TW201802259A - Rolled copper alloy material, production method therefor and electrical/electronic part - Google Patents

Abstract

Provided is a rolled copper alloy material with excellent platability. The maximum height Rz of the rolled copper alloy material in the direction orthogonal to the rolling direction is 0.1 [mu]m to 3 [mu]m. The ratio Rv/Rp of the maximum valley depth Rv to the maximum peak height Rp in the direction orthogonal to the rolling direction is 1.2-2.5. The maximum height Rz in the direction parallel to the rolling direction is 0.1 [mu]m to 3 [mu]m. The average length RSm of roughness curve elements in the direction parallel to the rolling direction is 0.02 mm to 0.08 mm.

Description

Copper alloy rolled material, manufacturing method thereof and electric and electronic parts

The invention relates to a rolled material of copper alloy, a manufacturing method thereof, and electric and electronic parts.

As a material for electric and electronic parts, a copper alloy material having excellent electrical and thermal conductivity is widely used. In recent years, with the miniaturization and weight reduction of electrical and electronic equipment, and the accompanying high-density construction, the requirements for copper alloy materials used in these electrical and electronic equipment have also required various characteristics and plating properties. And solder wettability. A Cu-Ni-Si-based alloy called a Corson alloy is a copper alloy containing nickel and silicon. The Cu-Ni-Si alloy is strengthened by precipitating a Ni-Si intermetallic compound composed of nickel and silicon by heat treatment. The Cu -Ni-Si based alloys are also alloys with very high strengthening ability among many precipitation type alloys.

In the production of Cu-Ni-Si based alloys, silicon oxide compounds are formed near the surface by heat treatment or melt treatment. However, if the silicon oxide compounds remain in the final product, the properties such as plating properties and solder wettability will be affected. Significant degradation. Therefore, a pickling process is performed to remove the silicon oxide compound near the surface. However, in order to quickly and sufficiently remove the silicon oxide compound, the surface of the Cu-Ni-Si-based alloy is polished with a brush or buff after pickling, so that the surface is roughened and roughened (rough )surface. If the unevenness on the surface is large, defects may occur in the plating layer when plating is applied, and the appearance, adhesion, and corrosion resistance of the plating layer may be deteriorated.

Such problems are not limited to Carson alloys such as Cu-Ni-Si-based alloys and Cu-Co-Si-based alloys, but also Cu-Cr-based alloys in precipitation-type alloys containing oxidizable elements such as chromium, zirconium, and titanium These problems also exist in alloys such as (chrome copper), Cu-Zr-based alloys (zirconium copper), and Cu-Ti-based alloys (titanium copper). Copper alloy materials for electrical and electronic parts are often plated. By applying plating, solder wettability, appearance, electrical connectivity of electrical contacts, and sliding properties can be improved. In addition, it is possible to suppress oxidation, corrosion, and the like during processing, assembly, and use of electrical and electronic parts.

In recent years, the thermal load in the processing and assembly of electrical and electronic parts has continued to increase and the ambient temperature has continued to increase. The thermal load on copper alloy materials used in electrical and electronic parts has also increased. The degree of oxidation, corrosion, etc. also increases. Therefore, it is required to reduce the defects of the plating layer applied to the surface of the copper alloy material more than ever, and to suppress the peeling of the plating layer accompanying the defects and the oxidation and corrosion of the base material.

The so-called Carson alloy or precipitation-type alloys containing oxidizable elements such as chrome copper, zirconium copper, and titanium copper are liable to reduce the plating properties due to the above reasons, the occurrence of plating defects or the accompanying peeling of the coating or the Oxidation and corrosion easily occur. In order to prevent the above-mentioned situation, a method of attaching the plating layer thickly is adopted, but various disadvantages such as an increase in material cost, a waste of resources, and a reduction in bending workability may occur. The technique disclosed in Patent Document 1 improves the Cu-Ni-Si by controlling the surface roughness Ra, Ry in the direction orthogonal to the rolling direction, and the peak position in the frequency distribution curve of the uneven component representing the surface roughness. Plating properties of alloys. However, because of the above, it is desired to further improve the plating properties.

[Prior Art Literature] (Patent Literature) Patent Literature 1: International Publication No. 2009/044822

[Problems to be Solved by the Invention] A problem to be solved by the present invention is to provide a copper alloy rolled material with excellent plating properties and a method for manufacturing the same. In addition, the problem to be solved by the present invention is to provide an electric and electronic part that is difficult to cause oxidation or corrosion.

[Means for Solving the Problem] The copper alloy rolled material according to one aspect of the present invention is intended to have a maximum height Rz in a direction orthogonal to the rolling direction of 0.1 μm to 3 μm, and orthogonal to the rolling direction. The ratio Rv / Rp of the maximum depression depth Rv to the maximum protrusion height Rp in the direction of R is 1.2 or more and 2.5 or less, and the maximum height Rz in the direction parallel to the rolling direction is 0.1 μm or more and 3 μm or less, parallel to the rolling direction. The average length RSm of the roughness curve element in the direction is 0.02 mm or more and 0.08 mm or less.

In addition, a method for manufacturing a copper alloy rolled material in another aspect of the present invention is a method for manufacturing a copper alloy rolled material by rolling a raw material composed of a copper alloy, and the main purpose of the method is to provide fine rolling ( The finish rolling step is a step of finishing rolling at a working rate of 20% or more so that the surface of the obtained copper alloy rolled material satisfies all four conditions of A, B, C, and D described below. (Condition A) The maximum height Rz in the direction orthogonal to the rolling direction is 0.1 μm or more and 3 μm or less. (Condition B) The ratio Rv / Rp of the maximum depression depth Rv in the direction orthogonal to the rolling direction to the maximum protrusion height Rp is 1.2 or more and 2.5 or less. (Condition C) The maximum height Rz in a direction parallel to the rolling direction is 0.1 μm or more and 3 μm or less. (Condition D) The average length RSm of the roughness curve element in a direction parallel to the rolling direction is 0.02 mm or more and 0.08 mm or less. Furthermore, the electric and electronic component of another aspect of this invention aims at providing the copper alloy rolled material concerning the said aspect.

[Effects of the Invention] The copper alloy rolled material of the present invention has excellent plating properties. In addition, according to the method for producing a copper alloy rolled material according to the present invention, a copper alloy rolled material having excellent plating properties can be produced. Furthermore, regarding the electronic and electrical parts of the present invention, it is difficult to cause oxidation and corrosion.

An embodiment of the present invention will be described below with reference to the drawings. In addition, this embodiment is an example showing the present invention, and the present invention is not limited to this embodiment. In addition, various changes or improvements can be added to the present embodiment, and various changes or improvements can be added to the present invention.

The copper alloy rolled material of this embodiment is a copper alloy material having a plate shape, for example, formed by rolling a raw material composed of a copper alloy, and its surface satisfies all four conditions of A, B, C, and D described below. (Condition A) The maximum height Rz in the direction orthogonal to the rolling direction is 0.1 μm or more and 3 μm or less. (Condition B) The ratio Rv / Rp of the maximum depression depth Rv in the direction orthogonal to the rolling direction to the maximum protrusion height Rp is 1.2 or more and 2.5 or less. (Condition C) The maximum height Rz in a direction parallel to the rolling direction is 0.1 μm or more and 3 μm or less. (Condition D) The average length RSm of the roughness curve element in a direction parallel to the rolling direction is 0.02 mm or more and 0.08 mm or less. The maximum height Rz, the maximum protrusion height Rp, the maximum depression depth Rv, and the average length RSm of the roughness curve element are defined by JIS B0601 (2001).

Since the rolled material of the copper alloy of this embodiment has a surface whose surface roughness is controlled as described above, it has excellent plating properties. Therefore, the rolled copper alloy material according to this embodiment can be suitably used for electrical and electronic parts such as lead frames, relays, switches, connectors, and terminals. The electrical and electronic parts provided with the copper alloy rolled material of this embodiment are excellent in plating properties of the used copper alloy rolled material. Therefore, it is difficult to cause peeling of the plating layer during processing, construction, use, and the like. It is difficult to cause oxidation and corrosion of the base material (copper alloy rolled material).

Here, an example of the manufacturing method of the copper alloy rolled material of this embodiment is demonstrated. First, an ingot of a copper alloy having a desired alloy composition is produced by melt casting (melt casting step). Then, the obtained ingot of the copper alloy is subjected to a homogenization heat treatment (homogenization heat treatment step), and then hot rolled to form a plate shape (hot rolling step). Since a thick surface oxide film generated from the homogenizing heat treatment step to the hot rolling step is attached to the surface of the obtained plate-like object, this surface oxide film is removed by cutting (surface milling step).

Then, cold rolling is performed on the plate after removing the surface oxide film to obtain a desired plate thickness (cold rolling step), and then an aging heat treatment is applied to precipitate fine precipitates in the mother phase of the copper alloy (aging heat treatment step). ). Before, during, or after the cold rolling step, a melt recrystallization heat treatment (melt recrystallization heat treatment step) may be performed as needed. A surface oxide film is attached to the surface of the obtained plate-like substance by aging heat treatment, melt recrystallization heat treatment, and the like, so a pickling treatment and a surface polishing (acid washing step) for removing the surface oxide film are applied. This pickling step is a step in which the surface of the plate-like object is cleaned (acid-washed) with an acid, and then the surface of the plate-like object is polished (surface-polished) using a polishing wheel or a brush to remove the surface oxide film. .

Next, finish rolling is performed on the plate after the surface oxide has been removed by pickling and surface polishing, whereby not only the desired plate thickness but also the surface properties (surface roughness) are processed to meet the above requirements. All of the four conditions A, B, C, and D (finishing rolling step) are performed to obtain the copper alloy rolled material of this embodiment. After the finish rolling step, annealing may be applied to remove distortion (stress relief annealing step).

Then, the above-mentioned steps are described in further detail. The content of the melt casting step is not particularly limited, and a general method can be adopted. The homogenization heat treatment step is performed in order to dissolve the coarse second phase generated in the casting into the mother phase of the copper alloy as a solid solution. The coarse second phase is a crystal or coarse precipitate composed of an alloy component (additive element) of a copper alloy or an intermetallic compound. Since the coarse second phase in the mother phase of the copper alloy is reduced, it becomes easy to obtain characteristics such as good plating properties and solder wettability. In addition, by increasing the amount of solid solution in the mother phase of the alloy component, the amount of fine precipitates is increased in the subsequent aging heat treatment, and material properties such as strength, bendability, and stress relaxation resistance are easily obtained.

The homogenization heat treatment conditions can be appropriately set, but for example, heating can be performed at a temperature of 850 ° C. or higher and 1050 ° C. for 0.5 hour or more and 10 hours or less. Under these conditions, since the coarse second phase is sufficiently dissolved in the mother phase as a solid solution, it is easy to obtain not only characteristics such as good plating properties and solder wettability, but also strength and bending work. Material properties such as resistance and stress relaxation properties. In addition, if the temperature is too high, the ingot is likely to dissolve, and even if the processing time is long, the effect of the homogenization heat treatment may not be further improved. Therefore, the conditions of the homogenization heat treatment may be set in consideration of these points.

The hot rolling step is a step of rolling an ingot of a copper alloy into a plate shape and thinning it to a predetermined plate thickness. The conditions for hot rolling can be appropriately set, but can be performed at a temperature of 600 ° C. or higher and 1000 ° C. or lower, for example. After hot rolling, the obtained plate-like material is rapidly cooled by water cooling or the like. If the cooling of the plate is slow, coarse precipitates will be formed in the mother phase of the copper alloy during cooling. Not only the properties such as plating properties and solder wettability may be reduced, but also it is difficult to obtain strength, bending workability, and resistance. Material properties such as stress relaxation properties.

The conditions of the face milling step can be appropriately set. In the face milling step, when the thick surface oxide film cannot be completely removed, there is a concern that characteristics such as plating properties and solder wettability may be reduced. The cold rolling step is a step of rolling the plate-shaped object after removing the surface oxide film to make it thinner to a predetermined plate thickness. Conditions for cold rolling can be appropriately set. By implementing the cold rolling step before the aging heat treatment step, not only does the amount of precipitates increase during the aging heat treatment, but also the precipitates in the parent phase of the copper alloy are easily and uniformly precipitated. This makes it easy to obtain material characteristics such as strength, electrical conductivity, bending workability, and stress relaxation resistance.

The aging heat treatment step is a step of precipitating fine precipitates into a mother phase of a copper alloy by heat treatment. The conditions of the heat treatment can be appropriately set, but it is preferably performed at a temperature of 400 ° C. or higher and 600 ° C. or lower for 0.5 hours to 5 hours. Under these conditions, not only the amount of fine precipitates becomes sufficient, but also it is difficult to cause coarsening of the precipitates or dissolve into the mother phase of the copper alloy as a solid solution, so it is easy to obtain strength, electrical conductivity, and bending work. Material properties such as resistance and stress relaxation properties. In addition, since the surface oxide film formed on the surface is reduced, the surface oxide film can be sufficiently removed in a subsequent pickling step, and characteristics such as good plating properties and solder wettability are easily obtained.

The melt recrystallization heat treatment step is a step that can be performed arbitrarily before, during, or after the cold rolling step. By melt recrystallization heat treatment, coarse precipitates formed in the mother phase of the copper alloy during cooling after hot rolling can be dissolved into the mother phase of the copper alloy as a solid solution and the mother of the copper alloy can be dissolved. The phase becomes a recrystallized structure. As a result, coarse precipitates in the mother phase of the copper alloy are reduced, and thus characteristics such as good plating properties and solder wettability are easily obtained. In addition, since the amount of fine precipitates is increased by the subsequent aging heat treatment, it is easy to obtain material characteristics such as strength, electrical conductivity, bendability, and stress relaxation resistance. Furthermore, by making the parent phase of the copper alloy into a recrystallized structure, bending workability is easily obtained, and when manufacturing a copper alloy rolled material, it is easy to perform processing such as rolling.

The conditions for the melt recrystallization heat treatment can be appropriately set, but it is preferably performed at a temperature of 700 ° C. or higher and 1000 ° C. or lower for 1 second to 60 seconds. Under these conditions, not only coarse precipitates are sufficiently dissolved in the mother phase of the copper alloy as a solid solution, but recrystallization is also sufficiently performed. In addition, since the surface oxide film formed on the surface is reduced, the surface oxide film can be sufficiently removed in the subsequent pickling step, and characteristics such as good plating properties and solder wettability are easily obtained. Furthermore, since it is difficult to coarsen the crystal grains, it is easy to obtain material properties such as strength and bending workability, and it is easy to maintain the shape when manufacturing a copper alloy rolled material.

The pickling step is a step performed to remove a surface oxide film formed in a process such as an aging heat treatment and a melt recrystallization heat treatment, and the surface of the plate is treated with an acidic pickling solution (such as hydrochloric acid, sulfuric acid, etc.). , Nitric acid) washing (acid washing treatment), and then use a polishing wheel or a brush to polish the surface of the plate (surface grinding) to remove surface oxides. If the removal of the surface oxide film is insufficient, characteristics such as plating properties and solder wettability may be reduced. Although it is also considered that the surface oxides are removed only by pickling treatment without surface polishing, it would take considerable time to remove the surface oxide film using only the pickling treatment, and the surface oxide film may not be sufficiently removed, so plating Properties such as solderability and solder wettability.

In addition, the surface of the pickling step is polished, and the polishing wheel or brush is relatively moved in a direction parallel to the rolling direction to polish the surface of the plate. Therefore, the surface of the plate may be polished by the polishing wheel. Or a brush or the like to form rib-like irregularities in a direction parallel to the rolling direction. When the surface is polished in order to sufficiently remove the surface oxide film, the rib-like unevenness easily increases. In addition, the rib-like unevenness formed by the buffing wheel, brush, or the like is not only a simple-shaped unevenness, but also a "burr" as shown in Fig. 1. If such a "burr" exists, the pickling liquid used for a pickling process, the rolling oil used for rolling, etc. will remain on a surface easily. If large irregularities are formed on the surface of the plate, and residues such as pickling liquid or rolling oil are present, the plating properties are reduced. Therefore, it is necessary to perform an unevenness reduction process after the pickling step.

Such an unevenness reduction treatment is generally a rolling treatment or an acid dissolution treatment. However, in a normal rolling treatment, the plating properties may be reduced due to oil pits generated by the rolling. In the acid dissolution treatment, Oxide particles such as stains are generated by the dissolution of the acid, which may reduce the plating properties. Therefore, in the present embodiment, the unevenness reduction process is performed in the finishing rolling step in which rolling is performed under appropriate rolling conditions. That is, not only suppress the occurrence of oil pits and finish rolling, but also eliminate and reduce tendon-like irregularities or "burrs", etc., and control the surface properties (surface roughness), so that the plating properties are good.

In order to suppress the occurrence of oil pits and to reduce tendon-like irregularities or "burrs", it is necessary to appropriately set the conditions for finish rolling. For example, it is preferable to set the finishing rate of finishing rolling to 20% or more, more preferably 30% or more and 80% or less, and still more preferably 40% or more and 60% or less. If the processing rate is within the above range, the rib-like asperities or "burrs" generated in the pickling step will be sufficiently reduced by finishing rolling, and the surface properties (surface roughness) satisfying the above four conditions A, B, C, and D will be obtained. Rolled material of copper alloy. The larger the processing rate, the more easily the tendon-like irregularities or "burrs" generated during the pickling step are reduced, but the bending workability is also liable to be reduced.

The surface roughness Ra (specified by JIS B0601 (2001)) of the roll used for finishing rolling is preferably 0.01 μm or more and 1 μm or less. When the surface roughness Ra of the roll is smaller than 0.01 μm, the amount of rolling oil captured by the surface unevenness of the roll is reduced, and oil pits are easily formed in the finishing rolling step. On the other hand, if the surface roughness Ra of the roll is larger than 1 μm, the unevenness on the roll surface is easily transferred to the plate, and a copper alloy rolled material having a large uneven surface is easily obtained.

The diameter of the roll used for finishing rolling may be 30 mm or more and 300 mm or less. If the diameter of the roll is less than 30 mm, the processing rate of each roll path becomes smaller and the time required for finishing rolling becomes longer, so the yield of the copper alloy rolled material will be reduced. On the other hand, if the diameter of the roll is larger than 300 mm, the amount of roll oil involved in the finish rolling becomes large, and the oil pits tend to be deepened.

Next, the four conditions A, B, C, and D will be described. The maximum height Rz of the surface of the copper alloy rolled material in a direction orthogonal to the rolling direction is 0.1 μm or more and 3 μm or less. If the maximum height Rz in the direction orthogonal to the rolling direction is less than 0.1 μm, although the rib-like unevenness or “burr” generated in the pickling step is reduced, the number of oil pits generated may increase. On the other hand, if the maximum height Rz in the direction orthogonal to the rolling direction exceeds 3 μm, the rib-like irregularities or “burrs” generated in the pickling step cannot be sufficiently reduced, and the plating properties may be lowered.

The ratio Rv / Rp of the maximum depression depth Rv in the direction orthogonal to the rolling direction on the surface of the rolled material of the copper alloy with respect to the maximum protrusion height Rp is a value that is an index of the degree of reduction of the rib-like unevenness or "burr". When Rv / Rp in a direction orthogonal to the rolling direction is 1.2 or more and 2.5 or less, tendon-like irregularities or "burrs" are reduced, and plating properties are excellent. If Rv / Rp in a direction orthogonal to the rolling direction is less than 1.2, rib-like irregularities or "burrs" may not be sufficiently reduced, and plating properties may be low. On the other hand, if Rv / Rp in a direction orthogonal to the rolling direction exceeds 2.5, although rib-like asperities or "burrs" will be reduced, the number of oil pits generated may increase.

The maximum height Rz of the surface of the copper alloy rolled material in a direction parallel to the rolling direction is set to 0.1 μm or more and 3 μm or less. If the maximum height Rz in a direction parallel to the rolling direction is less than 0.1 μm, although the amount of oil pits generated is small, the reduction of the rib-like irregularities or “burrs” generated in the pickling step may be insufficient. On the other hand, if the maximum height Rz in a direction parallel to the rolling direction exceeds 3 μm, there is a fear that the oil pits caused by the finish rolling become deeper and the plating properties become lower.

The average length RSm of the roughness curve element on the surface of the copper alloy rolled material in a direction parallel to the rolling direction is a value that is an index of the amount of oil pits generated. When the average length RSm of the roughness curve element in a direction parallel to the rolling direction is 0.02 mm or more and 0.08 mm or less, the amount of oil pits generated is small and the plating properties are excellent. If the average length RSm of the roughness curve element in the direction parallel to the rolling direction is less than 0.02 mm, there is a fear that the amount of oil pits will increase and the plating properties will be lowered. On the other hand, if the average length RSm of the roughness curve element in a direction parallel to the rolling direction exceeds 0.08 mm, although the amount of oil pits is small, it is likely that the rib-like irregularities or "burrs" generated during the pickling step Mitigation will be inadequate.

The stress relief annealing step is a step that can be arbitrarily performed after the finishing rolling step. Through stress relief annealing, the bending workability, elasticity, and stress relaxation resistance of copper alloy rolled materials are improved. The conditions for stress relief annealing can be appropriately set, but in the case of batch heat treatment type annealing, for example, it can be performed at a temperature of 250 ° C or higher and 400 ° C or lower for 0.5 hours to 10 hours, and in the case of progressive heat treatment type annealing , It can be performed at a temperature of 300 ° C. to 600 ° C. for 1 second to 60 seconds. When the conditions of the stress relief annealing are within the above range, not only the reduction in strength and the increase in oxides formed on the surface can be suppressed, but also the stress relief annealing can be performed.

Next, the alloy composition of a copper alloy is demonstrated. Although the type of the copper alloy is not particularly limited, examples of usable copper alloys include copper alloys containing at least one of nickel and cobalt and silicon (Cu-Ni-Si based alloys, Cu-Co-Si Based alloys, etc.); copper alloys containing at least one of chromium, zirconium, and titanium (Cu-Cr based alloys (chrome copper), Cu-Zr based alloys (zirconium copper), Cu-Ti based alloys (titanium copper), etc. ).

Examples of copper alloys containing at least one of nickel and cobalt and silicon include copper alloys containing nickel in an amount of 1% by mass or more and 5% by mass or less and 0.5% by mass or more and 2.5% by mass or less. At least one of cobalt and silicon in an amount of 0.1% by mass to 1.5% by mass, and the remaining portion (the remaining portion) is composed of copper and unavoidable impurities. Here, the term “unavoidable impurities” means trace elements that are inadvertently mixed from a raw material or a furnace wall of a casting furnace during melt casting.

This copper alloy may contain other alloy components, for example, it may further contain at least one of magnesium, tin, zinc, manganese, and chromium. Examples of such a copper alloy include copper alloys containing at least one of nickel in an amount of 1% by mass to 5% by mass, and cobalt in an amount of 0.5% by mass or more and 2.5% by mass or less, and 0.1% by mass. Silicon above 1.5% by mass, and further containing magnesium exceeding 0% by mass and 0.5% by mass, tin exceeding 0% by mass and 1% by mass, zinc exceeding 0% by mass and 1.5% by mass, and exceeding 0% At least one of manganese by mass% and 0.5 mass% or less, and chromium by more than 0 mass% and 1 mass% or less, the balance is composed of copper and unavoidable impurities.

In addition, examples of the copper alloy containing at least one of chromium, zirconium, and titanium include copper alloys containing chromium in an amount of 0.05% by mass or more and 1% by mass or less, and 0.01% by mass or more and 0.2% by mass. At least one of the following zirconium and titanium in an amount of 0.01% by mass to 3.5% by mass is composed of copper and unavoidable impurities.

This copper alloy may contain other alloy components, for example, it may further contain at least one of silicon, magnesium, tin, zinc, manganese, iron, silver, cobalt, and nickel. Examples of such a copper alloy include a copper alloy containing 0.05% by mass or more and 1% by mass or less of chromium, 0.01% by mass or more and 0.2% by mass or less of zirconium, and 0.01% by mass or more and 3.5% by mass or less. At least one of the following titanium, and further containing more than 0% by mass and 0.1% by mass of silicon, more than 0% by mass and 0.5% by mass of magnesium, more than 0% by mass and 1% by mass of tin, and more than 0% Mass% and 1.5 mass% of zinc, more than 0 mass% and 0.5 mass% of manganese, more than 0 mass% and 0.5 mass% of iron, silver more than 0 mass% and 1 mass% of silver, and more than 0 mass% In addition, at least one of cobalt in an amount of 2 mass% or less and nickel in an amount of more than 0 mass% to 1 mass% is composed of copper and unavoidable impurities.

(1) Copper alloy containing at least one of nickel and cobalt, and silicon [About nickel] Nickel (Ni) is an element that forms a Ni-Si-based compound with silicon and improves strength. The content of nickel is preferably 1% by mass or more and 5% by mass or less. If the content is 1% by mass or more, the strength is sufficiently improved, and if it is 5% by mass or less, the conductivity and manufacturability are good.

[About Cobalt] Cobalt (Co) is an element that forms a Co-Si-based compound with silicon and increases its strength. The content of cobalt is preferably 0.5% by mass or more and 2.5% by mass or less. If the content is 0.5% by mass or more, the strength is sufficiently improved. If the content is 2.5% by mass or less, the conductivity and manufacturability are good.

[About Silicon] Silicon (Si) is an element that forms a silicon-based compound with nickel, cobalt, or other alloy components and increases strength. The content of silicon is preferably 0.1% by mass or more and 1.5% by mass or less. If the content is 0.1% by mass or more, the strength is sufficiently improved, and if it is 1.5% by mass or less, the conductivity and manufacturability are good. In addition, the formation of oxides due to heat treatment can be suppressed, and characteristics such as plating properties and solder wettability become good.

[About Magnesium] Magnesium (Mg) is an element that contributes to the improvement of strength, heat resistance, and stress relaxation characteristics. Although magnesium may not be added, when it is added, it is preferable that the magnesium exceeds 0% by mass and 0.5% by mass or less. When it is 0.5% by mass or less, the electrical conductivity and the manufacturability are good. In addition, the formation of oxides due to heat treatment can be suppressed, and characteristics such as plating properties and solder wettability become good.

[About tin] Tin (Sn) is an element that contributes to the improvement of strength, heat resistance, and stress relaxation characteristics. Although tin may not be added, when it is added, tin is preferably more than 0% by mass and 1% by mass or less. When it is 1% by mass or less, the electrical conductivity and the manufacturability are good.

[About Zinc] Zinc (Zn) is an element that contributes to the improvement of strength and solder wettability. Although zinc may not be added, in the case where zinc is added, it is preferably more than 0% by mass and 1.5% by mass or less. When it is 1.5% by mass or less, the electrical conductivity and the manufacturability are good.

[About Manganese] Manganese (Mn) is an element that contributes to the improvement of hot workability. Although no manganese may be added, in the case of addition, the manganese is preferably more than 0% by mass and 0.5% by mass or less. If it is 0.5% by mass or less, the conductivity is good.

[About Chromium] Chromium (Cr) is an element that contributes to the improvement of strength, heat resistance, and stress relaxation characteristics. Although chromium may not be added, when it is added, the chromium is preferably more than 0% by mass and 1.5% by mass or less. If it is 1.5% by mass or less, formation of oxides due to heat treatment can be suppressed, and characteristics such as plating properties and solder wettability become good. Moreover, the manufacturability is good.

(2) Copper alloy containing at least one of chromium, zirconium, and titanium [about chromium] Chromium contributes to the improvement of strength, heat resistance, and stress relaxation characteristics while maintaining high electrical conductivity. element. The content of chromium is preferably 0.05% by mass or more and 1.5% by mass or less. If it is 0.05% by mass or more and 1.5% by mass or less, it is possible to suppress changes in characteristics such as oxide formation, plating properties, and solder wettability due to heat treatment. Well. Moreover, the manufacturability is good.

[About Zirconium] Zirconium (Zr) is an element that contributes to improvement in strength, heat resistance, and stress relaxation characteristics while maintaining high electrical conductivity. The content of zirconium is preferably 0.01% by mass or more and 0.2% by mass or less. When the content of zirconium is 0.01% by mass or more and 0.2% by mass or less, it is possible to suppress changes in characteristics such as oxide formation, plating properties and solder wettability due to heat treatment. Well. Moreover, the manufacturability is good.

[About Titanium] Titanium (Ti) is an element that contributes to the improvement of strength, heat resistance, and stress relaxation characteristics. The content of titanium is preferably 0.01% by mass or more and 3.5% by mass or less. If the content of titanium is 0.01% by mass or more and 3.5% by mass or less, it is possible to suppress changes in characteristics such as oxide formation, plating properties and solder wettability due to heat treatment. Well. Moreover, the manufacturability is good.

[About Silicon] Silicon is an element that forms a silicon-based compound with chromium, zirconium, titanium, or other alloy components and increases strength. Although silicon may not be added, when it is added, the silicon content is preferably more than 0% by mass and less than 0.1% by mass. If it is less than 0.1% by mass, the strength is good.

[About Magnesium] Magnesium is an element that contributes to the improvement of strength, heat resistance, and stress relaxation properties. Although magnesium may not be added, when it is added, it is preferable that the magnesium exceeds 0% by mass and 0.5% by mass or less. When it is 0.5% by mass or less, the electrical conductivity and the manufacturability are good. In addition, the formation of oxides due to heat treatment can be suppressed, and characteristics such as plating properties and solder wettability become good.

[About tin] Tin is an element that contributes to improvements in strength, heat resistance, and stress relaxation characteristics. Although tin may not be added, when it is added, tin is preferably more than 0% by mass and 1% by mass or less. When it is 1% by mass or less, the electrical conductivity and the manufacturability are good.

[About Zinc] Zinc is an element that contributes to the improvement of strength and solder wettability. Although zinc may not be added, in the case where zinc is added, it is preferably more than 0% by mass and 1.5% by mass or less. When it is 1.5% by mass or less, the electrical conductivity and the manufacturability are good.

[About Manganese] Manganese is an element that contributes to the improvement of hot workability. Although no manganese may be added, in the case of addition, the manganese is preferably more than 0% by mass and 0.5% by mass or less. If it is 0.5% by mass or less, the conductivity is good.

[About iron] Iron (Fe) is an element that contributes to the improvement of strength and heat resistance. Although iron may not be added, in the case where it is added, the iron is preferably more than 0% by mass and 0.5% by mass or less. If it is 0.5% by mass or less, the conductivity is good.

[About silver] Silver (Ag) is an element that contributes to the improvement of strength and heat resistance. Although silver may not be added, when it is added, the silver is preferably more than 0% by mass and 1% by mass or less. When it is 1% by mass or less, the conductivity is good.

[About Cobalt] Cobalt is an element that increases strength. Although cobalt may not be added, when it is added, the cobalt is preferably more than 0% by mass and 2% by mass or less. If it is 2% by mass or less, the conductivity is good.

[About nickel] Nickel is an element that contributes to the improvement of strength. Although nickel may not be added, in the case where nickel is added, it is preferably more than 0% by mass and 1% by mass or less. When it is 1% by mass or less, the conductivity is good.

[Examples] Examples and comparative examples are described below to more specifically describe the present invention. A copper alloy ingot having an alloy composition shown in Tables 1 and 2 was produced, and a copper alloy rolled material was produced by the same method as the method for producing a copper alloy rolled material in the above embodiment. That is, the ingot is subjected to a homogenization heat treatment under the conditions of 850 to 1050 ° C. for 0.5 to 10 hours, hot rolling is applied to form a plate shape, and water cooling is performed. After that, the surface oxide film of the plate-like object is removed by a surface milling step, cold rolling is applied, and a melt recrystallization heat treatment is further performed under conditions of 700 to 1000 ° C. and 1 to 60 seconds.

Then, after cold rolling is further applied, an aging heat treatment is performed under the conditions of 400 to 600 ° C and 0.5 to 5 hours. After the aging heat treatment, an acid pickling treatment is applied and the surface of the polishing wheel is polished to remove the surface oxide film of the plate. After that, finish rolling is applied at a working ratio of 20% to 80%. In the finish rolling, a roll having a surface roughness Ra of 0.01 to 1 μm and a diameter of 30 to 300 mm is used. After the finish rolling, stress relief annealing was applied under conditions of 300 to 600 ° C. for 1 to 60 seconds to obtain a copper alloy rolled material.

[Table 1]

[Table 2]

The copper alloy rolled materials of Examples 1 to 42 and Comparative Examples 1 to 14 obtained in this manner were evaluated. The evaluation items are surface roughness and plating properties. Each evaluation method is described below. (Method for Measuring Surface Roughness) According to JIS B0601 (2001), the maximum height Rz, the maximum protrusion height Rp, and the maximum depression depth Rv of the copper alloy rolled material in the direction orthogonal to the rolling direction, and the roll The maximum height Rz in the direction parallel to the rolling direction and the average length RSm of the roughness curve element were measured using a surface roughness measuring machine SURFCORDER SE3500 manufactured by Kosaka Research Laboratory Co., Ltd. The measurement conditions were set to a measurement distance of 4 mm, a cutoff of 0.8 mm (based on JIS B0601 (2001)), a scanning speed of 0.1 mm / s, and a probe diameter of 2 μm. Each measurement was performed 3 times, and these average values were calculated as each measured value.

(Method for Evaluating Plating Property) A copper base plating film having a thickness of 0.5 μm was formed on a copper alloy rolled material, and the plating property of the copper base plating was evaluated. In addition, after a copper base plated film having a thickness of 0.5 μm was formed on a copper alloy rolled material, a silver plated film having a thickness of 1 μm was formed on the copper base plated film to evaluate the plating properties of the silver plated layer.

By copper underplating, the adhesion between the base material, that is, the rolled material of the copper alloy, and the silver plating film can be improved, and peeling of the silver plating film can be suppressed even in a high temperature environment. However, the thickness of the copper underplating film is thin, and when the surface of the substrate is rough or when oxide particles are present, defects are likely to occur. If a defect occurs in the copper underplating film, even if there are few defects in the silver plating film attached thereto, the silver plating film may peel off in a high-temperature environment. Therefore, in order to withstand the high temperature environment in recent years, it is important to make the copper base coating film free of defects and the silver plating film free of defects.

Hereinafter, methods of copper underplating and silver plating will be described. First, before applying the plating, a pretreatment is applied to the copper alloy rolled material. The content of the pretreatment is: performing cathodic electrolytic degreasing on the copper alloy rolled material at a current density of 2.5A / dm ² for 30 seconds in an aqueous solution of sodium hydroxide at a temperature of 60 ° C. and a concentration of 10% by mass, and then at a concentration of 10 A pickling treatment was performed in a mass% sulfuric acid aqueous solution for 30 seconds.

Then, for the copper alloy rolled material to which the pretreatment has been applied, only copper underplating, or copper underplating and silver plating are applied. The rectangular area of 30 mm in length and 50 mm in width on the surface of the copper alloy roll material was plated. Copper underplating is performed in a plating solution containing 65 g / L copper (I) copper cyanide, 85 g / L potassium cyanide, and 7.5 g / L potassium carbonate at a temperature of 45 ° C. and a current density. The conditions were 1.5 A / dm ² . Silver plating is performed in a plating solution containing 55 g / L silver potassium cyanide, 75 g / L potassium cyanide, 10 g / L potassium hydroxide, and 25 g / L potassium carbonate at a room temperature and a current density of 1.0. A / dm ² was performed.

After the plating was completed, the surface of the plated film was observed under an optical microscope at a magnification of 50 times, and it was confirmed whether the surface of the plated film was defective. Specifically, arbitrarily select three areas with a square length of 10 mm from the surface of the coating (however, the area is selected so as not to include a portion of 5 mm from the peripheral edge portion of the copper alloy rolled material), and a diameter of 5 μm is calculated. The number of the above-mentioned plating knobs and the number of places where no plating layer is attached (hereinafter, these are referred to as defects) are totaled the number of defects found in the aforementioned three areas.

Therefore, when the total number of defects was 5 or less, it was evaluated that the plating property was particularly good, and Tables 1 and 2 are indicated by "○" marks. In addition, when the total number of defects is 6 or more and 20 or less, it is evaluated that the plating properties are good, and Tables 1 and 2 are indicated by "△" marks. Furthermore, when the total number of defects was 21 or more, it was evaluated as poor plating property, and it was shown by the mark "x" in Tables 1 and 2.

Table 1 shows the evaluation results of the case where the copper alloy rolled material is composed of a copper alloy containing at least one of nickel and cobalt, and silicon. Table 2 shows the copper alloy rolled material composed of chromium, zirconium, and titanium. Results of an assessment of the situation of at least one copper alloy.

In Examples 1 to 18 and Examples 19 to 42, the surface properties of the copper alloy rolled material satisfy the requirements of the present invention, and thus the plating properties are good. In particular, since Examples 1 to 15 and 19 to 38 also satisfy the requirements for the alloy composition of the copper alloy, the amount of oxide on the surface is small, and the plating properties are particularly good.

In contrast, in Comparative Example 1 and Comparative Example 8, since the surface roughness Ra of the roll used for finishing rolling was as small as 0.005 μm, many oil pits were generated. Therefore, the average length RSm of the roughness curve element in the direction parallel to the rolling direction becomes smaller, Rv / Rp becomes larger, and the plating properties are poor. In Comparative Example 2 and Comparative Example 9, since the surface roughness Ra of the roll used for finishing rolling was as large as 2 μm, the unevenness on the surface of the roll was transferred to the copper alloy rolled material, and the surface of the copper alloy rolled material became rough. Therefore, the maximum height Rz in the direction orthogonal to the rolling direction becomes large, and the plating properties are poor.

In Comparative Example 3 and Comparative Example 10, since the diameter of the roll used for finishing rolling was as large as 400 mm, many oil pits were generated and the depth was large. Therefore, the average length RSm of the roughness curve element in the direction parallel to the rolling direction becomes smaller, the maximum height Rz in the direction parallel to the rolling direction becomes larger, and the plating properties are poor.

In Comparative Example 4 and Comparative Example 11, since the finishing rate of the finish rolling is as small as 15%, the reduction of the rib-like irregularities or "burrs" generated in the pickling step is not sufficient. Therefore, the average length RSm of the roughness curve element in the direction parallel to the rolling direction becomes larger, the maximum height Rz in the direction orthogonal to the rolling direction becomes larger, Rv / Rp becomes smaller, and the plating properties are poor.

In Comparative Example 5 and Comparative Example 12, since the finish rolling and stress relief annealing were not performed, rib-like irregularities or "burrs" were generated in the pickling step, and the average length of the roughness curve element in the direction parallel to the rolling direction RSm The larger the maximum height Rz in the direction orthogonal to the rolling direction, the smaller the Rv / Rp, and the poor the plating property.

In Comparative Example 6 and Comparative Example 13, after the stress-relief annealing step, an acid dissolution treatment was performed as the relief treatment, the average length RSm of the roughness curve element in the direction parallel to the rolling direction became larger, and Rv / Rp became larger. It is small, stains are generated, and the plating properties of the copper underplating are poor. Comparative Example 7 and Comparative Example 14 are the same as those disclosed in Patent Document 1. In the pickling step after the aging heat treatment, only the pickling treatment using an aqueous sulfuric acid solution is performed, and the surface polishing is not performed. Further, finish rolling with a working ratio of 20% and stress relief annealing under conditions of 400 ° C. and 15 seconds were performed. Therefore, Rv / Rp becomes small, and the surface oxide is not sufficiently removed, and the plating properties of the copper underplating are poor.

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FIG. 1 is an enlarged view showing a surface of a rolled copper alloy material in a manufacturing process.

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Claims (7)

A copper alloy rolled material having a maximum height Rz in a direction orthogonal to the rolling direction of 0.1 μm to 3 μm and a ratio of a maximum depression depth Rv in a direction orthogonal to the rolling direction to a maximum projection height Rp Rv / Rp is 1.2 or more and 2.5 or less, the maximum height Rz in the direction parallel to the rolling direction is 0.1 μm or more and 3 μm or less, and the average length RSm of the roughness curve element in the direction parallel to the rolling direction is 0.02 mm or more and 0.08mm or less. The copper alloy rolled material according to claim 1, wherein the copper alloy rolled material is composed of a copper alloy, the copper alloy contains 1 mass% or more and 5 mass% or less of nickel, and 0.5 mass% or more and At least one of 2.5% by mass or less of cobalt and silicon of 0.1% by mass or more and 1.5% by mass or less of silicon are contained, and the balance is composed of copper and unavoidable impurities. The copper alloy rolled material according to claim 1, wherein the copper alloy rolled material is composed of a copper alloy, the copper alloy contains 1 mass% or more and 5 mass% or less of nickel, and 0.5 mass% or more and At least one of 2.5% by mass or less of cobalt, and 0.1% by mass to 1.5% by mass of silicon, and further containing more than 0% by mass and 0.5% by mass of magnesium, more than 0% by mass and 1% by mass At least one of tin, zinc exceeding 0% by mass and 1.5% by mass, manganese exceeding 0% by mass and 0.5% by mass, and chromium exceeding 0% by mass and 1% by mass, and the remainder is made of copper and Composed of unavoidable impurities. The copper alloy rolled material according to claim 1, wherein the copper alloy rolled material is composed of a copper alloy, the copper alloy contains 0.05% by mass or more and 1% by mass of chromium, 0.01% by mass or more, and At least one of the zirconium of 0.2 mass% or less and the titanium of 0.01 mass% or more and 3.5 mass% or less has the remainder composed of copper and unavoidable impurities. The copper alloy rolled material according to claim 1, wherein the copper alloy rolled material is composed of a copper alloy, and the copper alloy contains 0.05% by mass or more and 1.5% by mass or less of chromium, 0.01% by mass or more, and At least one of 0.2% by mass or less of zirconium and 0.01% by mass or more and 3.5% by mass or less of titanium, and further containing more than 0% by mass and less than 0.1% by mass of silicon, more than 0% by mass and 0.5% by mass or less Of magnesium, tin of more than 0% by mass and 1% by mass, zinc of more than 0% by mass and 1.5% by mass, manganese of more than 0% by mass and 0.5% by mass, iron of more than 0% by mass and 0.5% by mass At least one of silver exceeding 0% by mass and 1% by mass, cobalt exceeding 0% by mass and 2% by mass, and nickel exceeding 0% by mass and 1% by mass, the remainder being made of copper and inevitable Consisting of impurities. A method for manufacturing a copper alloy rolled material, which is a method for manufacturing a copper alloy rolled material by rolling a raw material composed of a copper alloy. The method includes a finishing rolling step. The step is finishing rolling at a processing rate of 20% or more. The surface of the obtained copper alloy rolled material satisfies all of the following four conditions A, B, C, and D: (Condition A) The maximum height Rz in a direction orthogonal to the rolling direction is 0.1 μm or more and 3 μm or less (Condition B) The ratio Rv / Rp of the maximum depression depth Rv to the maximum protrusion height Rp in a direction orthogonal to the rolling direction is 1.2 or more and 2.5 or less; (Condition C) the maximum in the direction parallel to the rolling direction The height Rz is 0.1 μm or more and 3 μm or less; (Condition D) The average length RSm of the roughness curve element in a direction parallel to the rolling direction is 0.02 mm or more and 0.08 mm or less. An electrical and electronic part comprising the copper alloy rolled material according to any one of claims 1 to 5.