JP7178454B2 - Copper alloy sheet material, its manufacturing method, and members for electrical and electronic parts - Google Patents

Description

TECHNICAL FIELD The present invention relates to a copper alloy sheet material, a method for producing the same, and a member for electric/electronic parts.

In general, copper alloy sheet materials used for connectors for electronic devices and shield cases for automobiles are subjected to press working such as punching, bending, drawing, and bulging, and burring (hole flanging).

In recent years, with the increasing performance of electronic devices and automotive on-board devices, the mechanical and electrical properties of copper alloy sheets used for electrical and electronic parts that make up electrical and electronic devices, and electrical and electronic parts. Along with the weight reduction and the complicated shape of materials, it is required to achieve a higher level of workability into the desired shape of the copper alloy sheet material.

For example, Patent Document 1 contains 0.1 to 0.6% by mass of Cr, a total of 0.01 to 0.30% by mass of one or two of Zr and Ti, and the balance is copper and unavoidable describes a copper alloy sheet in which 1,000 to 1,000,000/mm ² of second phase particles having a particle size of 0.1 μm or more are present in the matrix phase.

In Patent Document 1, by controlling the number of second phase particles in the Cu—Cr alloy, high strength, high conductivity, and bending workability are achieved. However, since burring processing for enlarging a circular hole is a completely different processing from bending processing, in a copper alloy plate in which the number of second phase particles of a Cu—Cr alloy as in Patent Document 1 is controlled, Burring workability is insufficient.

In addition, although copper alloy sheet materials manufactured by conventional methods can be burred under difficult conditions, mechanical and electrical properties must be sacrificed. Machining under difficult conditions means, for example, increasing the hole expansion rate of burring holes in order to increase the hole flange height of burring holes, or shortening the punch stroke to improve productivity. and increasing the tip angle of the punch for hole expansion with respect to the punch stroke.

In this way, without sacrificing the balance of strength and conductivity required for recent electrical and electronic component members, in the process of processing to the desired shape, even if burring processing is performed under difficult conditions, it is excellent. There is a demand for a copper alloy sheet material with good burring workability.

JP 2018-154910 A

An object of the present invention is to provide a copper alloy sheet material that exhibits excellent strength and conductivity and is excellent in burring workability even when burring is performed under difficult processing conditions, a method for producing the same, and a member for electric and electronic parts. to provide.

The gist and configuration of the present invention are as follows.
[1] An alloy composition containing 0.10% by mass or more and 0.80% by mass or less of Cr, the balance being Cu and inevitable impurities, a tensile strength of 350 MPa or more and 800 MPa or less, and an electrical conductivity of 55% IACS or more. 90% IACS or less, the average grain size in the plate thickness direction in the cross section S _{0 °} cut in the direction of 0 ° with respect to the rolling direction A _{0 °} , the average in the thickness direction in the cross section S _{45 °} cut in the direction of 45 ° The crystal grain size A _{45 °} and the average crystal grain size A ₉₀ ° in the plate thickness direction at the cross section S _{90 °} cut in the 90 ° direction are both 10.0 μm or less, and the standard deviation of A _{0 °} , A ₄₅ The average value of the standard deviation of _° and the standard deviation of A _{90 °} is 2.0 μm or less, the anisotropy B _{0 °} of the average crystal grain size A _{0 °} , the average crystal A copper alloy sheet material, wherein both the anisotropy _{B45 °} of the grain size A45° and the anisotropy _B90° of the average crystal grain size A90 _° are 10.0% or less.
B _m = 100 × (A _m - C) / C formula (1)
However, in the formula (1), m is 0°, 45° or 90°, and C is the average value of A _0° , A _45° and A _90° ((A _0° + A _45° + A _{90 °} )/3).
[2] The copper alloy sheet material according to [1] above, wherein an average crystal grain size D0 _° in the rolling direction at the cross section S0 _° is 15.0 μm or less.
[3] The average KAM value E _{0 ° at} the cross section S ₀ °, the average KAM value E 45 ° at the cross section S _{45 °} , and the average KAM value E _{90 °} at the cross section S ₉₀ ° are all 10.0 ° Below, and the average value of E _{0 °} standard deviation, E _{45 °} standard deviation and E _{90 °} standard deviation is 3.0 ° or less, the average KAM value E is represented by the following formula (2) The anisotropy F _{0 ° at} 0 °, the anisotropy F 45 ° at the average KAM value E _{45 °} , and the anisotropy F _{90 °} at the average KAM value E ₉₀ ° are all 10.0% or less. The copper alloy sheet material according to the above [1] or [2], characterized in that
F _m = 100 × (E _m - G) / G Expression (2)
However, in the above formula (2), m is 0°, 45° or 90°, and G is the average value of E _0° , E _45° and E _90° ((E _0° + E _45° + E _{90 °} )/3).
[4] An alloy composition containing 0.10% by mass or more and 0.80% by mass or less of Cr, the balance being Cu and inevitable impurities, a tensile strength of 350 MPa or more and 800 MPa or less, and an electrical conductivity of 55% IACS or more. 90% IACS or less, with respect to the rolling direction, the average KAM value E ₀ ° in the cross section S _{0 °} cut in the 0 ° direction, the average KAM value E ₄₅ ° in the cross section S _{45 °} cut in the 45 ° direction, and 90 ° The average KAM value E _{90 °} at the cross section S _{90 °} cut in the direction is all 10.0 ° or less, and the average value of the standard deviation of E _{0 °} , the standard deviation of E _{45 °} and the standard deviation of E _{90 °} is 3.0 ° or less, the anisotropy F _{0 °} at the average KAM value E _{0 °} , the anisotropy F _{45 ° at the average KAM value E 45 ° ,} and the A copper alloy sheet material, wherein an anisotropy F _90° of an average KAM value E _90° is 10.0% or less.
F _m = 100 × (E _m - G) / G Expression (2)
However, in the above formula (2), m is 0°, 45° or 90°, and G is the average value of E _0° , E _45° and E _90° ((E _0° + E _45° + E _{90 °} )/3).
[5] The alloy composition further contains one or more elements selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn and Si in a total of 0.05% by mass or more and 2.50% by mass or less. The copper alloy sheet material according to any one of [1] to [4] above.
[6] The copper alloy sheet material according to any one of [1] to [5] above, which has a thickness of 0.05 mm or more and 0.50 mm or less.
[7] A method for producing a copper alloy sheet according to any one of [1] to [6] above, wherein the copper alloy material is subjected to a casting step (step 1), a homogenization heat treatment step (step 2), Hot rolling process (process 3), facing process (process 4), cold rolling process (process 5), intermediate heat treatment process (process 6), finish cold rolling process (process 7) and temper annealing process (process 8) is performed in this order, and the ratio (T6 /R5) is 8.0 or more and 20.0 or less, the maximum temperature T6 is 400°C or more and 650°C or less, and the pair of work rolls provided in each pass of the finish cold rolling step (step 7) has the following The ratio (T8/M7) of the maximum temperature T8 (°C) of the annealed material in the temper annealing step (step 8) to the average value M7 of each pass of the roll gap shape ratio represented by formula (3) is 10 .0 or more and 100.0 or less, and the maximum temperature T8 is 250°C or more and 700°C or less.
M7=3×{r(h ₁ −h ₂ )} ^1/2 /{n(h ₁ +2h ₂ )} Equation (3)
However, in the above formula (3), r is the radius (mm) of the work roll, and h1 is the thickness (mm) of the rolled material before _each pass of the finish cold rolling step (step 7). where h2 is the thickness (mm) of the rolled material after _each pass in the finish cold rolling step (step 7), and n is the total number of passes in the finish cold rolling step (step 7). is.
[8] An electric/electronic component member comprising a copper alloy sheet according to any one of [1] to [6] above and having burring holes.
[9] The electric/electronic component member according to [8] above, wherein the burring hole has a hole expansion ratio λ of 20% or more, which is represented by the following formula (4).
λ=100×(d−d ₀ )/d ₀ Expression (4)
However, in the above formula (4), _d0 is the diameter (mm) of the hole before hole expansion, and d is the diameter (mm) of the burring hole after hole expansion.

ADVANTAGE OF THE INVENTION According to the present invention, a copper alloy sheet material that exhibits excellent strength and conductivity and is excellent in burring workability even when burring is performed under difficult processing conditions, a method for producing the same, and a member for electric and electronic parts. can provide.

FIG. 1 is a diagram for explaining a cross section _{S0 °} , a cross section S45 _° , and a cross section S90° of a copper alloy sheet. FIG. 2 is a diagram for explaining the average value M7 of the roll gap shape ratio in the finish cold rolling process (process 7). FIG. 3 is a schematic cross-sectional view showing an example of punching in burring. FIG. 4 is a schematic cross-sectional view showing an example of hole expansion in burring.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments.

As a result of extensive research, the present inventors have found that the KAM value corresponding to the crystal grain size and local strain amount of the copper alloy sheet material, as well as the uniformity and anisotropy thereof, can be controlled with high precision. The present inventors have found that excellent burring workability can be obtained even when burring is performed under difficult processing conditions without impairing the balance of conductivity. Based on this knowledge, the present invention has been completed.

The copper alloy sheet material of the embodiment has an alloy composition containing 0.10% by mass or more and 0.80% by mass or less of Cr, with the balance being Cu and inevitable impurities, and has a tensile strength of 350 MPa or more and 800 MPa or less, and electrical conductivity. is 55% IACS or more and 90% IACS or less, with respect to the rolling direction, the average crystal grain size in the plate thickness direction in the cross section S _{0 °} cut in the 0 ° direction, the average grain size in the plate thickness direction A _{0 °} in the cross section S _{45 °} cut in the 45 ° direction The average crystal grain size A _{45 °} in the plate thickness direction and the average crystal grain size A ₉₀ ° in the plate thickness direction at the cross section S _{90 °} cut in the 90 ° direction are both 10.0 μm or less and A _{0 °} The average value of the standard deviation, the standard deviation of A _{45 °} and the standard deviation of A _{90 °} is 2.0 μm or less, and the anisotropy B ₀ of the average crystal grain size A _{0 °} , represented by the following formula (1) , the anisotropy B45 _° of the average crystal grain size _{A45 °} , and the anisotropy _B90° of the average crystal grain size _A90° are all 10.0% or less.

B _m = 100 × (A _m - C) / C formula (1)

In the above formula (1), m is 0 °, 45 ° or 90 °, C is the average value of A _{0 °} , A _{45 °} and A _{90 °} ((A _{0 °} + A _{45 °} + A _{90 °} ) /3).

Further, the copper alloy sheet material of the embodiment has an alloy composition containing 0.10% by mass or more and 0.80% by mass or less of Cr, the balance being Cu and inevitable impurities, and has a tensile strength of 350 MPa or more and 800 MPa or less. The electrical conductivity is 55% IACS or more and 90% IACS or less, the average KAM value E _{0 °} at the cross section S _{0 °} cut in the 0 ° direction, and the average KAM value at the cross section S _{45 °} cut in the 45 ° direction with respect to the rolling direction E _{45 °} and the average KAM value E _{90 °} at the cross section S _{90 °} cut in the 90 ° direction are both 10.0 ° or less, and the standard deviation of E _{0 °} , the standard deviation of E _{45 °} and E ₉₀ The average value of the standard deviation of _° is 3.0 ° or less, the anisotropy F _{0 °} of the average KAM value E _{0 °} , the anisotropy of the average KAM value E _{45 °} , represented by the following formula (2) Both the degree F _45° and the anisotropy F _90° of the average KAM value E _90° are 10.0% or less.

F _m = 100 × (E _m - G) / G Expression (2)

In the above formula (2), m is 0 °, 45 ° or 90 °, G is the average value of E _{0 °} , E _{45 °} and E _{90 °} ((E _{0 °} + E _{45 °} + E _{90 °} ) /3).

First, the alloy composition of the copper alloy sheet will be described.

The copper alloy sheet material of the above embodiment has an alloy composition containing 0.10% by mass or more and 0.80% by mass or less of Cr, with the balance being Cu and unavoidable impurities.

<Cr: 0.10% by mass or more and 0.80% by mass or less>
Cr (chromium) is an element necessary for increasing the strength of the copper alloy sheet material, and it is necessary to contain 0.10% by mass or more and 0.80% by mass or less of Cr. When the Cr content is 0.10% by mass or more, the strength of the copper alloy sheet increases and the burring workability improves. Further, when the Cr content is 0.80% by mass or less, coarse crystallized substances containing Cr are less likely to occur during the casting process, and burring workability is improved. Therefore, the lower limit of the Cr content is 0.10% by mass, preferably 0.2% by mass, more preferably 0.3% by mass, and the upper limit of the Cr content is 0.80% by mass. %, preferably 0.7 mass %, more preferably 0.6 mass %.

<Subcomponents of copper alloy sheet material: 0.05% by mass or more and 2.50% by mass or less>
The alloy composition of the copper alloy sheet further includes one or more elements selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn and Si in a total amount of 0.05% by mass or more and 2.50% by mass or less. can contain. That is, the copper alloy sheet material contains Cr, which is an essential basic component, and further includes one selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn, and Si as an optional subcomponent. The above components can be contained in a total amount of 0.05% by mass or more and 2.50% by mass or less. When the content of the accessory component is 0.05% by mass or more, the strength of the copper alloy sheet material is improved, and the effect of retarding recrystallization in the hot rolling process and recrystallization in the intermediate heat treatment process is exhibited. The crystal grain size and KAM value, which are the crystal states of the alloy sheet material, as well as the uniformity and anisotropy thereof, can be easily controlled within a predetermined range, and the burring workability can be improved. Further, when the content of the accessory component is 2.50% by mass or less, a decrease in electrical conductivity of the copper alloy sheet can be suppressed. Therefore, the lower limit of the content of the subcomponent is preferably 0.05% by mass, more preferably 0.30% by mass, and even more preferably 0.50% by mass, and the upper limit of the content of the subcomponent is , preferably 2.50% by mass, more preferably 2.20% by mass, and still more preferably 1.90% by mass.

<Mg: 0.05% by mass or more and 0.20% by mass or less>
When the content of Mg (magnesium) is 0.05% by mass or more, the effect of solid-solution strengthening of the copper alloy sheet material is exhibited. When the Mg content is 0.20% by mass or less, a decrease in electrical conductivity of the copper alloy sheet can be suppressed. Therefore, the lower limit of the Mg content is preferably 0.05% by mass, and the upper limit of the Mg content is preferably 0.20% by mass.

<Ti: 0.05% by mass or more and 0.20% by mass or less>
When the content of Ti (titanium) is 0.05% by mass or more, it dissolves in the copper alloy sheet and raises the recrystallization temperature of the copper alloy sheet, thereby preventing dynamic recrystallization in the hot rolling process. It exhibits the effect of suppressing coarsening of grains. When the Ti content is 0.20% by mass or less, the amount of decrease in electrical conductivity of the copper alloy sheet can be suppressed to a level that can ensure the minimum required heat dissipation for shield cases and the like. Therefore, the lower limit of the Ti content is preferably 0.05% by mass, and the upper limit of the Ti content is preferably 0.20% by mass.

<Co: 0.05% by mass or more and 1.50% by mass or less>
When the Co (cobalt) content is 0.05% by mass or more, the strength of the copper alloy sheet increases. If the Co content exceeds 1.50% by mass, the electrical conductivity of the copper alloy sheet is lowered, and the base metal cost is increased. Therefore, the lower limit of the Co content is preferably 0.05% by mass, and the upper limit of the Co content is preferably 1.50% by mass.

<Zr: 0.05% by mass or more and 0.20% by mass or less>
When the Zr (zirconium) content is 0.05% by mass or more, coarsening of dynamically recrystallized grains during hot rolling is suppressed, contributing to improvement in strength of the copper alloy sheet material. When the Zr content exceeds 0.20% by mass, coarse crystallized substances are generated during the casting process, which may cause breakage during burring. Therefore, the lower limit of the Zr content is preferably 0.05% by mass, and the upper limit of the Zr content is preferably 0.20% by mass.

<Zn: 0.05% by mass or more and 0.60% by mass or less>
When the Zn (zinc) content is 0.05% by mass or more, the adhesion and migration properties of Sn plating and solder plating can be improved. When the Zn content is 0.60% by mass or less, a decrease in electrical conductivity of the copper alloy sheet can be suppressed, and sufficient heat dissipation can be obtained. Therefore, the lower limit of the Zn content is preferably 0.05% by mass, and the upper limit of the Zn content is preferably 0.60% by mass.

<Sn: 0.05% by mass or more and 0.30% by mass or less>
When the Sn (tin) content is 0.05% by mass or more, the effect of solid-solution strengthening of the copper alloy sheet material is exhibited. When the Sn content is 0.30% by mass or less, a decrease in electrical conductivity of the copper alloy sheet can be suppressed. Therefore, the lower limit of the Sn content is preferably 0.05% by mass, and the upper limit of the Sn content is preferably 0.30% by mass.

<Si: 0.02% by mass or more and 0.40% by mass or less>
If the Si (silicon) content is 0.02% by mass or more, Si compounds are formed with other additive elements such as Co, Mg, and Cr, increasing the strength of the copper alloy sheet. When the Si content is 0.40% by mass or less, a decrease in the thermal conductivity of the copper alloy sheet can be suppressed, and sufficient heat dissipation can be obtained. Therefore, the lower limit of the Si content is preferably 0.02% by mass, and the upper limit of the Si content is preferably 0.40% by mass.

<Remainder: Cu and inevitable impurities>
The balance other than the components mentioned above is Cu (copper) and unavoidable impurities. The unavoidable impurities are those that are unavoidably mixed in the manufacturing process and are originally unnecessary, but the amount is small and is allowed because it does not affect the characteristics of the copper alloy sheet material. The content of unavoidable impurities is preferably as small as possible. Examples of unavoidable impurities include Bi (bismuth), Se (selenium), As (arsenic), and Ag (silver). The upper limit of the content of these components is preferably 0.03% by mass for each of the above components, and preferably 0.10% by mass for the total amount of the above components.

Next, the tensile strength of the copper alloy sheet will be explained.

The tensile strength of the copper alloy sheet material is 350 MPa or more and 800 MPa or less. When the tensile strength of the copper alloy plate material is 350 MPa or more, the strength is improved. Improves heat dissipation. Further, when the tensile strength of the copper alloy sheet material is 800 MPa or less, it is possible to suppress deterioration of heat dissipation and workability of the copper alloy sheet material. Therefore, the lower limit of tensile strength is 350 MPa, preferably 370 MPa, more preferably 400 MPa, and the upper limit of tensile strength is 800 MPa, preferably 750 MPa, more preferably 700 MPa.

The tensile strength of a copper alloy sheet material can be measured by performing a tensile test based on JIS Z 2241:2011 using a JIS No. 13B test piece. The tensile strength of the copper alloy sheet is the tensile strength in the direction parallel to the rolling.

Next, the electrical conductivity of the copper alloy sheet will be described.

The electrical conductivity of the copper alloy sheet material is 55%IACS or more and 90%IACS or less. Thermal conductivity can be calculated from conductivity according to the Wiedemann-Franz law, and if the temperature is constant, it can be proportional to the conductivity regardless of the type of metal. Are known. Therefore, if the electrical conductivity of the copper alloy plate material is 55% IACS or more, it can have a high thermal conductivity. has excellent heat dissipation. Further, when the electrical conductivity of the copper alloy sheet material is 90% IACS or less, it is possible to ensure the minimum strength of the copper alloy sheet material required as a member for electric/electronic parts mounted in those electric/electronic devices. . Therefore, the lower limit of conductivity is 55%IACS, preferably 60%IACS, and the upper limit of conductivity is 90%IACS. Thus, the higher the electrical conductivity of the copper alloy sheet, the better.

The electrical conductivity of the copper alloy sheet material can be calculated by measuring the specific resistance by the four-terminal method in a constant temperature bath maintained at 20° C. (±0.5° C.) with a terminal distance of 100 mm.

Next, the average crystal grain size A and the anisotropy B of the copper alloy sheet will be described.

As shown in FIG. 1, the copper alloy sheet material 10 has an average crystal grain size A ₀ ° in the plate thickness direction at a cross section S _0° cut in the direction of 0° with respect to the rolling direction, and is 10.0 μm or less. In addition, the average crystal grain size A ₄₅ ° in the plate thickness direction in the cross section S _45° cut in the direction of 45° with respect to the rolling direction is 10.0 μm or less. In addition, the average crystal grain size A ₉₀ ° in the plate thickness direction in the cross section S _90° cut in the direction of 90° to the rolling direction is 10.0 µm or less. When the average crystal grain size A _0° , the average crystal grain size A _45° , or the average crystal grain size A _90° is larger than 10.0 μm, the shear surface and the fracture surface on the fracture surface of the through hole formed by press punching are different. The interface becomes non-uniform and induces cracks during hole expansion. From the viewpoint of improving burring workability, the average crystal grain size A _0° , the average crystal grain size A _45° , and the average crystal grain size A _90° are all 10.0 µm or less, preferably 8.0 µm or less, and more. It is preferably 5.0 μm or less. Thus, the smaller the average crystal grain size, the better.

The average value of the standard deviation of the average crystal grain size A of _0° , the standard deviation of the average crystal grain size A of _45° , and the standard deviation of the average crystal grain size A of _90° is 2.0 μm or less. If the average value calculated by averaging the standard deviations of these average crystal grain sizes is greater than 2.0 μm, the variation in crystal grain size is large, and the shear surface and the fracture surface on the fracture surface of the through hole formed by press punching. The interface with becomes uneven and induces cracks during hole expansion. From the viewpoint of improving burring workability, the average value of the standard deviation of the average crystal grain size is 2.0 μm or less, preferably 1.8 μm or less, more preferably 1.0 μm or less. Thus, the smaller the average value of the standard deviations, the better.

Further, the anisotropy B _0° at the average crystal grain size A _0° represented by the above formula (1) is 10.0% or less. The anisotropy B _45° of the average crystal grain size A _45° represented by the above formula (1) is 10.0% or less. The anisotropy B _90° of the average crystal grain size A _90° represented by the above formula (1) is 10.0% or less. When the anisotropy B _0° , the anisotropy B _45° , or the anisotropy B _90° is greater than 10.0%, the interface between the sheared surface and the fractured surface in the fractured surface of the through hole formed by press punching is It becomes non-uniform and induces cracks during hole expansion. From the viewpoint of improving burring workability, the anisotropy B _{0 °} , the anisotropy B _{45 °} , and the anisotropy B _{90 °} are all 10.0% or less, preferably 8.0% or less, more preferably is 5.0% or less. Thus, the smaller the anisotropy, the better.

Further, as shown in FIG. 1, the average crystal grain size D0 _° in the rolling direction of the cross section S0° cut in the direction of ₀ ° with respect to the rolling direction of the copper alloy sheet material 10 is preferably 15.0 μm or less, More preferably, it is 13.0 μm or less. If the average crystal grain size D0 _° is larger than 15.0 μm, deep wrinkles in the rolling direction are likely to occur at the base (flexion) of the hole flange formed after hole expansion, which induces cracks. Thus, the smaller the average crystal grain size D0 _° , the better.

The crystal grain size is determined from crystal orientation data continuously measured using an EBSD detector attached to a high-resolution scanning analytical electron microscope (manufactured by JEOL Ltd., JSM-7001FA) and analysis software (manufactured by TSL, OIM Analysis ) can be obtained from crystal orientation analysis data calculated using "EBSD" is an abbreviation of Electron Backscatter Diffraction, and is a crystal orientation analysis technology that uses backscattered electron Kikuchi line diffraction that occurs when a copper alloy plate material, which is a sample, is irradiated with an electron beam in a scanning electron microscope (SEM). That is. "OIM Analysis" is software for analyzing data measured by EBSD. As shown in FIG. 1, the measurement areas are a cross section S0° cut at _0° to the rolling direction, a cross section S45° cut at _45° to the rolling direction, and a cross section S45° to the rolling direction at 90°. The cross section S cut in the direction of _90° is the surface mirror-finished by electropolishing. The measurement is performed with a step size of 0.1 μm in a field of view of total plate thickness×width of 150 μm. An orientation difference of 15° or more is defined as a crystal grain boundary, and a crystal grain consisting of 2 pixels or more is analyzed.

Then, in the obtained IPF image (Inverse Pole Figure), two lines that are parallel to the plate thickness direction and cross the plate thickness are drawn at intervals of 50 μm, and the crystal grain size is measured by a cutting method and averaged. The average crystal grain size is A _0° , the average crystal grain size is A _45° , and the average crystal grain size is A _90° . In the obtained IPF image, two vertical lines with a length of 150 μm are drawn at intervals of 25 μm with respect to the plate thickness direction, and the crystal grain size is measured by a cutting method and averaged. The average crystal grain size D _{0 °} . The standard deviation of each average crystal grain size is calculated for each crystal grain on each line.

Next, the average KAM value E and the anisotropy F of the copper alloy sheet will be described.

As shown in FIG. 1, the copper alloy sheet 10 has an average KAM value E _0° of 10.0° or less at a cross section S _0° cut in the 0° direction with respect to the rolling direction. Further, the average KAM value E ₄₅ ° in the cross section S _45° cut in the direction of 45° with respect to the rolling direction is 10.0° or less. Further, the average KAM value E ₉₀ ° in the cross section S _90° cut in the direction of 90° with respect to the rolling direction is 10.0° or less. If the average KAM value E0 _° , the average KAM value E45 _° , or the average KAM value E90 _° is greater than 10.0°, it means that a large amount of strain has accumulated in the copper alloy sheet material, and the burring workability is poor. descend. From the viewpoint of improving burring workability, the average KAM value E _{0 °} , the average KAM value E _{45 °} , and the average KAM value E _{90 °} are all 10.0 ° or less, preferably 7.0 ° or less, more preferably is 3.0° or less. Moreover, from the viewpoint of material strength, each of the average KAM value E0 _° , the average KAM value E45 _° , and the average KAM value E90 _° is preferably 1.0° or more.

The average value of the standard deviation of the average KAM value E of _0° , the standard deviation of the average KAM value E of _45° , and the standard deviation of the average KAM value E of _90° is 3.0° or less. If the average value calculated by averaging the standard deviations of these average KAM values is greater than 3.0°, the strain distribution is uneven, and deformation tends to concentrate locally during hole expansion processing, so cracks occur. provoke. From the viewpoint of improving burring workability, the average value of the standard deviation of the average KAM value is 3.0° or less, preferably 1.0° or less, more preferably 0.5° or less. Thus, the smaller the average value of the standard deviations, the better.

Further, the anisotropy F _0° of the average KAM value E _0° represented by the above formula (2) is 10.0% or less. The anisotropy F _45° of the average KAM value E _45° represented by the above formula (2) is 10.0% or less. The anisotropy F90 _° of the average KAM value E90 _° represented by the above formula (2) is 10.0% or less. When the anisotropy F _{0 °} , the anisotropy F _{45 °} , or the anisotropy F _{90 °} is greater than 10.0%, the circumferential anisotropy of the strain distribution is large, and when performing circular hole expansion processing induce cracks in the From the viewpoint of improving the burring workability, each of the anisotropy F _0° , the anisotropy F _45° and the anisotropy F _90° is 10.0% or less, preferably 5.0% or less.

The KAM (Kernel Average Misorientation) value is the average value of crystal misorientation between a measurement point and all adjacent measurement points. The KAM value has a correlation with the dislocation density and corresponds to the amount of crystal lattice strain.

The KAM value is obtained from crystal orientation data continuously measured using an EBSD detector attached to a high-resolution scanning analytical electron microscope (manufactured by JEOL Ltd., JSM-7001FA) and analysis software (manufactured by TSL, OIM Analysis). can be obtained from crystal orientation analysis data calculated using As shown in FIG. 1, the measurement areas are a cross section S0° cut at _0° to the rolling direction, a cross section S45° cut at _45° to the rolling direction, and a cross section S45° to the rolling direction at 90°. The cross section S cut in the direction of _90° is the surface mirror-finished by electropolishing. The measurement is performed with a step size of 0.1 μm in a field of view of total plate thickness×width of 150 μm. An orientation difference of 15° or more is defined as a crystal grain boundary, and a crystal grain consisting of 2 pixels or more is analyzed.

Then, in the obtained KAM image, two lines that are parallel to the plate thickness direction and cross the plate thickness are drawn at intervals of 50 μm, and the KAM values in the crystal grains on each line are measured and averaged. Let the KAM value be E _0° , the average KAM value E _45° , and the average KAM value E _90° . The standard deviation of each average KAM value is calculated for each grain on each line.

As described above, the copper alloy sheet material in which the average crystal grain size A and its anisotropy B are controlled within predetermined ranges has good burring workability. Also, a copper alloy sheet material in which the average KAM value E and its anisotropy F are controlled within predetermined ranges has good burring workability. Furthermore, the copper alloy sheet material in which the average crystal grain size A and its anisotropy B are controlled within a predetermined range, and the average KAM value E and its anisotropy F are controlled within a predetermined range, are further improved in burring processing. have sex.

Further, the upper limit of the thickness of the copper alloy sheet is preferably 0.50 mm, and the lower limit thereof is preferably 0.05 mm. If the plate thickness of the copper alloy plate is more than 0.50 mm, deep wrinkles are likely to be formed on the outside and inside of the base of the hole flange formed after burring, and cracks may occur and develop. Further, when the plate thickness of the copper alloy plate is less than 0.05 mm, the rigidity of the copper alloy plate is lowered.

Next, a method for manufacturing the copper alloy sheet according to the embodiment will be described. In the method for producing a copper alloy sheet material of the embodiment, a copper alloy material is subjected to a casting step (step 1), a homogenization heat treatment step (step 2), a hot rolling step (step 3), a facing step (step 4), a cold The intermediate rolling step (step 5), the intermediate heat treatment step (step 6), the finish cold rolling step (step 7) and the temper annealing step (step 8) are performed in this order, and the rolled material in the cold rolling step (step 5) The ratio (T6/R5) of the maximum temperature T6 (°C) of the heat-treated material in the intermediate heat treatment step (step 6) to the processing rate R5 (%) is 8.0 or more and 20.0 or less, and the maximum temperature T6 is 400°C. Above 650 ° C. and below, the average value M7 for each pass of the roll gap shape ratio represented by the following formula (3) in a pair of work rolls provided in each pass of the finish cold rolling process (process 7). The ratio (T8/M7) of the maximum temperature T8 (°C) of the annealed material in the quality annealing step (step 8) is 10.0 or more and 100.0 or less, and the maximum temperature T8 is 250°C or more and 700°C or less.

M7=3×{r(h ₁ −h ₂ )} ^1/2 /{n(h ₁ +2h ₂ )} Equation (3)

In the above formula (3), r is the radius of the work roll (mm), h1 is the thickness (mm) of the rolled material before _each pass of the finish cold rolling step (step 7), h2 is the thickness (mm) of the rolled material after _each pass in the finish cold rolling step (step 7), and n is the total number of passes in the finish cold rolling step (step 7). .

In the casting step (step 1), alloy components are melted and cast to obtain a copper alloy ingot having a predetermined shape. For example, the melting is performed under the atmosphere using a high frequency melting furnace. The types of alloy components, casting conditions, etc. are appropriately set.

In the homogenization heat treatment step (step 2), the copper alloy ingot obtained in the casting step (step 1) is subjected to a homogenization heat treatment under predetermined heating conditions (for example, 1000° C. or less for 1 hour). The homogenization heat treatment step (step 2) is performed, for example, in the atmosphere.

In the hot rolling step (step 3), the plate is cooled immediately after it has a predetermined plate thickness (for example, 15 mm).

In the chamfering step (process 4), the surface of the hot-rolled plate is chamfered to a predetermined thickness (for example, 2.5 mm or more and 5.0 mm or less) to remove the oxide film.

In the cold rolling step (step 5), cold rolling is performed so that the working rate R5 of the rolled material is 25% or more and 70% or less.

In the intermediate heat treatment step (step 6), heat treatment is performed at a maximum temperature T6 of 400° C. or more and 650° C. or less and a holding time at the maximum temperature T6 of 1 minute or more and 10 hours or less. The intermediate heat treatment step (step 6) is performed under a non-oxidizing atmosphere such as argon. The lower limit of the maximum temperature T6 of the heat-treated material in the intermediate heat treatment step (step 6) is 400°C. When the maximum temperature T6 of the heat-treated material in the intermediate heat treatment step (step 6) is 400° C. or more, the heat-treated material recovers to improve the burring processability, and Cr particles precipitate to increase the strength and conductivity. . On the other hand, if the maximum temperature T6 is higher than 650°C, softening of the material progresses.

The ratio (T6/R5) of the maximum temperature T6 (°C) of the heat-treated material in the intermediate heat treatment step (step 6) to the reduction ratio R5 (%) of the rolled material in the cold rolling step (step 5) is 8.0 or more. 20.0 or less. When the ratio (T6/R5) is within the above range, strength and conductivity can be exhibited in a well-balanced manner.

The higher the reduction ratio R5, the lower the driving force for the formation of the second phase of the compound containing Cr in the copper alloy sheet material, thereby reducing the strength of the copper alloy sheet material due to the formation of the second phase. The highest temperature T6 in the intermediate heat treatment step (step 6) where the amount of increase peaks is lowered. Also, the higher the maximum temperature T6 in the intermediate heat treatment step (step 6), the more the second phase is generated, and the conductivity of the copper alloy sheet is improved. On the other hand, if the maximum temperature T6 is too high, the crystal grains will coarsen after recrystallization, and the burring workability will deteriorate. Therefore, the balance between the processing rate R5 and the maximum temperature T6 is important, and the control of the maximum temperature T6 itself is also important.

In the finish cold rolling step (step 7), cold rolling is performed by a pair of work rolls provided in each pass. The maximum temperature of the rolled material during finish cold rolling is, for example, 75° C. or higher and 150° C. or lower. The finish cold rolling step (step 7) is performed for working to a predetermined thickness, improving the strength of the copper alloy sheet material, and controlling the crystalline state such as grain size and KAM value.

The average value M7 of each pass of the roll gap shape ratio represented by the formula (3) in the finish cold rolling process (process 7) will be described with reference to FIG.

M7=3×{r(h ₁ −h ₂ )} ^1/2 /{n(h ₁ +2h ₂ )} Equation (3)

As shown in FIG. 2, in the finish cold rolling process (process 7), a pair of work rolls 20 are provided in each pass. A pair of work rolls 20 having a radius r rotate in opposite directions. As the rolled material moves toward the rolling direction, the rolled material 21 before _each pass having a thickness h1 is cooled and rolled by the rotation of the work rolls 20 into a rolled material 22 after _each pass having a thickness h2. processed.

In the temper annealing step (step 8), the annealed material is heat-treated at a maximum temperature T8 of 250° C. or more and 700° C. or less and a holding time at the maximum temperature T8 of 10 seconds or more and 1 hour or less. The temper annealing step (step 8) under such heat treatment conditions is performed to recover the elongation of the copper alloy sheet and to reduce the anisotropy of mechanical properties including elongation. The temper annealing step (step 8) is performed, for example, in a non-oxidizing atmosphere such as argon.

Regarding the ratio (T8/M7) of the maximum temperature T8 (°C) of the annealed material in the temper annealing step (step 8) to the average value M7 of each pass of the roll gap shape ratio in the finish cold rolling step (step 7), The lower limit is 10.0 and the upper limit is 100.0. When the ratio (T8/M7) is within the above range, the KAM value and the anisotropy of the KAM value are controlled, and burring workability is improved. Also, by controlling the ratio (T6/R5) and the ratio (T8/M7), the crystal grain size, its anisotropy and standard deviation can be controlled.

In general, in a rolled material, the deformed structure is different due to the difference in metal flow (grain flow) between the surface layer near the work roll and the interior far from the work roll. By appropriately adjusting the average value M7 of the roll gap shape ratio, it is possible to control the crystal grain size, the KAM value, and their anisotropy and standard deviation after the heat treatment in the temper annealing step (step 8).

When the average value M7 of the roll gap shape ratio in the finish cold rolling step (step 7) is large, that is, when the reduction amount per pass is large or the radius of the work roll is large, the entire surface of the rolled material to the inside A uniform deformed structure is likely to be obtained, and the copper alloy sheet material that has undergone strain relief in the refining annealing process (step 8) is likely to have a uniform structure. Therefore, the maximum temperature T8 and the holding time at the maximum temperature T8 in the temper annealing step (step 8) are determined from the balance between strain relief and softening. For example, if the ratio (T8/M7) is greater than 100.0, the softened interior of the strain-reliefed copper alloy sheet material is caused.

Further, in the method for producing a copper alloy sheet material of the above embodiment, a cold rolling step (step A1) and an intermediate heat treatment step (step A2 ). Specifically, the cold rolling step (step A1) is performed after the facing step (step 4), the intermediate heat treatment step (step A2) is performed after the cold rolling step (step A1), and the cold rolling The step (step 5) is performed after the intermediate heat treatment step (step A2).

The intermediate heat treatment step (step A2) is a step performed to easily adjust the working rate of the rolled material in the cold rolling step (step 5). A heat treatment is performed for a holding time at the maximum temperature of 10 seconds to 3 hours. In the cold rolling step (step A1), the working rate of the rolled material is appropriately adjusted so that the rolled material has a predetermined working rate in the cold rolling step (step 5). When the intermediate heat treatment step (step A2) is not performed, the cold rolling step (step A1) is not performed, and the cold rolling step (step 5) can be performed. The cold rolling step (step A1) and the intermediate heat treatment step (step A2) can be omitted depending on the plate thickness during the process and the plate thickness of the copper alloy plate material to be manufactured.

Next, the member for electric/electronic parts of the embodiment will be described. The electrical/electronic component member of the embodiment has a burring hole in the copper alloy plate material of the above embodiment.

A burring hole formed by burring will be described with reference to FIGS.

First, as shown in FIG. 3, a through hole 33 having a diameter of _d0 is formed in the copper alloy plate material 32 by punching the copper alloy plate material 32 with a punch 31 in the punching direction. Subsequently, as shown in FIG. 4, a hole-expanding punch 34 is inserted into the through-hole 33 in the direction of insertion, and hole-expanding processing is performed to plastically deform the periphery of the through-hole 33 so as to widen the through-hole 33 . Thus, a convex burring hole 35 with a diameter d, which protrudes in the inserting direction of the hole-enlarging punch 34, can be formed. In this way, the electric/electronic component member 30 having the burring holes 35 formed in the copper alloy plate material 32 can be obtained.

Here, an example of burring processing in which punching processing and hole enlarging processing are performed is shown, but burring processing is not particularly limited as long as a burring processing hole can be formed. For example, the burring process may be performed only by hole-expanding a copper alloy plate material having through-holes that have already been formed, without performing punching.

Moreover, it is preferable that the hole expansion rate λ of the burred hole represented by the following formula (4) is 20% or more. When the hole expansion ratio λ is 20% or more, it is possible to sufficiently design the shape when using the member for electric/electronic parts as a part of electric/electronic equipment.

λ=100×(d−d ₀ )/d ₀ Expression (4)

In the above formula (4), _d0 is the diameter (mm) of the hole before hole expansion, and d is the diameter (mm) of the burred hole after hole expansion. That is, _d0 is the diameter of the through hole formed by punching, and d is the diameter of the burring hole formed by enlarging the through hole.

Connectors, lead frames, relays, switches, sockets, shield cases, shield cans, liquid crystal reinforcing plates for electronic devices, which require excellent strength and conductivity as well as high burring workability, are required for the above electrical and electronic component members. , liquid crystal chassis, reinforcing plates for organic EL displays, camera modules, battery pack cases, automotive connectors, shield cases, shield cans, and other electrical and electronic equipment.

According to the embodiment described above, a copper alloy sheet material having a predetermined tensile strength and electrical conductivity and having a crystal grain size, a KAM value, and its standard deviation and anisotropy controlled within a predetermined range is manufactured. can do. The copper alloy sheet material obtained in this way is excellent in strength, conductivity, and burring workability compared to conventional copper alloy sheet materials in which the crystal grain size, KAM value, their standard deviation and anisotropy are not controlled. there is Therefore, electrical/electronic component members in which burring holes are formed in a copper alloy plate material can be used in various electrical/electronic devices that require a balance between strength and conductivity and high burring workability.

Although the embodiments have been described above, the present invention is not limited to the above embodiments, but includes all aspects included in the concept of the present invention and the scope of claims, and can be variously modified within the scope of the present invention. be able to.

EXAMPLES Next, examples and comparative examples will be described, but the present invention is not limited to these examples.

(Examples 1-17 and Comparative Examples 1-11)
Each alloy component was melted in a high-frequency melting furnace under the atmosphere and cast in a metal mold to obtain a copper alloy ingot having an alloy composition shown in Table 1 and a thickness of 30 mm. Next, after performing a homogenization heat treatment at 1000° C. for 1 hour in the air, it was immediately hot-rolled to a thickness of 15 mm and water-cooled. Next, the oxide film was removed from the surface layer of the rolled sheet by chamfering to a thickness of 5.0 mm or more and 10.0 mm or less. Next, cold rolling was performed so that the thickness became 1.25 mm or more and 2.50 mm or less, and intermediate heat treatment was performed at 300° C. or more and 1000° C. or less for 10 seconds. Next, as shown in Table 2, cold rolling (step 5) is performed at a working rate of R5 and a thickness of 0.25 mm or more and 1.25 mm or less, and the maximum temperature T6 and the retention time at the maximum temperature T6 are performed in an argon atmosphere. Intermediate heat treatment (step 6) is performed for 1 minute or more and 360 minutes or less, and finish cold rolling (step 7) is performed at an average value M7 of each pass of the roll gap shape ratio, and in an argon atmosphere, the maximum temperature is T8, and the maximum temperature is T8. was subjected to temper annealing (step 8) for a holding time of 1 minute or more and 60 minutes or less. Thus, copper alloy sheet materials having thicknesses shown in Table 2 were obtained. The copper alloy sheet material shown in Table 1 contains Bi, Se, As, and Ag as unavoidable impurities. % or less.

[Measurement and evaluation]
The following measurements and evaluations were performed on the copper alloy sheet materials obtained in the above examples and comparative examples. The results are shown in Tables 3-5.

[1] Crystal grain size and KAM value The crystal grain size and KAM value were measured with respect to the copper alloy sheet materials obtained in the above examples and comparative examples, using a high-resolution scanning analytical electron microscope (manufactured by JEOL Ltd., JSM- 7001FA) was obtained from crystal orientation analysis data calculated using analysis software (manufactured by TSL, OIM Analysis) from crystal orientation data continuously measured using an EBSD detector attached to the model.

As shown in FIG. 1, the measurement areas are a cross section S0° cut at _0° to the rolling direction, a cross section S45° cut at _45° to the rolling direction, and a cross section S45° to the rolling direction at 90°. The cross section S _90° cut in the direction was mirror-finished by electropolishing. The measurement was performed with a step size of 0.1 μm in a field of view of total plate thickness×width of 150 μm. An orientation difference of 15° or more was defined as a crystal grain boundary, and a crystal grain composed of two or more pixels was analyzed.

Regarding the crystal grain size, in the obtained IPF image, two lines parallel to the plate thickness direction and crossing the plate thickness are drawn at intervals of 50 μm, and the crystal grain size is measured by a cutting method and averaged. Grain size A _0° , average crystal grain size A _45° , and average crystal grain size A _90° were calculated respectively. In the obtained IPF image, two vertical lines with a length of 150 μm in the plate thickness direction are drawn at intervals of 25 μm, and the crystal grain size is measured by a cutting method and averaged to obtain an average crystal grain size D _0° was calculated. The standard deviation of each average grain size was calculated for each grain on each line. Then, the average of the standard deviations of these average crystal grain sizes was calculated.

Regarding the KAM value, in the obtained KAM image, draw two lines parallel to the plate thickness direction and cross the plate thickness at intervals of 50 μm, and measure and average the KAM value in the crystal grain on each line. , average KAM value E _0° , average KAM value E _45° , and average KAM value E _90° were calculated respectively. The standard deviation of each average KAM value was calculated for each grain on each line. Then, the average of the standard deviations of these average KAM values was calculated.

[2] Tensile strength (TS)
A tensile test was performed based on JIS Z 2241: 2011 using three JIS No. 13B test pieces (n = 3) for the copper alloy sheet materials obtained in the above examples and comparative examples, and three measured values were obtained. By averaging the tensile strength (TS) was calculated. The tensile strength is the tensile strength in the direction parallel to the rolling.

[3] Electrical conductivity (EC)
For the copper alloy plate materials obtained in the above examples and comparative examples, the distance between terminals was set to 100 mm, and the specific resistance was measured by the four-terminal method in a constant temperature bath kept at 20 ° C (± 0.5 ° C). By doing so, the electrical conductivity (EC) was calculated.

[4] Burring workability For the copper alloy sheet materials obtained in the above examples and comparative examples, a circular penetration with a diameter d ₀ of 10 mm was punched with a clearance of 1/2 the thickness of the copper alloy sheet material. After the hole was made, a punch with a tip angle of 60° and a diameter of 10 to 20 mm was used to expand the through hole. Then, the hole expansion rate when cracking occurred was defined as the hole expansion rate λ. Also, the burring workability was ranked as follows. The higher the hole expansion rate λ, the better the burring workability.

◎: λ is 50% or more ○: λ is 20% or more and less than 50% ×: λ is less than 20%

As shown in Tables 1 to 5, in Examples 1 to 17, the Cr content, tensile strength, electrical conductivity, crystal grain size, KAM value, and anisotropy were controlled within predetermined ranges. Both electrical conductivity and burring workability were good. In particular, in Examples 1 and 8, the processing rate R5, the maximum temperature T6, the average value M7 of the roll gap shape ratio, the maximum temperature T8, the ratio (T6/R5), and the ratio (T8/M7) are each adjusted within a suitable range. By doing so, the crystal grain size, KAM value, and anisotropy are further improved, so that the burring workability is further improved.

On the other hand, in Comparative Example 1, the Cr content was small, the anisotropy of the average KAM value was large, the maximum temperature T6 was low, the ratio (T6/R5) was large, the tensile strength was small, and the burring workability was poor. there were. In Comparative Example 2, the maximum temperature T6 was low and the tensile strength was small. In Comparative Example 3, the average grain size, its anisotropy, and the average standard deviation were large, the maximum temperature T6 was high, the tensile strength was small, and the burring workability was poor. In Comparative Example 4, the Cr content was high, and coarse crystallized substances containing Cr were formed during casting, and cracks were induced, resulting in poor burring workability. In Comparative Example 5, the anisotropy of the average KAM value was large, the electrical conductivity was low, and the burring workability was poor. In Comparative Example 6, the average KAM value and its anisotropy were large, the maximum temperature T6 was low, the maximum temperature T8 was low, the ratio (T6/R5) was small, and the burring workability was poor. In Comparative Example 7, the average grain size and standard deviation thereof were large, the maximum temperature T8 was high, the ratio (T8/M7) was large, the tensile strength was small, and the burring workability was poor. In Comparative Example 8, the ratio (T6/R5) was small and the tensile strength was small. In Comparative Example 9, the ratio (T8/M7) was large and the tensile strength was small. In Comparative Example 10, the anisotropy of the average KAM value was large, the ratio (T6/R5) was large, the tensile strength was small, and the burring workability was poor. In Comparative Example 11, the anisotropy of the average grain size and the average value of the standard deviation are large, the anisotropy of the average KAM value is large, the ratio (T6/R5) is large, and the ratio (T8/M7) is small. , the burring workability was poor.

REFERENCE SIGNS LIST 10 Copper alloy sheet material 20 Work roll 21 Rolled material before pass 22 Rolled material after pass 30 Electrical/electronic component member 31 Punching punch 32 Copper alloy sheet material 33 Through hole 34 Hole expanding punch 35 Burring hole

Claims (5)

An alloy composition containing 0.10% by mass or more and 0.80% by mass or less of Cr, with the balance being Cu and inevitable impurities,
Tensile strength is 350 MPa or more and 800 MPa or less,
Conductivity is 55% IACS or more and 90% IACS or less,
With respect to the rolling direction, the average KAM value E ₀ ° in the cross section S _{0 °} cut in the 0 ° direction, the average KAM value E ₄₅ ° in the cross section S _{45 °} cut in the 45 ° direction, and the cross section cut in the 90 ° direction The average KAM value E _{90 °} at S _{90 °} is 10.0 ° or less, and the average value of the standard deviation of E _{0 °} , the standard deviation of E _{45 °} and the standard deviation of E _{90 °} is 3.0 ° or less,
The anisotropy F _{0 °} of the average KAM value E _{0 °} , the anisotropy F _{45 ° of the average KAM value E 45 ° ,} and the difference of the average KAM value E _{90 °} , represented by the following formula (2) Direction F _{90 °} is 10.0% or less in any case,
A copper alloy sheet having a thickness of 0.05 mm or more and 0.50 mm or less.
F _m = 100 × (E _m - G) / G Expression (2)
However, in the above formula (2), m is 0°, 45° or 90°, and G is the average value of E _0° , E _45° and E _90° ((E _0° + E _45° + E _{90 °} )/3). The alloy composition further contains one or more elements selected from the group consisting of Mg, Ti, Co, Zr, Zn, Sn and Si in a total of 0.05% by mass or more and 2.50% by mass or less. The copper alloy sheet material according to claim 1. A method for producing a copper alloy sheet material according to claim 1 or 2,
Casting process (process 1), homogenization heat treatment process (process 2), hot rolling process (process 3), facing process (process 4), cold rolling process (process 5), intermediate heat treatment process for copper alloy material (Step 6), the finish cold rolling step (Step 7) and the temper annealing step (Step 8) are performed in this order,
The ratio (T6/R5) of the maximum temperature T6 (° C.) of the heat-treated material in the intermediate heat treatment step (step 6) to the reduction ratio R5 (%) of the rolled material in the cold rolling step (step 5) is 8. 0 or more and 20.0 or less,
the maximum temperature T6 is 400° C. or higher and 650° C. or lower;
The temper annealing step for the average value M7 of each pass of the roll gap shape ratio represented by the following formula (3) in a pair of work rolls provided in each pass of the finish cold rolling step (step 7) The ratio (T8/M7) of the maximum temperature T8 (°C) of the annealed material in (Step 8) is 10.0 or more and 100.0 or less,
A method for producing a copper alloy sheet material, wherein the maximum temperature T8 is 250°C or higher and 700°C or lower.
M7=3×{r(h ₁ −h ₂ )} ^1/2 /{n(h ₁ +2h ₂ )} Equation (3)
However, in the above formula (3), r is the radius (mm) of the work roll, and h1 is the thickness (mm) of the rolled material before _each pass of the finish cold rolling step (step 7). where h2 is the thickness (mm) of the rolled material after _each pass in the finish cold rolling step (step 7), and n is the total number of passes in the finish cold rolling step (step 7). is. 3. A member for an electric/electronic component, wherein the copper alloy sheet according to claim 1 or 2 has a burring hole. 5. The electric/electronic component member according to claim 4, wherein the burring hole has a hole expansion rate λ of 20% or more, which is expressed by the following formula (4).
λ=100×(d−d ₀ )/d ₀ Expression (4)
However, in the above formula (4), _d0 is the diameter (mm) of the hole before hole expansion, and d is the diameter (mm) of the burring hole after hole expansion.

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