TW201738394A - 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 average number of particles of Mg-P-containing compound having the grain size of 0.1 [mu]m or more is 0.5 particle/[mu]m2 in observation by the scanning electron microscope.

Description

Copper alloys for electronic and electrical equipment, copper alloy strips for electronic and electrical equipment, electronic and electrical equipment parts, terminals, bus bars, and relay movable sheets

The present invention relates to an electronic device suitable for a connector, a press-fit terminal, a lead frame, a bus bar, a relay movable piece, and the like. Electronics for electrical machine parts. Copper alloy for electrical equipment, and by the electron. An electronic device made of copper alloy for electrical equipment. Copper alloy sheet and strip for electrical equipment, electronics. Parts for electrical equipment, terminals, bus bars, and movable parts for relays.

This application claims priority based on Japanese Patent Application No. 2016-069080 filed in Japan on March 30, 2016, and Japanese Patent Application No. 2017-063418 filed on March 28, 2017 in Japan. In this article.

In the past, terminals and relays for connectors or press fits The movable piece, the lead frame, the bus bar, etc. For electrical equipment parts, copper or copper alloy with high conductivity is used.

Here, with the miniaturization of electronic equipment or electrical equipment, the electronic equipment used in such electronic equipment or electrical equipment is also realized. Miniaturization and thinning of parts for electrical equipment. Therefore, the composition of the electrons. Materials for electrical machine parts require high strength and good bending workability. Further, the terminal of the connector used in a high-temperature environment such as an engine room of an automobile or the like is also required to have stress relaxation resistance.

As a connector or press-fit terminal, relay movable piece, lead frame, bus bar, etc. For the materials used for the parts for electrical equipment, for example, Patent Documents 1 and 2 propose a Cu-Mg-based alloy.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent No. 5045783 (B)

[Patent Document 2] Japanese Laid-Open Patent Publication No. 2014-114464 (A)

In the Cu-Mg-based alloy described in Patent Document 1, since the Mg content is large, the conductivity is insufficient, and it is difficult to apply it to applications requiring high conductivity.

Further, in the Cu-Mg-based alloy described in Patent Document 2, the Mg content is set to 0.01 to 0.5 mass%, and the P content is set to 0.01 to 0.5 mass%, which is not In consideration of the coarse compound which is greatly deteriorated in cold workability and bending workability, cold workability and bending workability are insufficient.

Further, in the Cu-Mg-based alloy described above, since the viscosity of the molten alloy of the copper alloy is increased by Mg, when P is not added, there is a problem that the castability is lowered.

And, recently, with electronics. The weight of the electric equipment is reduced, and the terminals such as connectors, relay movable sheets, and lead frames used in such electronic equipment and electric equipment are realized. Thinning of parts for electrical equipment. Therefore, in the terminals of the connector or the like, in order to secure the pressure bonding, it is necessary to perform a strict bending process, and it is required to have more bending workability than ever.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electron having excellent conductivity and bending workability. Copper alloys and electronics for electrical equipment. Copper alloy sheet and strip for electrical equipment, electronics. Parts for electrical equipment, terminals, bus bars, and movable sheets for relays.

In order to solve this problem, the present invention is the same state of the art. Copper alloy for electric equipment (hereinafter referred to as "the copper alloy for electric and electric equipment of the present invention") is characterized in that it contains Mg in a range of 0.15 mass% or more and less than 0.35 mass%, and is 0.0005 mass% or more. P is contained in the range of 0.01 mass%, and the remainder is formed of Cu and unavoidable impurities, and the conductivity is more than 75% IACS, and the compound containing Mg and P having a particle diameter of 0.1 μm or more is observed by scanning electron microscopy. The average number is 0.5/μm ² or less.

According to the above composition of the electron. In the copper alloy for electric equipment, since the Mg content is in the range of 0.15 mass% or more and less than 0.35 mass%, the mother phase of copper solid-melts Mg, so that the electrical conductivity is not greatly lowered, and the strength and stress resistance can be improved. Moderate properties. Specifically, since the electrical conductivity exceeds 75% IACS, it can also be applied to applications requiring high electrical conductivity. Further, since P is contained in a range of 0.0005 mass% or more and less than 0.01 mass%, the molten bath of the copper alloy containing Mg can be lowered, and the castability can be improved.

In addition, in the observation by scanning electron microscopy, the average number of compounds containing Mg and P having a particle diameter of 0.1 μm or more is 0.5/μm ² or less, so that the mother's phase is coarse and contains Mg and P. Since many of the compounds are not dispersed, the bending workability is improved. Therefore, it is possible to form a connector such as a connector of a complicated shape, a movable piece for relay, a lead frame, or the like. Parts for electrical equipment, etc.

Here, the electron of the present invention. In the copper alloy for electric equipment, the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the following relationship: [Mg] + 20 × [P] < 0.5.

In this case, the formation of a coarse compound containing Mg and P can be suppressed, and the cold workability and the bending workability can be suppressed from being lowered.

Moreover, the electron of the present invention. In the copper alloy for electric equipment, the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the following relationship: [Mg] / [P] ≦ 400.

In this case, the ratio of the Mg content at which the castability is lowered to the P content at which the castability is improved is defined as described above, and the castability can be surely improved.

Furthermore, the electron of the present invention. In the copper alloy for electric equipment, it is preferable that the 0.2% proof force in the tensile test in the direction orthogonal to the rolling direction is 300 MPa or more.

In this case, since the 0.2% proof force in the tensile test in the direction perpendicular to the rolling direction is defined as described above, it is not easily deformed, and is particularly suitable as a terminal for a connector or a press fit, and a movable piece for relay. , lead frame, bus bar and other electronic. Copper alloy for parts used in electrical equipment.

Also, the electron of the present invention. In the copper alloy for electrical equipment, the preferable residual stress rate is 150 ° C and 50% or more in 1000 hours.

In this case, since the stress relaxation rate is defined as described above, the permanent deformation can be suppressed to be small even when used in a high-temperature environment, and for example, the pressure contact of the connector terminal or the like can be suppressed from being lowered. Therefore, it can be applied to a material for an electronic device component used in a high temperature environment such as an engine room.

Other forms of the invention. Copper alloy strips for electrical equipment (hereinafter referred to as "the copper alloy sheet strips for electronic and electrical equipment of the present invention") are characterized by the above-mentioned electrons. Electrical equipment is made of copper alloy.

According to the composition of the electron. Copper alloy strips for electrical machines, due to the above mentioned electrons. Since the electrical equipment is made of a copper alloy, it is excellent in electrical conductivity, strength, bending workability, and stress relaxation resistance, and is particularly suitable as a terminal for a connector or a press fit, a movable piece for relay, a lead frame, a bus bar, and the like. electronic. Material for parts used in electrical equipment.

Also, the electron of the present invention. A copper alloy sheet material for an electrical machine is a strip containing a sheet which is to be wound into a coil shape.

Here, the electron of the present invention. In the copper alloy sheet material for electric equipment, it is preferred that the surface has a Sn plating layer or an Ag plating layer.

In this case, since the surface has a Sn plating layer or an Ag plating layer, it is particularly suitable as a connector, a terminal for press fitting or the like, a relay movable sheet, a lead frame, a bus bar, and the like. Material for parts used in electrical equipment. Further, 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.

Other forms of the invention. The parts for electrical equipment (hereinafter referred to as "the parts of the electronic and electrical equipment of the present invention") are characterized by the above-mentioned electrons. Electrical machines are made of copper alloy strips. Also, the electron of the present invention. The parts for electrical equipment include terminals such as connectors and press fits, movable sheets for relays, lead frames, bus bars, and the like. The composition of the electron. Parts for electrical equipment use the above-mentioned electronics. Since the electrical equipment is made of a copper alloy sheet material, it can exhibit excellent characteristics even when it is miniaturized and thinned.

Also, the electron of the present invention. In the parts for electrical equipment, the surface may also have a Sn plating layer or an Ag plating layer. Moreover, the Sn plating layer and the Ag plating layer may be formed in advance in the electron. Copper alloy sheet metal for electrical equipment can also be used to form electrons. Formed after parts for electrical equipment.

Other terminals of the present invention (hereinafter referred to as "terminals of the present invention") are characterized by the above-mentioned electrons. Electrical machines are made of copper alloy strips.

The terminal of this configuration is due to the use of the above mentioned electrons. Electrical equipment is made of copper alloy strips, so it can be used even when miniaturized and thinned. Excellent characteristics.

Further, in the terminal of the present invention, the surface may have a Sn plating layer or an Ag plating layer. Moreover, the Sn plating layer and the Ag plating layer may be formed in advance in the electron. Copper alloy strips for electrical equipment can also be formed after forming the terminals.

The bus bar of other aspects of the present invention (hereinafter referred to as "the bus bar of the present invention") is characterized by the above-mentioned electrons. Electrical machines are made of copper alloy strips.

This constituent bus bar uses the above-mentioned electrons. Since the electrical equipment is made of a copper alloy sheet material, it can exhibit excellent characteristics even when it is miniaturized and thinned.

Further, in the bus bar of the present invention, the surface may have a Sn plating layer or an Ag plating layer. Moreover, the Sn plating layer and the Ag plating layer may be formed in advance in the electron. Copper alloy sheet strips for electrical equipment can also be formed after forming bus bars.

Another embodiment of the relay movable sheet (hereinafter referred to as "the relay movable sheet of the present invention") is characterized by the above-mentioned electronic. Electrical machines are made of copper alloy strips.

The relay movable piece of this configuration uses the above-mentioned electrons. Since the electrical equipment is made of a copper alloy sheet material, it can exhibit excellent characteristics even when it is miniaturized and thinned.

Further, in the movable movable sheet of the present invention, the surface may have a Sn plating layer or an Ag plating layer. Moreover, the Sn plating layer and the Ag plating layer may be formed in advance in the electron. Copper alloy strips for electrical equipment can also be formed after the movable piece for forming the relay.

According to the present invention, an electron having excellent conductivity and bending workability can be provided. Copper alloys and electronics for electrical equipment. Copper alloy sheet and strip for electrical equipment, electronics. Parts for electrical equipment, terminals, bus bars, and movable sheets for relays.

Figure 1 is the electron of this embodiment. Flowchart of a method for producing a copper alloy for electrical equipment.

Fig. 2A is a photograph showing an example of the observation result of the compound of the present example.

Fig. 2B is a result of EDX analysis showing an example of the observation result of the compound of the present example.

Hereinafter, an electron according to an embodiment of the present invention. The electrical machine is described by a copper alloy.

The electron of this embodiment. The copper alloy for electric equipment has a composition containing Mg in a range of 0.15 mass% or more and less than 0.35 mass%, P in a range of 0.0005 mass% or more, less than 0.01 mass%, and the balance being Cu and inevitable. Made up of impurities.

Moreover, the electron of this embodiment. Conductive in copper alloys for electrical equipment The rate is over 75% IACS.

Moreover, the electron of this embodiment. In the copper alloy for electric equipment, the average number of compounds containing Mg and P having a particle diameter of 0.1 μm or more is 0.5/μm ² or less in scanning electron microscope observation.

Moreover, the electron of this embodiment. In the copper alloy for electrical equipment, the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the following relationship:

[Mg] + 20 × [P] < 0.5.

Further, in the present embodiment, the content [Mg] (mass%) of Mg and the content [P] (mass%) of P satisfy the following relationship: [Mg]/[P]≦400.

Moreover, the electron of this embodiment. In the copper alloy for electric equipment, the 0.2% proof force when the tensile test is performed in the direction orthogonal to the rolling direction is 300 MPa or more. That is, in the present embodiment, an electron is created. The rolled material of the copper alloy for electrical equipment is 0.2% in the tensile test in the final step of rolling in the direction perpendicular to the rolling direction.

Furthermore, the electron of this embodiment. In the copper alloy for electric equipment, the residual stress rate is 50% or more at 150 ° C for 1,000 hours.

Here, the reason for specifying the component composition, the compound, and various characteristics as described above will be described below.

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

Mg is solidified in the mother phase of the copper alloy without causing conductivity It is greatly reduced and has an effect of improving strength and stress relaxation properties.

Here, when the Mg content is less than 0.15 mass%, the effect of the action cannot be sufficiently exhibited. On the other hand, when the Mg content is 0.35 mass% or more, the electrical conductivity is largely lowered and the viscosity of the molten alloy of the copper alloy is increased, and the castability is lowered.

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

Moreover, 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. Further, in order to surely suppress a decrease in electrical conductivity and a decrease in castability, the upper limit of the Mg content is preferably set to 0.30 mass% or less, and more preferably 0.28 mass% or less.

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

The P system has an effect of improving the effect of casting properties.

Here, when the P content is less than 0.0005 mass%, the effect is not sufficiently exhibited. On the other hand, when the P content is 0.01 mass% or more, since a coarse compound containing a particle diameter of Mg and P of 0.1 μm or more is easily formed, the compound may be used as a fracture starting point, and cracks may occur during cold working or bending. .

Based on the above, in the present embodiment, the P content is set to be in the range of 0.0005 mass% or more and less than 0.01 mass%. Further, in order to surely improve the castability, the lower limit of the P content is preferably 0.0007 mass%. Above, it is better than 0.001 mass%. Further, in order to surely suppress the formation of the coarse compound, the upper limit of the P content is preferably less than 0.009 mass%, more preferably less than 0.008 mass%, still more preferably 0.0075 mass% or less, still more preferably 0.0050 mass% or less.

([Mg]+20×[P]<0.5)

As described above, by coexisting Mg and P, a compound containing Mg and P is produced.

Here, when the content of Mg [Mg] and the content of P [P] are set in the mass ratio, when [Mg] + 20 × [P] is 0.5 or more, the total amount of Mg and P is large, and Mg is contained. The compound of P and P are coarsened and have a high density distribution, and are prone to cracking during cold working or bending.

Based on the above, in the present embodiment, [Mg] + 20 × [P] is set to be less than 0.5. Further, in order to suppress the coarsening and high-density distribution of the compound, and to suppress the occurrence of cracks during cold working or bending, it is preferable that [Mg] + 20 × [P] is set to be less than 0.48, preferably less than 0.46. . It is even better than 0.44.

([Mg]/[P]≦400)

Since Mg has an element which increases the viscosity of the copper alloy molten bath and lowers the castability, it is necessary to appropriately increase the content of Mg and P in order to surely improve the castability.

Here, when the content of Mg [Mg] and the content of P [P] are set by mass ratio, when [Mg]/[P] exceeds 400, the Mg content increases with respect to P, and The effect of improving the castability by adding P becomes small.

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

Further, when [Mg]/[P] is excessively low, Mg is consumed as a compound, and there is a possibility that the effect of solidification of Mg cannot be obtained. In order to suppress the formation of a compound containing Mg and P, and to achieve an improvement in endurance and stress relaxation resistance by solid solution of Mg, the lower limit of [Mg]/[P] is preferably more than 20, more preferably more than 25.

(Inevitable impurities: 0.1 mass% or less)

As other unavoidable impurities, for example, 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, C, Si, Li, H, O, S, etc. These inevitable impurities have an effect of lowering the electrical conductivity, so the total amount is 0.1 mass% or less.

Further, since Ag, Zn, and Sn are easily mixed into copper to lower the electrical conductivity, the total amount is preferably less than 500 mass ppm. In particular, Sn greatly reduces the electrical conductivity, so it is preferably less than 50 mass ppm alone.

Further, Si, Cr, Ti, Zr, Fe, and Co particularly deteriorate the electrical conductivity and deteriorate the bending workability by forming a compound. Therefore, the total amount of these elements is preferably less than 500 mass ppm.

(compounds containing Mg and P)

The electron of this embodiment. In the copper alloy for electric equipment, the average number of compounds containing Mg and P having a particle diameter of 0.1 μm or more is 0.5/μm ² or less in scanning electron microscope observation. When such a large-sized compound is present in a large amount, the compound becomes a crack origin, and the bending workability is largely deteriorated.

As a result of investigation, when the average number of the compound containing Mg and P having a particle diameter of 0.1 μm or more is 0.5/μm ² or less, that is, when there is no or a small amount of a compound containing Mg and P, good bending is obtained. Processability.

In addition, in order to surely exhibit the above-described effects, the average number of compounds containing Mg and P having a particle diameter of 0.05 μm or more in the alloy is preferably 0.5/μm ² or less.

Further, the average number of the compounds containing Mg and P was observed by a field emission type scanning electron microscope at a magnification of 50,000 times and a field of view of about 4.8 μm ² to obtain an average value.

Further, the particle diameter of the compound containing Mg and P is defined as the long diameter of the compound (the length of the longest straight line drawn in the grain under the condition that the period is not tangent to the grain boundary) and the short diameter (intersecting with the right angle of the long diameter) The direction is the average of the length of the longest straight line when the period is not tangent to the grain boundary. The average number per unit area (number density) of the compound containing Mg and P having a particle diameter of 0.1 μm or more can be mainly controlled by the casting speed, the intermediate heat treatment temperature, and the heat treatment time. In order to reduce the above compound per unit area The average number (number density) can be achieved by setting the casting speed to fast and the intermediate heat treatment to a high temperature for a short period of time. The casting speed and the intermediate heat treatment conditions are appropriately selected.

(Electrical conductivity: more than 75% IACS)

The electron of this embodiment. In the copper alloy for electrical equipment, by setting the electrical conductivity to more than 75% IACS, it is possible to use electrons such as terminals for connectors, press-fits, relay movable sheets, lead frames, bus bars, and the like. Parts for electrical machines.

Also, the conductivity is preferably more than 76% IACS, more preferably more than 77% IACS, more preferably more than 78% IACS, and even more preferably more than 80% IACS.

(0.2% endurance: 300MPa or more)

The electron of this embodiment. In the copper alloy for electric equipment, by setting the 0.2% proof force to 300 MPa or more, it is particularly suitable as a terminal for a connector or press fit, a movable piece for relay, a lead frame, a bus bar, and the like. Material for parts used in electrical equipment. Further, in the present embodiment, the 0.2% proof force when the tensile test is performed in the direction in which the rolling direction is orthogonal is 300 MPa or more.

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

(residual stress rate: 50% or more)

The electron of this embodiment. In the copper alloy for electric equipment, as described above, the residual stress rate is 50% or more at 1000 ° C for 1,000 hours.

When the residual stress rate under these conditions is high, even when used in a high-temperature environment, the permanent deformation can be suppressed to be small, and the reduction in pressure bonding can be suppressed. Therefore, the copper alloy for an electronic device of the present embodiment can be suitably used as a terminal for use in a high-temperature environment around an engine room such as an automobile. In the present embodiment, the residual stress rate in the stress relaxation test in the direction in which the rolling direction is orthogonal is 150% or more and 1000% in 1000 hours.

Here, the residual stress rate is preferably 150 ° C, 60 hours or more in 1000 hours, more preferably 150 ° C, and 70% or more in 1000 hours.

Hereinafter, the electron of the present embodiment thus constituted is described. The manufacturing method of the copper alloy for electric equipment is demonstrated with reference to the flowchart shown in FIG.

(melting. casting step S01)

First, in the copper melting bath obtained by melting the copper raw material, the above elements are added to adjust the composition to prepare a copper alloy molten bath. Further, in the addition of various elements, an elemental monomer or a mother alloy can be used. Further, a raw material containing the above element may be used as a copper raw material and melted. Further, the recycled material and the scrap material of the alloy can also be used. Here, the copper melting bath is preferably a so-called 4NCu or 99.999 mass% or more so-called 5NCu having a purity of 99.99 mass% or more. In the melting step, in order to suppress the oxidation of Mg, and to reduce the hydrogen concentration, it is preferred to carry out environmental melting by an inert atmosphere (for example, Ar gas) having a low vapor pressure of H ₂ O, and the holding time during melting is preferably limited to a minimum.

Next, the composition-adjusted copper alloy molten bath is injected into the mold to produce an ingot. Further, in consideration of mass production, it is preferred to use a continuous casting method or a semi-continuous casting method.

At this time, when the molten bath is solidified, a compound containing Mg and P is formed as a crystallization product. Therefore, by increasing the solidification rate, the compound containing Mg and P can be made finer in size. Therefore, the cooling rate of the molten bath is preferably 0.5 ° C / sec or more, more preferably 1 ° C / sec or more, and most preferably 15 ° C / sec or more.

(homogenization/melting step S02)

Next, heat treatment is performed in order to homogenize and melt the obtained ingot. Inside the ingot, there is an intermetallic compound containing Cu and Mg as main components due to segregation and concentration of Mg during solidification. Therefore, in order to cause the segregation and the intermetallic compound or the like to disappear or decrease, the ingot is heated to a temperature of 300 ° C or more and 900 ° C or less, whereby Mg is uniformly diffused in the ingot to solidify the Mg. In the mother phase. Further, the homogenization/melting step S02 is preferably carried out in a non-oxidizing or reducing environment.

Here, when the heating temperature is less than 300 ° C, the melt formation is incomplete, and there is a residual amount of an intermetallic compound containing Cu and Mg as a main component in the mother phase. 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 becomes uneven. Therefore, the heating temperature is set to a range of from 300 ° C to 900 ° C.

Further, for the roughing efficiency and the uniformity of the structure to be described later, hot working may be performed after the homogenization/melting step S02. In this case, The processing method is not particularly limited, and for example, calendering, wire drawing, extrusion, groove rolling, forging, pressing, or the like can be employed. Further, the hot working temperature is preferably in the range of from 300 ° C to 900 ° C.

(Roughing step S03)

Roughing is performed for processing into a specific shape. Further, the temperature condition in the roughing step S03 is not particularly limited, but in order to suppress recrystallization or to improve dimensional accuracy, it is preferably in the range of -200 ° C to 200 ° C in cold working or warm working, particularly preferably Normal temperature. The processing ratio (rolling ratio) is preferably 20% or more, more preferably 30% or more. Further, the processing method is not particularly limited, and for example, calendering, wire drawing, extrusion, groove rolling, forging, pressing, or the like can be employed.

(intermediate heat treatment step S04)

After the roughening step S03, heat treatment is performed for the purpose of softening for thorough melt, recrystallization, or improvement in workability. The heat treatment method is not particularly limited. However, in order not to increase the particle diameter of the compound formed by crystallization or the like, it is necessary to carry out a heat treatment step at a high temperature and for a short period of time. Therefore, it is preferably maintained at 400 ° C or higher and 900 ° C or lower. The temperature is maintained for 5 seconds or more and 1 hour or less, more preferably 500 ° C or more and 900 ° C or less, and a holding time of 5 seconds or more and 30 minutes or less. The heat treatment is carried out in a non-oxidizing environment or a reducing environment.

Further, the cooling method after heating is not particularly limited, but a method in which the cooling rate such as water quenching is 200 ° C / min or more is preferably employed.

Further, the roughing step S03 and the intermediate heat treatment step S04 may be repeated.

(finishing processing step S05)

In order to process the copper material after the intermediate heat treatment step S04 into a specific shape, finishing processing is performed. Further, the temperature condition in the finishing processing step S05 is not particularly limited, but in order to suppress recrystallization or to suppress softening, it is preferably in the range of -200 ° C to 200 ° C in cold working or warm working. It is normal temperature. Further, although the processing ratio is appropriately selected to approximate the final shape, in order to improve the strength by work hardening in the finishing processing step S05, the processing ratio is preferably 20% or more. Further, when the strength is further improved, the processing ratio is preferably 30% or more, and the processing ratio is preferably 40% or more, preferably 60% or more. Further, since the bending workability is deteriorated due to an increase in the processing rate, it is preferably set to 99% or less.

(finishing heat treatment step S06)

Next, the plastic working material obtained by the finishing process step S05 is subjected to finishing heat treatment in order to improve the stress relaxation resistance and the low-temperature burn-off hardening, and to remove the residual deformation.

The heat treatment temperature is preferably in the range of from 100 ° C to 800 ° C, more preferably in the range of from 200 ° C to 700 ° C. Further, in the finishing heat treatment step S06, it is necessary to set the heat treatment conditions (temperature, time, and cooling rate) so as to prevent the strength from being greatly lowered by recrystallization.

For example, it is preferably kept at 300 ° C for about 1 second to 120 seconds. The heat treatment is preferably carried out in a non-oxidizing environment or a reducing environment.

The heat treatment method is not particularly limited, but it is preferably a short-time heat treatment using a continuous blister furnace based on the effect of reducing the production cost.

Furthermore, the finishing process step S05 and the finishing heat treatment step S06 described above may be repeated.

Thus, the electron of the embodiment is produced. Copper alloy sheet strips for electrical machines (sheets or strips made into coil shapes). Again, the electron. The thickness of the copper alloy sheet material for electrical equipment is in the range of more than 0.05 mm and 3.0 mm or less, preferably in the range of more than 0.1 mm and less than 3.0 mm. electronic. When the thickness of the copper alloy sheet material for electrical equipment is 0.05 mm or less, it is disadvantageous for use as a conductor for high current use, and when the thickness exceeds 3.0 mm, it is difficult to press press processing.

Here, the electron of this embodiment. Copper alloy strips for electrical machines can be used directly in electronics. For electrical equipment parts, it is also possible to form a Sn plating layer or an Ag plating layer having a thickness of about 0.1 to 100 μm on one or both sides of the board surface. At this time, electronics. The thickness of the copper alloy sheet strip for electrical equipment is preferably 10 to 1000 times the thickness of the plating layer.

Furthermore, by using the electrons of this embodiment. A copper alloy for electrical equipment (a copper alloy sheet material for electric and electric equipment) is used as a material, and a press or a bending process or the like is formed, and a terminal such as a connector or a press fit, a relay movable piece, and a lead frame can be formed. The electrons of the bus bar. Parts for electrical machines.

According to the electronic embodiment of the present embodiment constructed as above. electric In the copper alloy for machine, since the Mg content is in the range of 0.15 mass% or more and less than 0.35 mass%, Mg is solid-melted in the mother phase of copper without significantly lowering the electrical conductivity, thereby improving strength and resistance. Stress relaxation properties. Further, since P is made 0.0005 mass% or more and less than 0.01 mass%, the viscosity of the molten copper alloy containing Mg can be lowered, and the castability can be improved.

Moreover, the electron of this embodiment. In the copper alloy for electric equipment, since the electrical conductivity is set to more than 75% IACS, it can also be applied to applications requiring high electrical conductivity.

Moreover, the electron of this embodiment. In the copper alloy for electrical equipment, the average number of compounds containing Mg and P having a particle diameter of 0.1 μm or more is 0.5/μm ² or less in the observation by scanning electron microscopy. The coarse Mg/P-containing compound is dispersed as a crack initiation point to improve bending workability. Therefore, it is possible to form a connector such as a connector of a complicated shape, a movable piece for relay, a lead frame, or the like. Parts for electrical machines.

Moreover, the electron of this embodiment. In the copper alloy for electric equipment, since the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the relationship of [Mg] + 20 × [P] < 0.5, Mg and The formation of a coarse compound of P suppresses a decrease in cold workability and bending workability.

Furthermore, the electron of this embodiment. In the copper alloy for electric equipment, since the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the relationship of [Mg] / [P] ≦ 400, Mg which reduces castability is obtained. content The ratio of the P content which improves the castability is made appropriate, and the casting effect can be surely improved by the addition effect of P.

Moreover, the electron of this embodiment. In the copper alloy for electrical equipment, the 0.2% proof stress is 300 MPa or more, and the residual stress rate is 150° C. and 1000 hours is set to 50% or more. Therefore, the strength and stress relaxation resistance are excellent, and it is particularly suitable as a connector or a press fit. The terminal, relay movable piece, lead frame, bus bar and other electronic. Material for parts used in electrical equipment.

Moreover, the electron of this embodiment. Copper alloy strips for electrical machines, due to the above-mentioned electronics. The electrical machine is made of a copper alloy, so by means of the electron. For bending of copper alloy plates and strips for electrical equipment, it is possible to manufacture terminals such as connectors or press-fit terminals, relay movable sheets, lead frames, bus bars, and the like. Parts for electrical machines.

Further, when a Sn plating layer or an Ag plating layer is formed on the surface, it is particularly suitable as a terminal for a connector or a press-fit, a relay movable sheet, a lead frame, a bus bar, or the like. Material for parts used in electrical equipment.

Furthermore, the electron of this embodiment. Parts for electrical equipment (terminals for connectors or press-fits, movable sheets for relays, lead frames, bus bars, etc.), due to the above-mentioned electronics. Since the electrical equipment is made of a copper alloy, it can exhibit excellent characteristics even in miniaturization and flaking.

Although the above is directed to the electronic body of the embodiment of the present invention. Copper alloys and electronics for electrical equipment. Copper alloy sheet and strip for electrical equipment, electronics. The components for electrical equipment (terminals, bus bars, etc.) are described, but the present invention is not limited to these, and may be appropriately changed without departing from the technical idea of the present invention. more.

For example, the above embodiment is directed to electronics. An example of a method for manufacturing a copper alloy for electrical equipment, but an electron. The method for producing the copper alloy for electric equipment is not limited to those described in the embodiment, and may be produced by appropriately selecting a conventional manufacturing method.

[Examples]

Hereinafter, the results of the confirmation experiment performed to confirm the effects of the present invention will be described.

A copper raw material made of oxygen-free copper (ASTM B152 C10100) having a purity of 99.99 mass% or more was prepared, placed in a high-purity graphite crucible, and subjected to high-frequency melting in an atmosphere furnace set to an Ar gas atmosphere. In the obtained copper melting bath, various additive elements were added to prepare a composition shown in Table 1, and an ingot was injected into the mold to prepare an ingot. Further, in the examples 2, 19, and 20 of the present invention, a heat insulating material (ISOWOOL) mold was used, and in the inventive examples 21 and 22, a carbon mold was used, and the present invention examples 1, 3 to 18, 23 to 34, and comparative examples 1 to 3 were used. A copper alloy mold having a water-cooling function was used, and in Comparative Examples 4 and 5, an iron mold having a heater having a heating function was used as a mold for casting. The size of the ingot was set to be about 100 mm thick by about 150 mm wide and about 300 mm long.

The surface of the ingot was ground near the casting surface, and the ingot was cut and resized so that the final product thickness was 0.5 mm.

The block was heated in an Ar gas atmosphere for 4 hours under the temperature conditions shown in Table 2 to carry out homogenization/melting treatment.

Subsequently, after the rough rolling was carried out under the conditions described in Table 2, The heat treatment was carried out under the temperature conditions described in Table 2 using a salt bath.

The copper material subjected to the heat treatment is subjected to cutting in order to prepare an appropriate final shape, and surface grinding is performed in order to remove the oxide film. Subsequently, finishing rolling (finishing processing) was carried out at room temperature at a rolling ratio as described in Table 2, and a sheet having a thickness of 0.5 mm, a width of about 150 mm, and a length of 200 mm was produced.

Next, after finishing rolling (finishing processing), finishing heat treatment was performed in an Ar environment under the conditions shown in Table 2, followed by water quenching to prepare a sheet for property evaluation.

(casting)

As the evaluation of the castability, it was observed whether or not the surface roughness was observed at the time of casting. Those who barely saw surface roughness at all were recorded as A, those with a small surface roughness of less than 1 mm were recorded as B, and those with a surface roughness of 1 mm or more and less than 2 mm were recorded as C. Further, a surface roughness having a depth of 2 mm or more was recorded as D, and the evaluation was stopped during the period. The evaluation results are shown in Table 3.

Further, the term "surface roughness depth" means the surface roughness depth from the end portion of the ingot toward the center.

(compound observation)

For the rolling surface of each sample, mirror polishing and ion etching were performed. In order to confirm the compound containing Mg and P, it was observed by FE-SEM (field emission type scanning electron microscope) with a 10,000-fold field of view (about 120 μm ² / field of view).

Next, in order to investigate the density (unit/μm ² ) of the compound containing Mg and P, a 10,000-fold field of view (about 120 μm ² / field of view) was selected, and in this region, 10 fields of view (about 4.8 μm ² /) were continuously performed at 50,000 times. Shooting). The particle size of the intermetallic compound is defined as the long diameter of the intermetallic compound (the length of the longest straight line drawn in the grain under the condition that the grain boundary is not tangent to the grain boundary) and the short diameter (intersecting with the right angle of the long diameter) The average value of the direction, which is the length of the longest straight line when the period is not tangent to the grain boundary. Next, the density (unit/μm ² ) of the compound containing Mg and P having a particle diameter of 0.1 μm or more and the compound containing Mg and P having a particle diameter of 0.05 μm or more was determined. One of the observation results of the compound is exemplified in Figs. 2A and 2B.

(mechanical characteristics)

From the strip for characteristic evaluation, a test piece No. 13B prescribed by JIS Z 2241 was used, and 0.2% proof stress was measured by the offset method of JIS Z 2241. Further, the test piece was taken in a direction orthogonal to the rolling direction. The evaluation results are shown in Table 3.

(Conductivity)

A test piece having a width of 10 mm and a length of 150 mm was taken from the strip for characteristic evaluation, and the electric resistance was obtained by a 4-terminal method. Further, the size of the test piece was measured using micrometers, and the test piece volume was calculated. Next, the conductivity was calculated from the measured resistance value and volume. Further, the test piece was taken such that its longitudinal direction was perpendicular to the rolling direction of the specific evaluation strip. The evaluation results are shown in Table 3.

(stress mitigation characteristics)

The stress relaxation resistance test was carried out by measuring the load stress at a temperature of 150 ° C for 1000 hours by a single-end screw-type method according to the Japanese copper-clad association technical standard JCBA-T309:2004. The evaluation results are shown in Table 3.

As a test method, a test piece (width: 10 mm) was taken from the strip for characteristic evaluation in the direction perpendicular to the rolling direction, and the initial deflection of the surface of the test piece was set to 80% of the endurance, and the initial deflection displacement was set to 2mm, adjustable span length. The following formula determines the maximum stress of the above surface.

Surface maximum stress (MPa) = 1.5Etδ ₀ /L _s ²

but,

E: Young's modulus (MPa)

t: sample thickness (t=0.5mm)

δ ₀ : initial deflection displacement (2mm)

L _s : span length (mm)

After the bending tendency was maintained at a temperature of 150 ° C for 1,000 hours, the residual stress rate was measured, and the stress relaxation resistance was evaluated. Further, the residual stress rate was calculated using the following formula.

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

but,

δ _t : permanent deflection displacement (mm) after 1000 hours at a temperature of 150 ° C - permanent deflection displacement (mm) after 24 hours at room temperature

δ ₀ : initial deflection displacement (mm)

(bending workability)

The bending process was carried out according to the test method of the Japanese Copper Association Technical Standard JCBA-T307:2007. A test piece having a width of 10 mm and a length of 30 mm was used for the self-characteristic evaluation sheet so that the bending axis was orthogonal to the rolling direction, and the bending angle was 90 degrees, and the bending radius was 85% when the finishing rolling ratio was more than 85%. 0.5 mm (R/t = 1.0), W-bending test was carried out on a W-shaped jig having a bending radius of 0.3 mm (R/t = 0.6) when the finishing rolling ratio was 85% or less.

When the crack was observed on the outer peripheral portion of the curved portion, "C" was observed, and when large wrinkles were observed, it was recorded as B, and when no crack or fine crack was observed, and A large wrinkle was observed, it was judged as A. Further, A and B are judged to be allowable bending workability. The evaluation results are shown in Table 3.

In Comparative Example 1, the Mg content was less than the range of the present invention (0.15 mass% or more and less than 0.35 mass%), and the endurance and stress relaxation resistance were insufficient.

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

In Comparative Example 3, the P content was more than the range of the present invention (0.0005 mass% or more and less than 0.01 mass%), and cracking occurred in the intermediate rolling, which was not evaluated.

In Comparative Examples 4 and 5, the content of Mg and P was large, and the cooling rate at the time of casting was slow, so that there were many compounds and the bending workability was poor.

On the other hand, in the examples of the present invention, it was confirmed that the castability, the strength (0.2% proof), the electrical conductivity, the stress relaxation resistance (residual stress ratio), and the bending workability were excellent. Based on the above, it was confirmed that an electron having excellent conductivity and bending workability can be provided according to the example of the present invention. Copper alloys and electronics for electrical equipment. Copper alloy sheet strip for electrical equipment.

[Industrial Applicability]

The present invention provides an electron having excellent conductivity and bending workability even when used for a member which is thinned with miniaturization. Copper alloys and electronics for electrical equipment. Copper alloy sheet and strip for electrical equipment, electronics. Parts for electrical equipment, terminals, bus bars, and movable sheets for relays.

Claims (15)

A copper alloy for electric and electronic equipment, characterized in that it contains Mg in a range of 0.15 mass% or more and less than 0.35 mass%, and contains P in a range of 0.0005 mass% or more and less than 0.01 mass%, and the balance is Cu and In the unavoidable impurity, the conductivity is more than 75% IACS, and the average number of the compound containing Mg and P having a particle diameter of 0.1 μm or more is 0.5/μm ² or less in the scanning electron microscope observation. The copper alloy for electric and electronic machines according to claim 1, wherein the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the following relationship: [Mg] + 20 × [P] <0.5. The copper alloy for electric and electronic machines according to claim 1 or 2, wherein the content of Mg [Mg] (mass%) and the content of P [P] (mass%) satisfy the following relationship: [Mg]/[P] ≦400. The copper alloy for electrical and electronic equipment according to any one of claims 1 to 3, wherein a 0.2% proof force when subjected to a tensile test in a direction orthogonal to the rolling direction is 300 MPa or more. The copper alloy for electric and electronic machines according to any one of claims 1 to 4, wherein the residual stress rate is 50% or more at 150 ° C for 1,000 hours. A copper alloy sheet material for an electric and electronic machine, which is characterized by being a copper alloy for an electric and electronic machine according to any one of claims 1 to 5. A copper alloy sheet material for an electrical and electronic machine according to claim 6 The surface has a Sn plating layer or an Ag plating layer. A component for an electrical and electronic machine, characterized by being made of a copper alloy sheet material for an electrical and electronic machine as claimed in claim 6 or 7. The electric and electronic machine part according to claim 8, which has a Sn plating layer or an Ag plating layer on its surface. A terminal characterized by being formed from a strip of copper alloy sheet for an electrical and electronic machine as claimed in claim 6 or 7. The terminal of claim 10 has a Sn plating layer or an Ag plating layer on its surface. A bus bar characterized by a copper alloy sheet material for an electrical and electronic machine as claimed in claim 6 or 7. The bus bar of claim 12 has a Sn plating layer or an Ag plating layer on its surface. A relay movable sheet characterized by being formed of a copper alloy sheet material for an electric and electronic machine as claimed in claim 6 or 7. The relay movable sheet of claim 14 has a Sn plating layer or an Ag plating layer on its surface.