WO2020121775A1 - Copper alloy sheet, method for manufacturing same, drawing product, electric/electronic component member, electromagnetic shield material, and heat dissipation component - Google Patents

Abstract

A copper alloy sheet according to the present invention has a composition containing 1.0-5.0 mass% in total of at least one among Ni and Co, and 0.1-1.5 mass% of Si, with the remainder comprising Cu and inevitable impurities, and has a conductivity of at least 38% IACS, wherein, for three types of test specimens respectively cut in a direction parallel to the rolling direction, a direction at 45° to the rolling direction, and a direction perpendicular to the rolling direction, the arithmetic mean value Aave. is in the range of 4.0-13.0 GPa·% as calculated by substituting values obtained from nominal stress-nominal strain curves obtained from tensile tests, and values of Cube azimuth area ratios obtained by the electron backscatter diffraction (EBSD) method into specific equation 1 to determine the values of A0°, A45°, and A90° for respective directions of parameter Ax (x: 0°, 45°, 90°), and substituting the determined values of A0°, A45°, and A90° for respective directions into specific equation 2. According to the present invention, excellent drawability can be reliably obtained without compromising the basic properties (in particular, heat dissipation) of conventional copper alloy sheets.

Description

Copper alloy sheet material, manufacturing method thereof, drawn product, electric/electronic component member, electromagnetic wave shield material and heat dissipation component

The present invention relates to a copper alloy plate material, a method for manufacturing the same, a drawn product, a member for electric/electronic parts, an electromagnetic wave shield material, and a heat dissipation part.

Copper alloy plate materials such as connectors for electric/electronic parts, lead frames, relays, switches, sockets, shield cases, shield cans, liquid crystal reinforcing plates, liquid crystal chassis, organic EL display reinforcing plates, and in-vehicle connectors. Copper alloy plate materials used for shield cases, shield cans and the like are usually subjected to press working such as punching, bending, drawing, and overhanging.

When using a conventional copper alloy sheet, mechanical and electrical characteristics had to be sacrificed in order to achieve a difficult-to-machine shape that would otherwise be difficult to achieve. The "difficult-to-machine shape" here means, for example, the shape formed when processed with a jig such as a punch whose radius of curvature of corners and edges is smaller than usual when manufacturing drawn products. To do. When manufacturing a drawn product having such a difficult-to-machine shape, it cannot be said that the original mechanical and electrical characteristics of the copper alloy sheet are fully utilized. Further, when the mechanical and electrical characteristics of the copper alloy sheet material are emphasized, it is necessary to give up processing to a target difficult-to-machine shape, and it is not possible to satisfy the demand for miniaturization of electronic devices. This is because, as a result, the radius of curvature of the jig (punch) must be increased to some extent, and as a result, the mounting space of the drawn product that constitutes the electronic component naturally increases. Furthermore, by optimizing the shape of the drawn product, there is room to improve the heat dissipation by sacrificing the focus on the drawability, but it is currently difficult to draw the optimum shape. There is.

In particular, with the high performance of electric/electronic parts and automotive in-vehicle parts in recent years, pressed products, which are one of the parts that compose them, have not only the mechanical and electrical characteristics and heat dissipation In order to enable deformation into a shape, it has been strongly required to have excellent workability even under severe processing conditions. However, in the present process, the level of drawability required by the customer has not been achieved in the process of processing into a target difficult-to-machine shape.

For example, in Patent Document 1, one or two kinds of Ni and Co are contained in 0.8 to 4.0 mass %, Si is contained in 0.2 to 1.0 mass %, and one or two kinds of Ni and Co are contained. The mass ratio of Si is 3.0 to 7.0, the balance is Cu and unavoidable impurities, the tensile strength in the rolling parallel direction is 570 MPa or more, the proof stress is 500 MPa or more, the elongation is 5% or more, and the rolling orthogonal direction is Tensile strength is 550MPa or more, proof stress is 480MPa or more, elongation is 5% or more, conductivity is more than 35%IACS, and ratio R/t of bending radius R and plate thickness t is 0.5, and bending line is rolled. The bending limit width when performing 90 degree bending in the vertical direction is 70 mm or more, the bending processing limit width when performing contact bending in which the bending line is in the vertical direction is 20 mm or more, and the Rank Ford value is 0.9. The above is the strength as a structural member, especially the strength to withstand deformation and drop impact resistance, the bending workability to withstand the processing of complex shapes, the workability such as overhanging and drawing, and the high heat radiation performance against heat from semiconductor elements, etc. There is described a copper alloy plate for a heat dissipation component.

Further, Patent Document 2 contains 0.5 to 3.0% by mass of Co, 0.1 to 2.0% by mass of Ni, and 0.1 to 1.5% by mass of Si in a mass ratio. (Ni+Co)/Si is 3 to 5, the balance is copper and inevitable impurities, 0.2% proof stress in the rolling parallel direction is 630 MPa or more, the conductivity is 50% IACS or more, and the average crystal grain in the rolling parallel cross section. X-ray diffraction integrated intensity I{200} from the {200} crystal plane on the surface, X-ray diffraction integrated intensity I{220} from the {220} crystal plane, and {311} crystal having a diameter of 10 to 20 μm X-ray diffraction integrated intensity I{311} from the plane satisfies the relationship of (I{220}+I{311})/I{200}≧5.0, which is 0.2% suitable for use in electronic materials. There is described a copper alloy for electronic materials, which has proof stress and conductivity, and can improve dimensional stability when pressed into a connector shape or the like.

Further, in Patent Document 3, 1.0 to 3.0% by mass of Ni is contained, Si is contained at a concentration of 1/6 to 1/4 with respect to the mass% concentration of Ni, and the balance is Cu and unavoidable. The average deviation Ra of the surface is 0.02 to 0.2 μm, and the standard deviation of the absolute values of the peaks and troughs based on the surface roughness average line is 0.1 μm or less, the average value of the aspect ratio of crystal grains in the alloy structure (minor axis of crystal grains/major axis of crystal grains) is 0.4 to 0.6, and the backscattered electron diffraction image system is provided. All crystals of GOS when the orientations of all pixels within the measurement area range are measured by the EBSD method with a scanning electron microscope and the boundaries where the orientation difference between adjacent pixels is 5° or more are regarded as crystal grain boundaries. The average value of the grains is 1.2 to 1.5°, and the ratio (Lσ/L) of the total length Lσ of the special grain boundaries to the total length L of the grain boundaries is 60 to 70%. Cu-Ni-, which has a spring limit value of 450 to 600 N/mm2, good solder heat resistance peeling resistance at 150°C for 1000 hours, little variation in fatigue resistance, and excellent deep drawability. A Si-based copper alloy (Corson alloy) plate is described.

The above-mentioned Patent Documents 1 to 3 are inventions relating to a copper alloy sheet material containing at least one of Ni and Co and Si and have good drawability, but copper alloys Among the steps constituting the method for manufacturing a plate material, particularly in the series of steps from the finish cold rolling step to the temper annealing step, control is not performed to suppress the generation of crystal grains that deteriorate the drawability. In particular, when the processing conditions are particularly severe when performing a deep drawing test, particularly when the punching is performed with a punch having a small radius of curvature R at the corner (for example, the radius of curvature R is 0.9 mm or less), a satisfactory level of drawing is obtained. There is a problem that workability cannot be stably obtained.

JP, 2017-89003, A Japanese Patent Laid-Open No. 2018-62705 International Publication No. 2012/160684

An object of the present invention is to provide a copper alloy sheet material capable of stably obtaining excellent drawability even under severe drawing conditions without impairing the basic properties (especially heat dissipation) of conventional copper alloy sheet materials. Another object of the present invention is to provide a manufacturing method thereof, a drawn product, a member for electric/electronic parts, an electromagnetic wave shielding material and a heat dissipation part.

In order to achieve the above object, the gist configuration of the present invention is as follows.
(1) It has a composition containing 1.0 to 5.0 mass% of Ni and Co in a total amount of 1.0 to 5.0 mass% and 0.1 to 1.5 mass% of Si, and the balance of Cu and unavoidable impurities. , The conductivity was 38% IACS or more, and obtained by performing a tensile test on three types of test pieces cut out in the rolling parallel direction, the direction of 45° to the rolling direction, and the vertical direction of the rolling. The value obtained from the nominal stress-nominal strain curve and the value of the Cube azimuth area ratio obtained by the electron backscatter diffraction (EBSD) method are substituted into the following formula (1) to obtain the parameter Ax(x:0° , 45°, 90°) in each direction, A _0° , A _45° and A _90° are obtained, and the obtained values in each direction A _0° , A _45° and A _90° are given in (2) below. A copper alloy sheet material, wherein an arithmetic mean value Aave. calculated by substituting in a formula is in a range of 4.0 to 13.0 GPa·%.

However, Sc:Cube orientation area ratio (%), σn is a nominal stress (GPa), εn is a nominal strain (%), and EL is a breaking elongation (%).

(2) The value B _{0 of} each direction of the parameter Bx (x: 0°, 45°, 90°) calculated by substituting the values of the arithmetic average value Aave. and the parameter Ax into the following equation (3). The copper alloy sheet material according to (1) above, wherein each of _° , B _45° and B _90° is 10% or less.

(3) The ratio (Er/t ratio) of the Erichsen value (Er) to the plate thickness (t) in the Erichsen test and the breaking elongation EL (%) when pulled in the rolling parallel direction are expressed by the following formula (4). The copper alloy sheet material according to (1) or (2), which satisfies the inequality relationship.

(4) The composition further contains at least one component selected from the group consisting of Sn, Mg, Mn, Cr, Zr, Ti, Fe and Zn in a total amount of 0.2 to 1.2% by mass or less. The copper alloy sheet material according to any one of (1) to (3) above.
(5) A drawn product obtained by drawing the copper alloy sheet material according to any one of (1) to (4).
(6) A member for electric/electronic parts produced using the copper alloy sheet material according to any one of (1) to (4) or the drawn product according to (5).
(7) An electromagnetic wave shielding material produced by using the copper alloy plate material according to any one of (1) to (4) or the drawn product according to (5).
(8) A heat dissipation component manufactured using the copper alloy sheet material according to any one of (1) to (4) or the drawn product according to claim 5.
(9) The method for manufacturing a copper alloy sheet according to any one of (1) to (4) above, wherein the copper alloy material is cast [step 1], homogenized [step 2], hot Rolling [step 3], chamfering [step 4], cold rolling [step 5], solution heat treatment [step 6], intermediate heat treatment [step 7], finish cold rolling [step 8], straightening [step 9] , And temper annealing [step 10] are sequentially performed, and the maximum temperature TR of the material at the time of rolling in the finish cold rolling [step 8] is controlled to be 75° C. or higher and 100° C. or lower, and in the straightening [step 9]. The elongation rate δ of the material is set to 0.1 to 1.0%, and the material temperature TA (° C.) of the temper annealing [step 10] is expressed by the following equation (5) in relation to the elongation rate δ. A method for manufacturing a copper alloy sheet material, which is controlled so as to satisfy the relationship of the inequalities shown.
55×δ+450≧TA≧55×δ+350 (5)

The copper alloy sheet of the present invention contains 1.0 to 5.0 mass% of Ni and Co in total and 0.1 to 1.5 mass% of Si, and the balance of Cu and unavoidable impurities. Tensile tests were carried out on three types of test pieces having a certain composition, an electric conductivity of 38% IACS or more, and cut in the rolling parallel direction, the direction of 45° to the rolling direction, and the vertical direction of the rolling. The value obtained from the nominal stress-nominal strain curve obtained by performing the above and the value of the Cube orientation area ratio obtained by the electron backscatter diffraction (EBSD) method are substituted into the above equation (1) to obtain the parameter Ax. (X: 0°, 45°, 90°) values A _0° , A _45° and A _90° in each direction are obtained, and the obtained values A _0° , A _45° and A _90° in each direction are obtained. Since the arithmetic mean value Aave. calculated by substituting in the above formula (2) is in the range of 4.0 to 13.0 GPa·%, the basic characteristics (especially heat dissipation) of the conventional copper alloy sheet can be It is possible to stably obtain excellent drawing workability even under severe drawing work conditions without loss.

The method for producing a copper alloy sheet according to the present invention is performed on a copper alloy material by casting [step 1], homogenizing treatment [step 2], hot rolling [step 3], chamfering [step 4], cold rolling [step. 5], solution heat treatment [Step 6], intermediate heat treatment [Step 7], finish cold rolling [Step 8], straightening [Step 9], and temper annealing [Step 10], and the finish cold rolling. The maximum temperature TR of the material during rolling in [Step 8] is controlled to 75° C. or higher and 100° C. or lower, and the elongation rate δ of the material in the straightening [Step 9] is set to 0.1 to 1.0%, and By controlling the material temperature TA (° C.) in the heat treatment annealing [step 10] so as to satisfy the inequality shown in the equation (5) in relation to the elongation δ, the above-mentioned copper alloy sheet material Can be manufactured.

FIG. 1 is a diagram showing, as an example, a nominal stress-nominal strain curve obtained by performing a tensile test on a test piece cut out from a copper alloy sheet according to an embodiment of the present invention in a rolling parallel direction. .. Fig. 2 shows the fracture ratio when the ratio (Er/t ratio) of the Erichsen value (Er) to the plate thickness (t) obtained by conducting Erichsen test for various copper alloy sheet materials was pulled in the rolling parallel direction. It is a figure when it plots in relation with elongation EL (%). FIG. 3 conceptually shows a state in which the center portion of the test plate W is pushed by a punch having a cylindrical tip and a small radius of curvature R at the corners in order to evaluate the drawability with a deep drawing tester. FIG. FIG. 4 is a view conceptually showing a state in which the central portion of the test plate W is pushed in by a punch having a hemispherical tip so as to obtain the Erichsen value by the Erichsen tester.

Hereinafter, preferred embodiments of the copper alloy sheet of the present invention will be described in detail.
The copper alloy sheet according to the present invention contains 1.0 to 5.0 mass% of Ni and Co in total, and 0.1 to 1.5 mass% of Si, and the balance of Cu and unavoidable impurities. Tensile tests were carried out on three types of test pieces having a certain composition, an electric conductivity of 38% IACS or more, and cut in the rolling parallel direction, the direction of 45° to the rolling direction, and the vertical direction of the rolling. The value obtained from the nominal stress-nominal strain curve obtained by performing and the value of the Cube azimuth area ratio obtained by the electron backscatter diffraction (EBSD) method are substituted into the following formula (1) to obtain the parameter Ax. (X: 0°, 45°, 90°) values A _0° , A _45° and A _90° in each direction are obtained, and the obtained values A _0° , A _45° and A _90° in each direction are obtained. The arithmetic mean value Aave. calculated by substituting in the following equation (2) is in the range of 4.0 to 13.0 GPa·%.

However, Sc:Cube orientation area ratio (%), σn is a nominal stress (GPa), εn is a nominal strain (%), and EL is a breaking elongation (%).

(I) Composition of Copper Alloy Sheet Material First, the reason for limiting the composition of the copper alloy sheet material of the present invention will be explained.
The copper alloy sheet material of the present invention contains 1.0 to 5.0 mass% of Ni and Co in total and 0.1 to 1.5 mass% of Si.

<1.0 to 5.0% by mass in total of at least one of Ni and Co>
Ni (nickel) and Co (cobalt) are elements necessary for increasing the strength of the copper alloy sheet material, and it is necessary to contain 1.0 to 5.0 mass% of Ni and Co in total. Is. If the total content of one or more of Ni and Co is less than 1.0% by mass, the material strength decreases, and the strength required for an electronic component such as a shield case that is a drawn product manufactured by drawing is obtained. I can't. Further, when the total content of one or more of Ni and Co is more than 5.0% by mass, Ni and Co cannot be completely dissolved in the solution heat treatment [step 6] described later and a metallic structure is formed as a second phase. It will remain in the (matrix), and in the subsequent intermediate heat treatment [Step 7] that will be described later, not only does it not contribute to the improvement in strength that should occur, but it also leads to an increase in the cost of metal. is there. Therefore, the total content of at least one of Ni and Co is set to the range of 1.0 to 5.0 mass %. The total content is preferably in the range of 1.0 to 4.0% by mass.

<Si: 0.1 to 1.5 mass%>
Si (silicon) is an element necessary for forming a compound with Ni or Co and increasing the strength of the copper alloy sheet, and it is necessary to contain Si in an amount of 0.1 to 1.5 mass %. This is because if the Si content is less than 0.1% by mass, the amount of the compound formed with Ni or Co will decrease and the material strength will decrease. Further, if the Si content is more than 1.5% by mass, the thermal conductivity of the copper alloy plate material is lowered and the heat dissipation is deteriorated. Therefore, the Si content is set to the range of 0.1 to 1.5 mass %. The Si content is preferably in the range of 0.2 to 1.0% by mass.

The copper alloy sheet of the present invention contains one or more components of Ni and Co and Si as essential basic components, and further contains Sn, Mg, Mn, Cr, Zr, as an optional additional component. At least one component selected from the group consisting of Ti, Fe and Zn may be contained in a total amount of 0.2 to 1.2% by mass or less. All of these components are components having an effect of improving the material strength, and in order to exert such an effect, the total content of these components is preferably 0.2% by mass or more. Further, if the total content of these components exceeds 1.2% by mass, the conductivity tends to decrease, so the total content of the above components is in the range of 0.2 to 1.2% by mass. It is preferable that 0.5 to 1.0% by mass is particularly preferable.

<Sn: 0.1 to 0.45 mass%>
Sn (tin) is an element having a high effect of solid-solution strengthening a copper alloy, and it is preferable to add 0.1 mass% or more, but if the addition amount exceeds 0.45 mass %, the conductivity decreases. Tend to let. Therefore, the amount of Si added is preferably in the range of 0.1 to 0.45 mass %.

<Mg: 0.1 to 0.25 mass%>
Mg (magnesium) is an element having a high effect of solid-solution strengthening a copper alloy, and it is preferable to add 0.1 mass% or more, but if the addition amount exceeds 0.25 mass%, the conductivity decreases. Tend to let. Therefore, the amount of Mg added is preferably in the range of 0.1 to 0.25% by mass.

<Mn: 0.1 to 0.2 mass%>
Mn (manganese) is an element having an effect of solid solution strengthening a copper alloy and an effect of improving hot workability, and is preferably added in an amount of 0.1% by mass or more, but more than 0.2% by mass. A larger amount tends to lower the conductivity. Therefore, the amount of Mn added is preferably in the range of 0.1 to 0.2 mass %.

<Cr: 0.1 to 0.25% by mass>
Cr (chromium) has the effect of strengthening the material by forming a second phase compound containing chromium and silicon and suppressing coarsening of the crystal grain size in the solution heat treatment step by the compound. It is desirable to add 1% by mass or more, but if the amount added is more than 0.25% by mass, coarse crystallized substances are formed during casting and the starting point of fracture during press working is likely to occur. Therefore, the Cr addition amount is preferably in the range of 0.1 to 0.25 mass %.

<Zr: 0.05 to 0.15 mass%>
Zr (zirconium) is an element that has a solid solution in the material and has an effect of suppressing the growth of recrystallized grains in the solution heat treatment by increasing the recrystallization temperature of the material, and is added in an amount of 0.05 mass% or more. However, if the addition amount is more than 0.15% by mass, coarse crystallized substances are generated during casting and are likely to be a starting point of fracture during press working. Therefore, the Zr addition amount is preferably in the range of 0.05 to 0.15 mass %.

<Ti: 0.02 to 0.1 mass%>
Ti (titanium) is an element having a solid solution in the material and having an effect of suppressing the growth of recrystallized grains in the solution heat treatment by increasing the recrystallization temperature of the material, and addition of 0.02 mass% or more However, if the addition amount is more than 0.1% by mass, the conductivity tends to decrease. Therefore, the Ti addition amount is preferably in the range of 0.02 to 0.1% by mass.

<Fe: 0.05 to 0.1 mass%>
Fe (iron) is an element having a high effect of solid-solution strengthening a copper alloy, and it is desirable to add 0.05 mass% or more, but if the addition amount is larger than 0.1 mass%, the conductivity decreases. Tend. Therefore, the amount of Fe added is preferably in the range of 0.05 to 0.1 mass %.

<Zn: 0.2 to 0.6 mass%>
Zn (zinc) is an element that has the effects of improving bending workability and improving adhesion and migration characteristics of Sn plating and solder plating. In order to exert such an effect, the Zn content is preferably 0.2% by mass or more. However, if the Zn content exceeds 0.6 mass %, there is a possibility that sufficient heat dissipation cannot be obtained due to a decrease in conductivity. Therefore, the amount of Zn added is preferably in the range of 0.2 to 0.6 mass %.

<Remainder: Cu and inevitable impurities>
The balance other than the above-mentioned components is Cu (copper) and inevitable impurities. The unavoidable impurities referred to here mean impurities at a content level that can be unavoidably included in the manufacturing process. Since the unavoidable impurities may be a factor that decreases the conductivity depending on the content, it is preferable to suppress the content of the unavoidable impurities to some extent in consideration of the decrease in the conductivity. Examples of the components that can be cited as the inevitable impurities include Bi, Se, As, Ag, and the like. The upper limit of the content of these components may be 0.03 mass% for each of the above components, and 0.10 mass% for the total amount of the above components.

(II) Electric Conductivity The copper alloy sheet material of the present invention needs to have an electric conductivity of 38% IACS or more. The thermal conductivity can be calculated from the conductivity according to the Wiedemann-Franz law, and if the temperature is constant, it is proportional to the conductivity regardless of the type of metal. Are known. Therefore, the copper alloy sheet material of the present invention can have high thermal conductivity by setting the electrical conductivity to 38% IACS or more, and as a result, can have excellent thermal conductivity. The conductivity can be calculated by measuring the specific resistance by the four-terminal method in a constant temperature bath kept at 20° C. (±0.5° C.) with the distance between terminals being 100 mm, for example.

(III) The arithmetic average value Aave. is in the range of 4.0 to 13.0 GPa·%. The copper alloy sheet of the present invention has the arithmetic average value Aave. in the range of 4.0 to 13.0 GPa·%. It is necessary to be. The arithmetic mean value Aave. is the rolling parallel direction, the direction of 45° with respect to the rolling direction (may be simply referred to as “45° direction”), and the vertical direction of rolling (may be simply referred to as “90° direction”). The values obtained from the nominal stress-nominal strain curves obtained by conducting a tensile test for three types of test pieces cut out in each direction and the Cube orientation area obtained by the electron backscatter diffraction (EBSD) method By substituting the value of the ratio into the following formula (1), the values A _0° , A _45° and A _90° of the parameter Ax (x: 0°, 45°, 90°) in each direction were obtained and obtained. It is calculated by substituting the values A _0° , A _45° and A _90° in each direction into the following formula (2).

However, Sc:Cube orientation area ratio (%), σn is a nominal stress (GPa), εn is a nominal strain (%), and EL is a breaking elongation (%).

The present inventors have obtained the knowledge that the parameter Aave. correlates well with the drawing workability of the material, through experiments until the present invention. It has been conventionally known that, among the crystallographic orientations of copper and copper alloys, in particular, the Cube orientation is integrated, which reduces the drawability of the material. However, a quantitative correlation between the degree of integration of the Cube orientation and the drawability and the quantitative evaluation of the drawability using the degree of integration of the Cube orientation have not been performed. In the first place, precipitation strengthened copper alloys such as Cu-Ni-Si and Cu-Co-Si alloys such as the component system of the present invention are copper and copper alloys conventionally used for drawing, such as pure copper and brass, Compared to pure metal such as nickel silver and solid solution reinforced type, influence of manufacturing process other than material components, for example, control process such as size, existing density, existing ratio of second phase compound and rolling process on mechanical properties of material Is very large, and moreover, because multiple material properties affect each other, they change at the same time, for example, the abundance ratio of the second phase compound and the material strength change at the same time. The fact that the influence on the workability cannot be extracted made it difficult to improve the drawability of the precipitation strengthened alloy and to evaluate the drawability.

Therefore, the present inventors have found that the drawability can be well evaluated by the precipitation-strengthened alloy by the formula (2), and further that there is a correlation between the formula (2) and the drawability. Has led to the invention of a precipitation-strengthened alloy with improved properties.

In the formula (1), the degree of integration of the Cube orientation that adversely affects the drawability is expressed so as to have a negative correlation with the parameter Ax, and the larger the integrated value of the nominal stress-nominal strain curve, the greater the drawability. It is expressed so that it has a positive correlation. FIG. 1 is a diagram showing, as an example, a nominal stress-nominal strain curve obtained by performing a tensile test on a test piece cut out from a copper alloy sheet according to an embodiment of the present invention in a rolling parallel direction. ..

Furthermore, the arithmetic mean value Aave. calculated by substituting the three-direction parameters A _0° , A _45°, and A _90° obtained from the formula (1) into the formula (2) is a parameter that correlates well with the drawing workability. I found that. By obtaining this correlation, it becomes possible to evaluate the drawability by the formula (2).

Here, when the arithmetic mean value Aave. is less than 4.0 GPa·%, a satisfactory level of drawability cannot be obtained under particularly severe deep drawing conditions, and when it is larger than 13.0 GPa·%. Then, the elongation of the material becomes large, and it becomes impossible to obtain sufficient strength, which is a contradictory characteristic. Therefore, in the present invention, the arithmetic mean value Aave. is set in the range of 4.0 to 13.0 GPa·%. The arithmetic mean value Aave. is preferably in the range of 6.0 to 11.0 GPa·%.

The integrated value obtained from the nominal stress-nominal strain curve used to calculate the parameter Ax is three types of JIS Z2241 No. 13B test pieces cut out in the rolling parallel direction, 45° direction and 90° direction, respectively. According to JIS Z2241, each 9 pieces (n=9) are prepared and measured, and when the case with the largest breaking elongation is the first, the test piece with the fifth largest breaking elongation is used. And the nominal stress-nominal strain curve is calculated, and the integral value shown in equation (1) is calculated from the area obtained by the trapezoidal approximation from the plot of the nominal stress-nominal strain curve obtained above. can do. The nominal stress may be measured, for example, every time the nominal strain is 0.001% or more and 0.300% or less.

The Cube azimuth area ratio (%) used to calculate the parameter Ax is continuously measured using an EBSD detector attached to a high resolution scanning analysis electron microscope (JEOL Ltd., trade name: JSM-7001FA). It can be calculated from the crystal orientation data measured by using analysis software (manufactured by TSL, trade name: OIM-Analysis). Here, “EBSD” is an abbreviation for Electron BackScatter Diffraction, which is a crystal orientation analysis technology that utilizes the reflected electron Kikuchi line diffraction that occurs when a sample is irradiated with an electron beam in a scanning electron microscope (SEM). Yes, and "OIM-Analysis" is an analysis software of data measured by EBSD.

Therefore, the values A _0° , A _45°, and A _90° in each direction of the parameter Ax are obtained by substituting the integral value calculated by the above-described method and the Cube azimuth area ratio (%) into the above formula (1). The values A _0° , A _45° and A _90° of the parameter Ax in each direction can be calculated, and the arithmetic average value Aave. is calculated by using the calculated A _0° , A _45° and A _90° in equation (2). It can be calculated by substituting into

The drawability is measured by a deep drawing tester (for example, a thin plate forming tester manufactured by Erichsen Co., Ltd.) 10 after tightening the edge of the test plate W between the die 12 and the wrinkle holding member 16 as shown in FIG. Then, the center portion of the test plate W was pushed by the punch 14 to form a cylindrical cup. The minimum punch corner radius R at which the cylindrical cup can be molded without cracking and the difference between the maximum valley depth and the maximum peak height of the undulation of the edge of the cylindrical cup were evaluated. In addition, the value of the moving distance (the depth of the depression) of the punch until the penetration crack occurs in the overhang test (Erichsen test), that is, the Erichsen value Er is measured, and in addition to this Erichsen value Er, the thickness of the test plate W (Mm), elongation at break (%) when pulled in the rolling direction, and the results were taken into consideration for comprehensive evaluation.

(IV) The values B _0° , B _45° and B _90° in each direction of the parameter Bx (x: 0°, 45°, 90°) are all 10% or less. , The arithmetic mean value Aave. and the value of the parameter Ax are substituted into the following equation (3), the values of the parameter Bx (x: 0°, 45°, 90°) in each direction are both It is preferably 10% or less.

By controlling the values B _0° , B _45° and B _90° of the parameter Bx defined in the above formula (3) in each direction to be 10% or less, the undulation of the edge after drawing is performed. Can be stably reduced, the shape can be made uniform, and the drawability can be further improved by twisting. If the values B _0° , B _45° , and B _90° in any direction of the parameter Bx are larger than 10%, the yield in the production of drawn products tends to decrease. Therefore, the value of the parameter Bx in each direction Each of B _0° , B _45° and B _90° is preferably 10% or less, and more preferably 5.5% or less.

The parameter Bx can be calculated by substituting the calculated parameter Ax and the arithmetic mean value Aave. into the equation (3) as described above.

(V) The ratio of the Erichsen value (Er) to the plate thickness (t) (Er/t ratio) and the elongation at break EL (%) when stretched in the rolling parallel direction are expressed by the following inequality (4). The copper alloy sheet of the present invention has a ratio (Er/t ratio) of the Erichsen value (Er) to the sheet thickness (t) in the Erichsen test, and an elongation at break EL (%) when pulled in the rolling parallel direction. Preferably satisfies the relation of the inequality of the following equation (4).

The inventors further calculated that the ratio (Er/t ratio) of the Erichsen value (Er) to the plate thickness (t) obtained by the Erichsen test and the breaking elongation EL (%) when pulled in the rolling parallel direction were The influence on the drawability was examined. Fig. 2 shows the ratio of the Erichsen value (Er) to the plate thickness (t) (Er/t ratio) on the vertical axis, and the elongation at break EL (%) when pulled in the rolling parallel direction on the horizontal axis. It is plotted about the Example and the comparative example shown. From the results shown in FIG. 2, it can be seen that all the examples are in the upper region and all the comparative examples are in the lower region with the linear function: Er/t=1.5EL as the boundary. Therefore, in the present invention, it is possible to determine whether the copper alloy plate material has excellent drawability by satisfying the above expression (4).

As shown in FIG. 4, the Erichsen value (Er value) is obtained by tightening the edge of the test plate W between the die 12 and the wrinkle holding member 16 by the Erichsen tester, and then measuring the central part of the test plate W as follows. The punch 14A having a hemispherical tip was pushed in, and the value of the moving distance of the punch (the depth of the depression) until the occurrence of through cracks was measured, and the measured value was used.

(VI) Method of Manufacturing Copper Alloy Sheet Material According to One Embodiment of the Present Invention The copper alloy sheet material described above can be realized by controlling the alloy composition and the manufacturing process in combination. Hereinafter, a suitable method for producing the copper alloy sheet of the present invention will be described.

Such a copper alloy sheet according to one embodiment of the present invention is formed by casting [step 1], homogenizing [step 2], and hot rolling on a copper alloy material having the same composition as the above-mentioned copper alloy sheet. [Step 3], chamfering [Step 4], cold rolling [Step 5], solution heat treatment [Step 6], intermediate heat treatment [Step 7], finish cold rolling [Step 8], straightening [Step 9], It is manufactured by sequentially performing and temper annealing [step 10]. More specifically, by optimizing a series of steps from the finish cold rolling step to the temper annealing step, more specifically, The maximum temperature TR of the material during rolling in the hot rolling [step 8] is controlled to 75° C. or more and 100° C. or less, and the elongation rate δ of the material in the straightening [step 9] is set to 0.1 to 1.0%, Then, by controlling the material temperature TA (° C.) of the temper annealing [step 10] so as to satisfy the relation of the inequality shown in the following equation (5) in relation to the elongation rate δ, the heat radiation property is particularly impaired. Even if the drawing conditions are severe, a copper alloy sheet material having excellent drawability can be manufactured.

55×δ+450≧TA≧55×δ+350 ・・・(5)

(I) Casting process [Process 1]
In the casting step, the alloy components shown in Table 1 are melted in a high frequency melting furnace in the atmosphere, and the alloy components are cast to produce an ingot of a predetermined shape (for example, thickness 30 mm, width 100 mm, length 150 mm).

(Ii) Homogenization treatment process [Process 2]
In the homogenization treatment step, heating was performed at a predetermined temperature (for example, 1000° C.) in an inert gas atmosphere for 1 hour to perform a homogenization heat treatment [step 2].

(Iii) Hot rolling process [Process 3]
The hot rolling step was performed immediately after the homogenizing heat treatment, and immediately after cooling to a predetermined plate thickness (for example, 10 mm), cooling was performed.

(Iv) Chamfering process [Process 4]
In the chamfering step, the surface of the hot-rolled sheet was chamfered to a predetermined thickness (for example, about 1 mm to 2 mm) to remove the oxide layer.

(V) Cold rolling process [Process 5]
In the cold rolling process, cold rolling was performed to 1 to 0.25 mm.

(Vi) Solution heat treatment step [Step 6]
In the solution heat treatment step, the temperature is raised at a predetermined heating rate (for example, 900° C. to 990° C. over 5 seconds to 10 seconds), held for 1 second to 1 hour, and then set to 250° C./s to 500° C./s. Cooled at rate.

(Vii) Intermediate heat treatment step [Step 7]
In the intermediate heat treatment step, heat treatment was performed at a predetermined temperature (for example, 300° C. to 600° C.) for 10 seconds to 10 hours.

(Viii) Finishing cold rolling process [Process 8]
The finish cold rolling process is a process mainly performed for processing to a desired plate thickness, improvement of material strength, and control of crystal orientation, and the maximum temperature TR of the material during rolling is 75°C or higher and 100°C or lower. Need to be controlled. By setting the maximum temperature TR of the material during rolling to 75° C. or higher, crystal rotation due to rolling is promoted, and the area ratio of Cube-oriented grains, which adversely affects the drawability, is likely to decrease. However, when the maximum temperature TR of the material during rolling becomes higher than 100° C., the viscosity of the lubricating oil used for rolling decreases, so that the surface roughness of the plate material becomes locally high due to rolling defects such as seizure. As a result, there is a high possibility that the drawability will deteriorate, such as the starting point of fracture. Therefore, the maximum temperature TR of the material during rolling is set to 75°C or higher and 100°C or lower.

(Ix) Straightening process [Process 9]
The straightening process is a process performed for the purpose of removing/uniformizing the residual stress of the material, and the elongation rate δ of the material during the straightening by the tension leveler is in the range of 0.1 to 1.0%. is necessary. If the elongation δ is less than 0.1%, the effect of removing and uniformizing residual stress is small, and the shape uniformity after drawing is deteriorated. On the other hand, if the elongation δ is larger than 1.0%, the processing strain due to the repeated bending of the tension leveler becomes large, and the corner radius of the punch tip where cracks do not occur during drawing processing cannot be made small, resulting in severe drawing. The drawability is reduced under the processing conditions. Therefore, the elongation rate δ of the material in the straightening step is set in the range of 0.1 to 1.0%.

(X) Tempering annealing process [Process 10]
The temper annealing step is a step for recovering the elongation of the material and further for reducing the anisotropy of mechanical properties including elongation, and the material temperature TA (° C.) of the temper annealing [step 10]. Must be controlled so as to satisfy the relation of the inequality shown in the equation (5) in relation to the elongation rate δ(%) of the material in the straightening step.

55×δ+450≧TA≧55×δ+350 ・・・(5)

Drawability is improved by controlling the material temperature TA in the temper annealing process according to the equation (5). By recovering the dislocations introduced in the series of steps up to the straightening step by the temper annealing step, the arithmetic mean value Aave. and the Erichsen value Er, which are the parameters of the material, become large. If the material temperature TA in the temper annealing step is lower than the lower limit value in the equation (5), recovery of dislocations by rolling (that is, removal of work strain) becomes insufficient. Further, when the material temperature TA in the temper annealing step exceeds the upper limit value in the equation (5), the precipitate of the compound of Ni or Co and Si becomes coarse, and accordingly, the material strength decreases. Therefore, the material temperature TA (° C.) in the temper annealing [step 10] is set so as to satisfy the relationship of the inequality shown in the expression (5) in relation to the elongation rate δ(%) of the material in the straightening step.

(VII) Use of Copper Alloy Plate Material The copper alloy material of the present invention is particularly suitable for use in producing a drawn product by subjecting it to drawing, for example, a member for electric/electronic parts, an electromagnetic wave shielding material and It can be used as a heat dissipation component. For example, connectors for electric/electronic parts, lead frames, relays, switches, sockets, shield cases, shield cans, liquid crystal reinforcement plates, liquid crystal chassis, reinforcement plates for organic EL displays, connectors for automobiles, shield cases, A shield can or the like can be manufactured.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes various aspects included in the concept of the present invention and the scope of the claims, and various modifications within the scope of the present invention. Can be modified to.

Next, examples of the present invention and comparative examples will be described in order to further clarify the effects of the present invention, but the present invention is not limited to these examples.

(Examples 1 to 15 and Comparative Examples 1 to 11)
A copper alloy material having the composition shown in Table 1 was melted in a high-frequency melting furnace in the air and cast to obtain an ingot having a thickness of 30 mm, a width of 100 mm, and a length of 150 mm. Next, immediately after the homogenizing heat treatment of heating and holding at 1000° C. for 1 hour in an inert gas atmosphere, hot rolling was performed to obtain a hot-rolled sheet having a thickness of 10 mm, and then immediately cooled. Then, chamfering and cold rolling were sequentially performed to make the plate thickness 0.25 to 1.0 mm. Then, the solution heat treatment is performed at 800 to 990° C. for 1 minute, immediately after cooling, the intermediate heat treatment is performed at 300° C. to 600° C. for 1 hour. Then, after finishing cold rolling 0.1% to 60% at the maximum temperature TR of the material shown in Table 3, it is corrected by the elongation δ of the material shown in Table 3, and then the material temperature TA shown in Table 3 is obtained. Was heat-annealed to obtain a copper alloy plate material having a plate thickness of 0.25 to 0.3 mm. In Comparative Example 11, since the maximum temperature TR of the material during the finish cold rolling was high, the surface of the plate material was defective due to seizure, so that various parameters could not be calculated and the performance could not be evaluated.

[Various measurement and evaluation methods]
Using the copper alloy sheet materials according to the above Examples and Comparative Examples, the following characteristic evaluation was performed. The evaluation conditions for each characteristic are as follows.

[1] Method for measuring composition of copper alloy sheet material The alloy composition was measured by fluorescent X-ray analysis.

[2] Conductivity measurement method The conductivity was calculated by measuring the specific resistance by the four-terminal method in a thermostat kept at 20° C. (±0.5° C.) with the distance between the terminals being 100 mm, for example. ..

[3] Method of calculating integral value in equation (1) The integral value in equation (1) is three kinds of JIS Z2241 No. 13B, which are cut out in the rolling parallel direction, 45° direction and 90° direction. According to JIS Z2241, 9 pieces (n=9) each were prepared and measured, and when the case where the breaking elongation was the largest was the first, the test piece having the fifth largest breaking elongation was The nominal stress-nominal strain curve when measured using the above is determined, and the integral value shown in the equation (1) is obtained by the trapezoidal approximation from the plot of the nominal stress-nominal strain curve obtained above. Calculated from the area. The nominal stress was measured every 0.01% of the nominal strain.

[4] Calculation method of Cube azimuth area ratio The Cube azimuth area ratio is continuously measured using an EBSD detector attached to a high resolution scanning analysis electron microscope (JEOL Ltd., trade name: JSM-7001FA). It was calculated from the obtained crystal orientation data using analysis software (manufactured by TSL, trade name: OIM-Analysis).

[5] Calculation Method of Parameter Bx Parameter Bx is a parameter Ax obtained by substituting the integral value calculated in [3] above and the Cube orientation area ratio calculated in [4] above into equation (1). The values A _0° , A _45° and A _{90° in the direction} and the arithmetic mean value Aave. obtained by substituting these values A _0° , A _45° and A _90° into the equation (2) It can be calculated by substituting in (3).

[6] Method for measuring Erichsen value Er The Erichsen value Er is measured by an Erichsen tester after the edge of the test plate W is clamped between the die 12 and the wrinkle holding member 16 as shown in FIG. The central portion of W was pushed in by the punch 14A, the value of the moving distance of the punch (the depth of the recess) until the occurrence of through cracks was measured, and it was taken as the measured value.

[7] Evaluation of heat dissipation The heat dissipation was evaluated by the conductivity measured in the above [2]. The evaluation criteria for heat dissipation are shown below. In this example, "1" and "2" in the heat dissipation evaluation criteria shown below are considered to be acceptable levels. Table 2 shows the evaluation results of heat dissipation.

<Heat dissipation evaluation criteria>
1 (excellent): When the conductivity is 50% IACS or more 2 (Good): When the conductivity is 30% IACS or more and less than 50% IACS 3 (Improper): When the conductivity is less than 30% IACS

[8] Evaluation of drawing workability As for drawing workability, as shown in FIG. After tightening between the members 16, the center portion of the test plate W is pushed by the punch 14 having a columnar tip and a small radius of curvature R at the corners to form a cylindrical cup without cracking. It was comprehensively evaluated from the minimum value of the radius of curvature R of the corner portion at the tip of the punch and the maximum value of the difference between the maximum peak height and the maximum valley depth of the undulation of the cup edge after molding. The evaluation criteria of drawability are shown below. Table 2 shows the evaluation results of the drawability. In the above test, the clearance between the punch and the die was 2.3 mm, R-303P was used as the lubricating oil applied to the surface of the test plate W, and the ratio of the punch diameter to the blank diameter (punch diameter/blank diameter) was used. ) Was performed under the test conditions of 0.64.

(A) Evaluation criteria for the minimum value of the radius of curvature R at the corner of the punch tip ◎ (excellent): When the minimum value of the radius of curvature R is 0.5 mm or less ○ (Good): The minimum value of the radius of curvature R is 0 In the case of more than 0.5 mm and less than 1.0 mm × (Not possible): When the minimum value of the radius of curvature R is 1.0 mm or more

(B) Evaluation criteria for the maximum difference between the maximum peak height and the maximum valley depth of the undulation of the cup edge ◎ (excellent): When the maximum value of the difference is 0.5 mm or less ○ (Good): The maximum value of the difference Is more than 0.5 mm and less than 1.0 mm x (Not possible): When the maximum value of the difference is 1.0 mm or more

<Evaluation of drawability>
1 (excellent): When both of the evaluations (a) and (b) are “⊚” 2 (Good): Both of the evaluations (a) and (b) are “◯” or more Case 3 (No): When at least one of the evaluations (a) and (b) is “x”.

From the results of Tables 1 to 4, the copper alloy sheet materials of Examples 1 to 15 all have an alloy composition within the proper range of the present invention, a conductivity of 38% IACS or more, and an arithmetic average value Aave. Since it is in the range of 0 to 13.0 GPa·%, it can be seen that both heat dissipation and drawing workability are at or above the passing level. Particularly, in Examples 3, 6, 8 and 12, the alloy composition and the manufacturing conditions were appropriate, and therefore the conductivity was particularly excellent. In Examples 1, 8 and 13, the conditions from casting to temper annealing were appropriate, and the parameters A and B showed good values. Therefore, the minimum radius of curvature of the corner portion of the punch tip where cracks do not occur. And the maximum value of the difference between the ridges and valleys of the undulation of the cup edge became small, so that the drawability was particularly excellent.

On the other hand, in Comparative Examples 1, 2, 4, 5, and 8, since the Ni+Co content or Si was small, the arithmetic average value Aave. fell outside the appropriate range of the present invention, and the drawability was poor. In Comparative Example 6, the straightening was not performed by the tension leveler and the elongation was 0%, so that the anisotropy was high, and thus Bx was out of the range. In Comparative Examples 8 and 10, the rolling temperature in finish cold rolling was low, and many Cube orientations remained, so that the arithmetic average value Aave. In Comparative Example 5, the parameter B 90° was out of the range, and the maximum height difference after drawing was large. In each of Comparative Examples 3, 7, and 9, the component content was larger than the appropriate range of the present invention, and thus the conductivity was particularly low. Particularly, in Comparative Example 7, the elongation in straightening was larger than the specified value, and the Erichsen value/plate thickness value was also outside the specified value, so the drawability was also poor. In Comparative Example 11, the material temperature during finish rolling became high, seizure of the material and the rolling roll occurred, and defects such as large unevenness occurred on the surface of the material. Therefore, the characteristic evaluation was not performed, but the drawability was remarkably reduced. Was obvious.

10 Erichsen Testing Machine 12 Die 14, 14A Punch (Punch)
16 Wrinkle holding member W Test plate material R Punch corner radius of curvature

Claims (9)

1. It has a composition containing 1.0 to 5.0 mass% of one or more of Ni and Co in total, and 0.1 to 1.5 mass% of Si, and the balance of Cu and inevitable impurities.
   Conductivity is 38% IACS or more,
   A value obtained from the nominal stress-nominal strain curve obtained by performing a tensile test on three types of test pieces cut out in the rolling parallel direction, the direction of 45° to the rolling direction, and the vertical direction of the rolling. When,
   The value of the Cube azimuth area ratio obtained by the electron backscattering diffraction (EBSD) method was substituted into the following formula (1), and the value A of each direction of the parameter Ax (x: 0°, 45°, 90°) was calculated. _0° , A _45° and A _90° are obtained, and the obtained values A _0° , A _45° and A _90° in each direction are substituted into the following formula (2) to calculate the arithmetic mean value Aave. Is in the range of 4.0 to 13.0 GPa·%, a copper alloy sheet material.
   

   

   However, Sc:Cube orientation area ratio (%), σn is a nominal stress (GPa), εn is a nominal strain (%), and EL is a breaking elongation (%).
   

   
2. The values B _0° and B _{0 of the} respective directions of the parameter Bx (x: 0°, 45°, 90°) calculated by substituting the values of the arithmetic average value Aave. and the parameter Ax into the following equation (3). The copper alloy sheet material according to claim 1, wherein both _45° and B _90° are 10% or less.
   

   
3. The ratio (Er/t ratio) of the Erichsen value (Er) to the plate thickness (t) in the Erichsen test and the breaking elongation EL (%) when stretched in the rolling parallel direction are expressed by the following inequality (4). The copper alloy sheet material according to claim 1, which satisfies the above condition.
   

   
4. The composition further contains at least one component selected from the group consisting of Sn, Mg, Mn, Cr, Zr, Ti, Fe and Zn in a total amount of 0.2 to 1.2% by mass or less. The copper alloy sheet material according to any one of 1 to 3.
5. A drawn product obtained by drawing the copper alloy sheet according to any one of claims 1 to 4.
6. A member for electric/electronic parts produced by using the copper alloy sheet according to any one of claims 1 to 4 or the drawn product according to claim 5.
7. An electromagnetic wave shield material produced by using the copper alloy plate material according to any one of claims 1 to 4 or the drawn product according to claim 5.
8. A heat dissipation component manufactured using the copper alloy sheet according to any one of claims 1 to 4 or the drawn product according to claim 5.
9. A method for manufacturing a copper alloy sheet according to any one of claims 1 to 4,
   Casting [step 1], homogenizing treatment [step 2], hot rolling [step 3], chamfering [step 4], cold rolling [step 5], solution heat treatment [step 6] on copper alloy material, Intermediate heat treatment [step 7], finish cold rolling [step 8], straightening [step 9], and temper annealing [step 10] are sequentially performed,
   The maximum temperature TR of the material at the time of rolling in the finish cold rolling [step 8] is controlled to 75° C. or higher and 100° C. or lower,
   The elongation rate δ of the material in the straightening [step 9] is set to 0.1 to 1.0%, and
   A material temperature TA (° C.) of the temper annealing [step 10] is controlled so as to satisfy the relationship of the inequality shown in the following expression (5) in relation to the elongation δ. Production method.
   55×δ+450≧TA≧55×δ+350 (5)

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