TWI709651B - Copper alloy for electronic/electric device, copper alloy sheet or strip for electronic/electric device, component for electronic/electric device, terminal, bus bar, and movable piece for relay - Google Patents

Abstract

The copper alloy includes: 0.15 mass% or more and less than 0.35 mass% of Mg; 0.0005 mass% or more and less than 0.01 mass% of P; and the Cu balance containing inevitable impurities, wherein the conductivity exceeds 75%IACS, the Mg content [Mg] (mass%) and the P content [P] (mass%) satisfy the formula [Mg]+20×[P]<0.5, the H content is 10mass ppm or less, the O content is 100 mass ppm or less, the S content is 50 mass ppm or less, and the C content is 10 mass ppm or less.

Description

Copper alloys for electronic/electrical equipment, copper alloy plates and strips for electronic/electrical equipment, parts for electronic/electrical equipment, terminals, bus bars, and movable pieces for repeaters

The present invention relates to a copper alloy for electronic/electric equipment suitable for terminals such as connectors or press-fitted bodies, movable pieces for repeaters, lead frames, bus bars, and other electronic/electric equipment parts, and copper alloys for electronic/electric equipment. Copper alloy sheets and strips for electronic/electric equipment, parts for electronic/electric equipment, terminals, bus bars, and movable pieces for repeaters made of alloys.

This case claims priority based on Japanese Patent Application No. 2016-069079 filed on March 30, 2016 and Japanese Patent Application No. 2017-063258 filed on March 28, 2017, and its content is used here.

Conventionally, high-conductivity copper or copper alloys have been used for parts for electronic/electrical equipment such as terminals such as connectors and press-fit bodies, movable pieces for repeaters, lead frames, and bus bars.

Here, with the miniaturization of electronic equipment, electrical equipment, etc., the figure seeks to reduce the size and thickness of electronic/electric equipment parts used in such electronic equipment, electrical equipment, and the like. Therefore, for the materials constituting electronic/electric equipment parts, high strength or good bending workability is sought. In addition, in terminals such as connectors used in high-temperature environments such as the engine room of automobiles, stress relaxation resistance characteristics are also sought.

Here, in terms of materials used for electronic/electric equipment parts such as connectors and press-fitted bodies, movable pieces for repeaters, lead frames, and bus bars, for example, Cu-Mg has been proposed in Patent Documents 1 and 2 Department of alloys.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2007-056297 A (A)

[Patent Document 2] JP 2014-114464 A (A)

However, in the Cu-Mg-based alloy described in Patent Document 1, the content of P is as high as 0.08 to 0.35 mass%. Therefore, cold workability and bending workability are insufficient, and it is difficult to use a predetermined shape of electronic/electric equipment. The part is shaped.

In addition, in the Cu-Mg alloy described in Patent Document 2, The content of Mg is 0.01 to 0.5 mass% and the content of P is 0.01 to 0.5 mass%. Therefore, coarse crystals are generated, and cold workability and bending workability are insufficient.

Furthermore, in the above-mentioned Cu-Mg-based alloy, the viscosity of the copper alloy molten metal increases due to Mg. Therefore, if P is not added, there will be a problem of lowering the castability.

In addition, the above-mentioned Patent Documents 1 and 2 do not consider the content of O or the content of S. Intermediates composed of Mg oxides, Mg sulfides, etc. may occur, which may become defects during processing and cause cold storage. The workability and bending workability may deteriorate. In addition, since the content of H is not taken into consideration, pore defects may occur in the ingot, which may become defects during processing and may deteriorate cold workability and bending workability. In addition, since the content of C is not considered, defects that occur due to the inclusion of C during casting may deteriorate cold workability.

The present invention was completed in view of the foregoing circumstances, and aims to provide copper alloys for electronic/electrical equipment, copper alloy plates for electronic/electrical equipment, and electronic products with excellent electrical conductivity, cold workability, bending workability, and castability. /Movable pieces for electrical equipment parts, terminals, bus bars, and repeaters.

In order to solve this problem, the inventors of the present invention have made careful research and found that the content of Mg and P contained in the alloy can be set within the range of a predetermined relational expression, and the content of H, O, C, and S can be specified. , This can reduce the crystallized products containing Mg and P and the intermediary substances formed by Mg oxides or Mg sulfides, and without reducing cold workability and bending workability, the strength, Knowledge of stress relaxation resistance and improved castability.

The invention of the present case was completed based on the above-mentioned knowledge. One aspect of the invention of the present case, the copper alloy for electronic/electric equipment (hereinafter referred to as "the copper alloy for electronic/electric equipment of the present invention"), is characterized by: 0.15 mass% or more , Mg is contained in the range of less than 0.35 mass%, and P is contained in the range of 0.0005 mass% or more and less than 0.01 mass%, the residual part is made of Cu and inevitable impurities, and the conductivity exceeds 75% IACS, and The content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the relational expression of [Mg]+20×[P]<0.5, and the H content is set to 10 massppm or less, The content of O is set to 100 massppm or less, the content of S is set to 50 massppm or less, and the content of C is set to 10 massppm or less.

With the above-mentioned copper alloy for electronic/electric equipment, the Mg content is set to be 0.15 mass% or more and less than 0.35 mass%. Therefore, Mg is solid-dissolved in the copper matrix, which can prevent In the case of greatly reducing the electrical conductivity, the strength and stress relaxation characteristics are improved.

In addition, since P is contained in the range of 0.0005 mass% or more and less than 0.01 mass%, the castability can be improved.

Next, the Mg content [Mg] and the P content [P] are in a mass ratio, satisfying the relationship: [Mg]+20×[P]<0.5, so the formation of coarse crystals containing Mg and P can be suppressed , And can suppress cold workability and bending Sexual decrease.

Furthermore, since the content of O is set to 100 massppm or less and the content of S is 50 massppm or less, it is possible to reduce intermediary substances such as Mg oxides or Mg sulfides, and to prevent defects during processing. In addition, it is possible to prevent Mg from being consumed by reacting with O and S, and it is possible to suppress the deterioration of mechanical properties.

In addition, since the H content is set to 10 massppm or less, the occurrence of pore defects in the ingot can be suppressed, and the occurrence of defects during processing can be suppressed.

Furthermore, since the content of C is set to 10 massppm or less, cold workability can be ensured, and the occurrence of defects during processing can be suppressed.

In addition, since the conductivity exceeds 75% IACS, it is also suitable for applications that used pure copper in the past.

Here, in the copper alloy for electronic/electric equipment of the present invention, it is preferable that the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy: [Mg]/[P ]≦400 relational expression.

At this time, by defining the ratio of the content of Mg to reduce the castability and the content of P to improve the castability as described above, the castability can be surely improved.

In addition, in the copper alloy for electronic/electric equipment of the present invention, it is preferable that the 0.2% endurance when the tensile test is performed in a direction orthogonal to the rolling direction is 300 MPa or more.

At this time, as described above, the 0.2% resistance when the tensile test is carried out in a direction orthogonal to the rolling direction is specified, so there will be no easy deformation. It is particularly suitable as a copper alloy that constitutes parts for electronic/electric equipment such as terminals such as connectors and press-fitted bodies, movable pieces for repeaters, lead frames, and bus bars.

In addition, in the copper alloy for electronic/electric equipment of the present invention, it is preferable that the residual stress rate is 50% or more at 150° C. and 1000 hours.

In this case, since the residual stress rate is specified as described above, even in the case of use in a high-temperature environment, permanent deformation can be suppressed to be small and, for example, a reduction in contact pressure of a connector terminal can be suppressed. Therefore, it can be used as a material for parts for electronic equipment used in high-temperature environments such as engine rooms.

The other aspect of the invention of the invention of the copper alloy sheet and strip for electronic/electric equipment (hereinafter referred to as the "copper alloy sheet and strip for the electronic/electric equipment of the invention of the invention") is characterized by: Made of alloy.

The copper alloy sheet material for electronic/electric equipment with this structure is composed of the above-mentioned copper alloy for electronic/electric equipment, so it has excellent electrical conductivity, strength, cold workability, bending workability, and stress relaxation resistance. It is particularly suitable as a material for parts for electronic/electric equipment such as terminals such as connectors and press-fitted bodies, movable pieces for repeaters, lead frames, and bus bars.

Among them, the copper alloy slab material for electronic/electric equipment of the present invention includes a plate material and a strip material wound into a coil shape.

Here, in the copper alloy sheet material for electronic/electric equipment of the present invention, it is preferable to have a Sn plating layer or an Ag plating layer on the surface.

At this time, due to the Sn plating layer or Ag plating layer on the surface, This is particularly suitable as a material for parts for electronic/electric equipment such as terminals such as connectors and press-fit bodies, movable pieces for repeaters, lead frames, and bus bars. Among them, in the present invention, "Sn plating" includes pure Sn plating or Sn alloy plating, and "Ag plating" includes pure Ag plating or Ag alloy plating.

Another aspect of the present invention of electronic/electric equipment parts (hereinafter referred to as "the electronic/electric equipment parts of the present invention") is characterized by being made of the above-mentioned copper alloy sheet and strip for electronic/electric equipment. Among them, the electronic/electric equipment parts in the present invention refer to those including terminals such as connectors or press-fit bodies, movable pieces for repeaters, lead frames, bus bars, and the like.

The electronic/electric equipment parts of this structure are manufactured using the above-mentioned copper alloy lath material for electronic/electric equipment, so even in the case of miniaturization and thinning, excellent characteristics can be exhibited.

In addition, in the electronic/electric device parts of the present invention, a Sn plating layer or an Ag plating layer may be provided on the surface. Among them, the Sn plating layer and the Ag plating layer may be formed in advance on the copper alloy sheet material for electronic/electric equipment, or may be formed after the parts for electronic/electric equipment are formed.

The terminal of another aspect of the present invention (hereinafter referred to as the "terminal of the present invention") is characterized by being made of the above-mentioned copper alloy sheet material for electronic/electric equipment.

The terminal of this structure is manufactured using the above-mentioned copper alloy sheet and strip for electronic/electrical equipment, so even in the case of miniaturization and thinning, it can exhibit excellent characteristics.

In addition, in the terminal of the present invention, a Sn plating layer or Ag plating layer may be provided on the surface. Among them, the Sn plating layer and the Ag plating layer may be formed in advance on the copper alloy sheet material for electronic/electric equipment, or may be formed after the terminal is formed.

Another aspect of the bus bar of the present invention (hereinafter referred to as "the bus bar of the present invention") is characterized by being made of the above-mentioned copper alloy sheet and strip for electronic/electric equipment.

The bus bar of this structure is manufactured using the above-mentioned copper alloy sheet and strip for electronic/electric equipment, so even in the case of miniaturization and thinning, it can exhibit excellent characteristics.

In addition, in the bus bar of the present invention, a Sn plating layer or Ag plating layer may be provided on the surface. Among them, the Sn plating layer and the Ag plating layer may be formed in advance on the copper alloy sheet material for electronic/electric equipment, or may be formed after the bus bar is formed.

The movable piece for repeater of another aspect of the present invention (hereinafter referred to as the "movable piece for repeater of the present invention") is characterized by being made of the above-mentioned copper alloy sheet and strip for electronic/electric equipment.

The movable piece for the repeater of this structure is manufactured using the above-mentioned copper alloy sheet material for electronic/electric equipment, and therefore, it can exhibit excellent characteristics even in the case of downsizing and thinning.

In addition, the movable piece for a repeater of the present invention may have a Sn plating layer or an Ag plating layer on the surface. Among them, the Sn plating layer and the Ag plating layer may be formed in advance on the copper alloy sheet material for electronic/electric equipment, or may be formed after the movable piece for the repeater is formed.

According to the present invention, it is possible to provide copper alloys for electronic/electrical equipment, copper alloy plates for electronic/electrical equipment, parts for electronic/electrical equipment, excellent in conductivity, cold workability, bending workability, and castability. Movable pieces for terminals, bus bars, and repeaters.

Fig. 1 is a flowchart of a method of manufacturing a copper alloy for electronic/electric equipment of this embodiment.

Hereinafter, a copper alloy for electronic/electric equipment as an embodiment of the present invention will be described.

The copper alloy system for electronic/electric equipment of this embodiment has: Mg is contained in the range of 0.15 mass% or more and less than 0.35 mass%, and P is contained in the range of 0.0005 mass% or more and less than 0.01 mass%. Composition of Cu and unavoidable impurities.

In addition, in the copper alloy for electronic/electric equipment of this embodiment, the electrical conductivity is set to exceed 75% IACS.

Furthermore, in the copper alloy for electronic/electric equipment of this embodiment, the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy: [Mg]+20×[P]<0.5 relational expression.

Next, in the copper alloy for electronic/electric equipment of this embodiment, the content of H is 10massppm or less, the content of O is 100massppm or less, the content of S is 50massppm or less, and the content of C is 10massppm or less. the following

In addition, in the copper alloy for electronic/electric equipment of this embodiment, the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy: [Mg]/[P]≦400 relational expression.

In addition, in the copper alloy for electronic/electric equipment of the present embodiment, the 0.2% resistance when the tensile test is performed in a direction orthogonal to the rolling direction is set to 300 MPa or more. That is, in this embodiment, the rolled material is formed as a copper alloy for electronic/electrical equipment, and in the final rolling process, the 0.2% endurance when the tensile test is carried out in a direction orthogonal to the rolling direction is specified as above Narrated.

In addition, in the copper alloy for electronic/electric equipment of this embodiment, the residual stress ratio is set to 50% or more at 150°C for 1000 hours.

Here, the reason why the component composition and various characteristics are specified as described above will be explained as follows.

(Mg: 0.15mass% or more, less than 0.35mass%)

The Mg-based solid solution in the mother phase of the copper alloy has an element that has the effect of improving the strength and stress relaxation characteristics without greatly reducing the electrical conductivity.

Here, if the content of Mg is less than 0.15 mass%, the effect may not be sufficiently effective. On the other hand, if the content of Mg is 0.35 mass% or more, the electrical conductivity is greatly reduced, the viscosity of the copper alloy molten metal increases, and the castability may decrease.

Based on the above, in the present embodiment, the Mg content is set to be within a range of 0.15 mass% or more and less than 0.35 mass%.

Among them, in order to further improve the strength and the stress relaxation resistance, the lower limit of the Mg content is preferably 0.16 mass% or more, and more preferably 0.17 mass% or more. In addition, in order to surely suppress the decrease in electrical conductivity and the decrease in castability, the upper limit of the Mg content is preferably 0.30 mass% or less, and more preferably 0.28 mass% or less.

(P: 0.0005mass% or more, less than 0.01mass%)

The P-based element has the effect of improving castability.

Here, if the content of P is less than 0.0005 mass%, there is a possibility that the effect may not be sufficiently effective. On the other hand, if the P content is 0.01 mass% or more, the crystallized product containing Mg and P is coarsened, and the crystallized product becomes the starting point of failure, and there is a risk of cracking during cold working or bending.

Based on the above, in the present embodiment, the content of P is set within the range of 0.0005 mass% or more and less than 0.01 mass%.

Among them, in order to surely improve the castability, the lower limit of the P content is preferably 0.0007 mass% or more, and more preferably 0.001 mass% or more. In addition, in order to surely suppress the formation of coarse crystals, the content of P The upper limit of the amount is preferably less than 0.009 mass%, more preferably less than 0.008 mass%, and more preferably less than 0.0075 mass%. It is more preferably less than 0.0060 mass%, and most preferably less than 0.0050 mass%.

([Mg]+20×[P]<0.5)

If P is added, Mg and P coexist as described above, thereby forming a crystal containing Mg and P.

Here, if the content of Mg [Mg] and the content of P [P] are set as mass%, if [Mg]+20×[P] is 0.5 or more, the total amount of Mg and P is large , There is a possibility that crystals containing Mg and P are coarsened and distributed with high density, and are likely to be broken during cold working or bending.

Based on the above, in this embodiment, [Mg]+20×[P] is set to less than 0.5. Among them, in order to surely suppress the coarsening and densification of crystals, and to suppress cracks during cold working or bending, it is better to set [Mg]+20×[P] to be less than 0.48. It is better if it is less than 0.46. It is more preferably less than 0.44, and most preferably less than 0.42.

([Mg]/[P]≦400)

The Mg is an element that has the effect of increasing the viscosity of the molten copper alloy and reducing the castability. Therefore, in order to reliably improve the castability, the ratio of the content of Mg and P must be optimized.

Here, if the content of Mg [Mg] and the content of P [P] are set as mass%, if [Mg]/[P] exceeds 400, the content of Mg will increase relative to P. The castability improvement effect caused by the addition of P may be reduced.

Based on the above, if P is added in this embodiment, [Mg]/[P] is set to 400 or less. In order to further improve the castability, it is better to set [Mg]/[P] to 350 or less, and more preferably to 300 or less.

Among them, if [Mg]/[P] is too low, Mg is formed as crystals and is consumed, and there is a possibility that the effect obtained by Mg solid solution cannot be obtained. In order to suppress the formation of crystals containing Mg and P, and to achieve the improvement of endurance and stress relaxation resistance due to Mg solid solution, it is better to set the lower limit of [Mg]/[P] to more than 20. More than 25 is better.

(H: 10massppm or less)

H is an element that combines with O during casting to form water vapor and generate pore defects in the ingot. The porosity defect is a cause of cracks during casting, and causes defects such as bulging and peeling during rolling. These defects such as cracking, bulging and peeling are known to have stress concentration and become the starting point of failure, thus deteriorating strength and stress corrosion cracking resistance. Here, if the content of H exceeds 10 massppm, the above-mentioned pore defects are likely to occur.

Therefore, in this embodiment, the content of H is specified to be 10 massppm or less. Among them, in order to further suppress the occurrence of pore defects, the H content is preferably 4 massppm or less, and more preferably 2 massppm or less.

However, the lower limit of the H content is not specifically set, but excessively reducing the H content will increase the manufacturing cost. Therefore, the content of H is usually 0.1 massppm or more.

(O: 100massppm or less)

The O system reacts with each component element in the copper alloy to form an oxide. These oxides become the starting point of destruction, so cold workability is reduced, and even bending workability is also deteriorated. In addition, if O exceeds 100 massppm, Mg is consumed by reacting with Mg, and the amount of solid solution of Mg in the parent phase of Cu may decrease and mechanical properties may deteriorate.

Therefore, in this embodiment, the content of O is specified to be 100 massppm or less. Among them, the O content is particularly preferably 50 massppm or less within the above range, and more preferably 20 massppm or less.

However, the lower limit of the O content is not particularly set, but excessively reducing the O content will increase the manufacturing cost. Therefore, the O content is usually 0.1 massppm or more.

(S: 50massppm or less)

S is an element that exists in crystal grain boundaries in the form of intermetallic compounds or complex sulfides. These intermetallic compounds or composite sulfides existing in the grain boundaries cause grain boundary cracks during thermal processing, which causes processing cracks. In addition, since these become the starting point of failure, cold workability or bending workability deteriorates. Furthermore, by reacting with Mg, Mg is consumed, and the amount of solid solution of Mg in the parent phase of Cu decreases, which may cause deterioration of mechanical properties.

Therefore, in this embodiment, the content of S is specified to be 50 massppm or less. Among them, the content of S is within the above range, and is particularly preferably 40 massppm or less, and more preferably 30 massppm or less.

However, the lower limit of the content of S is not particularly set, but excessively reducing the content of S leads to an increase in manufacturing costs. Therefore, the content of S is usually 1 massppm or more.

(C: 10massppm or less)

C is an element that is used to coat the surface of molten metal for the purpose of deacidification of molten metal and is used to coat the surface of molten metal during melting and casting. If the content of C exceeds 10 massppm, the involvement of C during casting will increase. The segregation of the solid solution of C or composite carbides and C degrades cold workability.

Therefore, in this embodiment, the content of C is specified to be 10 massppm or less. Among them, the content of C is preferably 5 massppm or less within the above range, and more preferably 1 massppm or less.

However, the lower limit of the content of C is not particularly set, but excessively reducing the content of C leads to an increase in manufacturing costs. Therefore, the content of C is usually 0.1 massppm or more.

(Inevitable impurities: 0.1mass% or less)

In terms of other inevitable impurities, include: Ag, B, Ca, Sr, Ba, Sc, Y, rare earth elements, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re , Fe, Ru, Os, Co, Se, Te, Rh, Ir, Ni, Pd, Pt, Au, Zn, Cd, Hg, Al, Ga, In, Ge, Sn, As, Sb, Tl, Pb, Bi , Be, N, Si, Li, etc. These unavoidable impurities have the effect of reducing the conductivity, so the total amount is set to Below 0.1mass%.

In addition, Ag, Zn, and Sn are easily mixed into copper and lower the conductivity, so the total amount is preferably less than 500 massppm. In particular, the Sn system greatly reduces the conductivity, so it is better to set it individually to less than 50 massppm.

Furthermore, the Si, Cr, Ti, Zr, Fe, and Co systems in particular greatly reduce the electrical conductivity, and the bending workability is degraded by the formation of intermediaries. Therefore, the total amount of these elements is preferably less than 500 massppm.

(Conductivity: more than 75%IACS)

In the copper alloy for electronic/electric equipment of this embodiment, the conductivity is set to more than 75% IACS, so that it can be used well as terminals such as connectors or press-fit bodies, movable pieces for repeaters, lead frames, bus bars, etc. Parts for electronic/electrical equipment.

Among them, the conductivity is preferably more than 76% IACS, more preferably more than 77% IACS, more preferably more than 78% IACS, and more preferably more than 80% IACS.

(0.2% endurance: above 300MPa)

In the copper alloy for electronic/electric equipment of this embodiment, the 0.2% endurance is set to 300 MPa or more, making it particularly suitable for use as terminals such as connectors or press-fit bodies, movable pieces for repeaters, lead frames, bus bars, and other electronics. /Materials for electrical equipment parts. Among them, in this embodiment, the 0.2% endurance when the tensile test is carried out in a direction orthogonal to the rolling direction It is set to 300 MPa or more.

Here, the above-mentioned 0.2% endurance is preferably 325 MPa or more, and more preferably 350 MPa or more.

(Residual stress rate: more than 50%)

In the copper alloy for electronic devices of this embodiment, as described above, the residual stress ratio is set to 50% or more at 150°C for 1000 hours.

If the residual stress rate under this condition is high, even when used in a high-temperature environment, permanent deformation can be suppressed to be small, and reduction in contact pressure can be suppressed. Therefore, the copper alloy system for electronic equipment of the present embodiment can be suitably used as a terminal used in a high-temperature environment such as around the engine room of an automobile. In this embodiment, the residual stress rate of the stress relaxation test performed in the direction orthogonal to the rolling direction is set to 50% or more at 150° C. for 1000 hours.

Among them, the residual stress ratio is preferably 60% or more at 150°C for 1000 hours, and more preferably 70% or more at 150°C for 1000 hours.

Next, referring to the flowchart shown in FIG. 1, the method of manufacturing the copper alloy for electronic/electric equipment of the present embodiment having the above-mentioned configuration will be described.

(Melting/Casting Engineering S01)

First, the copper molten metal obtained by melting the copper raw material is added with the aforementioned elements to adjust the composition, and a copper alloy molten metal is produced. Among them, in For the addition of various elements, single element or master alloy can be used. In addition, the raw material containing the above-mentioned elements may be melted together with the copper raw material. In addition, recycled materials and scrap materials of this alloy can also be used. Here, the copper molten metal is preferably a so-called 4NCu whose purity is 99.99 mass% or more, or a so-called 5NCu whose purity is 99.999 mass% or more. In particular, in the present embodiment, the contents of H, O, S, and C are specified as described above, and therefore, raw materials with low contents of these elements are selected and used. Specifically, it is preferable to use a raw material having an H content of 0.5 massppm or less, an O content of 2.0 massppm or less, an S content of 5.0 massppm or less, and a C content of 1.0 massppm or less.

In the melting process, in order to suppress the oxidation of Mg, and because the hydrogen concentration is reduced, the gas atmosphere melting by the inert gas atmosphere (such as Ar gas) with a low vapor pressure of H ₂ O is performed, and the retention time during melting is limited to the minimum .

Next, the copper alloy molten metal whose composition has been adjusted is poured into a mold to produce an ingot. Among them, if mass production is considered, it is better to use a continuous casting method or a semi-continuous casting method.

At this time, when the molten metal solidifies, crystals containing Mg and P are formed. Therefore, by increasing the solidification rate, the size of the crystals can be made finer. Therefore, the cooling rate of the molten metal is preferably 0.1°C/sec or more, more preferably 0.5°C/sec or more, and most preferably 1°C/sec or more.

(Homogenization/Meltization Engineering S02)

Then, in order to homogenize and melt the obtained ingot, heating is performed deal with. In the interior of the ingot, there are intermetallic compounds containing Cu and Mg as main components, which are generated by the Mg segregation and concentration during the solidification process. Therefore, in order to make the segregation and intermetallic compounds disappear or reduce, the ingot is heated to 400°C or higher and 900°C or lower, so that Mg is uniformly diffused or solid solution in the ingot. In the mother phase. Among them, the homogenization/melting process S02 is implemented in a non-oxidizing or reducing gas environment. In addition, the copper material heated to 400°C or higher and 900°C or lower is cooled to a temperature of 200°C or lower at a cooling rate of 60°C/min or higher.

Here, if the heating temperature is less than 400° C., the melting becomes incomplete, and there is a possibility that many intermetallic compounds mainly composed of Cu and Mg remain in the matrix. On the other hand, when the heating temperature exceeds 900°C, a part of the copper material becomes a liquid phase, and the structure or surface state may become uneven. Therefore, the heating temperature is set to a range of 400°C or higher and 900°C or lower. It is preferably 500°C or higher and 850°C or lower, and more preferably 520°C or higher and 800°C or lower.

(Hot processing engineering S03)

In order to improve the efficiency of roughing and the uniformity of the structure, hot processing is also possible. The temperature conditions in this hot working process S03 are not particularly limited, but it is preferable to set it in the range of 400°C to 900°C. In addition, the cooling method after processing is preferably water quenching at a cooling rate of 60°C/min or more to 200°C or less. Furthermore, the processing method is not particularly limited. For example, rolling, wire drawing, extrusion, groove rolling, forging, press Wait.

(Rough machining process S04)

For processing into a predetermined shape, rough machining is performed. Among them, the temperature conditions in the rough machining process S04 are not particularly limited, but in order to suppress recrystallization or improve dimensional accuracy, it is better to set it as cold or warm processing in the range of -200°C to 200°C , Especially at room temperature. Regarding the processing rate (rolling rate), 20% or more is preferable, and 30% or more is more preferable. In addition, the processing method is not particularly limited, and for example, rolling, wire drawing, extrusion, groove rolling, forging, pressing, etc. can be used.

(Intermediate heat treatment engineering S05)

After the rough machining process S04, heat treatment is carried out for the purpose of thorough melting, softening for recrystallization and improvement of workability. The method of heat treatment is not particularly limited, but it is preferable to perform the heat treatment in a non-oxidizing gas atmosphere or a reducing gas atmosphere at a holding temperature of 400° C. or more and 900° C. or less, and a holding time of 10 seconds or more and 10 hours or less. In addition, the cooling method after heating is not particularly limited, but it is preferable to use a method in which a cooling rate such as water quenching becomes 200° C./min or more.

Among them, rough machining process S04 and intermediate heat treatment process S05 can also be implemented repeatedly.

(Final processing process S06)

In order to process the copper material after the intermediate heat treatment process S05 into a predetermined Shape, final processing. Among them, the temperature conditions in the final processing step S06 are not particularly limited, but in order to suppress recrystallization or softening, it is preferable to set it as the range of -200°C to 200°C for cold or warm processing. , Especially at room temperature. In addition, the processing rate is appropriately selected so as to approximate the final shape, but in order to increase the strength by work hardening in the finishing process S06, the processing rate is preferably set to 20% or more. In addition, if further improvement in strength is desired, the processing rate is preferably 30% or more, the processing rate is 40% or more, and the processing rate is 60% or more. In addition, because the processing rate increases, the bending workability deteriorates, so it is better to set it to 99% or less.

(Final heat treatment process S07)

Next, for the plastic processed material obtained by the finishing process S06, in order to improve the stress relaxation resistance and low temperature annealing hardening, or to remove residual strain, the final heat treatment is performed.

The heat treatment temperature is preferably within the range of 100°C or higher and 800°C or lower. Among them, in the final heat treatment process S07, it is necessary to set the heat treatment conditions (temperature, time, cooling rate) in a way that avoids a significant decrease in strength due to recrystallization. For example, if it is 300°C, it is better to keep it for about 1 second to 120 seconds. The heat treatment is performed in a non-oxidizing gas environment or a reducing gas environment.

The method of heat treatment is not particularly limited. In view of the effect of reducing the manufacturing cost, a short-time heat treatment by a continuous annealing furnace is preferable.

Furthermore, the above-mentioned finishing process S06 and the final Heat treatment engineering S07.

As shown above, the copper alloy plate strip (plate material or strip formed into a coil shape) for electronic/electric equipment of this embodiment was produced. Among them, the thickness of the copper alloy lath material for electronic/electric equipment is set to be in the range of more than 0.05 mm and 3.0 mm or less, and preferably in the range of more than 0.1 mm and less than 3.0 mm. If the thickness of the copper alloy sheet for electronic/electric equipment is less than 0.05mm, it is not suitable for use as a conductor in high current applications. If the thickness exceeds 3.0mm, it is difficult to punch and punch.

Here, the copper alloy sheet and strip for electronic/electric equipment of this embodiment can also be directly used for parts for electronic/electric equipment, but it can also be formed on one or both sides of the board with a thickness of about 0.1-100μm. Sn plating layer or Ag plating layer. At this time, the thickness of the copper alloy sheet for electronic/electric equipment is preferably 10 to 1000 times the thickness of the plating layer.

In addition, the copper alloy for electronic/electric equipment (copper alloy sheet and strip for electronic/electric equipment) of this embodiment is used as a material, and punching or bending processing is performed to make terminals such as connectors or press-fit bodies , Movable pieces for repeaters, lead frames, bus bars and other electronic/electric equipment parts are formed.

With the copper alloy for electronic/electric equipment of this embodiment formed into the above-mentioned configuration, the Mg content is set to be within the range of 0.15 mass% or more and less than 0.35 mass%, so Mg is solid-dissolved in In the mother phase of copper, the electrical conductivity will not be greatly reduced by this, but the strength and stress relaxation characteristics can be improved.

In addition, in the copper alloy for electronic/electric equipment of the present embodiment, since the content of P is set to 0.0005 mass% or more and less than 0.01 mass%, the viscosity of the molten copper alloy can be reduced, and Can improve the castability.

In addition, in the copper alloy for electronic/electric equipment of this embodiment, since the conductivity is set to exceed 75% IACS, it can also be applied to applications requiring high conductivity.

Next, the content of Mg [Mg](mass%) and the content of P [P](mass%) satisfy the relational expression of [Mg]+20×[P]<0.5, so the production of Mg and P can be suppressed. Crystals.

In addition, since the content of O is set to 100 massppm or less, and the content of S is set to 50 massppm or less, it is possible to reduce intermediary substances such as Mg oxide or Mg sulfide.

Furthermore, since the H content is set to 10 massppm or less, it is possible to suppress the occurrence of pore defects in the ingot.

In addition, since the C content is set to 10 massppm or less, cold workability can be ensured.

Based on the above, the occurrence of defects during processing can be suppressed, and cold workability and bending workability can be greatly improved.

Furthermore, in the copper alloy for electronic/electric equipment of this embodiment, the Mg content [Mg] (mass%) and the P content [P] (mass%) satisfy [Mg]/[P]≦400 Therefore, the ratio of the content of Mg that reduces the castability to the content of P that improves the castability is optimized. The effect of adding P can reduce the viscosity of the molten copper alloy, and The castability can be indeed improved.

In addition, in the copper alloy for electronic/electric equipment of this embodiment, the 0.2% endurance is set to 300 MPa or more, and the residual stress rate is set to 50% or more at 150°C for 1000 hours, so the strength and stress relaxation resistance are Excellent, especially suitable as a material for parts for electronic/electric equipment such as terminals such as connectors and press-fit bodies, movable pieces for repeaters, lead frames, and bus bars.

In addition, the copper alloy slab for electronic/electric equipment of this embodiment is composed of the above-mentioned copper alloy for electronic/electric equipment, so by bending the copper alloy slab for electronic/electric equipment, etc., It can manufacture electronic/electric equipment parts such as connectors and press-fitted terminals, movable pieces for repeaters, lead frames, and bus bars.

Among them, if a Sn plating layer or an Ag plating layer is formed on the surface, it is particularly suitable as a material for parts for electronic/electric equipment such as terminals such as connectors and press-fit bodies, movable pieces for repeaters, lead frames, and bus bars.

Furthermore, the electronic/electric equipment parts (terminals such as connectors or press-fit bodies, movable pieces for repeaters, lead frames, bus bars, etc.) of this embodiment are composed of the above-mentioned copper alloy for electronic/electric equipment, Therefore, even with miniaturization and thinning, excellent characteristics can be achieved.

The copper alloys for electronic/electrical equipment, copper alloy plates and strips for electronic/electrical equipment, and parts (terminals, bus bars, etc.) for electronic/electrical equipment have been described above, but the invention of this application is not limited to this. Appropriate changes can be made without departing from the technical idea of the present invention.

For example, in the above-mentioned embodiment, the An example of a method of manufacturing a copper alloy, but the method of manufacturing a copper alloy for electronic/electric equipment is not limited to those described in the embodiment, and an existing manufacturing method may be appropriately selected and manufactured.

[Example]

The following description is the result of a confirmation experiment conducted to confirm the effect of the present invention.

Prepare H content of 0.1 mass ppm or less, O content of 1.0 mass ppm or less, S content of 1.0 mass ppm or less, C content of 0.3 mass ppm or less, and Cu purity of 99.99 mass% or more. This is put into a high-purity alumina crucible, and melted in a high-purity Ar gas (dew point below -80°C) gas environment using a high-frequency melting furnace. To add various elements to the copper alloy molten metal and introduce H and O, use high-purity Ar gas (dew point -80°C or less) and high-purity N ₂ gas (dew point -80°C or less) ), high-purity O ₂ gas (dew point -80°C or less), high-purity H ₂ gas (dew point -80°C or less), forming an Ar-N ₂ -H ₂ and Ar-O ₂ mixed gas environment. To introduce C, during melting, the C particles are coated on the surface of the molten metal and contact the molten metal. In addition, if you want to import S, add S directly. In addition, as the Mg raw material, a magnesium purity of 99.99 mass% or more was used. Thereby, the alloy molten metal with the composition shown in Table 1 and Table 2 was melted and poured into the mold to produce an ingot. Among them, Example 11 of the present invention uses a carbon mold, Example 28 of the present invention uses a heat insulating material (ISOWOOL) mold, Examples 1-10, 12-27, 29-37 of the present invention and Comparative Examples 1-11 use water-cooling Copper alloy molds are used as molds for casting. In addition, the size of the ingot was set to be about 20 mm in thickness × about 200 mm in width × about 300 mm in length.

From the obtained ingot, the cast surface was face-cut near the cast surface, and a block of 16mm×200mm×100mm was cut out.

This block was heated for 4 hours under the temperature conditions described in Table 3 and Table 4 in an Ar gas environment, and homogenization/melting treatment was performed.

In order to appropriately form it into a form suitable for the final shape, the heat-treated copper material is cut, and surface grinding is performed. After that, at normal temperature, rough rolling was performed at the rolling rates described in Table 3 and Table 4.

Next, the obtained strips were subjected to intermediate heat treatment under the conditions described in Table 3 and Table 4 in an Ar gas atmosphere. After that, water quenching is performed.

Next, the final rolling was performed at the rolling rates shown in Table 3 and Table 4, and a thin plate having a thickness of 0.5 mm and a width of about 200 mm was produced. In the above-mentioned final rolling, rolling oil is applied to the surface to perform cold rolling.

Next, after the final rolling, the final heat treatment was performed in an Ar gas atmosphere under the conditions shown in Table 3 and Table 4, and then water quenching was performed to produce a sheet for characteristic evaluation.

(Ingredient composition)

The component analysis was performed using the characteristic evaluation sheet obtained as described above. At this time, the analysis of Mg and P was performed by inductively coupled plasma emission spectroscopy. In addition, the analysis of H was performed by the thermal conductivity method, and the analysis of O, S, and C was performed by the infrared absorption method.

(Castability)

For the evaluation of castability, the presence or absence of surface roughness at the time of casting was observed. Visually, the surface roughness is completely or almost undetected as A, the surface roughness with a depth of less than 1 mm is designated as B, and the surface roughness with a depth of 1 mm or more and less than 2 mm is designated as C. In addition, those with larger surface roughness with a depth of 2mm or more are set as D, and the evaluation is stopped on the way. The evaluation results are shown in Table 5 and Table 6.

Here, the depth of surface roughness refers to the depth of surface roughness from the end of the ingot toward the center.

(Mechanical characteristics)

A test piece No. 13B specified in JIS Z 2241 was taken from the strip for property evaluation, and 0.2% endurance was measured by the offset method of JIS Z 2241. Among them, the test piece was taken in a direction orthogonal to the rolling direction. The evaluation results are shown in Table 5 and Table 6.

(Number of breaking times in tensile test)

Using the above-mentioned No. 13B test piece, the tensile test was performed 10 times, and the number of breaks in the tensile test piece in the elastic region was set as the number of breaks in the tensile test before reaching the 0.2% endurance, and the measurement was performed. The evaluation results are shown in Table 5 and Table 6.

Among them, the elastic region refers to the region satisfying the linear relationship in the stress-strain curve. The greater the number of breaks, the lower the processability due to intervening materials.

(Conductivity)

A test piece with a width of 10 mm × a length of 150 mm was taken from the strip for characteristic evaluation, and the electrical resistance was determined by the 4-terminal method. In addition, using a micrometer, the size of the test piece was measured, and the volume of the test piece was calculated. Next, the conductivity is calculated from the measured resistance value and volume. Among them, the test piece is taken so that its longitudinal direction becomes perpendicular to the rolling direction of the strip for property evaluation. The evaluation results are shown in Table 5 and Table 6.

(Resistance to stress relaxation characteristics)

The stress relaxation characteristic test is based on the cantilever spiral method according to the technical standard of the Japan Copper Wire Association-JCBAT309:2004, load stress, and the residual stress rate after being kept at a temperature of 150°C for 1000 hours.

In terms of the test method, a test piece (width 10mm) is taken from each characteristic evaluation strip in a direction orthogonal to the rolling direction, and the maximum surface stress of the test piece is 80% of the endurance. Set the displacement to 2mm and adjust the span length. The above-mentioned maximum surface stress is set by the following formula.

Maximum surface stress (MPa)=1.5Etδ ₀ /L _s ²

among them,

E: Young's modulus (MPa)

t: The thickness of the sample (t=0.5mm)

δ ₀ : Initial deflection displacement (2mm)

L _s : Span length (mm).

The residual stress ratio was measured from the bending undulations after being kept at a temperature of 150°C for 1000 hours, and the stress relaxation resistance characteristics were evaluated. The residual stress rate is calculated using the following formula.

Residual stress rate (%)=(1-δ _t /δ ₀ )×100

among them,

δ _t : Permanent flexural displacement after keeping at 150℃ for 1000 hours (mm)-Permanent flexural displacement after keeping at room temperature for 24 hours (mm)

δ ₀ : Initial deflection displacement (mm).

(Bending workability)

According to the 4 test method of Japan Copper Drawing Association technical standard JCBA-T307:2007, the bending process is carried out. With respect to the rolling direction, the bending axis was perpendicular to the direction, and a plurality of test specimens with a width of 10 mm and a length of 30 mm were taken from the sheet for characteristic evaluation. The bending angle used is set to 90 degrees, the bending radius is 1.0mm (R/t=2) if the final rolling rate exceeds 85%, and the bending radius is 0.5mm (R/t= 1) W-shaped fixture, W bending test.

If cracks are observed by visually observing the outer periphery of the curved part, set it as "C". If large wrinkles are observed, set B. If cracks or fine cracks or large wrinkles cannot be confirmed , Set as A, to judge. Among them, A and B are judged to be allowable bending workability. The evaluation results are shown in Table 5 and Table 6.

In Comparative Example 1, the content of Mg is less than the range of the present invention (above 0.15 mass% and less than 0.35 mass%), the 0.2% endurance is low, and the strength is insufficient.

In Comparative Example 2, the Mg content is more than the range of the present invention (0.15 mass% or more and less than 0.35 mass%), and the conductivity is low.

In Comparative Example 3, the content of P was more than the range of the present invention (0.0005 mass% or more and less than 0.01 mass%). Since large cracks occurred during the rough rolling, the subsequent evaluation was suspended.

Comparative Examples 4 to 6 series [Mg]+20×[P] exceeded 0.5, and large cracks occurred during the rough rolling, so the subsequent evaluation was suspended.

In Comparative Example 7, the content of H was higher than the range of the present invention (10 massppm or less), and since large cracks occurred during the rough rolling, the subsequent evaluation was discontinued.

Comparative Example 8 The content of O is higher than the scope of the present invention (100massppm or less), as a result of performing the tensile test 10 times, the tensile test piece in the elastic region broke 8 times, and it was found that the workability was deteriorated due to the intermediary. The bending workability is also insufficient.

In Comparative Example 9, the S content was higher than the range of the present invention (50massppm or less). As a result of performing the tensile test 10 times, the tensile test piece in the elastic region was broken 8 times, and it was found that it was caused by the substance. The processability is deteriorated. The bending workability is also insufficient.

In Comparative Examples 10 and 11, the content of C is higher than the range of the present invention (10massppm or less). As a result of performing the tensile test 10 times, the tensile test piece in the elastic region broke 6 times and 7 times. Deterioration of workability due to intervening objects. The bending workability is also insufficient.

In contrast, in the examples of the present invention, it was confirmed that the castability, strength (0.2% endurance), electrical conductivity, stress relaxation resistance (residual stress ratio), and bending workability were excellent. Furthermore, as a result of performing the tensile test 10 times, it was confirmed that the tensile test piece in the elastic region was not broken, and the workability was particularly excellent.

Based on the above, it was confirmed that copper alloys for electronic/electric equipment and copper alloy sheets and strips for electronic/electric equipment with excellent conductivity, cold workability, bending workability, and castability can be provided by the examples of the present invention.

[Industrial availability]

Even in the case of components that have been thinned due to downsizing, it can provide copper alloys and electrical appliances for electronic/electrical equipment with excellent electrical conductivity, cold workability, bending workability, and castability. Copper alloy plates for sub/electric equipment, parts for electronic/electric equipment, terminals, bus bars, and movable pieces for repeaters.

Claims (14)

A copper alloy for electronic/electrical equipment, characterized in that it contains Mg in the range of 0.15 mass% or more and less than 0.35 mass%, and contains P in the range of 0.0005 mass% or more and less than 0.008 mass%. Cu and unavoidable impurities, the conductivity exceeds 75% IACS, and the content of Mg [Mg] (mass%) and the content of P [P] (mass%) meet: [Mg]+20×[ The relational expression of P]<0.5, H content is set to 10 massppm or less, O content is set to 100 massppm or less, S content is set to 50 massppm or less, and C content is set to 10 massppm or less. For example, the copper alloy for electronic/electric equipment in the first item of the scope of patent application, where the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy: [Mg]/[P] ≦400 relational expression. For example, the copper alloy for electronic/electric equipment in item 1 or item 2 of the scope of patent application, in which the 0.2% resistance when the tensile test is carried out in a direction orthogonal to the rolling direction is 300 MPa or more. For example, the copper alloy for electronic/electric equipment in the first item of the scope of patent application, wherein the residual stress rate is more than 50% at 150°C and 1000 hours. A copper alloy plate and strip for electronic/electrical machines, characterized by: from the electronic/ Made of copper alloy for electrical equipment. For example, the copper alloy plate and strip for electronic/electric equipment in the 5th item of the scope of the patent application has a Sn plating layer or an Ag plating layer on the surface. An electronic/electric machine part, which is characterized in that it is made of copper alloy plate and strip for electronic/electric machine as in item 5 or item 6 of the scope of patent application. For example, the electronic/electric machine parts of item 7 of the scope of patent application, which have Sn plating layer or Ag plating layer on the surface. A terminal, characterized in that it is made of copper alloy plates and strips for electronic/electrical equipment such as item 5 or item 6 of the scope of patent application. Such as the terminal of item 9 of the scope of patent application, which has Sn plating layer or Ag plating layer on the surface. A bus bar, which is characterized in that it is made of copper alloy plates and strips for electronic/electrical equipment such as item 5 or item 6 of the scope of patent application. For example, the bus bar of item 11 in the scope of patent application, which has a Sn plating layer or Ag plating layer on the surface. A movable piece for a repeater, which is characterized in that it is made of copper alloy plates and strips for electronic/electrical equipment such as item 5 or item 6 of the scope of patent application. For example, the movable piece for repeater in the scope of patent application, which has a Sn plating layer or Ag plating layer on the surface.

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