JP5827090B2 - Cu-Fe-P based copper alloy plate excellent in conductivity, heat resistance and bending workability, and method for producing the same - Google Patents

Description

  The present invention relates to a Cu-Fe-P-based copper alloy plate excellent in conductivity, heat resistance and bending workability and a method for producing the same, and more particularly, a conductivity suitable for a material for a lead frame for a semiconductor device is 90. The present invention relates to a Cu-Fe-P-based copper alloy plate having a Vickers hardness of not less than 100% and having a Vickers hardness of 100 or more after heating at 400 ° C. for 1 hour and a method for producing the same.

As a copper alloy plate for a semiconductor lead frame, a Cu-Fe-P-based copper alloy having excellent strength, conductivity, and thermal conductivity in which an intermetallic compound such as Fe or Fe-P is precipitated in a copper matrix is used. Although it is widely used, with the recent increase in capacity, size, and functionality of semiconductor devices used in electronic devices, lead frames used in semiconductor devices have become smaller in cross-sectional area, further increasing strength. There is a demand for improved conductivity and heat resistance.
In recent years, the development of LED lamps using light-emitting diodes in liquid crystal displays, backlights for mobile phones and information terminals, etc. has been dramatically advanced. When applying LED lamps to various applications, it is important to obtain white light emission, and for the purpose of increasing brightness and heat dissipation, a plurality of LED chips are mounted on a substrate (board), and a resin layer Chip-on-board (COB) coated with a copper alloy substrate for lead frames used in these has been balanced with thermal conductivity, press workability, conductivity, and mechanical strength Cu-Fe-P based copper alloys are beginning to be used.
In particular, electrical conductivity is required to have further superior characteristics from the viewpoint of miniaturization of light emitting diodes and reduction of Joule heat, and heat resistance is processed in order to remove residual stress due to press working or the like. Even if a heat treatment at 400 to 450 ° C. is performed later, there is a demand for characteristics that do not cause a decrease in strength due to recrystallization of the crystal structure of the copper alloy.

Patent Document 1 discloses an orientation distribution of the Brass orientation measured by a crystal orientation analysis method using EBSP by FE-SEM, which has both high strength and excellent oxide film adhesion and relatively low Fe content. Cu-Fe- having a texture with a density of 25% or more, an average crystal grain size of 6.0 μm or less, high strength, improved oxide film adhesion, and improved semiconductor package reliability A P-based copper alloy plate is disclosed.
In Patent Document 2, the tensile modulus obtained by a tensile test is 120 GPa or more, the ratio between uniform elongation and total elongation, uniform elongation / total elongation is less than 0.50, and the shearing area ratio is reduced. A Cu—Fe—P-based copper alloy plate having high strength and improved press punchability during stamping is disclosed.
In Patent Literature 3, as a copper alloy having excellent bending resistance suitable for a conductive member of a flexible substrate, an integrated intensity ratio I {200} / I {111} obtained by X-ray diffraction on a rolled surface is 1.5 or less. As a specific composition, the mass ratio is Fe: 0.045-0.095%, P: 0.010-0.030%, and the total of elements other than Fe, P, and Cu is 1%. Less than, composition with Cu being the balance, and mass%, Ni: 0.5-3.0%, Sn: 0.5-2.0%, P: 0.03-0.10%, Ni, A copper alloy having a composition in which the total of elements other than Sn, P, and Cu is less than 1%, the balance is made of Cu, and the conductivity is 85% IACS or more is disclosed.

JP 2008-45204 A JP 2008-88499 A JP 2006-63431 A

  In Cu-Fe-P copper alloy plates disclosed in prior art documents, the balance of conductivity, heat resistance and bending workability required with the diversification of lead frames used in recent semiconductor devices. There was a shortage.

  The present invention has been made in view of such circumstances, and has an electrical conductivity of 90% IACS or more, a Vickers hardness of 100 or more after heating at 400 ° C. for 1 hour, and excellent bending workability. It is an object of the present invention to provide a Cu—Fe—P-based copper alloy plate suitable as a material for a lead frame for a semiconductor device and a method for manufacturing the same.

  As a result of intensive studies, the present inventors have found that Fe; 0.05 to 0.15% by mass, P; 0.015 to 0.05% by mass, Zn; 0.01 to 0.2% by mass, Cr; 0 Crystal grains measured by an EBSD method using a scanning electron microscope with a backscattered electron diffraction image system in a copper alloy plate containing a composition of 0.055 to 0.003% by mass and the balance consisting of Cu and inevitable impurities When the average value of all the crystal grains in the crystal structure of the average orientation difference between all the pixels is 2.5 to 5.0 °, the conductivity of the copper alloy plate is particularly improved. When the Copper orientation density measured in the above is 13.0 to 25.5%, the heat resistance of the copper alloy sheet is particularly improved, and the average grain size measured by the EBSD method is 2.0 to 6.5. When the thickness is 0 μm, the bending workability of the copper alloy sheet is particularly improved. Furthermore, it was found that the tensile strength of the copper alloy plate can be maintained when the Brass orientation density measured by the EBSD method is 11.0 to 22.0%.

That is, the electrical conductivity of the present invention is 90% IACS or higher, the Vickers hardness after heating at 400 ° C. for 1 hour is 100 or higher, and no crack is generated in the 90 ° W bending test in the rolling vertical direction. The copper alloy sheet having bending workability is Fe: 0.05-0.15 mass%, P: 0.015-0.05 mass%, Zn: 0.01-0.2 mass%, Cr: 0 .0005 to 0.003% by mass, with the balance consisting of Cu and inevitable impurities, all in the crystal grains measured by the EBSD method with a scanning electron microscope with a backscattered electron diffraction image system The average value of the average orientation difference between pixels in all crystal grains in the crystal structure is 2.5 to 5.0 °, the Brass orientation density is 11.0 to 22.0%, and the Copper orientation density is 13. 0 to 25.5%, and the average grain size is It is characterized by being 2.0 to 6.0 μm.

If the average value of all the crystal grains in the crystal structure of the average orientation difference between all the pixels in the crystal grains measured by the EBSD method is less than 2.5 ° or exceeds 5.0 °, the conductivity is 90%. No more than IACS.
When the Copper orientation density in the crystal structure measured by the EBSD method is less than 13.0% or more than 25.5%, the Vickers hardness after heating at 400 ° C. for 1 hour does not become 100 or more.
When the Brass orientation density in the crystal structure measured by the EBSD method is less than 11.0% or exceeds 22.0%, the tensile strength does not become 590 MPa or more.
When the average crystal grain size in the crystal structure measured by the EBSD method is less than 2.0 μm or exceeds 6.0 μm, the bending workability is lowered.

Excellent bending with an electrical conductivity of 90% IACS or more according to the present invention, a Vickers hardness of 100 or more after heating at 400 ° C. for 1 hour, and no cracking in the 90 ° W bending test in the vertical direction of rolling. The copper alloy sheet having workability further contains 0.01 to 0.2% by mass of at least one element selected from Ni and Co.
Addition of these elements has an effect of further improving heat resistance. If the added amount is less than 0.01% by mass, there is no effect, and if it exceeds 0.2% by mass, the conductivity is lowered.

Excellent bending with an electrical conductivity of 90% IACS or more according to the present invention, a Vickers hardness of 100 or more after heating at 400 ° C. for 1 hour, and no cracking in a 90 ° W bending test in the vertical direction of rolling. The manufacturing method of a copper alloy sheet having workability is to produce a copper alloy in a process including melt casting, hot rolling, rough rolling, annealing, cold rolling, final annealing, finish cold rolling, and tension leveling in this order. At this time, the cold rolling is carried out at a rolling rate of 25 to 90%, and the finish cold rolling is applied with a back tension of 45 to 70 N / mm ² and a front tension of 75 to 100 N / mm. performed at ^2, the tension leveling, 10~60N / mm ² back tension to load the copper alloy sheet, the line tension 15~90N / mm ^2, the front tension Which comprises carrying out at 0~60N / mm ^2.

  When the rolling ratio of cold rolling is less than 25%, the Brass orientation density and Copper orientation density do not develop, and when it exceeds 90%, the Brass orientation density and Copper orientation density increase, and the tensile strength increases. Heat resistance tends to decrease. By this cold rolling, a base material that fits the Brass orientation density and the Copper orientation density within the optimum ranges is made, and the Brass orientation density and the Copper orientation density are kept within the optimum ranges by the finish cold rolling.

Of the tensions acting on the material in finish cold rolling, if the back tension is less than 45 N / mm ² or the front tension is less than 75 N / mm ² , the Copper orientation density does not develop and the back tension is 70 N / mm. ² or if the front tension exceeds 100 N / mm ² , the Brass orientation density does not develop and the Copper orientation density increases, but the copper alloy plate may be cracked or cut.

Of the tensions acting on the material in tension leveling, the back tension is 10 to 60 N / mm ² , the line tension is 15 to 90 N / mm ² , and the front tension is 10 to 60 N / mm ^2. The average value of all crystal grains in the crystal structure of the average orientation difference between pixels is 2.5 to 5.0 °, and the average crystal grain size is 2.0 to 6.0 μm. The back tension and the front tension mainly control the average value of the average orientation difference between all the pixels in the crystal grains in all the crystal grains in the crystal structure, and the line tension mainly controls the average crystal grain diameter. .

In the finish cold rolling defined in the present invention, the back tension is the tension applied to the material inserted into the work roll in the copper strip rolling mill, and is applied between the uncoiler and the work roll. The front tension is a tension applied to the material drawn from the work roll in a copper strip rolling machine, and is applied between the work roll and the recoiler.
The tension leveling defined in the present invention is a process of correcting the flatness of the material by applying a tension in the front-rear direction to a roller leveler that repeatedly bends the material in a staggered roll through the material in the reverse direction. The back tension is the tension applied to the material between the uncoiler and the input side tension load device, and the line tension is the tension applied to the material in the roller leveler by the input side and winding side tension load devices. The front tension is the tension applied to the material between the recoiler and the winding side tension load device.

  According to the present invention, Cu having a conductivity of 90% IACS or higher, a Vickers hardness of 100 or higher after heating at 400 ° C. for 1 hour, and having excellent bending workability is suitable as a material for a lead frame for a semiconductor device. -Fe-P type copper alloy board and its manufacturing method are provided.

It is the schematic which shows one Embodiment for demonstrating the back tension and front tension loaded on the finish cold rolling mill used by this invention. It is the schematic which shows one Embodiment for demonstrating the back tension, line tension, and front tension loaded on the tension leveler used by this invention.

Hereinafter, a Cu—Fe—P based copper alloy plate and a method for manufacturing the same according to an embodiment of the present invention will be described.
[Component composition of copper alloy sheet]
The Cu-Fe-P-based copper alloy plate having an electrical conductivity of 90% IACS or higher, a Vickers hardness of 100 or higher after heating at 400 ° C. for 1 hour, and having excellent bending workability is Fe 0.05 to 0.15 mass%, P; 0.015 to 0.05 mass%, Zn; 0.01 to 0.2 mass%, Cr; 0.0005 to 0.003 mass%, The balance has a basic composition composed of Cu and inevitable impurities, and Ni and Co described later may be further selectively contained with respect to this basic composition.
(Fe)
Fe has the effect of forming precipitate particles dispersed in the copper matrix and improving the strength, heat resistance and electrical conductivity. However, when the content is less than 0.05% by mass, there is no effect. When it exceeds mass%, the strength and heat resistance are improved, but the conductivity is lowered. For this reason, it is preferable to make content of Fe into the range of 0.05-0.15 mass%.
(P)
P has the effect of improving the strength and heat resistance by forming precipitate particles dispersed in the copper matrix with Fe, but if the content is less than 0.015% by mass, there is no effect, and 0.05% by mass If it exceeds V, the strength and heat resistance are improved, but the electrical conductivity and hot workability are reduced. For this reason, it is preferable to make content of P into the range of 0.015-0.05 mass%.
(Zn)
Zn has the effect of improving the heat resistance peelability of the solid solution by dissolving in the copper matrix, and if it is less than 0.01% by mass, it has no effect. It is difficult to obtain the effect, and the amount of solid solution in the mother layer increases, resulting in a decrease in conductivity. For this reason, it is preferable to make content of Zn into the range of 0.01-0.2 mass%.
(Cr)
Cr has an effect of improving the bending workability by dissolving in a copper matrix, and if it is less than 0.0005% by mass, it has no effect. It becomes difficult to obtain the effect, and the amount of solid solution in the mother layer increases, resulting in a decrease in conductivity. For this reason, it is preferable to make content of Cr into the range of 0.0005-0.003 mass%.
(Ni, Co)
Ni and Co are dissolved in the matrix phase and have the effect of improving heat resistance and conductivity. If the content is less than 0.01% by mass, there is no effect. Will cause a decline. For this reason, it is preferable that at least one content of Ni and Co is within a range of 0.01 to 0.20 mass%.

[Crystal structure of copper alloy sheet]
The Cu-Fe-P-based copper alloy sheet having an electrical conductivity of 90% IACS or higher, a Vickers hardness of 100 or higher after heating at 400 ° C. for 1 hour, and having excellent bending workability The average value of all the crystal grains in the crystal structure is 2.5 to 5 in terms of the average orientation difference between all the pixels in the crystal grains measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system. 0.0 °, the Brass orientation density is 11.0 to 22.0%, the Copper orientation density is 13.0 to 25.5%, and the average crystal grain size is 2.0 to 6.0 μm. It is characterized by that.

[Average value of all crystal grains in crystal structure, Brass orientation density, Copper orientation density of average orientation difference between all pixels in crystal grains measured by EBSD method using scanning electron microscope with backscattered electron diffraction image system] ]
Measurement of the average value of the average orientation difference between all the pixels in the crystal grains by the EBSD method is usually performed by dividing the measurement area of the sample into areas such as hexagons, and for each divided area on the sample surface. The Kikuchi pattern is obtained from the reflected electrons of the incident electron beam, the electron beam is scanned two-dimensionally on the sample surface, the orientation of all the pixels within the measurement area range is measured at a step size of 1.0 μm, and adjacent. A boundary where the orientation difference between pixels is 15 ° or more is regarded as a crystal grain boundary, and for each individual crystal grain surrounded by the crystal grain boundary, an average which is an average value of orientation differences between all pixels in the crystal grain An orientation difference (GOS: Grain Orientation Spread) was calculated by equation (1), and an average value of all crystal grains in the measurement region was defined as an average value of average orientation differences in all crystal grains. In addition, the crystal grains are those in which two or more pixels are connected.

In the above formula, i and j indicate the numbers of pixels in the crystal grains.
n indicates the number of pixels in the crystal grains.
α _ij represents the difference in orientation between pixels i and j.
When the average value of the average orientation difference between all the pixels in the crystal grains is less than 2.5 ° or exceeds 5.0 °, the conductivity is not 90% IACS or more.

The measurement of the Brass orientation density by the EBSD method usually divides the measurement area of the sample into areas such as hexagons, and for each divided area, obtains a Kikuchi pattern from the reflected electrons of the electron beam incident on the sample surface. The surface of the sample is scanned two-dimensionally on the sample surface, the orientation of all pixels within the measurement area range is measured at a step size of 1.0 μm, and the boundaries where the orientation difference between adjacent pixels is 15 ° or more are crystal grains Considering the boundary, the distribution of crystal grains on the sample surface was determined. Then, it was determined whether or not each crystal grain had a target Brass orientation (within 15 ° from the ideal orientation), and the Brass orientation density (area ratio of crystal orientation) in the measurement region was determined.
If the Brass orientation density is less than 11.0% or exceeds 14.5%, the tensile strength does not become 590 MPa or more.

The measurement of Copper orientation density by the EBSD method usually divides the measurement area of the sample into areas such as hexagons, and for each divided area, obtains a Kikuchi pattern from the reflected electrons of the electron beam incident on the sample surface, The surface of the sample is scanned two-dimensionally on the sample surface, the orientation of all pixels within the measurement area range is measured at a step size of 1.0 μm, and the boundaries where the orientation difference between adjacent pixels is 15 ° or more are crystal grains Considering the boundary, the distribution of crystal grains on the sample surface was determined. Then, it was determined whether or not each crystal grain had a target Copper orientation (within 15 ° from the ideal orientation), and a Copper orientation density (area ratio of crystal orientation) in the measurement region was determined.
When the Copper orientation density is less than 13.0 or exceeds 25.5%, the Vickers hardness after heating at 400 ° C. for 1 hour does not become 100 or more.

The average crystal grain size is measured by the EBSD method. The measurement area of the sample is usually divided into hexagonal areas, and the Kikuchi pattern is obtained from the reflected electrons of the electron beam incident on the sample surface for each divided area. , Scan the sample surface in two dimensions on the sample surface, measure the orientation of all pixels within the measurement area range with a step size of 1.0 μm, and crystallize the boundary where the orientation difference between adjacent pixels is 15 ° or more The grain size of each crystal grain on the sample surface was determined as a grain boundary, and the average value was defined as the average grain size.
When the average crystal grain size is less than 2.0 μm or exceeds 6.0 μm, the bending workability is lowered.

[Production method]
Next, a Cu-Fe-P-based copper alloy sheet having an electrical conductivity of 90% IACS or higher, a Vickers hardness of 100 or higher after heating at 400 ° C. for 1 hour, and having excellent bending workability. The manufacturing method will be described.
The average value of all the crystal grains in the crystal structure of the average orientation difference between all the pixels in the crystal grains measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system is 2.5 to 5.0 °. , Cold rolling and finish cooling to make the Brass orientation density 11.0-22.0%, Copper orientation density 13.0-25.5%, and average grain size 2.0-6.0 μm Except for the conditions of hot rolling and tension leveling, it is not necessary to greatly change the normal manufacturing process itself.

That is, the method for producing a copper alloy sheet according to the present invention melts and casts a copper alloy adjusted to a preferred component range, hot rolling, rough rolling, annealing, cold rolling, final annealing, finish cold rolling, tension leveling. When the copper alloy is manufactured in the process including the steps, the cold rolling is performed at a rolling rate of 25 to 90%, and a back tension for loading the finish cold rolling on the copper alloy plate is 45 to 70 N. / mm ^2, the front tension carried out at 75~100N / mm ^2, the tension leveling, 10~60N / mm ² back tension to load the copper alloy sheet, 15~90N / mm ² line tension, front The tension is performed at 10 to 60 N / mm ² .
When the rolling ratio of cold rolling is less than 25%, the Brass orientation density and Copper orientation density do not develop, and when it exceeds 90%, the Brass orientation density and Copper orientation density increase, and the tensile strength increases, but the heat resistance Tends to decrease. By this cold rolling, a base material that fits the Brass orientation density and the Copper orientation density within the optimum ranges is made, and the Brass orientation density and the Copper orientation density are kept within the optimum ranges by the finish cold rolling.
Of the tensions acting on the material in finish cold rolling, if the back tension is less than 45 N / mm ² or the front tension is less than 75 N / mm ² , the Copper orientation density does not develop and the back tension is 70 N / mm. ² or when the front tension exceeds 100 N / mm ² , the Brass orientation density does not develop and the Copper orientation density increases, but the copper alloy thin plate may be cracked or cut.
Of the tensions acting on the material in tension leveling, the back tension is 10 to 60 N / mm ² , the line tension is 15 to 90 N / mm ² , and the front tension is 10 to 60 N / mm ^2. The average value of all crystal grains in the crystal structure of the average orientation difference between pixels is 2.5 to 5.0 °, and the average crystal grain size is 2.0 to 6.0 μm. The back tension and the front tension mainly control the average value of the average orientation difference between all the pixels in the crystal grains in all the crystal grains in the crystal structure, and the line tension mainly controls the average crystal grain diameter. .

In a copper alloy sheet rolling mill, the back tension is the tension applied to the material inserted into the work roll, and is applied between the uncoiler and the work roll. The front tension is the work roll. The tension applied to the material drawn out from the work roll is applied between the work roll and the recoiler.
As shown in FIG. 1, a copper alloy plate 1 that has been subjected to final annealing and wound around an uncoiler 3 is sandwiched between work rolls 4 of a rolling mill and finish-rolled to become a copper alloy plate 2 that is wound around a recoiler 5. At this time, the back tension B is a tension applied to the copper alloy plate 1 inserted into the work roll 4, and the front tension F is a tension applied to the copper alloy plate 2 drawn from the work roll 4.
The tension leveling of the copper alloy plate is a process of correcting the flatness of the material by applying tension in the front-rear direction to a roller leveler that repeatedly bends the material through rolls arranged in a staggered manner in the reverse direction.
The back tension of this tension leveling is the tension applied to the material between the uncoiler and the input side tension load device, and the line tension is applied to the material in the roller leveler by the input side and winding side tension load devices. The tension applied is the front tension, which is the tension applied to the material between the recoiler and the take-up side tension loading device.
As shown in FIG. 2, the copper alloy plate 6 wound around the uncoiler 9 passes through the entrance side tension load device 11 of the tension leveler 10 and is repeatedly bent by the roller leveler 13 to become the copper alloy plate 7. After passing through the side tension load device 12, it becomes a copper alloy plate 8 and is wound around the recoiler 14. At this time, the back tension B <b> 1 is loaded on the copper alloy plate 6 between the uncoiler 9 and the entry side tension load device 11. The line tension L is applied to the copper alloy plate 7 between the inlet side tension load device 11 and the winding side tension load device 12 (the tension is uniform in the roller leveler 13). The front tension F <b> 1 is a tension applied to the copper alloy plate 8 between the recoiler 14 and the winding side tension load device 12.

  A copper alloy having the composition shown in Table 1 (components other than additive elements is Cu and inevitable impurities) is melted in a reducing atmosphere by an electric furnace to form an ingot having a thickness of 20 mm, a width of 120 mm, and a length of 200 mm. After producing and heating at 950 ° C. for 1 hour, hot rolling was performed at a rolling rate of 60% to finish the plate thickness to 8 mm, and the surface was faced by milling until the plate thickness became 7 mm. Next, rough cold rolling and batch annealing were performed to finish a copper alloy plate having a plate thickness of 1.0 mm. Next, after cold-rolling these copper alloy sheets under the conditions shown in Table 1, the final annealing was performed at 750 ° C. for 10 seconds, and further, each finish shown in Table 1 was subjected to finish cold rolling, Tension leveling was carried out to produce copper alloy thin plates of Examples 1 to 12 and Comparative Examples 1 to 5 having a plate thickness of 0.076 to 0.68 mm. In Table 1, BT represents back tension, FT represents front tension, and LT represents line tension.

Next, for the samples obtained from each copper alloy thin plate, all the crystals in the crystal structure of the average orientation difference between all the pixels in the crystal grains by EBSD method using a scanning electron microscope with a backscattered electron diffraction image system The average value, Brass orientation density, Copper orientation density, and average crystal grain size of the grains were measured.
The average value of the average orientation difference between all the pixels in the crystal grains by the EBSD method was measured as follows.
The measurement area of the sample is usually divided into hexagonal areas, and for each divided area, a Kikuchi pattern is obtained from the reflected electrons of the electron beam incident on the sample surface, and the electron beam is scanned two-dimensionally on the sample surface Measure the orientation of all pixels within the measurement area range with a step size of 1.0 μm, consider the boundary where the orientation difference between adjacent pixels is 15 ° or more as the crystal grain boundary, and be surrounded by the crystal grain boundary For all of the individual crystal grains, the average orientation difference (GOS: Grain Orientation Spread), which is the average value of the orientation differences between all the pixels in the crystal grains, is calculated by equation (1), The average value of the values in the crystal grains was defined as the average value of the average orientation difference in all the crystal grains. In addition, what connected 2 pixels or more was made into the crystal grain.

In the above formula, i and j indicate the numbers of pixels in the crystal grains.
n indicates the number of pixels in the crystal grains.
α _ij represents the difference in orientation between pixels i and j.
The Brass orientation density by the EBSD method was measured as follows.
The measurement area of the sample is usually divided into hexagonal areas, and for each divided area, a Kikuchi pattern is obtained from the reflected electrons of the electron beam incident on the sample surface, and the electron beam is scanned two-dimensionally on the sample surface And measure the orientation of all pixels in the measurement area range at a step size of 1.0 μm, and consider the boundary where the orientation difference between adjacent pixels is 15 ° or more as the crystal grain boundary, The distribution of was obtained. Then, it was determined whether or not each crystal grain had a target Brass orientation (within 15 ° from the ideal orientation), and the Brass orientation density (area ratio of crystal orientation) in the measurement region was determined.
The Copper azimuthal density by the EBSD method was measured as follows.
The measurement area of the sample is usually divided into hexagonal areas, and for each divided area, a Kikuchi pattern is obtained from the reflected electrons of the electron beam incident on the sample surface, and the electron beam is scanned two-dimensionally on the sample surface And measure the orientation of all pixels in the measurement area range at a step size of 1.0 μm, and consider the boundary where the orientation difference between adjacent pixels is 15 ° or more as the crystal grain boundary, The distribution of was obtained. Then, it was determined whether or not each crystal grain had a target Copper orientation (within 15 ° from the ideal orientation), and a Copper orientation density (area ratio of crystal orientation) in the measurement region was determined.
The average crystal grain size by the EBSD method was measured as follows.
The measurement area of the sample is usually divided into hexagonal areas, and for each divided area, a Kikuchi pattern is obtained from the reflected electrons of the electron beam incident on the sample surface, and the electron beam is scanned two-dimensionally on the sample surface And measure the orientation of all the pixels within the measurement area range at a step size of 1.0 μm, and consider each boundary of the sample surface as a grain boundary with a boundary where the orientation difference between adjacent pixels is 15 ° or more. The average grain size was determined as the average grain size.
These measurement results are shown in Table 2.

Next, the electrical conductivity, Vickers hardness after heating at 400 ° C. for 1 hour, and bending workability were measured for each sample.
The electrical conductivity was calculated by an average cross-sectional area method by processing a strip-shaped test piece having a width of 10 mm and a length of 300 mm by milling, measuring an electrical resistance with a double bridge resistance measuring device.
For Vickers hardness, a 10 × 10 mm test piece was cut out from each sample obtained, held in a heating furnace at 400 ° C. for 1 hour, and then a micro Vickers hardness meter (trade name “micro hardness meter”) manufactured by Matsuzawa Seiki Co., Ltd. A load of 0.5 kg was applied to measure the hardness at four locations, and the hardness was an average value thereof.
The bending workability is obtained by cutting a plate material into a width of 10 mm and a length of 60 mm, performing a BW (BadWay: vertical direction of rolling) 90 ° W bending in units of 0.025 mm of bending R = 0 to 0.4 mm, The presence or absence of cracks was observed with a 50 × optical microscope, and the ratio between the minimum bending radius R at which no cracks occurred and the thickness t of the copper alloy sheet was evaluated as R / t.
These measurement results are shown in Table 2.

  As is apparent from Table 2, the Cu-Fe-P-based copper alloy plate produced by the production method of the present invention has a conductivity of 90% IACS or more and Vickers hardness after heating at 400 ° C for 1 hour. Is 100 or more, and has excellent bending workability, and is found to be suitable as a material for a lead frame for a semiconductor device.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this description, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Copper alloy plate 2 Copper alloy plate 3 Uncoiler 4 Work roll 5 Recoiler B Back tension F Front tension 6 Copper alloy plate 7 Copper alloy plate 8 Copper alloy plate 9 Uncoiler 10 Tension leveler 11 Input side tension load device 12 Winding side tension load Equipment 13 Roller leveler 14 Recoiler B1 Back tension F1 Front tension L Line tension

Claims (3)

Fe: 0.05-0.15 mass%, P: 0.015-0.05 mass%, Zn: 0.01-0.2 mass%, Cr: 0.0005-0.003 mass% In the crystal structure of the average orientation difference between all the pixels in the crystal grains measured by the EBSD method using a scanning electron microscope with a backscattered electron diffraction image system, the balance having a composition consisting of Cu and inevitable impurities The average value in all crystal grains is 2.5 to 5.0 °, the Brass orientation density is 11.0 to 22.0%, the Copper orientation density is 13.0 to 25.5%, and the average crystal Conductivity characterized by a particle size of 2.0-6.0 μm is 90% IACS or more, Vickers hardness after heating for 1 hour at 400 ° C. is 100 or more, and in the vertical direction of rolling It does not occur cracks at 90 ° W bending test, excellent bending Copper alloy plate having a workability.   Furthermore, the electrical conductivity according to claim 1 is 90% IACS or more and contains at least one element of Ni and Co in an amount of 0.01 to 0.2% by mass, and at 400 ° C. for 1 hour. A copper alloy plate having a Vickers hardness of 100 or more after heating and excellent bending workability. It is a manufacturing method of the copper alloy plate of Claim 1 or Claim 2, Comprising: Melt casting, hot rolling, rough rolling, annealing, cold rolling, final annealing, finish cold rolling, tension leveling in this order When producing a copper alloy in the process of including, the rolling rate of the cold rolling is carried out at 25 to 90%, the back tension for loading the finish cold rolling on the copper alloy plate is 45 to 70 N / mm ² , the front tension carried out at 75~100N / mm ^2, the tension leveling, 10~60N / mm ² back tension to load the copper alloy sheet, the line tension 15~90N / mm ^2, the front tension 10 It implements at 60 N / mm < ² >, The manufacturing method of the copper alloy plate characterized by the above-mentioned.

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