JP5638357B2 - Copper alloy for electrical and electronic parts and method for producing the same - Google Patents

Description

  The present invention relates to a copper alloy for electric / electronic parts and a method for producing the same, and particularly to a copper alloy for electric / electronic parts having excellent strength and conductivity suitable for electric / electronic parts such as lead frames, terminals and connectors, and the production thereof. It is about the method.

  As semiconductor products used in electronic devices have larger capacities, smaller sizes, and higher functions, lead frames used for these products have become increasingly multi-pin and thinner, and further strength and conductivity have been required. In response to such requirements, a copper alloy having a standard chemical composition of Cu-2.2 wt% Fe-0.03% wt P-0.12 wt% Zn as a material that satisfies these characteristics relatively well ( CDA Alloy 194) (for example, refer to Patent Document 1).

  However, with the increase in the number of pins and the thinning of the lead frame, the distortion that occurs during the punching process from the material to the lead frame is increasing. In a situation where annealing is required to remove the strain, the copper alloy has insufficient heat resistance, and there is a problem of strength reduction due to annealing for strain relief in the lead frame. Other electrical / electronic parts such as terminals and connectors also have the same problem due to the increased strain accumulation due to the processing of materials due to the downsizing of electronic equipment.

  Therefore, in order to improve the heat resistance of the copper alloy, for example, a method of delaying recovery / recrystallization by dispersing Fe particles of 40 nm or less at a volume ratio of 0.2% or more and acting as pinning grains ( For example, see Patent Document 2).

Japanese Patent Publication No.52-20404 Japanese Patent Laid-Open No. 11-80862

  However, in a situation where more heat resistance is required, the recovery / recrystallization delay due to the pinning effect of Patent Document 2 is still insufficient.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a copper alloy for electric / electronic parts having high strength and high conductivity and excellent heat resistance, and a method for producing the same.

According to the first aspect of the present invention, Fe is 2.0 wt% or more and 2.6 wt% or less, P is 0.01 wt% or more and 0.2 wt% or less, Zn is 0.01 wt% or more and 1 wt% or less. In a copper alloy for electrical and electronic parts that contains 0.0% by weight or less and the balance is Cu and inevitable impurities,
Among the particles containing Fe dispersed in the copper matrix, the ratio N ₂ / N ₁ of the number density N _{1 of} particles having a diameter larger than 50 nm and the number density N _{2 of} particles having a diameter of 50 nm or less is 5 or more
Provided is a copper alloy for electric / electronic parts having an average particle spacing of 50 nm to 300 nm in particles having a diameter of 20 nm to 50 nm.

According to the second aspect of the present invention, Fe is 2.0 wt% or more and 2.6 wt% or less, and P is 0.0 wt%.
An ingot containing 1% by weight or more and 0.2% by weight or less, Zn of 0.01% by weight or more and 1% by weight or less, with the balance being Cu and inevitable impurities, is combined with a rolling process and a heat treatment process to obtain a desired ingot. In the method of manufacturing a copper alloy for electrical and electronic parts that is processed to a plate thickness,
In the heat treatment step, heat treatment is performed at a temperature of 500 ° C. or more and 550 ° C. or less for a time of 30 minutes or more and 6 hours or less,
Then, the manufacturing method of the copper alloy for electrical / electronic components which heat-processes at the temperature of 400 to 480 degreeC further for 1 hour or more and 8 hours or less is provided.

  ADVANTAGE OF THE INVENTION According to this invention, while having high intensity | strength and high electroconductivity, it can provide the copper alloy for electrical / electronic components excellent in heat resistance, and its manufacturing method.

It is explanatory drawing of the manufacturing process flow of the copper alloy which concerns on one embodiment of this invention. It is a calculation model of the average particle interval which concerns on one embodiment of this invention.

  The copper alloy for electric / electronic parts and the manufacturing method thereof according to one embodiment of the present invention will be described below.

Copper alloy for electric / electronic parts The copper alloy of the present embodiment is a Cu-Fe-P alloy (CDA Alloy 194). In this Cu—Fe—P alloy, excellent heat resistance means that the strength that decreases when annealed at a certain temperature and time is small. From the viewpoint of materials, it is considered that the strength reduction in the annealing process is caused by a phenomenon called recovery / recrystallization. Here, both recovery and recrystallization are phenomena of eliminating distortion of the copper matrix phase, and are phenomena that occur due to heating or the like. The difference between recovery and recrystallization is that the former is a dislocation (one of nano-level material defects) that causes the strain itself to move and rearrange itself, while the latter reduces the strain of the copper matrix. The field is to reduce the strain by absorbing dislocations. In addition, since recrystallization is a crystal grain boundary movement phenomenon (the driving force is strain energy due to dislocations or the like), the crystal grains of the copper matrix phase become coarse.

  Thus, since the strength reduction is caused by recovery / recrystallization, it can be said that the recovery / recrystallization may be delayed in order to improve the heat resistance. As a result of observing the target Cu—Fe—P alloy with a transmission electron microscope, the starting point of recovery / recrystallization is a place in contact with particles larger than 50 nm, and the size is coarse and larger than 300 nm.

  For this reason, it is important to reduce the number of particles larger than 50 nm dispersed in the copper matrix as much as possible for the strength reduction due to recrystallization. Furthermore, it is also important to suppress the growth of recrystallization by pinning even when recrystallization nuclei are generated by setting the average interval of particles not serving as the starting point of recrystallization to 300 nm or less. Here, pinning is an effect that suppresses the movement of crystal grain boundaries in the copper matrix phase by dispersing precipitates in the copper matrix phase, and suppresses the grain boundary migration even if recrystallization occurs. It can be expected to suppress the coarsening of recrystallized grains.

In addition, it is important to suppress the occurrence of strength reduction due to recovery by maintaining the consistency of Fe precipitates. When the Fe particles are processed, the state changes from the aligned state to the non-aligned state. Further, it is reported that non-matched Fe particles have a property of attracting dislocations (in the case of matched particles, repulsive force acts between the dislocations). From this, it is considered that dislocations of non-matching Fe particles are likely to increase in dislocations at the interface between the non-matching Fe particles and the copper matrix phase than at other places. An increase in dislocations increases the driving force for recovery / recrystallization, and is considered to be a starting point that facilitates recovery / recrystallization during heating and becomes easy to soften. For this reason, it is necessary to maintain the consistency of the Fe precipitate.

  In the copper alloy of the present embodiment, work hardening (crystal refinement and dislocation strengthening) by third cold rolling, which will be described later, is one of means for obtaining alloy strength, so that recovery / recrystallization occurs. Strength decreases. Since recovery / recrystallization is a phenomenon that occurs by heating as described above, if this occurs easily, the strength decreases due to, for example, applying strain relief annealing included in the lead frame manufacturing process of the customer. This decrease in strength in the lead frame manufacturing process causes problems such as insufficient rigidity of the lead frame pins and the like, and it is necessary to prevent this.

  As a countermeasure, in this embodiment, by controlling the alloy to disperse matched Fe precipitates, recovery / recrystallization is suppressed, and recovery / recrystallization delay due to the pinning effect is not sufficient. This prevents the strength from being lowered by heating (heat resistance test) and enhances heat resistance.

  Next, the components of the copper alloy and the metal structure of the copper alloy that improve the heat resistance will be described.

1. Components of copper alloy In the present embodiment, the reason for addition and the reason for limitation of the components constituting the copper alloy will be described below.

(1) Fe
The Fe content in the present embodiment is 2.0 wt% or more and 2.6 wt% or less, preferably 2.1 wt% or more and 2.3 wt% or less. Fe is contained in order to improve strength and heat resistance by solid solution or precipitation in the copper matrix. If it is less than 2.1% by weight, in the final material after the third cold rolling, the solid solution amount and precipitation amount of Fe are insufficient, and the strength and heat resistance are lowered. The decrease in heat resistance due to insufficient amount of solid solution and precipitation amount is considered to be mainly due to a decrease in viscous resistance in the case of solid solution amount and a decrease in pinning effect in the case of precipitation (in general, the recrystallization suppression effect is (Pinning effect)> (Viscous resistance) It is said that the pinning effect is greater in securing heat resistance.)
On the other hand, when the content exceeds 2.6% by weight, the decrease in conductivity due to Fe solid solution is large, and coarse Fe crystallization is generated during casting. Can be.

(2) P
The P content in the present embodiment is 0.01% by weight or more and 0.2% by weight or less, preferably 0.01% by weight or more and 0.1% by weight or less. P has an action of deoxidizing oxygen mixed in the molten metal during melt casting, but if it is less than 0.01% by weight, it is not sufficient to obtain the effect. When the content exceeds 0.1% by weight, a saturation tendency is observed in the deoxidation effect, but it forms a precipitate by combining with Fe, and this precipitate also contributes to improvement in strength and heat resistance. On the other hand, if it exceeds 0.2%, the deoxidation effect and the contribution to the strength are not only saturated, but the P and Fe compound precipitated at the grain boundaries, etc. may cause core cracks during casting, It may cause adverse effects such as intergranular cracking during hot rolling.

(3) Zn
In the present embodiment, the Zn content is 0.01 wt% or more and 1.0 wt% or less, preferably 0.05 wt% or more and 0.15 wt% or less. Zn improves solder wettability and has a deoxidizing and degassing action and a Cu migration suppressing action, but if it is less than 0.01% by weight, it is not sufficient to obtain the effect. On the other hand, if it exceeds 1.0% by weight, the conductivity is lowered.

(4) Other element components The copper alloy in the present embodiment basically includes Cu as a main component and contains specific amounts of Fe, P, and Zn. However, it may be unavoidable that other elements are mixed in as impurities, and may contain Mg, Al, Si, Ti, Cr, Mn, Co, Ni, Mn, Zr, Sn, and the like. However, if it is less than 0.1% by weight, it does not adversely affect heat resistance and the like, and is a range that may be allowed as an inevitable impurity. The present embodiment is formed by organically relating the above-described composition and the metal composition described below.

2. Metal structure of copper alloy The reason for control and the reason for limitation of the metal structure factor constituting the copper alloy in the present embodiment will be described below.

(1) In the N2 / N1 ratio present embodiment, among the particles containing Fe dispersed in Dohaha phase, the number of number density _{N 1} and the diameter is 50nm or less particles having a diameter of 50nm larger particles The ratio N ₂ / N ₁ with respect to the density N ₂ is 5 or more, preferably less than 10. When the N ₂ / N ₁ ratio is smaller than 5, the heat resistance is lowered. This is because recrystallization is started from a position in contact with particles having a diameter of 50 nm or more. If there are many particles of this size or more, recrystallization is promoted, that is, softening is promoted, and the strength is lowered. It has been reported that the change from matching to non-matching of Fe particles proceeds from coarse particles, and the Fe particles of about 50 nm start to change at the third cold working degree of 85%. The step of starting recrystallization is, for example, a step of heating performed after the third cold rolling (after formation of the final material) (for example, strain relief annealing performed after press working for forming the lead frame). . This is a customer process. In practice, after the final material is formed, this is simulated to conduct a heat resistance test. At this time, if the strength decreases due to recovery and recrystallization, problems such as insufficient rigidity of the lead frame pins occur.

In order to prevent the degree of processing in the third cold working of the present embodiment from changing to non-matching particles, it is necessary to precipitate and disperse Fe particles having a diameter smaller than 50 nm. Note that the Fe precipitate is also formed in the melting step and the hot rolling step. This size is from a few hundred nanometers to a micrometer size. This size is in an inconsistent state in the final material and promotes recovery and recrystallization, but it is difficult to avoid this. In order to suppress this adverse effect, the N ₂ / N ₁ ratio is defined in the present embodiment, and the majority of Fe precipitates are dispersed in a consistent state by this definition.

(2) Average particle spacing In the present embodiment, the average particle spacing of particles having a diameter of 20 nm to 50 nm containing Fe dispersed in the copper matrix is 50 nm to 300 nm, preferably 50 nm to 200 nm. When the average particle spacing is smaller than 50 nm, the strength decreases. In this case, when the average particle spacing is controlled to be smaller than 50 nm, it is necessary to control the size of dispersed particles to be smaller than 10 nm. However, it is considered that particles smaller than 10 nm are sheared by dislocations and cannot contribute to the strength. On the other hand, when the Fe particles are dispersed with an average particle interval of 300 nm or more, the interval is too wide, so that the recrystallized grains (the crystal grain size of the copper parent phase) become coarse, thereby suppressing recovery and growth of the recrystallized grains. The effect is reduced and softening by heat treatment cannot be delayed. That is, the heat resistance is reduced.

Further explanation will be given. It is considered that recovery and recrystallization proceed from the periphery of the Fe particles that have changed inconsistently as described above. When recrystallization is promoted, the strength decreases, so it is important to stop the progress at the earliest possible stage even if the recrystallization phenomenon occurs. It is thought that particles having a diameter of 20 nm or more and 50 nm or less containing matched Fe (matched Fe particles) can have a role of causing a pinning effect by dispersing the particles in a copper matrix. . The pinning effect varies depending on the size of the dispersed particles and the distance between the dispersed particles. The smaller the particle size and the smaller the distance, the greater the effect. In addition, since the maximum volume ratio of Fe particles to the copper matrix phase (which can be calculated from the size and number density of particles. The average interval of precipitates also depends on this) is determined by the added Fe component. In the case of an alloy component, in order to disperse at an interval of 50 nm, it is necessary to disperse with an extremely fine size of 10 nm or less. However, since Fe particles having a diameter of 20 nm or less are sheared and absorbed at the grain boundaries and re-dissolved, the pinning effect cannot be expected (recrystallization cannot be suppressed, causing a decrease in strength). In addition, since the exact size of the Fe precipitate absorbed in the crystal grain boundary of the copper matrix is not known, the minimum size of 20 nm that can be confirmed is set as the lower limit of the precipitate diameter in the present embodiment.

(Effects of Embodiments Related to Copper Alloys for Electric / Electronic Parts)
According to the present embodiment, since N ₂ / N ₁ is 5 or more, particles larger than 50 nm dispersed in the copper matrix can be reduced as much as possible. In addition, by setting the average interval of particles that do not serve as the starting point of recrystallization to 300 nm or less, the growth of recrystallization can be suppressed by pinning even when recrystallization nuclei are generated. Since the growth of recrystallization can be suppressed in this way, the heat resistance can be improved. Therefore, it is possible to provide a Cu—Fe-based (standardized by CDA Alloy 194) material that is used for a lead frame or the like that has a relatively small decrease in strength due to strain relief annealing, that is, excellent in heat resistance.

(Manufacturing method of copper alloy for electric / electronic parts)
FIG. 1 shows an example of a manufacturing process flow of a copper alloy according to the present embodiment. The present embodiment is a method of manufacturing a copper alloy for electrical / electronic parts, in which the ingot having the above-described copper alloy composition is processed to a desired plate thickness by combining a rolling process and a heat treatment process. Heat treatment is performed under the heat treatment conditions set within the specified range as follows. Heat treatment is performed at a temperature of 500 ° C. or more and 550 ° C. or less for 30 minutes or more and 6 hours or less, and then, a heat treatment is further performed at a temperature of 400 ° C. or more and 480 ° C. or less for 1 hour or more and 10 hours or less.

  Hereafter, the manufacturing process of a copper alloy is explained in full detail for every process using FIG.

(1) Hot rolling, first cold rolling (steps 102 and 103)
In the present embodiment, the copper alloy is hot-rolled at a predetermined temperature. In hot rolling, the copper alloy is kept at a temperature of 800 ° C. or higher and 1050 ° C. or lower in a furnace at a predetermined temperature, and then rolled at room temperature. Allow to cool to room temperature during rolling or after rolling. When the temperature is less than 800 ° C., the amount of Fe deposited is large, and cracking is likely to occur during hot rolling. Next, the first cold rolling is performed. In the first cold rolling, processing heat is applied, but there is no external heating and cooling, rolling is performed at room temperature, and after processing is stored at room temperature (second and third cold rolling described later) The same). In order to transmit heat uniformly and efficiently to the entire material during the solution treatment following the first cold rolling, it is preferable to set the area reduction rate so that the plate thickness is 3 mm or less.

(2) Solution treatment (step 104)
After the hot rolling and cold rolling, after rapidly heating at a temperature of 900 ° C. or higher and holding for 30 seconds or more, immediately cool to 500 ° C. at a cooling rate of 100 ° C. or more per minute, and further naturally cool to room temperature at room temperature. To do. The solution treatment is performed in order to re-dissolve the precipitate deposited during hot rolling. Fe is precipitated (nano-order) in the aging process from a solid solution (atomic level (sub-nano-order) mixed) state by solution treatment. However, several nano-order Fe precipitates are absorbed when processed (the crystal grain boundary of the Cu parent phase passes) and become a solid solution state again. This is a re-solution state. It is considered that the solid solution state is less preferable than the precipitated state because the effect of suppressing recovery and recrystallization is small. If this melt treatment step is omitted, the target strength and heat resistance cannot be obtained.

(3) Second cold rolling (step 105)
After the solution treatment, cold rolling is performed. It is preferable to perform the cold rolling so that the area reduction rate is 50% or more. Thereby, precipitation at the aging described below can be made smooth.

(4) First aging treatment (step 106)
In this embodiment, aging is performed in two steps. Heat resistance is insufficient with only one aging. The first aging is performed at a temperature of 500 ° C. to 550 ° C. for 30 minutes to 6 hours, preferably 500 ° C. to 530 ° C. for 2 hours to 6 hours. Cool gradually after heat treatment. Cooling is slower than cooling at room temperature (second aging is the same). If the aging temperature is less than 500 ° C., particles containing Fe cannot be sufficiently precipitated, and the target strength and heat resistance cannot be obtained. On the other hand, when the temperature exceeds 550 ° C., there arises a problem that the materials wound in the coil shape stick to each other. Further, even if the aging time is less than 30 minutes or exceeds 6 hours, the target heat resistance and strength cannot be obtained for the same reason as described above.

  The adhesion between the materials described above means that the materials wound in a coil shape are diffusion-bonded unintentionally when the temperature is too high in order to rapidly precipitate Fe. Here, it is important that the conditions are set so that the materials do not stick to each other. Adhesion between materials is a problem in a process of winding a material in a coil shape and performing a heat treatment, and this problem becomes more prominent as the temperature becomes higher. Therefore, it is set as the conditions which can obtain the copper alloy of the 1st form required in order to maintain heat resistance from the aging temperature in the range which does not produce adhesion.

(5) Second aging process (step 107)
The second aging is performed at a temperature of 400 ° C. to 480 ° C. for 1 hour to 8 hours, preferably at a temperature of 400 ° C. to 450 ° C. for 2 hours to 6 hours. Precipitation takes a long time at temperatures lower than 400 ° C., and target heat resistance cannot be obtained at temperatures higher than 480 ° C. Since the first aging and the second aging are performed continuously, the temperature history is raised to the first aging temperature, held at the first aging temperature, lowered to the second aging temperature, and the second aging. Hold at temperature and cool to room temperature.

(6) Third cold rolling (step 108)
After the aging, finish rolling is performed cold at a working degree of 70% to 85%. Thereby, the target intensity can be obtained. Further, after this, low-temperature annealing may be performed to improve elongation and remove strain.

(Effects of Embodiment of Manufacturing Method of Copper Alloy for Electric / Electronic Parts)
In the method of manufacturing a copper alloy for electric / electronic parts, which is a combination of a rolling process and a heat treatment process, and the ingot of the first embodiment is processed to a desired plate thickness, Heat treatment at a temperature of 30 minutes to 6 hours and then heat treatment at a temperature of 400 ° C. to 480 ° C. for a time of 1 hour to 8 hours. Among the particles containing Fe to be dispersed, the ratio N ₂ / N ₁ of the number density N _{1 of} particles having a diameter larger than 50 nm and the number density N _{2 of} particles having a diameter of 50 nm or less is 5 or more, A copper alloy having an average particle interval of 50 nm to 300 nm in particles having a diameter of 20 nm to 50 nm can be realized. In particular, since the aging temperature is set to 550 ° C. or lower, it is possible to prevent the materials from sticking to each other which becomes a problem in the process of winding the materials in a coil shape and performing the heat treatment. Therefore, it is possible to produce a copper alloy for electric / electronic parts having excellent heat resistance without causing adhesion between materials.

  Note that the number of aging treatments is not limited to two, but may be three or more. In that case, each item condition is appropriately set according to the number of times.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to these.

Example 1
A copper alloy containing 2.2% Fe, 0.03% P, and 0.01% Zn, with the balance being Cu and inevitable impurities, is melted in a high-frequency induction crucible, and then a copper mold. Semi-continuous casting was performed to produce a rectangular ingot having a cross section of 200 mm × 450 mm and a length of 4000 mm.

  The surface of each ingot was chamfered by 5 mm, held at 950 ° C. for 2 hours, and then hot-rolled to a plate thickness of 12 mm. Further, the front surface and the back surface were each cut by 1 mm, and then the plate thickness was adjusted to 2.5 mm by first cold rolling.

  Next, the material was run through the heating zone of the continuous annealing furnace while controlling the maximum temperature of the material to be 925 ° C. at the maximum. Subsequent to the heating zone, the solution was quenched by passing through a cooling zone and a water-cooled pool.

  Furthermore, after grind | polishing the surface and the back surface, it was set as plate | board thickness 0.7mm by the 2nd cold rolling.

  Next, annealing was performed for 4 hours at a temperature of 550 ° C. in a nitrogen gas atmosphere using an electric furnace, and the temperature was lowered to 450 ° C. at a cooling rate of 5 ° C./min. After reaching 450 ° C., annealing was performed for 2 hours, and the temperature was lowered to room temperature at a cooling rate of 5 ° C./min.

  Next, the plate thickness was set to 0.25 mm by third cold rolling.

At this time, Fe-containing particles and properties were evaluated.
The size distribution and volume ratio of precipitates of particles containing Fe particles were evaluated using the X-ray small angle scattering method. For analysis of the measurement results by the X-ray small angle scattering method, spherical Fe particles were evaluated as a scatterer model. The reason why the scatterer model is assumed to be a spherical particle of Fe is that, as a result of observing the dispersed phase in two dimensions using a transmission electron microscope, the majority were circular particles containing a large amount of Fe. . That is, because it is circular regardless of the direction of the cross section, it is considered to be a spherical particle in three dimensions.

The average particle interval was derived as follows using the analysis result of the particles by the small angle scattering method and referring to the calculation model of the average particle interval shown in FIG. f and d are the volume ratio (relative to the parent phase) and the maximum value of the particle diameter in the particle 1 containing 20 to 50 nm in diameter containing and measured and analyzed by the X-ray small angle scattering method.
The volume ratio f is
f = {(4/3) · π · (d / 2) ³ } / x ³ (1)
x is
x = l + d (2)
From the equations (1) and (2), the average particle spacing l is obtained as follows.
l = {(π / 6f) ^1/3 −1} · d (3)

Tensile strength was measured by tensile strength, 0.2% proof stress, and elongation was measured by a tensile test in accordance with JIS Z2241, and conductivity was evaluated using a sigma tester (IACS% measuring instrument using eddy current). Further, as an evaluation of heat resistance, Vickers hardness before and after heat treatment was evaluated by the following method. That is, the difference (change) between the Vickers hardness after the finish rolling and the Vickers hardness after the heat treatment of 450 ° C. × 5 minutes simulating the heat treatment for removing the strain processed after processing into the lead frame was evaluated. 20Hv or less is an allowable range.

表１に示したとおり、実施例１は、Ｎ_２／Ｎ_１比８、平均粒子間隔２５４ｎｍ、引張強さ５４２ＭＰａ、導電率６９％ＩＡＣＳ、熱処理前後のビッカース硬さの変化１８Ｈｖと良好な特性であった。 The evaluation results are shown in Table 1. Table 1 shows changes in aging conditions, N ₂ / NI ratio, average particle spacing, tensile strength, electrical conductivity, and Vicker hardness before and after heat treatment in Examples and Comparative Examples of the present invention.

As shown in Table 1, Example 1 has good characteristics such as an N ₂ / N ₁ ratio of 8, an average particle interval of 254 nm, a tensile strength of 542 MPa, an electrical conductivity of 69% IACS, and a change in Vickers hardness before and after heat treatment of 18 Hv. there were.

(Examples 2-3)
Examples 2 to 3 were produced in the same manner as Example 1 except for the aging treatment conditions shown in Table 1. In Examples 2 to 3 in which the aging treatment conditions were set within the specified range, good characteristics were obtained as in Example 1.

(Comparative Examples 1-4)
Comparative Examples 1 to 4 were also produced in the same manner as Example 1 except for the aging treatment conditions shown in Table 1. Comparative Example 1 in which the first aging time was set to 8 hours outside the specified range, Comparative Example in which the first aging temperature was set to 480 ° C., the first aging time was set to 10 hours, and both conditions were set outside the specified range. 2 and the second aging temperature was 380 ° C., the second aging time was 10 hours, and both of the two conditions were set outside the specified range, the N ₂ / N ₁ ratio or / and the average particle spacing were Deviating from the specified range, the decrease in Vickers hardness after heat treatment exceeded the specified range. Further, in Comparative Example 4 in which the first aging temperature was set to 600 ° C. and out of the specified range, N ₂ / N ₁ ratio, average particle spacing, tensile strength, conductivity, and changes in Vickers hardness before and after heat treatment Although good characteristics were obtained, adhesion was generated between the materials wound in a coil shape.

1 Fe-containing particles

Claims (4)

Fe containing 2.0 wt% or more and 2.6 wt% or less, P containing 0.01 wt% or more and 0.2 wt% or less, Zn containing 0.01 wt% or more and 1.0 wt% or less, with the balance being Cu In copper alloys for electrical and electronic parts consisting of inevitable impurities
Among the particles containing Fe dispersed in the copper matrix, the ratio N ₂ / N ₁ of the number density N _{1 of} particles having a diameter larger than 50 nm and the number density N _{2 of} particles having a diameter of 50 nm or less is 5 or more and 8 or less ,
The diameter determined by the equation (3) using the volume fraction f with respect to the parent phase and the maximum value d of the particle diameter in particles containing 20 to 50 nm in diameter and containing Fe measured and analyzed by the X-ray small angle scattering method is A copper alloy for electrical / electronic parts, wherein an average particle spacing l of particles of 20 nm to 50 nm is 50 nm to 300 nm.
l = [{π / (6f)} ^1/3 −1] · d Formula (3) The copper alloy for electrical / electronic parts according to claim 1, wherein the average particle interval 1 is 50 nm or more and 200 nm or less. Fe is contained in an amount of 2.0% to 2.6% by weight, P is contained in an amount of 0.01% to 0.2% by weight, Zn is contained in an amount of 0.01% to 1% by weight, and the balance is inevitable with Cu. The ingot made of mechanical impurities is subjected to hot rolling, first cold rolling, solution treatment for holding at 900 ° C or higher for 30 seconds or longer, second cold rolling, 500 to 550 ° C for 30 minutes. The first aging treatment for ˜6 hours, the second aging treatment for 400 to 480 ° C. for 1 to 8 hours, and the third cold rolling are sequentially performed to obtain a desired plate thickness. Or the manufacturing method of the copper alloy for electrical / electronic components of 2. In the first aging treatment, heat treatment is performed at a temperature of 500 ° C. or more and 530 ° C. or less for 2 hours or more and 6 hours or less,
The method for producing a copper alloy for electrical / electronic parts according to claim 3, wherein in the second aging treatment, heat treatment is performed at a temperature of 400 ° C or higher and 450 ° C or lower for a time of 2 hours or longer and 6 hours or shorter.

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