ni and Co, more preferably 2.28% by mass or more, even more preferably 3.00% by mass or more, and even more preferably 3.50% by mass or more. Conversely, the copper alloy plate of this embodiment preferably contains a total of 4.50% by mass or less of Ni and Co, more preferably 4.30% by mass or less, and even more preferably 4.00% by mass or less. Furthermore, regarding the Co-Ni ratio, it is preferably set to 0.05 to 0.10, more preferably 0.05 to 0.09, and even more preferably 0.05 to 0.08.

[0018] (Ni + Co) / Si mass ratio) The Ni-Co-Si precipitates formed by Ni, Co, and Si are considered to be intermetallic compounds mainly composed of (Ni+Co)Si. However, not all Ni, Co, and Si in the copper alloy plate will necessarily become precipitates due to the aging treatment during the manufacturing process; some may exist in a solid solution state within the Cu matrix. While the solid solution state of Ni, Co, and Si can improve the strength of the copper alloy plate, its effect is smaller compared to the precipitated state, and it may also be a major cause of decreased conductivity. Therefore, the content of Ni, Co, and Si is preferably close to the composition ratio of (Ni+Co)Si. In this embodiment, the mass ratio of the total Ni and Co to Si ((Ni+Co) / Si) of the copper alloy plate is preferably 3.4 to 5.4, more preferably 3.8 to 5.0, and even more preferably 4.0 to 4.5.

[0019] (Add element) At least one element selected from the group consisting of Mg, Fe, P, Cr, Ag, Zn, Sn, Pb, Zr, Al, As, Se, Te, Sb, Bi, Au, Ti, Nb, V, Ta, W, Mo, and Mn (also referred to as "additive elements" in this specification) not only improves manufacturability, such as by refining the ingot structure, through the addition of a specified amount, but also enhances the strength, electrical conductivity, and heat resistance of the copper alloy sheet. Therefore, by adding one or more of these additive elements to achieve the properties required for the copper alloy sheet according to this embodiment, it is expected that the properties of the copper alloy sheet can be further improved.

[0020] The copper alloy plate of this embodiment preferably contains a total of 0.01 to 2.00% by mass of one or more elements selected from the group consisting of Mg, Fe, P, Cr, Ag, Zn, Sn, Pb, Zr, Al, As, Se, Te, Sb, Bi, Au, Ti, Nb, V, Ta, W, Mo, and Mn. The total content of the added elements is preferably 0.03 to 1.00% by mass, more preferably 0.05 to 0.50% by mass.

[0021] (Cr content) In the addition of elements, Cr, through appropriate heat treatment, precipitates in the copper matrix as elemental Cr or in the form of compounds with Si. This not only improves hot rollability but also enhances the strength, electrical conductivity, and heat resistance of the copper alloy sheet of this embodiment. On the other hand, if Cr exceeds 0.500% by mass, it may sometimes form large inclusions that do not contribute to strengthening, thus impairing processability. The copper alloy sheet of this embodiment may contain 0.05 to 0.50% by mass Cr in the Cu-Ni-Co-Si alloy, preferably 0.01 to 0.50% by mass, more preferably 0.20 to 0.50% by mass, and even more preferably 0.20 to 0.30% by mass.

[0022] (Mg content) In the addition of elements, Mg, by containing an appropriate amount, not only stabilizes the Si precipitates contained in the copper alloy plate of the topographic cost embodiment, but also has the effect of obtaining a copper alloy plate with strength, conductivity, and heat resistance. The copper alloy plate of this embodiment may contain 0.005 to 0.50% by mass of Mg in the Cu-Ni-Co-Si alloy, preferably 0.01 to 0.50% by mass, more preferably 0.05 to 0.50% by mass, and even more preferably 0.10 to 0.30% by mass.

[0023] The copper alloy plate of this embodiment, apart from the components described above, consists of Cu and unavoidable impurities. Here, unavoidable impurities refer to impurity elements that cannot be avoided from being mixed into the copper alloy plate during the manufacturing process. The concentration of each element of these unavoidable impurities can be set to less than 0.001% by mass, preferably 0% (undetectable).

[0024] The composition of copper alloys can be determined using fluorescence X-ray analysis. The fluorescence X-ray analysis apparatus can be a Rigaku Simultix14 or an equivalent device. The analytical surface can be a surface that has been machined or mechanically ground to achieve a maximum surface roughness Rz (JIS B 0601:2013) of 6.3 μm or less. When collecting samples for fluorescence X-ray analysis from the molten metal during the self-melting casting process, the sample is cast into a shape of approximately 30–40 mm Φ and 50–80 mm thickness, then cut into sections approximately 10–20 mm thick, and the cut surface is used as the analytical surface. Fluorescence X-ray analysis is performed based on JIS K 0119:2008, using a wavelength dispersion method.

[0025] The composition of copper alloys can also be determined by wet analysis. Ni can be determined using the copper-separated dimethylglyoxime nickel gravimetric method (JIS H1056:2003), and Si can be determined using the silica gravimetric method (JIS H1061:2006). Other additive and impurity elements can be determined using ICP emission spectrometry. The analysis of other additive elements is performed using an internal standard method, with Yttrium (Y) as the internal standard. Elements other than Y can also be selected as the internal standard. ICP emission spectrometry is performed using a Hitachi High-Tech Science ICP emission spectrometer (ICP-OES) SPS3100 or an equivalent device. In the case of ICP emission spectrometry, the sample of the copper alloy can be diluted with a mixture of hydrochloric acid and nitric acid (containing hydrochloric acid, nitric acid, and water in a volume ratio of 2:1:2) for use.

[0026] The shape of the copper alloy plate in this embodiment is not particularly limited if it is a three-dimensional shape with a specified thickness. The term "plate" in copper alloy plate also includes sheets, strips, and foils. Furthermore, the copper alloy plate in this embodiment includes, for example, not only copper alloy plates before processing for use in electronic components, but also copper alloy plates in the process of processing or after processing. The thickness of the copper alloy plate is, for example, 0.03 to 1.2 mm. This thickness is preferably 0.03 to 0.60 mm, more preferably 0.08 to 0.30 mm.

[0027] (Vickers hardness) Regarding the copper alloy sheet of this embodiment, the Vickers hardness after annealing at 450°C for 5 minutes is above 250 HV. If the copper alloy sheet is processed by pressing, residual stress may be generated. To reduce this residual stress, short-time annealing is sometimes performed; however, if this annealing reduces the heat resistance of the copper alloy sheet, it will soften, potentially causing deformation after processing. With the copper alloy sheet according to this embodiment, since it is heat-resistant to short-time annealing used to reduce residual stress, deformation is not easily generated even after short-time annealing following processing, thus achieving the target Vickers hardness.

[0028] In one embodiment, regarding the copper alloy plate of this embodiment, the Vickers hardness after annealing the copper alloy plate at 450°C for 5 minutes is preferably 262 HV or higher, more preferably 280 HV or higher, and even more preferably 290 HV or higher. The upper limit of the Vickers hardness after annealing the copper alloy plate at 450°C for 5 minutes is not particularly limited, and may be below 350 HV, below 320 HV, or below 300 HV. Specifically, regarding the copper alloy plate of this embodiment, the Vickers hardness after annealing the copper alloy plate at 450°C for 5 minutes is 262–350 HV, further 280–350 HV, and even more preferably 290–320 HV.

[0029] The Vickers hardness of the copper alloy plate can be determined according to JIS Z 2244-1:2020, using the method described in the Examples section below. Furthermore, the Vickers hardness of the annealed copper alloy plate can be controlled within the desired range by controlling the composition of the copper alloy plate within the aforementioned range and by manufacturing it using the manufacturing method described below. Moreover, by adjusting the X value in equation (1) of the manufacturing method described below to be larger, the Vickers hardness value can be adjusted to be even greater.

[0030] (Tensile strength) The copper alloy sheet of this embodiment has a tensile strength of 870 MPa or more in the direction parallel to the rolling direction. By achieving a tensile strength of 870 MPa or more, deformation of the copper alloy sheet can be suppressed when manufacturing electronic components using the copper alloy sheet. More preferably, the tensile strength of the copper alloy sheet of this embodiment in the direction parallel to the rolling direction is 930 MPa or more. Furthermore, there is no particular upper limit to the tensile strength in the direction parallel to the rolling direction; for example, it can be 1200 MPa or less, or 1100 MPa or less. The tensile strength of the copper alloy sheet of this embodiment in the direction perpendicular to the rolling direction is preferably 900 MPa or more, more preferably 950 MPa, and even more preferably 977 MPa or more. The tensile strength of the copper alloy sheet can be measured according to JIS Z 2241:2011 using the method described in the Examples section below.

[0031] (0.2% yield strength) The copper alloy sheet of this embodiment has a 0.2% yield strength of 850 MPa or more in the direction parallel to the rolling direction. This allows for more effective suppression of deformation of the copper alloy sheet during the manufacturing process of electronic components. The 0.2% yield strength in the direction parallel to the rolling direction is preferably 870 MPa or more, more preferably 900 MPa or more, and even more preferably 936 MPa or more. There is no particular limitation on the upper limit of the 0.2% yield strength in the direction parallel to the rolling direction; for example, it can be 1200 MPa or less, 1100 MPa or less, or 1000 MPa or less. The 0.2% yield strength can be measured according to JIS Z 2241:2011 using the method described in the Examples section below.

[0032] (Conductivity) The conductivity of the copper alloy plate in this embodiment can be 35.0% IACS or higher. By achieving a conductivity of 35.0% IACS or higher, it can be effectively used as a copper alloy component for electronic parts. The conductivity is preferably 37.0% IACS or higher, more preferably 40.0% IACS or higher, and even more preferably 40.2% IACS or higher. There is no particular limitation on the upper limit of the conductivity; for example, it can be 90.0% IACS or lower, or even 80.0% IACS or lower.

[0033] Conductivity can be determined according to JIS H 0505:1975 using the four-terminal method. A double bridge can be used for measurement, and resistance can be determined based on the average cross-sectional area method. Regarding conductivity, it can be measured at room temperature (25°C) in the direction parallel to the rolling direction. Regarding the gauge length (distance between resistance measurements), conductivity can be measured at 50 mm.

[0034] (Manufacturing method of copper alloy plate) The following describes the manufacturing method of the copper alloy plate according to this embodiment.

[0035] The manufacturing method of the copper alloy plate in this embodiment includes the following steps in sequence: Hot rolling is performed on copper alloy ingots containing 1.50–4.60% by mass of Ni, 0.10–0.80% by mass of Co, 0.10–1.30% by mass of Si, with the remainder consisting of Cu and unavoidable impurities. The obtained copper alloy intermediate was subjected to solution treatment; The copper alloy intermediate was subjected to aging treatment. The copper alloy intermediate was subjected to precision cold rolling; and The copper alloy intermediate was subjected to stress-relief annealing. The method for manufacturing the aforementioned copper alloy plate includes manufacturing a copper alloy intermediate in such a way that the tensile strength A (MPa), 0.2% yield strength B (MPa), and conductivity C (%IACS) of the copper alloy intermediate, after the solution treatment step and before the aging treatment step, have an X value of 582 or higher as expressed by the following formula.

[0036] X = (A × B) / C (1) If the manufacturing method of the copper alloy plate according to this embodiment focuses on the heat resistance of the copper alloy plate after forming, and the manufacturing conditions are adjusted in such a way that the X value of formula (1) is 582 or above when manufacturing the copper alloy intermediate, it is possible to obtain a copper alloy that does not easily produce a decrease in hardness even after a short-term annealing treatment after the copper alloy plate is formed into a specified shape.

[0037] Specifically, the manufacturing method of the copper alloy plate according to this embodiment can be carried out as follows. First, a step of melting and casting the copper alloy raw material having the desired composition is performed. In this step, the copper alloy raw material is melted using the same method as for general copper alloy melting, and an ingot is manufactured by continuous casting or semi-continuous casting. That is, using an atmospheric melting furnace, electrolytic copper, Ni, Co, Si, and other raw materials are melted to obtain a molten liquid with the target composition. Then, the ingot is cast by pouring this molten liquid into a mold of any size. Subsequently, homogenization annealing is performed at 800–1000°C, followed by hot rolling.

[0038] Hot rolling is performed in several passes at temperatures ranging from 500 to 900°C. The total finishing degree of hot rolling is preferably set to 90% or more. Regarding the finishing degree (%), if the thickness of the workpiece before rolling is denoted as TB and the thickness of the workpiece after rolling is denoted as TA, then the finishing degree (%) is expressed as [(TB - TA) / TB] × 100.

[0039] In the solution treatment after hot rolling, the following heat treatment is performed: Ni-Si compounds, Co-Si compounds, Cr-Si compounds, and other silicides are dissolved in the Cu base, and the Cu base is recrystallized at the same time. In the copper alloy plate manufacturing method of this embodiment, by adjusting the X value of the copper alloy intermediate after solution treatment to be 582 or higher, a copper alloy plate and electronic components with excellent heat resistance and high hardness of 250 HV or higher even after annealing can be obtained.

[0040] The X value expressed in equation (1) is preferably 3000 or more, more preferably 5000 or more, and even more preferably 8000 or more. There is no particular limitation on the upper limit of X, but typically it is preferably 17000 or less, more preferably 15000 or less, and even more preferably 13000 or less. By adjusting the X value in equation (1) to be larger, the Vickers hardness value after annealing the copper alloy plate at 450°C for 5 minutes can be further increased.

[0041] Figure 1 This is a graph showing the relationship between X in equation (1) above and the Vickers hardness (HV) of the copper alloy sheet after stress-relief annealing, which is then annealed at 450°C for 5 minutes. Here, the tensile strength (A), 0.2% yield strength (B), and conductivity (C) are all values ​​obtained by measurement in a direction parallel to the rolling direction. By setting the value of X in equation (1) to 582 or higher, a copper alloy sheet with excellent heat resistance and high hardness even after annealing can be obtained. Furthermore, the values ​​of conductivity (A (%IACS)), 0.2% yield strength (B (MPa)), and tensile strength (C (MPa)) of the solution-treated copper alloy intermediate in equation (1) above can be measured by the method described in the Examples section below.

[0042] In this embodiment, in order to improve the heat resistance of the copper alloy plate, the value of X in the solution treatment step is adjusted by adjusting the heating temperature, material temperature, and heating time during the solution treatment. The heating temperature of the solution treatment can be appropriately selected from the range of 800 to 1100°C. The heating temperature of the solution treatment can be set to 900 to 1100°C or 950 to 1100°C. The material temperature can be appropriately selected from the range of 750 to 950°C. After the solution treatment, the material temperature is slowly cooled to 400 to 500°C. The heating time can be appropriately selected from the range of 1 second to 10 minutes. By relatively increasing the heating temperature and material temperature of the solution treatment within the range of 800 to 1100°C, and setting the heating time to the range of 1 second to 10 minutes, the value of X in equation (1) can be adjusted to 582 or higher.

[0043] By appropriately selecting and combining the heating temperature, material temperature, and heating time during solution treatment, Ni-Co-Si compounds can be dissolved in the Cu matrix, while the Cu matrix recrystallizes. During aging treatment, precipitates that contribute to hardness are appropriately formed, improving not only strength and electrical conductivity but also heat resistance. This allows for an increase in the Vickers hardness of stress-relieved copper alloys annealed at 450°C for 5 minutes.

[0044] The aging temperature for solution-treated copper alloy intermediates can be, for example, 375–625°C, 400–550°C, or 450–500°C. The aging time can be 1–50 hours, 1.5–25 hours, or 10–15 hours. By appropriately adjusting the aging temperature or time, the amount of Ni-Co-Si compounds precipitated becomes sufficient, achieving the desired strength, preventing coarsening or re-solution of the precipitates, easily improving strength and conductivity, and enhancing heat resistance. Aging treatment is preferably carried out in inactive environments such as Ar, N2, and H2 to suppress the formation of oxide coatings.

[0045] The aging treatment followed by cold rolling can be performed in several passes. The total machining degree of the cold rolling can be 40% or more. This imparts machining strain to the copper alloy intermediate, increasing its strength. By setting the total machining degree of the cold rolling to 40% or more, the strength in various directions relative to the rolling direction can be improved. The machining degree of the cold rolling is preferably 55% or more, more preferably 60% or more. The machining degree of the cold rolling can be 90% or less. This prevents the decrease in conductivity caused by machining strain due to high machining degree.

[0046] After precision cold rolling, a stress-relief annealing step may be included. The heating temperature for stress-relief annealing can be, for example, 300–600°C, preferably 400–600°C, and more preferably 420–550°C. The heating time for stress-relief annealing can be, for example, 5–900 seconds, or 200–650 seconds. Stress-relief annealing can be performed in the atmosphere or in an inactive environment such as nitrogen or argon. Furthermore, the stress-relief annealed copper alloy sheet can be cooled by air cooling.

[0047] In the manufacturing method of the copper alloy plate according to this embodiment, cold rolling can be performed before solution treatment, or after solution treatment and before aging treatment. Furthermore, solution treatment and aging treatment can be performed more than twice each. After each of the above manufacturing steps, in order to remove the oxide scale on the surface, grinding, pickling, polishing, degreasing, face cutting (face trimming), bead blasting, finishing, etc., can be performed as needed.

[0048] Furthermore, the manufacturing method of the copper alloy plate in this embodiment may also include the following steps: annealing the copper alloy plate after stress-relief annealing at 300°C or higher for at least 1 second. In particular, by performing this annealing step after processing such as pressing the copper alloy plate following stress-relief annealing, residual stress in the copper alloy plate generated during processing can be reduced. The processed copper alloy plate treated in this way is less prone to deformation and possesses both high conductivity and strength.

[0049] The heating temperature during this annealing step can be 300–600°C or 400–500°C. The heating time can be 1 second to 60 minutes, 30 seconds to 20 minutes, or 1 minute to 10 minutes.

[0050] (Electronic components) The electronic component of this embodiment is an electronic component comprising the copper alloy plate of this embodiment. More specifically, the electronic component of this embodiment comprises a copper alloy component manufactured from the aforementioned copper alloy plate. Semiconductor packages can be cited as examples of electronic components. The miniaturized copper alloy component manufactured from the copper alloy plate of this embodiment has the characteristic that its hardness is improved after processing in the manufacturing steps of the electronic component. Therefore, the copper alloy plate of this embodiment is suitable for manufacturing semiconductor packages with more miniaturized structures.

[0051] When the electronic component is a semiconductor package, the semiconductor package is not particularly limited and can be manufactured, for example, by using the copper alloy plate of this embodiment to manufacture a lead frame, then supporting and fixing the semiconductor component on the lead frame, wire bonding the semiconductor component with the lead wire to form internal wiring, and then sealing the semiconductor component with a specified resin component. As described above, the electronic component of this embodiment may also contain the copper alloy plate of the above embodiment.

[0052] The embodiments of the present invention have been described in detail above, but the copper alloy plate, electronic components and manufacturing method of the copper alloy plate of the present invention are not limited to the above examples and can be appropriately modified.

[0053] (The solution of this invention) The first aspect of the present invention is a copper alloy plate containing 1.50 to 4.60% by mass of Ni, 0.10 to 0.80% by mass of Co, 0.10 to 1.30% by mass of Si, with the remainder being Cu and unavoidable impurities. The Vickers hardness of the copper alloy plate after annealing at 450°C for 5 minutes is 250 HV or higher.

[0054] The second aspect of the present invention is a copper alloy plate as described in the first aspect, which further contains a total of 0.01 to 2.00% by mass of one or more elements selected from the group consisting of Mg, Fe, P, Cr, Ag, Zn, Sn, Pb, Zr, Al, As, Se, Te, Sb, Bi, Au, Ti, Nb, V, Ta, W, Mo and Mn.

[0055] The third aspect of the present invention is a copper alloy plate as described in the first or second aspect, which further contains 0.01 to 0.50% by mass of Cr.

[0056] The fourth aspect of the present invention is a copper alloy plate as described in any of the first to third aspects, which contains 0.20 to 0.50% by mass of Co.

[0057] The fifth aspect of the present invention is a copper alloy plate as described in any of the first to fourth aspects, which contains a total of 1.60% by mass or more of Ni and Co.

[0058] The sixth aspect of the present invention is a copper alloy plate as described in any one of the first to fifth aspects, which contains a total of 2.28% by mass or more of Ni and Co.

[0059] The seventh aspect of the present invention is a copper alloy plate as described in any of the first to sixth aspects, which contains a total of less than 4.50% by mass of Ni and Co.

[0060] The eighth aspect of the present invention is a copper alloy plate as described in any of the first to seventh aspects, having a Vickers hardness of 262 HV or higher.

[0061] The ninth aspect of the present invention is a copper alloy plate as described in any of the first to eighth aspects, having a Vickers hardness of 350 HV or less.

[0062] The tenth aspect of the present invention is a copper alloy plate as described in any of the first to ninth aspects, having a tensile strength of 870 MPa or more in a direction parallel to the rolling direction.

[0063] The eleventh aspect of the present invention is a copper alloy plate as described in any of the first to tenth aspects, having a tensile strength of 930 MPa or more in a direction parallel to the rolling direction.

[0064] The 12th aspect of the present invention is a copper alloy plate as described in any one of the 1st to 11th aspects, having a conductivity of 35.0% IACS or higher.

[0065] The 13th aspect of the present invention is a copper alloy plate as described in any of the 1st to 12th aspects, having a conductivity of 40.2% IACS or higher.

[0066] The 14th aspect of the present invention is an electronic component comprising a copper alloy plate as described in any one of the 1st to 13th aspects.

[0067] The 15th aspect of the present invention is a method for manufacturing a copper alloy plate, which includes the following steps in sequence: Hot rolling is performed on copper alloy ingots containing 1.50–4.60% by mass of Ni, 0.10–0.80% by mass of Co, 0.10–1.30% by mass of Si, with the remainder consisting of Cu and unavoidable impurities. The obtained copper alloy intermediate was subjected to solution treatment; Aging treatment of copper alloy intermediates; Precision cold rolling of copper alloy intermediates; and Stress-relief annealing is performed on copper alloy intermediates. The method for manufacturing the aforementioned copper alloy plate includes: manufacturing a copper alloy intermediate in such a way that the tensile strength A (MPa), 0.2% yield strength B (MPa), and conductivity C (%IACS) of the copper alloy intermediate before the solution treatment and aging treatment steps are expressed by the following formula (1) and the X value is 582 or higher. X = (A × B) / C (1).

[0068] The 16th aspect of the present invention is a method for manufacturing a copper alloy plate as described in the 15th aspect, which includes the following steps: annealing the copper alloy plate after the stress-relief annealing step at 300°C or higher for 1 second or more.

[0069] [Example] The present invention will be described in more detail below through embodiments, but the present invention is not limited to the following embodiments.

[0070] Using electrolytic copper as raw material, the copper alloys of the Examples and Comparative Examples with the compositions shown in Table 1 were melted and cast in an atmospheric melting furnace. The obtained ingots were subjected to homogenization annealing at 980°C for 25 minutes. Subsequently, they were hot-rolled to a thickness of 10 mm and then face-cut. Subsequently, solution treatment and aging treatment were performed sequentially under the conditions shown in Table 1. The obtained intermediates were then pickled and ground, and then precision cold-rolled to a thickness of 0.151 mm with the finish shown in Table 1. Subsequently, stress-relief annealing was performed in the atmosphere under the conditions shown in Table 1. The copper alloy plates of Example 1 and Comparative Example 1 were obtained by air cooling the stress-relief annealed copper alloy plates.

[0071] [Table 1] The physical properties of the copper alloy plates of Example 1 and Comparative Example 1 were measured by the following methods. The measurement results are shown in Table 2.

[0072] (composition) The composition of the obtained copper alloys was confirmed by fluorescence X-ray analysis. A Simultix14 manufactured by Rigaku Co., Ltd. was used as the fluorescence X-ray analysis apparatus. The analysis surfaces were the surfaces of the copper alloy plates of Example 1 and Comparative Example 1 that had been cut or mechanically ground to achieve a maximum surface roughness Rz (JIS B0601:2013) of 6.3 μm or less. Fluorescence X-ray analysis was performed based on JIS K 0119:2008, and measurements were taken in a wavelength dispersion manner.

[0073] (Tensile strength) The tensile strength in the direction parallel to the rolling direction was determined using a tensile testing machine (Autocom AC-100KN-C, manufactured by TSE Co., Ltd.) according to JIS Z2241:2011. Specifically, JIS Z 2241 13B test pieces were prepared from each specimen using a pressing machine with the tensile direction parallel to the rolling direction. Regarding the tensile test conditions, the test piece width was set to 12.5 mm, the test temperature was set to room temperature (15–35°C), the tensile speed (crosshead displacement speed) was set to 5 mm / min, and the gauge length was set to 50 mm. For the measurement, two test pieces were used, and the average of the two data points was calculated.

[0074] (0.2% yield strength) The 0.2% yield strength in the direction parallel to the rolling direction was determined using a tensile testing machine (Autocom AC-100KN-C, manufactured by TSE Corporation) according to JIS Z2241:2011 (offset method, 0.2%). Specifically, test pieces were prepared using the same method as described above for tensile strength testing, and the tests were conducted under the same conditions.

[0075] (Conductivity) Conductivity was measured according to JIS H 0505:1975 using the four-terminal method. A double bridge was used for the measurement, and resistance was measured based on the average cross-sectional area method. Conductivity was measured at room temperature (25°C) in the direction parallel to the rolling direction. Furthermore, the gauge length (distance between resistance measurements) was 50 mm for conductivity measurement.

[0076] (Elongation) Elongation was determined by tensile testing according to JIS Z 2241:2011. Test pieces No. 5 or No. 13B as specified in JIS Z 2241:2011 were used, taken in a direction parallel to the rolling direction, with a gauge length of 50 mm. The tensile test conditions were the same as those for the tensile strength test. The length was measured by pressing a caliper against the gauge length of the broken test piece. The elongation was calculated using the following formula: "Elongation at break (%) = (Final gauge length - Original gauge length) ÷ Original gauge length × 100". The definitions of the final gauge length and the original gauge length are the same as in JIS-Z2241 (2011).

[0077] (Hardness after annealing) According to JIS Z 2244-1:2020, the copper alloy plates of Example 1 and Comparative Example 1 were annealed in a tube furnace at 450°C for 5 minutes under nitrogen atmosphere. The annealed copper alloy plates were then cooled to room temperature by air cooling. The Vickers hardness of the cooled copper alloy plates was determined using a Vickers hardness tester. An HM-103 manufactured by Mitutoyo Co., Ltd. was used as the Vickers hardness tester. Copper alloy plates cut to 20 mm × 20 mm were resin-embedded and then mechanically ground. The thickness of the plate at the center of the rolled parallel section was measured. For resin embedding, epoxy resin (Epikote #828) manufactured by Mitsubishi Chemical Co., Ltd. was used, and a hardener (Acmex H-89) manufactured by Nippon Synthetic Chemical Co., Ltd. was used. The resin was heated to 100°C for 60 minutes to harden. The test force was set to 490.3 mN, the indenter approach speed was set to 60 μm / s, and the holding time was set to 15 seconds. The average value of the values ​​obtained from measuring three points on the measuring section was calculated. During the measurement, a 50x objective lens was used, and the concave areas were spaced at least 3d apart relative to the average diagonal length d of the concave area.

[0078] [Table 2] According to Example 1, a copper alloy material with an excellent balance of strength, conductivity and heat resistance compared to Comparative Example 1, and whose hardness after annealing is also suitable for electronic component applications, can be obtained.

[0079] (Potential contribution to the SDGs) According to one embodiment of the present invention, a copper alloy plate with excellent heat resistance and high strength even after annealing, and electronic components containing the same, can be provided, thereby potentially improving the stability of electronic machinery operation and contributing to enhanced reliability. Therefore, one embodiment of the present invention may benefit from UN-led Sustainable Development Goal (SDG) Goal 9, "Seeking resilient infrastructure, promoting inclusive and sustainable industrialization and advancing innovation."

Claims

1. A copper alloy plate comprising 1.50–4.60% by mass of Ni, 0.10–0.80% by mass of Co, 0.10–1.30% by mass of Si, with the remainder being Cu and unavoidable impurities, wherein the copper alloy plate, after being annealed at 450°C for 5 minutes, has a Vickers hardness of 250 HV or higher.

2. The copper alloy plate according to claim 1, further comprising a total of 0.01 to 2.00% by mass of one or more elements selected from the group consisting of Mg, Fe, P, Cr, Ag, Zn, Sn, Pb, Zr, Al, As, Se, Te, Sb, Bi, Au, Ti, Nb, V, Ta, W, Mo and Mn.

3. The copper alloy plate according to claim 1, further comprising 0.01 to 0.50% by mass of Cr.

4. The copper alloy plate according to claim 1, wherein it contains 0.20 to 0.50% by mass of Co.

5. The copper alloy plate according to claim 1, wherein it contains a total of 1.60% by mass or more of Ni and Co.

6. The copper alloy plate according to claim 1, wherein it contains a total of 2.28% by mass or more of Ni and Co.

7. The copper alloy plate according to claim 1, wherein it contains a total of less than 4.50% by mass of Ni and Co.

8. The copper alloy plate according to claim 1, wherein, The Vickers hardness is above 262 HV.

9. The copper alloy plate according to claim 1, wherein, The Vickers hardness is below 350 HV.

10. The copper alloy plate according to claim 1, wherein the tensile strength in the direction parallel to the rolling direction is 870 MPa or higher.

11. The copper alloy plate according to claim 1, wherein the tensile strength in the direction parallel to the rolling direction is 930 MPa or higher.

12. The copper alloy plate according to claim 1, wherein the conductivity is 35.0% IACS or higher.

13. The copper alloy plate according to claim 1, wherein the conductivity is above 40.2% IACS.

14. An electronic component comprising a copper alloy plate according to any one of claims 1 to 13.

15. A method for manufacturing a copper alloy plate, comprising the following steps in sequence: Hot rolling is performed on copper alloy ingots containing 1.50–4.60% by mass of Ni, 0.10–0.80% by mass of Co, 0.10–1.30% by mass of Si, with the remainder consisting of Cu and unavoidable impurities. The obtained copper alloy intermediate was subjected to solution treatment; The copper alloy intermediate was subjected to aging treatment. The copper alloy intermediate was subjected to precision cold rolling; and The copper alloy intermediate was subjected to stress-relief annealing. The method for manufacturing the copper alloy plate includes: manufacturing the copper alloy intermediate such that the tensile strength A (MPa), 0.2% yield strength B (MPa), and conductivity C (%IACS) of the copper alloy intermediate, after the solution treatment step and before the aging treatment step, have an X value of 582 or higher as expressed by the following formula (1). X = (A × B) / C (1).

16. The method for manufacturing a copper alloy plate according to claim 15, comprising the following steps: annealing the copper alloy plate after the stress-relief annealing step at 300°C or higher for more than 1 second.

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