KR20140075788A

KR20140075788A - Corson alloy and method for producing same

Info

Publication number: KR20140075788A
Application number: KR1020147012756A
Authority: KR
Inventors: 다카아키 하타노
Original assignee: 제이엑스 닛코 닛세키 킨조쿠 가부시키가이샤
Priority date: 2011-10-21
Filing date: 2012-09-28
Publication date: 2014-06-19
Also published as: TW201317371A; KR101967017B1; JP5039863B1; CN103890206A; TWI494450B; CN103890206B; KR20160148716A; WO2013058083A1; JP2013100591A

Abstract

A corundum alloy having high strength and high notch bendability, and a method of manufacturing the same. A rolled material containing 0.8 to 5.0% by mass of at least one of Ni and Co and 0.2 to 1.5% by mass of Si, the balance being copper and inevitable impurities, and having a sectional area of 45 to 55% EBSD measurement was performed in parallel with the plate thickness direction at the central portion in the thickness direction, and the crystal orientation was analyzed. It was found that the area ratio of the crystals oriented in the Cube orientation {001} < 100 & > The Korson alloy having an area ratio of crystals oriented in the width direction (TD) of the rolled material is 50% or less.

Description

[0001] CORSON ALLOY AND METHOD FOR PRODUCING SAME [0002]

The present invention relates to a lead frame material for a semiconductor device such as a conductive spring material such as a connector, a terminal, a relay, and a switch, a semiconductor device such as a transistor or an integrated circuit Korson alloy and a manufacturing method thereof.

BACKGROUND ART [0002] In recent years, miniaturization of electric and electronic parts has progressed, and copper alloy used for these parts has been required to have good strength, electric conductivity and bending workability. In response to this demand, there has been an increasing demand for precipitation hardening type copper alloys such as Korson alloys having high strength and electrical conductivity instead of conventional solid solution copper alloys such as phosphor bronze or brass. Korson alloy is an alloy in which an intermetallic compound such as Ni-Si, Co-Si and Ni-Co-Si is deposited in a Cu matrix, and has high strength, high conductivity and good bending workability. Generally, strength and bending workability are contradictory, and it is desired to improve the bending workability while maintaining high strength even in the Korson alloy.

In order to improve the dimensional accuracy of the bending portion when the copper alloy plate is press-processed by electronic or electronic parts such as a connector, the surface of the copper alloy plate is previously subjected to a nicking process called a notching process, The alloy plate may be bent (hereinafter, also referred to as notch bending). This notch bending has been widely used, for example, in press working of vehicle terminal. Since the copper alloy is subjected to work hardening and loses its ductility by the notching process, cracks tend to occur in the copper alloy in the subsequent bending process. Therefore, the copper alloy used for notch bending is particularly required to have good bending workability.

In recent years, as a technique for improving the bending property of the Korson alloy, a measure for controlling the area ratio of the Cube orientation ({001} < 100) is proposed. For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2006-283059) discloses a casting method in which (1) casting, (2) hot rolling, (3) cold rolling (95% (5) Cold rolling (20% or less), (6) Aging treatment, (7) Cold rolling (1 to 20% Is controlled to 50% or more, and the bending workability is improved.

In Patent Document 2 (Japanese Unexamined Patent Publication No. 2010-275622), (1) casting, (2) hot rolling (carried out while lowering the temperature from 950 캜 to 400 캜), (3) cold rolling (More than 50%), (4) intermediate annealing (450 to 600 캜, conductivity is adjusted to 1.5 times or more and hardness is adjusted to 0.8 times or less), (5) cold rolling Ray diffraction intensity of {200} (the same meaning as {001}) was obtained by X-ray diffractometry of the copper powder standard sample, And the bending workability is improved by controlling the diffraction intensity or more.

In Patent Document 3 (Japanese Unexamined Patent Publication No. 2011-17072), the area ratio of the Cube orientation is controlled to 5 to 60%, and the area ratio of the Brass orientation and the Copper orientation is controlled to 20% or less, And the bending workability is improved. (1) casting, (2) hot rolling, (3) cold rolling (85 to 99% of processing), (4) heat treatment at 300 to 700 ° C for 5 to 20 hours, 5) cold rolling (processing degree 5 to 35%), (6) solution treatment, (7) aging treatment, (8) cold rolling (processing degree 2 to 30%), and (9) The most favorable bending property is obtained.

On the other hand, in Patent Document 4 (WO2011 / 068126), the bending workability is improved by reducing the region facing the (111) face in the width direction, instead of controlling the Cube orientation. (1) casting, (2) hot rolling (cooling at 30 to 98% at 500 to 1020 占 폚, cold rolling), (3) cold rolling (50 to 99% (6) Intermediate recrystallization heat treatment (10 to 200 ° C lower than the solute solidus temperature), (6) Heat treatment (holding at 600 to 900 ° C for 10 seconds to 5 minutes, non-uniform recrystallized structure) (7) solution treatment (holding at a temperature 10 to 150 ° C higher than solute solidification temperature for 1 second to 10 minutes), (8) aging treatment, (9) cold rolling 2 to 45% in the degree of processing), and (10) a process comprising tempering annealing.

Japanese Patent Application Laid-Open No. 2006-283059 Japanese Laid-Open Patent Publication No. 2010-275622 Japanese Laid-Open Patent Publication No. 2011-17072 WO2011 / 068126

The present inventor conducted a verification test on the effects of the above-described prior art. As a result, when the bending workability was evaluated by the W bending test, a certain improvement effect was confirmed. However, regarding the notch bending, the bending workability which can be considered to be sufficient was not obtained. Therefore, it is an object of the present invention to provide a corundum alloy having both high strength and high notch bendability, and a method for producing the same.

In the prior art, for example, the crystal orientation of the copper alloy is analyzed by the EBSD method, and the characteristics of the copper alloy are improved on the basis of the obtained data. Here, EBSD (Electron Back Scattering Diffraction) is a method of determining the electron back scattering diffraction (EBSD) by using a reflection electron kinkchain ray diffraction (kikuchi pattern) generated when an electron beam is irradiated on a sample in an SEM (Scanning Electron Microscope) It is a technique to interpret bearing. Generally, the electron beam is irradiated on the surface of the copper alloy, and the information obtained at this time is azimuth information up to a depth of several 10 nm in which the electron beam enters, that is, azimuth information on the polar surface layer.

On the other hand, the present inventor has found that it is necessary to control the crystal orientation inside the copper alloy plate with respect to notch bending. This is because the internal angle of the bending is moved to the inside of the plate by the notching process. Then, the crystal orientation at the central portion in the plate thickness direction was optimized for notch bending, and a manufacturing method for obtaining this crystal orientation was revealed.

The present invention has been completed in view of the above findings. In one aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: providing an alloy containing 0.8 to 5.0% by mass of at least one of Ni and Co and 0.2 to 1.5% by mass of Si and the balance of copper and inevitable impurities The Cube orientation {001} < 100 > was measured when the EBSD measurement was performed parallel to the plate thickness direction and the crystal orientation was analyzed at a central portion in the plate thickness direction of 45 to 55% And the area ratio of crystals in which the <111> direction is oriented in the width direction TD of the rolled material is 50% or less.

According to one embodiment of the present invention, the Corseon alloy according to the present invention is subjected to EBSD measurement parallel to the plate thickness direction at a central portion in the plate thickness direction having a cross-sectional position of 45 to 55% with respect to the plate thickness, , The area ratio of the crystals oriented in the Cube orientation {001} < 100 > is 5 to 70%.

According to another embodiment of the present invention, there is provided a corundum alloy comprising at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag in a total amount of 0.005 to 3.0 Mass%.

In a further embodiment according to the present invention, the bending flexural modulus in the rolling direction is 106 to 119 mm.

According to another aspect of the present invention, there is provided an ingot including 0.8 to 5.0 mass% of at least one of Ni and Co, 0.2 to 1.5 mass% of Si, and the balance of copper and inevitable impurities, The ingot is hot-rolled at a temperature of 800 to 1000 占 폚 to adjust the thickness to 5 to 20 mm and the conductivity to 30% IACS or more. Thereafter, cold rolling at a degree of processing of 30 to 99.5%, preliminary annealing at a softening degree of 0.20 to 0.80, Cold rolling at a working temperature of 3 to 50%, solution treatment at 700 to 950 ° C. for 5 to 300 seconds, cold rolling at a working temperature of 0 to 60%, aging treatment at 350 to 600 ° C. for 2 to 20 hours, To < RTI ID = 0.0 > 50% < / RTI >

The degree of softening is represented by the following formula with softening degree S,

S = (? ₀ -?) / (? ₀ -? ₉₅₀ )

(Where? ₀ is the tensile strength before pre-annealing,? And? ₉₅₀ are the tensile strength after pre-annealing and after annealing at 950 ° C, respectively)

In one embodiment, the ingot comprises at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag. 0.005 to 3.0% by mass in total.

According to another aspect of the present invention, there is provided a new article having the above-mentioned Korson alloy.

According to another aspect of the present invention, there is provided an electronic device part having the above-mentioned Korson alloy.

According to the present invention, it is possible to provide a corundum alloy having high strength and high notch bendability and a method for producing the same.

1 is a graph showing the relationship between annealing temperature and tensile strength when an alloy according to the present invention is annealed at various temperatures.
2 is a view showing a test procedure of the notch bending test in the embodiment.

(Addition amount of Ni, Co and Si)

Ni, Co, and Si are precipitated as intermetallic compounds such as Ni-Si, Co-Si, and Ni-Co-Si by appropriate aging treatment. The strength improves by the action of the precipitate, and the Ni, Co and Si solidified in the Cu matrix by the precipitation decrease, and the conductivity is improved. However, if the total amount of Ni and Co is less than 0.8 mass% or Si is less than 0.2 mass%, desired strength can not be obtained. On the contrary, if the total amount of Ni and Co exceeds 5.0 mass% or Si exceeds 1.5 mass% The notch bending property remarkably deteriorates. Therefore, in the corundum alloy according to the present invention, the addition amount of at least one of Ni and Co is 0.8 to 5.0 mass%, and the addition amount of Si is 0.2 to 1.5 mass%. The addition amount of at least one of Ni and Co is more preferably 1.0 to 4.0 mass%, and the addition amount of Si is more preferably 0.25 to 0.90 mass%.

(Other added elements)

Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag contribute to the strength increase. In addition, Zn is effective for improving the heat peelability of Sn plating, Mg for improving stress relaxation property, and Zr, Cr and Mn for improving hot workability. If the total amount of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag is less than 0.005 mass%, the above effect can not be obtained. . Therefore, in the corundum alloy according to the present invention, it is preferable that these elements are contained in a total amount of 0.005 to 3.0 mass%, more preferably 0.01 to 2.5 mass%.

(Crystal orientation)

When the orientation of the Cube is increased, uneven deformation is suppressed and the bendability is improved. Here, the Cube bearing is expressed by an index of {001} < 100 > in a state in which the (001) plane faces the rolling plane normal direction ND and the (100) plane faces the rolling direction RD.

When the area ratio of the Cube orientation in the central portion of the plate thickness is less than 5%, the notch bending property sharply decreases. Therefore, the area ratio of crystals oriented in the Cube orientation in the central portion of the plate thickness is set to 5% or more, more preferably 10% or more.

The upper limit value of the area ratio of crystals oriented in the Cube orientation in the central portion of the plate thickness is not particularly restricted in terms of the notch bending property of the present invention. However, if the Cube bearing area ratio at the center of the plate thickness exceeds 70%, the bending flexural coefficient remarkably decreases. When the bending flexural coefficient is lowered, sufficient contact force at the contact point can not be obtained when machining with a connector, and the contact electrical resistance is increased. Therefore, the Cube bearing area ratio is preferably 70% or less. When the cube bearing area ratio is controlled to 70% or less, a sufficiently high flexural flexural modulus is obtained at 116 ㎬ or more. The bending flexural modulus of the cornson alloy according to the present invention is typically 106 to 119..

In addition to the control of the above-described Cube orientation, in a crystal in which the <111> direction is oriented in the width direction (perpendicular to ND and RD, hereinafter referred to as TD) of the alloy rolled material of the present invention, Is controlled to be not more than 50%, more preferably not more than 30%, notch bending becomes possible.

The lower limit value of the area ratio of crystals oriented in the < 111 > direction in the < 111 > direction in the central portion of the plate thickness is not regulated in terms of notch bending property. However, in the present invention alloy produced under the conditions described below, .

Here, the central portion of the plate thickness refers to a cross-sectional position of 45 to 55% with respect to the plate thickness.

(Manufacturing method)

In the general manufacturing process of the Korson alloy, the raw materials such as electric copper, Ni, Co, and Si are first dissolved in the melting furnace to obtain a molten metal having a desired composition. Then, the molten metal is cast into an ingot. After that, hot rolling, cold rolling, solution treatment and aging treatment are finished in the order of the desired thickness and characteristics. After the heat treatment, the surface may be pickled or polished to remove the surface oxide film generated during the heat treatment. In order to increase the strength, the solution treatment and the cold rolling after aging or aging may be performed.

In the present invention, in order to obtain the above-described crystal orientation, a heat treatment (hereinafter also referred to as preliminary annealing) and a cold rolling (hereinafter also referred to as light rolling) of relatively low cost are performed before the solution treatment, The conductivity is adjusted to a predetermined range.

The preliminary annealing is carried out for the purpose of partially producing recrystallized grains in a rolled structure formed by cold rolling after hot rolling. The ratio of the recrystallized grains in the rolled structure has an optimum value, and the above-described crystal orientation can not be obtained even if it is excessively large or excessively large. The optimum ratio of recrystallized grains is obtained by adjusting the preliminary annealing conditions so that the softness S defined below is 0.20 to 0.80.

FIG. 1 illustrates the relation between the annealing temperature and the tensile strength when the alloy according to the present invention is annealed at various temperatures. A specimen equipped with a thermocouple was inserted into a tubular furnace at 1000 ° C., and when the specimen temperature measured by a thermocouple reached a predetermined temperature, the specimen was taken out from the furnace, water cooled, and the tensile strength was measured. Recrystallization proceeds at a sample arrival temperature of 500 to 700 ° C, and the tensile strength is rapidly lowered. The gradual decrease in tensile strength on the high temperature side is due to the growth of recrystallized grains.

The degree of softening S in the preliminary annealing is defined by the following equation.

S = (? ₀ -?) / (? ₀ -? ₉₅₀ )

Here, σ ₀ is the tensile strength before the pre-annealing, and σ and σ ₉₅₀ are the tensile strength after pre-annealing and after annealing at 950 ° C, respectively. The temperature of 950 占 폚 is employed as a reference temperature for determining the tensile strength after recrystallization in that the alloys according to the present invention are annealed at 950 占 폚 to be stably completely recrystallized.

When S is less than 0.20, the area ratio of the Cube orientation becomes less than 5% at the central portion of the plate thickness, and the area ratio of crystals oriented in the <111> direction to TD increases.

If S exceeds 0.80, the area ratio of the Cube orientation becomes less than 5% at the central portion of the plate thickness, and the area ratio of crystals oriented in the <111> direction to TD increases.

The temperature and time of the preliminary annealing are not particularly limited, and it is important to adjust S to the above range. In general, in the case of using a continuous annealing furnace, the furnace temperature is in the range of 400 to 750 ° C for 5 seconds to 10 minutes, and in the case of the batch annealing furnace, the temperature is in the range of 350 to 600 ° C for 30 minutes to 20 hours .

The preliminary annealing conditions can be set by the following procedure.

(1) The tensile strength (? ₀ ) of the material before the pre-annealing is measured.

(2) The material before the pre-annealing is annealed at 950 占 폚. Specifically, a material with a thermocouple is inserted into a tubular furnace at 1000 DEG C, and when the sample temperature measured by a thermocouple reaches 950 DEG C, the sample is taken out of the furnace and cooled.

(3) The tensile strength (? ₉₅₀ ) of the material after the annealing at 950 占 폚 is obtained.

(4) For example, when σ ₀ is 800 MPa and σ ₉₅₀ is 300 MPa, tensile strengths corresponding to softenings of 0.20 and 0.80 are 700 MPa and 400 MPa, respectively.

(5) The conditions of the preliminary annealing are determined so that the tensile strength after annealing is 400 to 700 MPa.

After the preliminary annealing, prior to the solution treatment, a light rolling of 3 to 50% is carried out. The machinability R (%) is defined by the following formula.

R = (t ₀ - t) / t ₀ x 100 (t ₀ : plate thickness before rolling, t: plate thickness after rolling)

If the degree of processing is out of this range, the Cube orientation area ratio becomes less than 5%, and the area ratio of crystals oriented in the <111> direction to TD also increases.

In addition to the preliminary annealing and light rolling, the crystal orientation of the present invention is obtained by adjusting the conductivity after completion of hot rolling to 30% IACS or higher, more preferably 32% IACS or higher. When the conductivity is less than 30% IACS, the Cube bearing area ratio becomes less than 5%, and the area ratio of crystals oriented in the <111> direction to TD also increases.

Conventional hot rolling of the Korson alloy is carried out under the condition that Ni, Co and Si are solved as much as possible (solved in Cu) in order to lower the load in the subsequent solution heat treatment. For this reason, the electrical conductivity of the Korson alloy after completion of the conventional hot rolling is about 25% IACS. It is necessary to suppress the precipitation of Ni-Si, Co-Si, Ni-Co-Si, and the like during cooling after the completion of the hot rolling so that the material after hot rolling is quenched do.

The present invention intends to precipitate Ni, Co, and Si as much as possible in hot rolling. An ingot heated to 800 to 1000 占 폚 is rolled to a thickness of 5 to 20 mm and then quenched by, for example, , The above conductivity is obtained. The material immediately after hot rolling may be inserted into a heat insulating container, heated with a burner, or inserted into a heating furnace and subjected to lengthening to actively slow down the cooling and promote precipitation. However, if the conductivity is to be higher than 50% IACS, it takes a long time for cooling and the production efficiency is extremely lowered. Therefore, it is preferable to set the upper limit of the conductivity to 50% IACS. It is more preferable that the conductivity is less than 40% in terms of controlling the Cube bearing area ratio at the center of the plate thickness to 70% or less.

The manufacturing method of the alloy of the present invention is listed in the order of the steps as described below.

(1) Ingot casting (thickness 20 to 300 mm)

(2) Hot rolling (temperature: 800 ~ 1000 ℃, thickness: 5 ~ 20 ㎜, conductivity: 30% IACS or higher)

(3) Cold rolling (processing degree 30 to 99.5%)

(4) Preliminary annealing (degree of softening: S = 0.20 to 0.80)

(5) Light rolling (3 to 50% processing)

(6) Solution treatment (700 ~ 950 ℃ for 5 ~ 300 seconds)

(7) Cold rolling (machining degree 0 to 60%)

(8) Aging treatment (2 ~ 20 hours at 350 ~ 600 ℃)

(9) Cold rolling (0 to 50% processing)

(10) Stress-relieving annealing (5 seconds to 10 hours at 300 to 700 ° C)

Here, the degree of working of the cold-rolled steel (3) is preferably 30 to 99.5%. In order to partially recrystallize the preliminary annealing 4, it is necessary to introduce the stress in the cold rolling 3, and a stress which is effective at a processing rate of 30% or more can be obtained. On the other hand, when the degree of processing exceeds 99.5%, cracks are generated on the edge of the rolled material and the like, and the material during rolling may be broken.

Cold rolling (7) and (9) are carried out arbitrarily in order to increase the strength. However, the strength increases with the increase of the rolling process degree, while the area ratio of crystals oriented in the <111> direction to TD increases, and the Cube bearing area ratio tends to decrease. If the degree of processing in each of the cold rolling (7) and (9) exceeds the upper limit value, the area ratio of crystals oriented in the < 111 > direction to TD in the center of the plate thickness deviates from the present invention, Cracks occur in the notch bend.

The stress relieving annealing 10 is carried out arbitrarily in order to recover the spring limit value or the like which is lowered in the cold rolling in the case of performing the cold rolling 9. The effect of the present invention is obtained that the notch bendability is improved by controlling the crystal orientation of the central portion of the plate thickness irrespective of the presence or absence of the stress relieving annealing 10. [ The stress relieving annealing 10 may or may not be performed.

Regarding the steps (6) and (8), it is only necessary to select the general manufacturing conditions of the Korson alloy.

The Korson alloy of the present invention can be processed into various kinds of new articles, for example, plates, tumbles and foils. The Korson alloy of the present invention can be used as a lead frame, a connector, a pin, a terminal, a relay, And can be used for electronic device parts such as battery foil.

Example

Examples of the present invention will be described below with reference to comparative examples. However, these examples are provided for better understanding of the present invention and its advantages, and are not intended to limit the scope of the present invention.

(Example 1)

An alloy containing 2.6% by mass of Ni, 0.58% by mass of Si, 0.5% by mass of Sn and 0.4% by mass of Zn and the balance of copper and inevitable impurities was used as an experimental material and subjected to preliminary annealing, And the relationship between the conductivity and the crystal orientation after the completion of the hot rolling and the effect of the crystal orientation on the bending property and the mechanical properties of the product.

In a high-frequency melting furnace, 2.5 kg of electric copper was dissolved in an argon atmosphere using a graphite crucible having an inner diameter of 60 mm and a depth of 200 mm. The alloying element was added so that the alloy composition was obtained, the molten metal temperature was adjusted to 1300 캜, and the ingot was poured into a cast iron mold to prepare an ingot having a thickness of 30 mm, a width of 60 mm and a length of 120 mm. The ingots were processed in the order of the following steps to prepare a product sample having a thickness of 0.15 mm.

(1) Hot rolling: The ingot was heated at 950 占 폚 for 3 hours and rolled to a thickness of 10 mm. In order to change the conductivity after completion of the hot rolling, the material immediately after the rolling was cooled by the following three methods.

(A) into a water tank (water-cooling).

(B) Leave in air (air-cooling).

(C) After being inserted into an electric furnace heated to 300 ° C or 400 ° C, the furnace is cut off and cooled in the furnace (norang).

(2) Grinding: The oxide scale produced in the hot rolling was removed by a grinder. The thickness after grinding was 9 mm.

(3) Cold Rolling: Cold rolling was performed to a predetermined thickness according to the rolling process of light rolling.

(4) Preliminary annealing: After inserting a sample into an electric furnace adjusted to a predetermined temperature and holding it for a predetermined time, the sample was put in a water bath and cooled.

(5) Light rolling: Cold rolling was carried out to various thicknesses of 0.18 ㎜ on various rolling processes.

(6) Solution treatment: A sample was inserted into an electric furnace adjusted to 800 DEG C and held for 10 seconds, and then the sample was placed in a water bath and cooled. The crystal grain size after the solution treatment was about 10 mu m.

(7) Aging treatment: An electric furnace was used for heating in an Ar atmosphere at 450 DEG C for 5 hours.

(8) Cold rolling: Cold rolling was carried out from 0.18 mm to 0.15 mm at a working rate of 17%.

(9) Stress relieving annealing: After a sample was inserted into an electric furnace adjusted to 400 ° C and held for 10 seconds, the sample was left in the atmosphere and cooled.

After the hot rolling, the sample after the pre-annealing, and the sample of the product (in this case, the stress relieving annealed), the following evaluation was carried out.

(Measurement of conductivity after hot rolling)

The surface of the sample after the hot rolling was mechanically polished, and the scale was removed and planarized. On this surface, the conductivity was measured under the condition of a frequency of 60 kHz using Sigma Test D2.068 manufactured by Ulster Co., Ltd.

(Softness evaluation in preliminary annealing)

The tensile strength of the specimen before and after the pre-annealing was measured in parallel with the rolling direction in accordance with JIS Z 2241 using a tensile tester, and the respective values were defined as? ₀ and?. The 950 占 폚 annealing sample was prepared in the above procedure (inserted into the furnace at 1000 占 폚 and cooled when the sample reached 950 占 폚), and the tensile strength was measured in parallel with the rolling direction to obtain? ₉₅₀ . The softening degree S was obtained from? ₀ ,?,? ₉₅₀ .

S = (? ₀ -?) / (? ₀ -? ₉₅₀ )

(Measurement of crystal orientation of product)

The area ratio of the {100} < 001 > orientation and the area ratio of the crystal oriented in the < 111 > direction to TD were measured in the plate thickness direction surface layer and the plate thickness direction center portion.

As a sample for analyzing the crystal orientation of the surface layer, the surface of the sample was mechanically polished to remove minute concavities and convexities such as rolling, and then finished by mirror polishing by electrolytic polishing. The polishing depth of this surface was in the range of 2 to 3 占 퐉.

As a sample for analyzing the crystal orientation of the central portion of the plate thickness, the area from the one surface to the central portion of the plate thickness was removed by etching using a ferric chloride solution, and then the surface was finished by mechanical polishing and electrolytic polishing. Respectively. The thickness of the sample after finishing was in the range of 45 to 55% with respect to the original plate thickness.

In the EBSD measurement, the crystal orientation distribution was measured by scanning at a step size of 0.5 mu m for a sample area of 500 mu m square including 200 or more crystal grains. Then, the crystal orientation density function analysis was performed to obtain the area of the area having an azimuth difference within 15 degrees in the {100} < 001 > orientation and dividing this area by the entire measurement area to obtain " Cube azimuth {001} < 100 &Lt; / RTI >

Further, the area of the region where the <111> direction of the crystal and the angle formed by the TD with the TD is 15 ° or less is obtained, and this area is divided by the total measured area to obtain the "area ratio of <111> .

The information obtained in the orientation analysis by the EBSD includes azimuth information up to a depth of several tens of nm at which the electron beam enters the sample, but is described as the area ratio because it is sufficiently small for the area to be measured.

(Tensile test of the product)

Using a tensile tester, the tensile strength was measured in parallel with the rolling direction in accordance with JIS Z 2241.

(W bending test of product)

According to JIS H 3100, the W bending test was performed in the Good Way direction (the bending axis was orthogonal to the rolling direction) with the bending radius being t (plate thickness). Then, the bent section was finished with a mirror-finished surface by mechanical polishing and buff polishing, and the presence or absence of cracks was observed with an optical microscope. The case where no crack was confirmed was evaluated as & cir & and the case where cracks were confirmed was evaluated as " X ".

(Notch bending test of product)

The test procedure is shown in Fig. A notching process with a depth of 1 / 2t was performed on the plate thickness t. An angle of the tip of the notch was 90 degrees, and a flat portion having a width of 0.1 mm was formed at the tip. Next, in accordance with JIS H 3100, the W bending test was performed in the Good Way direction (the bending axis was orthogonal to the rolling direction) with the bend radius being t. Then, the bent section was finished with a mirror-finished surface by mechanical polishing and buff polishing, and the presence or absence of cracks was observed with an optical microscope. The case where no crack was confirmed was evaluated as & cir & and the case where cracks were confirmed was evaluated as " X ".

(Measurement of flexural flexural modulus)

The bending flexural modulus in the rolling direction was measured in accordance with JACBA technical standard " Method of measuring bending flexural modulus by cantilever of copper and copper alloy plate ".

A sample having a monolith shape having a plate thickness t, a width w (= 10 mm) and a length of 100 mm was sampled so that the longitudinal direction of the sample was parallel to the rolling direction. One end of the specimen was fixed and a load of P (= 0.15 N) was applied to the position of L (= 100 t) from the fixed end. From the flexure d at this time, the Young's modulus E was obtained using the following equation.

E = 4 · P · (L / t) ³ / (w · d)

Table 1 shows the test conditions and evaluation results.

In Examples 1 to 11, preliminary annealing, light rolling and hot rolling were carried out under the conditions specified by the present invention, in which the crystal orientation of the central portion of the plate thickness satisfies the requirements of the present invention, and cracks are generated in both W bending and notch bending And a high tensile strength exceeding 800 MPa was obtained. However, in Inventive Example 11 in which the Cube bearing surface area ratio at the central portion of the plate thickness exceeded 70%, the flexural flexural modulus was significantly lower than in the other Examples. Such lowering of the bending bending coefficient is not preferable from the viewpoint of the contact force because it causes a reduction in the contact force at the contact when machined with a connector.

In Comparative Example 1, since the softening degree in the preliminary annealing was less than 0.20, the Cube bearing surface area ratio at the central portion of the plate thickness was less than 5%.

In Comparative Example 2, since the degree of softening in the preliminary annealing exceeded 0.80, the Cube bearing area ratio at the central portion of the plate thickness was less than 5%.

In Comparative Example 3, since the degree of softening in the preliminary annealing was more than 0.80, the Cube bearing area ratio at the center of the plate thickness was less than 5%, and the <111> direction The area ratio of the crystals oriented in TD exceeded 50%.

In Comparative Examples 4 and 5, the degree of processing of light rolling was deviated from the specification of the present invention, and the Cube bearing surface area ratio at the central portion of the plate thickness was less than 5%.

In Comparative Example 6, since the conductivity after completion of hot rolling was less than 30% IACS, the Cube bearing area ratio at the center of the plate thickness was less than 5% and the <111> direction at the center of the plate thickness was oriented in TD The area ratio of crystals exceeded 50%. Comparative Example 6 was produced under the conditions recommended by Patent Document 3.

Comparative Example 7 was produced under the conditions recommended by Patent Document 4. Since the steel was cooled immediately after the completion of the hot rolling, the electric conductivity after completion of the hot rolling was less than 30% IACS. The preliminary annealing was carried out under the condition that the entire surface was not re-crystallized, and the degree of softening incidentally came within the scope of the present invention. Heat treatment was added immediately before the solution treatment, and the solution was heated at 650 占 폚 (10 to 200 占 폚 lower than the solute solidus temperature) for 1 hour to effect recrystallization. As in the other examples, the solution treatment was carried out at 800 ° C (10 to 150 ° C higher than solute solubilization temperature) for 10 seconds. In Comparative Example 7, the area ratio of crystals oriented in the <111> direction to TD was low in the surface layer portion but exceeded 50% in the center portion of the plate thickness. In addition, the Cube bearing surface area ratio was less than 5% in both the surface layer portion and the center portion of the plate thickness.

In the above comparative example, cracks did not occur in W bending, but cracks occurred in notch bending.

In Comparative Example 8, the steel sheet was subjected to surface grinding after being cooled by hot rolling and then rolled to a plate thickness of 0.18 mm without preliminary annealing or light rolling at a plate thickness of 9 mm. This step corresponds to a general manufacturing method of a conventional corseon alloy. The area ratio of the Cube bearing area was less than 5% in both the plate thickness central portion and the surface layer portion, and the area ratio of crystals oriented in the <111> direction to TD exceeded 50%. As a result, cracks occurred in both the W bending and the notch bending.

(Example 2)

In order to further verify that the central portion of the plate thickness is valid as the crystal orientation measurement position for controlling the notch bending property, the crystal orientations at 1/4 of the plate thickness were measured for the samples of Comparative Examples 1 and 3. That is, the depth (0.038 mm) of 1/4 of the plate thickness from one surface was removed by etching with a ferric chloride solution, and thereafter, with respect to the surface finished by mirror polishing by mechanical polishing and electrolytic polishing, The measurement was carried out in the manner described above. As a result,

[Comparative Example 1] Cube: 10%, {111} TD: 21%

[Comparative Example 3] Cube: 7%, {111} TD: 19%

A value very close to the measured value in the surface layer was obtained. From this, it was found that the measurement at the plate thickness 1/4 position can not evaluate the notch bending property, and measurement at the plate thickness central portion is necessary.

(Example 3)

It was examined whether the effect of improving the notch bending property as shown in Example 1 could be obtained even with the different components and the Korson alloy of the manufacturing conditions.

First, casting was carried out in the same manner as in Example 1 to obtain ingots having the components shown in Table 2.

(1) Hot rolling: The ingot was heated at 950 占 폚 for 3 hours and rolled to a thickness of 10 mm. The material immediately after the rolling was cooled by water cooling or air cooling.

(2) Grinding: The oxide scale produced by hot rolling was removed by a grinder. The thickness after grinding was 9 mm.

(3) Cold rolling

(5) Light rolling

(6) Solution treatment: A sample was inserted into an electric furnace adjusted to a predetermined temperature and held for 10 seconds, and then the sample was placed in a water bath and cooled. The temperature was selected so that the average diameter of the recrystallized grains was in the range of 5 to 25 mu m.

(7) Cold rolling (Rolling 1)

(8) Aging treatment: An electric furnace was used and heated in an Ar atmosphere at a predetermined temperature for 5 hours. The temperature was chosen so that the tensile strength after aging was at a maximum.

(9) Cold rolling (rolling 2)

(10) Stress relieving annealing: After inserting a sample into an electric furnace adjusted to a predetermined temperature and holding it for 10 seconds, the sample was allowed to stand in the atmosphere and cooled.

The samples after hot rolling, samples after preliminary annealing, and product samples were evaluated in the same manner as in Example 1. Tables 2 and 3 show test conditions and evaluation results. In the case where either rolling 1, rolling 2 or stress relieving annealing was not carried out, they were marked as "none" in the respective degrees of processing or temperature.

Examples 12 to 29 are obtained by preliminary annealing, light rolling and hot rolling under the conditions specified by the present invention, containing Ni, Co and Si at the concentrations specified by the present invention. The crystal orientation of the plate thickness central portion is A high tensile strength exceeding 650 MPa was obtained, satisfying the requirements of the present invention, enabling notched bending.

In Comparative Examples 10 and 17, the degree of processing of Rolled 2 exceeded 50%, and in Comparative Example 11, the degree of processing of Rolled 1 exceeded 60%. In these Comparative Examples, the crystal orientation of the central portion of the plate thickness deviated from the specification of the present invention, and cracking occurred in the notch bending.

In Comparative Examples 9 and 16, the degree of processing of light-rolling did not satisfy the requirements of the present invention. In Comparative Examples 12 and 14, the degree of softening in the preliminary annealing did not satisfy the requirements of the present invention. In Comparative Examples 13 and 15, the electric conductivity after completion of hot rolling was less than 30% IACS. In these Comparative Examples, the crystal orientation of the central portion of the plate thickness deviated from the specification of the invention, and cracking occurred in the notch bending, as in the alloy of Comparative Example of Example 1. [

In Comparative Example 18, the total concentration of Ni and Co and the Si concentration were below those of the present invention, and the notch bending property was good, but the tensile strength did not reach 500 MPa.

In Comparative Example 19, the total concentration of Ni and Co exceeded the specification of the present invention, and the crystal orientation of the central portion of the plate thickness satisfied the requirements of the present invention, but cracking occurred at the notch bending.

Claims

A rolled material containing 0.8 to 5.0% by mass of at least one of Ni and Co and 0.2 to 1.5% by mass of Si, the balance being copper and inevitable impurities, and having a sectional area of 45 to 55% EBSD measurement was performed in parallel with the plate thickness direction at the central portion in the thickness direction, and the crystal orientation was analyzed. It was found that the area ratio of the crystals oriented in the Cube orientation {001} < 100 & > The Korson alloy having an area ratio of crystals oriented in the width direction (TD) of the rolled material is 50% or less.

The method according to claim 1,
EBSD measurement was performed parallel to the plate thickness direction at the central portion in the plate thickness direction at a cross-sectional position of 45 to 55% with respect to the plate thickness, and when the crystal orientation was analyzed, the orientation was oriented to the Cube orientation {001} Korson alloy with an area ratio of 5 to 70%.

3. The method according to claim 1 or 2,
Wherein the alloy contains 0.005 to 3.0 mass% of at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag.

4. The method according to any one of claims 1 to 3,
Korson alloy having a bending flexural modulus in the rolling direction of 106 to 119..

An ingot containing 0.8 to 5.0% by mass of at least one of Ni and Co and 0.2 to 1.5% by mass of Si and the remainder being copper and inevitable impurities is prepared. The ingot is hot rolled , The thickness is adjusted to 5 to 20 mm and the conductivity is adjusted to 30% IACS or more. Thereafter, cold rolling at a working rate of 30 to 99.5%, preliminary annealing at a softening degree of 0.20 to 0.80, cold rolling at a working rate of 3 to 50% A solution treatment at 950 ° C for 5 to 300 seconds, a cold rolling at 0 to 60% in cold working, an aging treatment at 350 to 600 ° C for 2 to 20 hours, and a cold rolling at 0 to 50% to,
The degree of softening is represented by the following formula with softening degree S,
S = (? ₀ -?) / (? ₀ -? ₉₅₀ )
Where? ₀ is the tensile strength before the pre-annealing, and? And? ₉₅₀ are the tensile strength after pre-annealing and after annealing at 950 ° C, respectively.

6. The method of claim 5,
Wherein the ingot contains at least one of Sn, Zn, Mg, Fe, Ti, Zr, Cr, Al, P, Mn, Co, Cr and Ag in a total amount of 0.005 to 3.0 mass%.

A new article having the corson alloy according to any one of claims 1 to 4.

An electronic device part having the corseon alloy according to any one of claims 1 to 4.