KR100929276B1 - Copper alloy - Google Patents

Abstract

As a copper alloy containing 2.0-4.5 mass% of Ni and 0.3-1.0 mass% of Si, and remainder consists of Cu and an unavoidable impurity,

Copper alloy for electronic devices with excellent bending workability, which satisfies the following formula (1):

Ⅰ {311} × A / (Ⅰ {311} + Ⅰ {220} + Ⅰ {200}) <1.5

In the above formula, I {311} is the X-ray diffraction intensity from the {311} plane on the plate surface; I {220} is the X-ray diffraction intensity from the {220} plane; I {20O} is the X-ray diffraction intensity from the {200} plane; A (μm) represents the crystal grain diameter, respectively.

Description

Copper Alloy {COPPER ALLOY}

The present invention relates to a copper alloy with improved properties.

With the recent miniaturization and high performance of electric and electronic devices, improvements in properties have also been required in all aspects of materials such as connectors used therein. Specifically, for example, the thickness of the plate material used for the spring contact portion of the connector is very thin, making it difficult to secure the contact pressure. That is, in the spring contact portion of the connector, the plate member (spring member) is usually bent, and the contact pressure necessary for the electrical connection is obtained by the reaction force. Therefore, when the thickness or thickness of the plate is reduced, it is necessary to increase the amount of warpage in order to obtain the same contact pressure. However, there may be a case where the sheet is plastically deformed beyond the elastic limit. For this reason, further improvement of an elastic limit is calculated | required by a board | plate material.

In addition, the material of the spring contact portion of the connector requires a variety of properties such as stress relaxation characteristics, thermal conductivity, bending workability, heat resistance, plating adhesion, migration resistance. Among them, mechanical strength, stress relaxation characteristics, thermal and electrical conductivity, and bending workability are important. By the way, although phosphor bronze is used in large quantities in the spring contact part of the said connector conventionally, phosphor bronze did not fully satisfy the said request | requirement. Therefore, in recent years, the conversion to the low beryllium copper alloy (alloy described in JIS C 1753) which is high intensity | strength, excellent in stress relaxation characteristic, and also excellent in electroconductivity is progressing.

In addition, there is an example of a Cu-Ni-Si-based alloy having a relatively high strength as a material having properties equivalent to those of low beryllium copper and having a low cost and high safety. In addition, the contact portion material has an example of a copper alloy in which the stress relaxation characteristics of the Cu—Ni—Si alloy are improved by the addition of Mg. There is also an example of a copper alloy having a strength equivalent to that of low beryllium copper by increasing the Ni and Si amounts of the Cu-Ni-Si-based alloy.

However, low beryllium copper is very expensive, and there is a problem that metal beryllium is toxic. Therefore, it is attempted to make Cu-Ni-Si type alloy high strength. However, excessively high amounts of Ni and Si deteriorate the bending workability, which is one of the required characteristics of the connector, and therefore, a limitation arises in the use of the connector that can be used. Specifically, when the bending process is performed, embrittlement cracks occur and the bending workability is lowered. Therefore, in the Cu-Ni-Si-based alloy, the strength, conductivity, and bending workability have never been comparable to those of low beryllium copper. Further, in the stress relaxation characteristic, even if Mg is added, it does not reach low beryllium copper.

Other features and advantages of the present invention are described in more detail below.

According to the present invention, the following means are provided.

[1] A copper alloy containing 2.0 to 4.5 mass% of Ni and 0.3 to 1.0 mass% of Si, with the balance being made of Cu and unavoidable impurities,

Copper alloy for electronic devices with excellent bending workability, which satisfies the following formula (1):

I {311} × A / (I {311} + I {220} + I {200}) <1.5. (One)

In Formula (1), I {311} is the X-ray diffraction intensity from the {311} plane on the plate surface; I {220} is the X-ray diffraction intensity from the {220} plane; I {20O} is the X-ray diffraction intensity from the {200} plane; A (μm) represents the crystal grain diameter, respectively.

[2] A copper alloy containing 2.0 to 4.5 mass% of Ni, 0.3 to 1.0 mass% of Si, and less than 0.005 mass% of S, with the remainder being Cu and inevitable impurities,

Copper alloy for electronic devices with excellent bending workability, which satisfies the following formula (1):

I {311} × A / (I {311} + I {220} + I {200}) <1.5. (One)

In Formula (1), I {311} is the X-ray diffraction intensity from the {311} plane on the plate surface; I {220} is the X-ray diffraction intensity from the {220} plane; I {20O} is the X-ray diffraction intensity from the {200} plane; A (μm) represents the crystal grain diameter, respectively.

[3] The copper alloy according to the above [1] or [2], further containing 0.2 to 1.5 mass% of Zn.

[4] The copper alloy according to any one of [1] to [3], further containing 0.01 to 0.2% by weight of Mg.

[5] The copper alloy according to any one of [1] to [4], further containing 0.05 to 1.5 mass% of Sn.

[6] 2.0-4.5 mass% of Ni, 0.3-1.0 mass% of Si, 0.01-0.2 mass% of Mg, 0.05-1.5 mass% of Sn, 0.2-1.5 mass% of Zn, and 0.005 mass% of S As a copper alloy containing less than the remainder and remainder Cu and an unavoidable impurity,

Copper alloy for electronic devices with excellent bending workability, which satisfies the following formula (1):

I {311} × A / (I {311} + I {220} + I {200}) <1.5. (One)

In Formula (1), I {311} is the X-ray diffraction intensity from the {311} plane on the plate surface; I {220} is the X-ray diffraction intensity from the {220} plane; I {20O} is the X-ray diffraction intensity from the {200} plane; A (μm) represents the crystal grain diameter, respectively.

[7] The resin according to any one of the above [1] to [5], wherein at least one selected from the group consisting of Zr from 0.005 to 0.3 mass%, Co from 0.05 to 2.0 mass%, and B from 0.001 to 0.02 mass% A copper alloy containing 0.001 to 2.0 mass% of one element in total.

[8] A copper alloy containing 2.0 to 4.5% by mass of Ni, 0.3 to 1.0% by mass of Si, 0.1 to 0.5% by mass of Cr, and less than 0.005% by mass of S, with the remainder being Cu and inevitable impurities,

A copper alloy which satisfies the following formula (2):

I {311} / (I {311} + I {220} + I {200}) <0.15. (2)

In Equation (2), I {311 is the X-ray diffraction intensity from the {311} plane on the plate surface; I {220 is the X-ray diffraction intensity from the {220} plane; I { 200} represents the X-ray diffraction intensity from the {200} plane, and A (µm) represents the crystal grain diameter, respectively.

[9] A copper alloy containing 2.0 to 4.5% by mass of Ni, 0.3 to 1.0% by mass of Si, 0.1 to 0.5% by mass of Cr, and less than 0.005% by mass of S, with the remainder being Cu and inevitable impurities,

A copper alloy which satisfies the following formula (3):

I {311} × A / (I {311} + I {220} + I {200}) <1.5... (3)

In Equation (3), I {311 is the X-ray diffraction intensity from the {311} plane on the plate surface; I {220 is the X-ray diffraction intensity from the {220} plane; I { 200} represents the X-ray diffraction intensity from the {200} plane, and A (µm) represents the crystal grain diameter, respectively.

[10] The copper alloy according to the above [8] or [9], further containing 0.2 to 1.5 mass% of Zn.

[11] The copper alloy according to any one of [8] to [10], further containing 0.01 to 0.2 mass% of Mg.

[12] The copper alloy according to any one of [8] to [11], which further contains 0.05 to 1.5 mass% of Sn.

[13] The composition of any one of the above [8] to [12], wherein the alloy has a composition of 0.005 to 0.3 mass% of Zr, 0.05 to 2.0 mass% of Co, 0.005 to 0.3 mass% of Ti, and 0.005 of Ag. The copper alloy which further contains-0.3 mass% and at least 1 sort (s) chosen from the group which consists of 0.001-0.02 mass% of B.

In the following, the first embodiment of the present invention includes the copper alloy described in the above [1] to [7].

The second embodiment of the present invention includes the copper alloy described in the above [8] to [13].

Hereinafter, the present invention shall include both of the first and second embodiments, unless specifically specified otherwise.

Best Mode for Carrying Out the Invention

The invention is described in detail below.

[First embodiment]

According to the first embodiment, in a copper alloy having a suitable strength and conductivity in which a Ni-Si compound is precipitated in the Cu matrix, bending workability can be improved by strictly controlling the degree of crystal orientation integration and the grain size of the crystal.

Below, the relationship of the crystal orientation of the copper alloy (henceforth simply a 1st copper alloy) in 1st Embodiment is demonstrated. In the copper alloy containing Ni and Si, the inventors have found that the degree of integration of the crystal orientation can be determined by limiting the X-ray diffraction intensity, and the bending workability and the strength are improved by a function derived therefrom. That is, bending workability and strength improve by satisfying following formula (1):

I {311} × A / (I {311} + I {220} + I {200}) <1.5. (One)

Here, I {311} is the X-ray diffraction intensity from the {311} plane on the plate surface, I {220} is the X-ray diffraction intensity from the {220} plane, and I {200} is {200}. The X-ray diffraction intensity from the surface, and A (µm) represent the crystal grain diameter.

In the formula (1), the definition of crystal orientation and grain size is less than 1.5, preferably less than 1.2. The lower limit of this value is not specified, but is generally 0.3 or more. If this value becomes too large, bending workability and strength will be incompatible. The copper alloy containing Ni and Si is recrystallized, and as the particle diameter becomes larger, the integration rate of {200} and {311} planes on the plate surface increases. Copper alloys increase the integration rate of the {220} plane in cold rolling at a higher reduction rate. The relationship between the crystal orientation density and the X-ray diffraction intensity is that the greater the X-ray diffraction intensity, the higher the degree of integration of the crystal orientation seen above. Here, the integration ratio (the degree of integration of the crystal orientation) of the X-ray diffraction surface refers to the ratio of the crystal growth degree in each diffraction surface direction, and can be evaluated by the ratio of the X-ray diffraction intensity (I) of each diffraction surface. Do. In this invention, it evaluates by the left side of Formula (1) (in this case, A = 1). The first copper alloy is, for example, "hot rolled", "cold rolled", "solventized", "aging", as required, followed by "cold-rolled" and "distortion elimination annealing". ) ". The degree of integration and crystal grain size of the crystal orientation change with a combination of solutionization preprocessing rate, solutionization condition, and quenching rate. In the present invention, the grain boundary embrittlement at the time of bending at the time of high concentration of Ni and Si is suppressed, and for the purpose of improving the bending workability, the equation (1) which defines the integration degree and crystal grain size of these crystal orientations is defined. By this, an appropriate range is obtained.

Below, the composition element of a 1st copper alloy is demonstrated.

The addition of Ni and Si in Cu, Ni-Si-based compound (Ni ₂ Si phase) is precipitated and to improve the strength and conductivity in the Cu matrix. The content of Ni is defined as 2.0 to 4.5 mass%. The reason is that when Ni content is less than 2.0 mass%, the strength more than equivalent to low beryllium copper cannot be obtained. On the other hand, if the Ni content is more than 4.5% by mass, precipitation occurs that does not contribute to the strength improvement during casting or hot working, so that the strength suitable for the added amount cannot be obtained, and the hot workability and bending workability are deteriorated, which adversely affects the problem. Because it happens. Preferably, the content of Ni is 2.2 to 4.2 mass%, more preferably 3.0 to 4.0 mass%.

Since Si forms a Ni ₂ Si phase together with Ni, the amount of Si added is determined when the amount of Ni is determined. If the amount of Si is less than 0.3% by mass, the same strength as that of the low beryllium copper cannot be obtained as in the case where the amount of Ni is small. Moreover, when Si amount exceeds 1.0 mass%, the same problem as the case where there is much Ni amount arises. Preferably Si content is 0.5-0.95 mass%, More preferably, it is 0.7-0.9 mass%.

The strength changes with the amount of Ni and Si, and the stress relaxation characteristics also change correspondingly. Therefore, in order to obtain the stress relaxation characteristic equivalent to or less than the low beryllium copper, it is necessary to reliably control the content of Ni and Si within the range of this embodiment. In addition, content of Mg, Sn, and Zn, crystal grain diameter, and crystal grain shape mentioned later are appropriately controlled.

Mg, Sn and Zn are important alloy elements constituting the present invention. These elements are related to each other to achieve a good balance of properties.

Mg greatly improves the stress relaxation characteristics, but adversely affects bending workability. In order to improve the stress relaxation characteristic, the amount of Mg is better, for example, 0.01 mass% or more. However, when content of Mg exceeds 0.20 mass%, bending workability will not satisfy a required characteristic. In the present invention, since the amount of strengthening due to precipitation of the Ni ₂ Si phase is significantly larger than that of the conventional Cu—Ni—Si alloy, the bending workability tends to be lowered, so the amount of Mg must be strictly controlled. The content of Mg is 0.10 to 0.2 mass%, preferably 0.05 to 0.15 mass%.

Sn further improves the stress relaxation characteristic in relation to Mg. However, the effect is not as great as Mg. When Sn is too low, an effect will not fully be exhibited, and when too large, electroconductivity will fall significantly. The content of Sn is usually 0.05 to 1.5 mass%, preferably 0.1 to 0.7 mass%.

Zn slightly improves bending workability. By specifying the amount of Zn at 0.2-1.5 mass%, even if it adds up to 0.2 mass% of Mg, the bending workability of the level which is satisfactory practically can be obtained. In addition, Zn improves the adhesiveness and migration characteristics of Sn plating and solder plating. If the amount of Zn is too low, the effect may not be sufficiently obtained. If the amount of Zn exceeds too much, the conductivity decreases. Content of Zn becomes like this. Preferably it is 0.3-1.0 mass%.

Next, subcomponent elements of Co and Zr effective for improving the strength will be described. Co, like Ni, forms a compound with Si to improve strength. If the content of Co is too low, the effect may not be sufficiently obtained. If the content of Co is too high, the bending workability is lowered. Content of Co is approximately 0.05-2.0 mass%, Preferably it is 0.1-1.0 mass%.

Zr finely precipitates in copper, contributes to strength improvement, and has an effect of lowering the crystal orientation density of Equation (1). If the content of Zr is low, the effect is not sufficiently obtained. If the content of Zr is too high, the bending workability deteriorates. From these viewpoints, the optimum content of Zr is made into 0.005 to 0.3 mass%. Preferably it is 0.05-0.2 mass%.

The total content in the case of adding 2 or more types of said Co, Zr, and B is 0.001-2.0 mass% according to a required characteristic, Preferably it is determined in the range of 0.005-2.0 mass%. B forms a compound with Ni and lowers the crystal orientation density in Formula (1). When content of B is too low, an effect will not fully be acquired, and when too high, hot workability will fall. From these viewpoints, the optimum content of B is 0.001-0.02 mass%, Preferably it is 0.005-0.01 mass%.

Although S is contained in a trace amount in a copper alloy, when too high, hot workability will deteriorate. Therefore, content of S is less than 0.005 mass%, Especially preferably, it is less than 0.002 mass%.

In the present invention, an appropriate amount of other elements such as Fe, P, Mn, Ti, V, Pb, Bi, and Al can be added in a range that does not lower the characteristics such as strength and conductivity. For example, Mn has the effect of improving the hot working characteristics, and it is effective to add 0.01 to 0.5% by mass to the extent that the conductivity is not deteriorated.

As the copper alloy containing Ni and Si is recrystallized and its grain size increases, the integration ratio of {200} and {311} planes on the plate surface increases, and the rolling ratio of {220} planes increases when rolling. .

The copper alloy is produced by, for example, hot rolling, cold rolling, solution treatment, aging treatment, and optionally cold rolling and distortion removal annealing as necessary. In this manufacturing process, each of the conditions of hot rolling (temperature time), cold rolling, solution treatment (temperature and time), and subsequent cold rolling (processing rate), which are carried out in a narrower range than the general conditions By controlling so as to control the accumulation ratio and the crystal grain diameter, the expression (1) can be satisfied.

In the production of the copper alloy, specifically, the hot rolling temperature in the range of 900 to 1,000 ° C., the cold rolling after hot rolling, 90% or more for the processing rate, and the solution treatment temperature within 20 seconds at the temperature of 820 to 930 ° C., cold The rolling is adjusted in the range of 30% or less to satisfy the formula (1).

The final plastic working direction refers to the rolling direction in the case where the finally processed plastic working is in the rolling process, and in the case of drawing (linear drawing). On the other hand, plastic working is rolling processing and drawing processing, and does not include the processing for the purpose of leveling (vertical leveling) using a tension leveler.

[2nd Embodiment]

In this embodiment, the Cu-Ni-Si-based alloy is improved to satisfy recent demands by the following means, and the amount of Cr and the crystal orientation of the copper alloy in which Ni and Si compounds are precipitated in the Cu matrix. By controlling the degree of integration, bending workability and strength are improved.

Each component element of the copper alloy of the second embodiment (hereinafter, simply referred to as a second copper alloy) will be described.

The addition of Ni and Si in Cu, Ni-Si-based compound (Ni ₂ Si phase) is known to improve the strength and conductivity by precipitating the Cu matrix. In this invention, content of Ni is 2.0-4.5 mass%, Preferably it is 2.2-4.2 mass%, More preferably, it is 3.0-4.0 mass%.

The reason for defining Ni content in this way is that if it is less than the lower limit, the strength which is not equal to or higher than that of copper beryllium is obtained. In addition, this is because a problem of adversely affecting hot workability and bending workability occurs.

Since Si forms Ni and Ni ₂ Si phases, the optimum amount of Si added is determined when the amount of Ni is determined. Si amount is 0.3-1.0 mass%, Preferably it is 0.5-0.95 mass%, More preferably, it is 0.7-0.9 mass%. When the amount of Si is small, the same strength as that of the beryllium copper cannot be obtained as in the case where the amount of Ni is small. If the amount of Si exceeds the upper limit, the same problem as in the case where the amount of Ni is large.

Cr limits the content and the X-ray diffraction intensity, thereby improving the bending workability and strength of the alloy sheet.

That is, by making Cr into 0.1-0.5 mass% and satisfy | filling Formula (2) Formula or Formula (3) mentioned later, both bending workability and strength are attained.

In addition, Cr is a Cr compound such as Cr-Si or Cr-Ni-Si in the alloy, which suppresses the coarsening of the crystal grain diameter during the solution treatment and lowers the crystal orientation density in the diet. However, if Cr is too small, the effect is not sufficiently obtained, and if too large, the bending workability deteriorates. From these viewpoints, Cr content is 0.1-0.5 mass%, Preferably it is 0.15-0.4 mass%.

Mg, Sn, and Zn are important alloying elements constituting the copper alloy of the present invention, and each of them realizes good characteristics in a balanced manner.

Mg improves stress relaxation characteristics, but adversely affects bending workability. In order to improve the stress relaxation characteristic, the amount of Mg is more preferably 0.01 mass% or more, but more than the required amount of Mg, the bending workability does not satisfy the required characteristics. In the present invention, since the amount of strengthening due to precipitation of the Ni ₂ Si phase is significantly larger than that of the conventional Cu—Ni—Si alloy, the bending workability tends to be lowered, so the amount of Mg must be strictly controlled. The content of Mg is approximately 0.01 to 0.2% by mass, preferably 0.05 to 0.15% by mass.

Sn is correlated with Mg to further improve stress relaxation characteristics. When there is too little Sn, the effect will not fully appear, and when too much Sn, electroconductivity will fall significantly. Content of Sn is approximately 0.05-1.5 mass%, Preferably it is 0.1-0.7 mass%.

Zn improves bending workability. By defining the amount of Zn at 0.2-1.5 mass%, the bending workability of the level which is satisfactory practically even if Mg is added up to 0.20 mass% can be obtained. In addition, Zn improves the adhesiveness and migration characteristics of Sn plating and solder plating. If the amount of Zn is too small, the effect is not sufficiently obtained. If the amount of Zn is exceeded, the conductivity decreases. Preferably it is 0.3-1.0 mass%.

Zr, Co, Ti, Ag, and B all have an effect of lowering the crystal orientation density of a diet to be described later.

Zr has the effect of lowering the crystal orientation density of the later diet and contributes to the strength improvement. When Zr is too low, the effect will not be fully acquired, and when too large, bending workability will deteriorate. From these viewpoints, content of Zr is made into 0.005 to 0.3 mass%. Preferably it is 0.05-0.2 mass%.

Co, like Ni, forms a compound with Si to improve strength and lowers crystal orientation density in a diet. The reason for specifying Co content as 0.05-2.0 mass% is because the effect is not fully acquired when it is lower than it, and when it is more, bending workability falls. Content of Co becomes like this. Preferably it is 0.1-1.0 mass%.

Co, like Cr, Zr, Ti, Ag, etc., has the effect of suppressing coarsening of the crystal grain diameter and lowering the crystal orientation density of the diet.

B has the effect of lowering the crystal orientation density in the diet. When content of B is too low, an effect will not fully be acquired, and when too much, hot workability will fall. From these viewpoints, the optimum content of B is 0.001-0.02 mass%, Preferably it is 0.005-0.01 mass%.

Ti improves the heat resistance and strength, and suppresses the coarsening of the grain size, thereby reducing the crystal orientation density of the diet. If the amount of Ti is too low, the effect is not sufficiently obtained. If the amount of Ti is too high, unemployed Ti remains, and the effect is not obtained, and adversely affects the plating property. From these viewpoints, the addition amount of Ti is 0.005-0.3 mass%, Preferably it is 0.05-0.2 mass%.

Ag has the effect of improving the heat resistance strength, suppressing coarsening of the grain size, and lowering the crystal orientation density of the diet. If the amount of Ag is too low, the effect is not sufficiently obtained, and even if a large amount of Ag is added, there is no adverse effect on characteristics but the cost is high. From these viewpoints, Ag amount is 0.005-0.3 mass%, Preferably it is 0.05-0.2 mass%.

The total content in the case of adding two or more kinds of Co, Zr, Ti, Ag, and B at the same time is determined within the range of 0.005 to 2.0% by mass depending on the required characteristics.

Although S is contained in a trace amount in a copper alloy, when too much, hot workability deteriorates, the content is prescribed | regulated to less than 0.005 mass%. Especially less than 0.002 mass% is preferable.

In this invention, you may add Fe, P, Mn, V, Pb, Bi, Al, etc. in an appropriate amount in the range which does not reduce characteristics, such as intensity | strength and electroconductivity. For example, Mn has an effect of improving hot workability, and it is effective to add 0.01 to 0.5% by mass to the extent that the conductivity is not deteriorated.

Next, the crystal orientation of the second copper alloy will be described.

In the copper alloy containing Ni and Si, the crystals are recrystallized, and as the particle diameter increases, the integration ratio of the {200} and {311} planes to the plate surface increases, and when rolled, the integration ratio of the {220} planes is obtained. This increases.

The second copper alloy is produced by, for example, hot rolling, cold treatment, aging treatment, if necessary, followed by finishing cold rolling and distortion elimination annealing, but in this manufacturing process, for example, hot rolling (temperature And time), subsequent cold rolling and solution treatment (temperature time) and subsequent cold rolling processes (processing rate). Can be controlled.

The present inventors have found that bending workability and strength improve that the crystal orientation integration degree obtained from the X-ray diffraction intensity indicating this integration ratio is in a specific range. Here, the integration ratio (degree of integration of crystal orientation) of the X-ray diffraction surface refers to the ratio of crystal growth degree in each diffraction surface direction, and can be evaluated by the ratio of X-ray diffraction intensity (I) of each diffraction surface. Do. Specifically, the X-ray diffraction intensity from the {311} plane on the plate surface is represented by the X-ray diffraction intensity from the {I} 311 and {220} planes and the X-ray diffraction intensity from the {{220} and {200} planes. When I is set to {{200}, bending workability and strength are improved as long as the following formula (2) is satisfied and the above limited Cr amount is obtained.

I {311} / (I {311} + I {220} + I {200}) <0.15. … … (2)

In the formula (2), the value of crystal orientation density is 0.15 or less, preferably 0.12 or less. If this value is too large, bending workability and strength will not be compatible.

Similarly, the X-ray diffraction intensity from the {311} plane on the plate surface and the X-ray diffraction intensity from the {I} 311 and {220} planes and the X-ray diffraction intensity from the I {220} and {200} planes. When I is set to {{200} and the crystal grain diameter is set to A (µm), the bending workability and the tensile strength are improved by satisfying the following formula (3).

I {311} × A / (I {311} + I {220} + I {200}) <1.5. … … (3)

In the formula (3), the regulation obtained from the crystal orientation density and the grain size is 1.5 or less, preferably 1.2 or less. If this value is too large as mentioned above, bending workability and strength will be incompatible. For this reason, the smaller the crystal grain diameter is, the better it is preferably less than 10 µm, and still more preferably 5 to 8 µm.

In the production of the second copper alloy, specifically, the hot rolling temperature in the range of 900 to 1,000 ° C., the cold rolling after hot rolling is 90% or more for the processing rate, and the solution treatment temperature is within 20 seconds at 820 to 930 ° C. The cold rolling is adjusted in the range of 30% or less, and the expression (2) or (3) is satisfied.

According to the present invention, for example, it is possible to provide a copper alloy which is a material such as a terminal, a connector, a switch, etc., which has strength, conductivity, and bendability, and in some cases, even stress relaxation characteristics.

The copper alloy of the present invention is excellent in strength, conductivity, and bendability (the first embodiment), and in addition to these, stress relaxation characteristics (the second embodiment). The copper alloy material which processed this can respond to the miniaturization and high performance of the said electronic component. Although the copper alloy of this invention is suitable for the use of a terminal, a connector, a switch, etc., it is suitable also as general conductive materials, such as other switches and a relay.

EXAMPLE

Although this invention is demonstrated in more detail based on an Example below, this invention is not limited to these. In the examples, Examples 1 and 2 are the first embodiment, and Examples 3 and 4 are the respective examples of the second embodiment.

(Example 1)

(Ingots No.A to V, WA to WH, X, Z) of the copper alloy of the prescribed composition shown in Table 1 were dissolved in a high frequency melting furnace and cast into a ingot having a thickness of 30 mm, a width of 100 mm, and a length of 150 mm by the DC method. . Subsequently, these ingots were heated at 1,000 degreeC, hold | maintained at this temperature for 1 hour, and then hot rolled to thickness 12mm, and cooled rapidly.

Subsequently, the hot rolled plate was cut by 1.5 mm on both sides, and the oxide film was removed, followed by cold rolling (a) to a thickness of 0.15 to 025 mm, followed by changing the solution treatment temperature in a temperature range of 825 to 925 ° C. Heat treatment was performed for 15 seconds, and then immediately cooled at a cooling rate of 15 ° C./sec or more.

Subsequently, an aging treatment was performed at 475 ° C. for 2 hours in an inert gas atmosphere, and then cold rolling (c), which is a final plastic working, was performed to prepare a final sheet thickness of 0.15 mm. After the final plastic working, further low temperature annealing was performed at 375 ° C. for 2 hours to prepare a copper alloy sheet material (Paper Nos. 1 and 5 to 41).

(Example 2)

The copper alloy (Ingot No. J) of the prescribed composition described in Table 1 was processed on condition of the following, and the copper alloy plate material of thickness 0.15mm was manufactured. In other words, the production conditions were the same as those in Example 1 until the oxide film was removed after hot rolling, and then processed to a thickness of 0.15 to 0.5 mm by cold rolling (a), and then the solution treatment temperature. Heat treatment is performed for 15 seconds in the temperature range of 825 ° C to 925 ° C, and then immediately cooled at a cooling rate of 15 ° C / sec or more.

Thereafter, cold rolling (b) having a reduction rate of 50% or less is performed, and then, after aging treatment in an inert gas atmosphere under the same conditions as in Example 1, the final plastic working (cold rolling (c), final sheet thickness: 0.15 mm) ), Low temperature annealing was carried out to produce copper alloy sheet materials (Samples No. 2 to 4).

TABLE 1

NOTE The balance of each alloy is copper and inevitable impurities; "-" Is not added

For each copper alloy sheet produced above, ① crystal grain diameter, ② crystal orientation, ③ tensile strength, ④ conductivity, and ⑤ bendability were evaluated. The crystal grain diameter of ① was measured based on JIS H0501 (cutting method).

(2) The crystal orientation made X-rays incident on the surface of the copper alloy plate in the final product state (0.15 mm thickness), and measured the intensity from each diffraction surface. Among them, the diffraction intensities of {200}, {220} and {311} planes having a strong correlation with bending workability were compared to determine the crystal orientation intensity ratio ([I {311} × A / (Ⅰ {311} + I {220}). + I {200})]). On the other hand, the conditions of X-ray irradiation are the kind of X-ray CuK (alpha) 1, a tube voltage of 40 kV, and a tube current of 20 mA. (3) Tensile strength was calculated | required based on JISZ 2241 using the 5 test piece of JISZ2201.

(4) Conductivity was calculated | required based on JISH0505. Evaluation of the bending workability of (5) was based on the method described in JIS H3110. The test piece width was 10 mm, and it bent under the load of 1000 kgf. The test piece sampling direction is set to GW (axis of bending perpendicular to the rolling direction) and BW (axis of bending parallel to the rolling direction), and the minimum bending radius R at which cracking does not occur and the ratio R / t of the test plate thickness t Rated by

As apparent from Table 2, Sample Nos. 1, 5 to 19 (Example 1), and Sample Nos. 2 to 4 (Example 2) had a bending workability (R / t) of less than 2, a tensile strength of 800 MPa or more, The electrical conductivity satisfies all 35% IACS or more, and it has the outstanding characteristic. Further, Sample Nos. 34 to 41 were slightly inferior in tensile strength, but had a bending workability (R / t) of less than 2 and a conductivity of 35% IACS or more, and had excellent characteristics.

On the other hand, Sample No. 20-25 (comparative example) is an example in which the value of Formula (1) becomes out of specification and it is inferior to bending workability. This is considered to be because the solution treatment temperature was too high.

No. 26 (comparative example) had a large amount of Ni and Si, so that cracks occurred during hot working and could not be normally produced.

No. 27 (comparative example of the above item [3]) satisfies the value of formula (1) and is excellent in bending workability, but is poor in electrical conductivity because of a large amount of Zn.

No. 28 (the comparative example of the said item [4]) is inferior to bending workability because there is much Mg amount.

No. 29 (comparative example of item [5]) had a large amount of Sn, and thus could not be produced because edge cracks occurred during cold rolling.

No. 31 (the comparative example of the above-mentioned item [7]) has many Bs, and therefore cracks occurred during hot working and could not be normally produced.

No. 32 (the comparative example of the above-mentioned item [2]) had a large content of S, so that cracks occurred during hot working, and the production was stopped.

No. 33 provided the value of Formula (1) outside the range prescribed | regulated by this invention, and since Ni and Si amount are small, it is inferior in strength and does not reach beryllium copper.

TABLE 2

(Example 3)

Copper alloy (Ingot No.2-A to 2-O, 2-PA to 2-PH, 2-Q to 2-S, 2-Z, 2-A-1) of the component composition shown in Table 3 is a high frequency melting furnace. It melt | dissolved in the and cast by the DC method to the ingot of thickness 30mm, width 100mm, and length 150mm. Subsequently, these ingots were heated at 1,000 degreeC, hold | maintained at this temperature for 1 hour, and then hot rolled to thickness 12mm, and cooled rapidly.

Next, the hot rolled sheet was cut by 1.5 mm on each side of each side to remove the oxide film, followed by cold rolling (2-a) to a thickness of 0.15 to 0.25 mm, and then the solution treatment temperature was 825 ° C to 925 ° C. Heat was changed for 15 seconds in the temperature range, and then immediately cooled at a cooling rate of 15 ° C./sec or more. Next, an aging treatment was performed at 475 ° C. for 2 hours in an inert gas atmosphere, and then cold rolling (2-c), which is a final plastic working, was carried out, and the final sheet thickness was brought to 0.15 mm. After the final plastic working, a low temperature annealing was performed at 375 ° C. for 2 hours to prepare a copper alloy sheet (sample Nos. 2-0 to 2-2, 2-1-1, and 2-5 to 2-30). did.

(Example 4)

The copper alloy (Ingot No. 2-B) of the component composition described in Table 3 was processed on condition of the following, and the copper alloy plate material of thickness 0.15mm was manufactured. In other words, the production conditions were the same as those in Example 3 until the oxide film was removed after hot rolling, followed by cold rolling (2-a) to a thickness of 0.15 to 0.5 mm, followed by solution treatment. The temperature is heat treated for 15 seconds in the temperature range of 825 ° C to 925 ° C, and then immediately cooled at a cooling rate of 15 ° C / sec or more. Thereafter, cold rolling (2-b) of 50% or less is performed, and then, under the same conditions as in Example 3, an aging treatment is performed in an inert gas atmosphere, and the final plastic working (cold rolling (2-c), final Low-temperature annealing was carried out through plate | board thickness: 0.15 mm, and the copper alloy plate materials (sample No. 2-3 and 2-4) were produced.

TABLE 3

NOTE The balance of each alloy is copper and inevitable impurities; "-" Is not added

For each copper alloy sheet produced in Examples 3 and 4, ① crystal grain diameter, ② crystal orientation, ③ bending workability, ④ tensile strength, ⑤ conductivity, ⑥ stress relaxation characteristics were measured and evaluated.

(1) The crystal grain diameter was measured based on JIS H 0501 (cutting method).

(2) The crystal orientation made X-rays incident on the surface of the copper alloy plate in the final product state (0.15 mm thickness), and measured the intensity from each diffraction surface. Among them, diffraction intensities of {200} and {220} grade {311} planes were compared, and crystal orientation density ([I {311} / (I {311} + I {220} + I {200})]), And I {311} × A / (I {311} + I {220} + I {200}). On the other hand, the conditions for X-ray irradiation were X-ray kind: CuKα1, tube voltage: 40 kV, and tube current: 20 mA.

(3) Evaluation of the bendability was based on the method described in JIS H3110. The test piece width was 10 mm, and it bent under the load of 1000 kgf. The specimen collection direction is GW (axis of bending perpendicular to the rolling direction) and BW (axis of bending parallel to the rolling direction), and the minimum bending radius R at which no cracking occurs and the ratio R / t of the test plate thickness t Evaluated as.

(4) Tensile strength was calculated | required based on JISZ22241 using the 5 test piece of JISZ2201.

⑤ Obtained according to JIS H 0505.

(6) The stress relaxation characteristic adopts the one-side holding block type of the Japan Electronic Materials Industry Association Standard Specification (EMAS-3003), and sets the load stress so that the maximum surface stress is 80% YS (0.2% yield strength). The relaxation rate (SRR) was obtained by maintaining for 1,000 hours.

The obtained results are shown in Table 4.

TABLE 4

As apparent from Table 4, Sample Nos. 2-0 to 2-2, 2-1-1, 2-5 to 2-11 (Example 3) and Samples No. 2-3 and 2-4 (Example 4) ) Satisfies both the bending workability (R / t) of less than 2, the tensile strength of 810 MPa or more, the electrical conductivity of 35% IACS or more, and the relaxation rate of 10% or less. In addition, although samples No. 2-23 to 2-30 are slightly inferior to tensile strength and relaxation rate, the bending workability (R / t) is less than 2, and the electrical conductivity satisfies 35% IACS or more. It has excellent characteristics.

On the other hand, Sample No. 2-12 and 2-13 (comparative example) are examples in which the value of (2) or (3) of the prescribed formula is out of range and inferior to bendability. This is considered to be because the solution treatment temperature was too high.

No. 2-14 (comparative example) was inferior in bending workability because of a large amount of Cr.

No. 2-15 (Comparative Example) had a large amount of Ni and Si, so that cracks occurred during hot working and could not be manufactured.

No. 2-16 (comparative example of item [10]) was inferior in electrical conductivity because of the large amount of Zn.

No. 2-17 (the comparative example of the above-mentioned item [11]) was excellent in stress relaxation characteristics because of a large amount of Mg, but was inferior in bending workability.

No. 2-18 (Comparative example of item [12]) had a large amount of Sn and could not be produced because of cold working cracks.

No. 2-19 (Comparative Example) was inferior in bending workability because the amount of Zr amount Co was large.

Since No.2-20 (comparative example) had many Ss, it could not manufacture because a crack generate | occur | produced during hot working.

No.2-21 (comparative example) had poor values of bending workability because the sample had values of formulas (2) and (3) outside the range defined by the present invention.

No. 2-22 (comparative example) was inferior in strength and stress relaxation rate because of the low amount of Ni and Si.

The copper alloy of the present invention is suitable not only for use in terminals, connectors, lead frames and the like, but also for general conductive materials such as switches and relays.

Although the present invention has been described in connection with the present embodiment, it is not intended to be limited only to this description, and unless specifically indicated, it may be embodied broadly within the spirit and scope disclosed in the appended claims. have.

Claims (14)

delete delete delete delete delete delete delete delete delete delete delete As a copper alloy containing 2.0-4.5 mass% of Ni, 0.3-1.0 mass% of Si, 0.1-0.27 mass% of Cr, and less than 0.005 mass% of S, and remainder contains Cu and an unavoidable impurity, The copper alloy which satisfy | fills following formula (3). I {311} × A / (I {311} + I {220} + I {200}) <1.5... (3) In Equation (3), I {311} is the X-ray diffraction intensity from the {311} plane on the plate surface, I {220} is the X-ray diffraction intensity from the {220} plane, and I {200} Is the X-ray diffraction intensity from the {200} plane, and A (µm) represents the crystal grain diameter, respectively. 13. The compound of claim 12, further comprising one or two or more elements selected from the group consisting of 0.2 to 1.5 mass% of Zn, 0.01 to 0.2 weight% of Mg, and 0.05 to 1.5 mass% of Sn. Copper alloy. The group according to claim 12, wherein the group is composed of 0.005 to 0.3 mass% of Zr, 0.05 to 2.0 mass% of Co, 0.005 to 0.3 mass% of Ti, 0.005 to 0.3 mass% of Ag, and 0.001 to 0.02 mass% of B. Copper alloy further containing l or 2 or more elements selected from.