JP4798942B2 - Copper alloy for electrical and electronic parts - Google Patents

Description

  The present invention is a copper alloy for electrical and electronic parts such as terminals / connectors, relays, bus bars, etc., particularly excellent in strength (strength), conductivity, spring limit value, stress relaxation resistance, bending workability, and Sn plating ability. Also relates to an excellent copper alloy for electrical and electronic parts.

  As automobiles become more and more electrical, the number of connectors in wiring harnesses for batteries, control devices, various electrical components, actuators, sensors, and the like has increased, and miniaturization thereof has been demanded. Further, the connector mounted in the vicinity of the engine unit is always in a high temperature and high vibration environment of the engine unit. Particularly, the power system (power supply) connector is self-heated by a large current flowing and becomes further hot. Therefore, such a connector (particularly a female terminal) is required to have high reliability (no sag) in the above environment.

  On the other hand, Cu-Fe-P alloys (CDA19400) and Cu-Mg-P alloys are known as conventional copper alloy connector materials for automobiles and the like. The former is an alloy in which Fe and P are co-added to precipitate an Fe-P compound to improve the strength, and Zn is further added to improve migration resistance (see JP-A-1-168830). ), Alloys in which Mg is added to improve the stress relaxation resistance (see JP-A-4-358033) are also known. The latter improves the strength and thermal creep characteristics by co-adding Mg and P, and improves the tensile strength, conductivity, and stress relaxation resistance (see Japanese Patent Publication No. 1-54420).

  In order to reduce the size of wiring connectors (especially female terminals) for automotive electrical components and to ensure their reliability (maintain contact pressure), the material strength (proof strength) and spring characteristics (spring limit value) are further improved. It is necessary to let In addition, in order to prevent sag (decrease in mating force over time) even if kept at a high temperature for a long time, it is necessary to improve the stress relaxation resistance. It is necessary to suppress it. In addition, it is required to have excellent formability (particularly bending workability) for forming small connectors, and to have excellent Sn plating adhesion to reduce contact resistance of male and female terminals and improve corrosion resistance. It is done.

However, the Cu—Fe—P copper alloy, which is a conventional connector material, is excellent in moldability, but has a problem that the spring limit value is low and the stress relaxation resistance is inferior. In addition, although an alloy in which Mg is added to this system has an improved spring limit value, the moldability and conductivity are lowered. Further, the Cu—Mg—P based copper alloy is excellent in stress relaxation resistance, but has a problem that molding processability is inferior and Sn plating adhesion is also inferior.
The present invention has been made in view of such problems of the prior art, and has excellent proof stress, electrical conductivity, spring limit value, stress relaxation resistance, bending workability, and excellent Sn plating properties. It aims at obtaining the copper alloy for electronic components.

The copper alloy for electrical / electronic parts according to the present invention is Fe: 0.5-2.4%, Si: 0.02-0.1%, Mg: 0.01-0.2%, Sn: 0.00. 01 to 0.7%, Zn: 0.01 to 0.2%, P: less than 0.03%, Ni: 0.03% or less, Mn: 0.03% or less, and the balance It consists of Cu and inevitable impurities.
The copper alloy for electrical / electronic parts according to the present invention may further include Pb: 0.0005 to 0.015%, or / and Be, Al, Ti, V, Cr, Co, Zr, Nb, and Mo as required. , Ag, In, Hf, Ta, or B may be contained in a total amount of 1% or less.
As an inevitable impurity of the copper alloy, Bi, As, Sb and S are individually 0.003% or less, and the total of these is limited to 0.005% or less from the viewpoint of production. It is desirable to limit the H content to 10 ppm or less and the H content to 20 ppm or less.

The copper alloy for electric / electronic parts according to the present invention has strength (yield strength), electrical conductivity, spring limit value, stress relaxation resistance, bending workability, Sn plating property, etc. It has all of the characteristics required as a material for electronic parts, and is particularly suitable as a wiring material for automobiles, especially as a material for small connectors for power supply.
In addition, the copper alloy for electrical and electronic parts according to the present invention can be manufactured at low cost and with high productivity by adding Si having deoxidizing action to minimize the amount of P added to inhibit uniform recrystallization. There are advantages.

Hereinafter, the component composition of the copper alloy for electric / electronic parts according to the present invention will be described.
Fe;
Fe precipitates to improve the strength of the copper alloy. However, if the content exceeds 2.4%, coarse Fe particles are crystallized or precipitated, and bending workability is deteriorated. On the other hand, if it is less than 0.5%, precipitation of Fe hardly occurs, strength and conductivity. , And recrystallized grains grow and cracks tend to occur during bending. Therefore, the content of Fe is set to 0.5 to 2.4%. Desirably, it is 1.0 to 2.1%, and within this range, the stress relaxation resistance and the spring limit value are further improved. More desirably, it is 1.8 to 2.0%, and within this range, the effect of suppressing the occurrence of cracks during hot rolling becomes high.

Si;
Si deoxidizes the copper alloy in place of conventional P (Fe also contributes to deoxidation together with Si), and if the P content is less than 0.03%, the inhibitory action of recrystallization by P is suppressed. And has the effect of promoting uniform fine recrystallization. Moreover, it has the effect | action which improves a stress relaxation resistance and a spring limit value with Mg and Sn, without reducing an electrical conductivity too much. These effects are not sufficiently exerted with an addition amount of less than 0.02%. On the other hand, when the content exceeds 0.1%, bending workability deteriorates. Therefore, the Si content is 0.02 to 0.1%. Desirably, it is 0.03 to 0.07%, and the stress relaxation resistance is further improved in this range.

Mg;
Mg has the effect of greatly improving the stress relaxation resistance and the spring limit value by co-adding with solute Sn. However, Mg is easy to oxidize, and if the amount added is increased, it becomes difficult to dissolve in the atmosphere and the conductivity is also lowered. Therefore, in the copper alloy, part of the action of Mg and Sn is supplemented with Si. In the above copper alloy (Cu-Fe system), if the added amount of Mg exceeds 0.2%, uniform recrystallization is hindered and bending workability deteriorates. Relaxation properties are not improved. Therefore, the content of Mg is set to 0.01 to 0.2%. Desirably, it is 0.05 to 0.15%, and the stress relaxation resistance and the spring limit value are further improved by co-addition with solute Sn in this range. In the case where Mg and Sn are not co-added, the stress relaxation resistance and the like are not improved.

Sn;
Sn co-added with solute Mg has the effect of greatly improving the spring limit value and the stress relaxation resistance and further improving the bending workability. However, if the added amount of Sn exceeds 0.7%, the electrical conductivity decreases, while if it is less than 0.01%, the spring limit value and bending workability are not particularly improved. Therefore, the Sn content is set to 0.01 to 0.7%. Desirably, it is 0.05 to 0.15%, and in this range, the spring limit value, stress relaxation resistance and bending workability are further improved by co-addition with solute Mg.
Zn;
Zn has a great effect in preventing peeling of Sn and solder plating. However, if the content exceeds 0.2%, Zn removal occurs and bending workability also deteriorates. On the other hand, if it is less than 0.01%, Sn and solder plating cannot be prevented from peeling off. Therefore, the Zn content is set to 0.01 to 0.2%. Desirably, it is 0.1 to 0.2%, and the above effect is particularly great within this range.

P;
P is mixed as an unavoidable impurity, or added as necessary to aid deoxidation and improve hot water flow. However, if the content increases, uniform recrystallization is inhibited, so the content is made less than 0.03% (including 0%). When the P content is 0.03% or more, even if Si is added in an amount of 0.02% or more, a uniform and fine recrystallized structure cannot be obtained by intermediate annealing. In this case, even if the temperature of the intermediate annealing is raised, the non-recrystallized portion remains, the hardness of the copper alloy plate varies, and the bending workability decreases. In addition, this non-recrystallized part cannot be eliminated even if the number of annealing times is simply increased to 2 or more within the annealing condition range normally performed in the mass production process.
Incidentally, when the P content is set to 0.005% or less, Fe, Si, Mg, in a copper alloy containing Sn in the above range, the improvement peak conductivity by Fe precipitation during intermediate annealing, recrystallization Completion can be nearly matched (recrystallization is almost complete when conductivity peaks) . An example in which the P content is 0.005% or less is disclosed as a reference example in the column of Examples described later.

Ni;
Ni is mixed as an inevitable impurity, or has the effect of strengthening the grain boundaries and preventing cracking during hot rolling in the copper alloy, and is added as necessary. However, if it exceeds 0.03%, a Ni—Si intermetallic compound is formed and the stress relaxation resistance is lowered. Therefore, the content is 0.03% or less (including 0%).
Mn;
Mn is mixed as an unavoidable impurity, or has an effect of strengthening grain boundaries and preventing cracking during hot rolling in the copper alloy, and is added as necessary. However, if it exceeds 0.03%, a Mn—Si intermetallic compound is formed and the stress relaxation resistance is lowered. Therefore, the content is 0.03% or less (including 0%). Desirably, it is 0.01% or less.
Pb;
Pb is mixed as an inevitable impurity, or is added as necessary in order to improve machinability and press punchability. Pb does not affect the properties of the final product plate, but if it exceeds 0.015%, it segregates at the grain boundaries and cracks occur during hot rolling, whereas if it is less than 0.0005% The above action cannot be obtained. Therefore, the Pb content is 0.015% or less (including 0%), and 0.0005% or more is contained when the above action is required.

Be-B;
These elements are added as necessary because they are mixed as inevitable impurities or have the effect of increasing the recrystallization temperature and improving the stress relaxation resistance. However, if these elements are precipitated or crystallized, the conductivity is lowered, so the total amount is restricted to 1% or less. Desirably, it is 0.5% or less.
Bi to H;
These elements are mixed as inevitable impurities. Bi, As, Sb, and S segregate at the grain boundaries and generate cracks during hot rolling, so it is desirable to limit each individually to 0.003% or less, and to a total of 0.005% or less. If there is a lot of O and H, blowholes are generated in the ingot, and if there is a lot of O, a large amount of oxide is generated in the molten metal and hinders the flow of the molten metal. It is desirable to limit to:

  As shown in the following examples, the copper alloy for electric / electronic parts is subjected to homogenization after casting, then hot rolled, followed by cold rolling and intermediate annealing, and further, final cold rolling. Then, it can manufacture with the general manufacturing method of performing finish annealing. Cold rolling and intermediate annealing can be repeated two or more times as necessary. In addition, when short-time annealing is performed at 650 ° C. to 750 ° C. for 5 to 20 seconds between cold rolling and intermediate annealing, recrystallization occurs in advance during this annealing treatment, and Fe particles that inhibit recrystallization are generated. It does not precipitate. When this recrystallized sheet material is annealed by the subsequent intermediate annealing, Fe precipitation occurs, the conductivity and strength are improved, and a recrystallized structure with no unrecrystallized portion remaining can be obtained, and bending workability is improved. Further improvement can be achieved.

Next, examples of the copper alloy for electric / electronic parts according to the present invention will be described in comparison with comparative examples.
Copper alloys having compositions shown in Tables 1 and 2 (examples of the present invention and reference examples ) and Tables 3 and 4 (comparative examples) were melted and cast in the kryptor furnace under the charcoal coating. Here, it was judged whether casting was possible.
Next, the ingot was held at 800 ° C. to 1000 ° C. for 30 minutes, and then subjected to hot rolling at a processing rate of 50% to 80% to produce a plate material having a thickness of 18 mm. Here, whether or not cracking occurred during hot rolling was determined by visual inspection and a fluorescent flaw detection method. In addition, the fluorescent flaw detection method is applied to the entire surface of these test materials with a fluorescent dye Super Glow DN-2800II made by Marktec Co., Ltd., washed and dried, and sprayed with the same Super Glow DN-600S developer. Thereafter, this test material was irradiated with ultraviolet light.

  Next, this hot-rolled material was introduced into the next-step chamfering machine to determine whether or not the milling blade of the chamfering machine was seized. At this time, the milling blade was made of chromoly steel, and the milling blade was brazed with a tungsten carbide carbide tip to the base with silver brazing, the peripheral speed of the blade was 6 m / sec, and the cutting amount Is 1.5 mm / 1 surface. No cutting oil is used. Prepare 20 hot rolled materials with dimensions of 200mm width x 18mm thickness x 180mm length for each alloy, and after chamfering both sides until they all have a thickness of 15mm, observe the surface of the milling blade with SEM, The surface burn-in situation was investigated. If there was any trace of chip welding on the blade surface, it was judged that there was seizure.

From the above criteria, First No. It was confirmed whether 1 to 51 copper alloy sheet materials could be created. The results are shown in Table 5.
As shown in Table 5, no. No. 44 was castable, but the Pb addition amount was excessive, and cracking occurred during hot rolling.
No. 50 was not enough to shield the molten metal from the atmosphere, so there was a lot of H and O, which caused oxides of the additive elements Si, Mg, Sn to be generated in the molten metal, and the flowability of the molten metal was extremely deteriorated. Abandoned.
No. No. 43 could be cast and hot-rolled, but the amount of Pb added was small, and seizure of the milling blade occurred.

No. Nos. 45 to 49 were able to be cast. In Nos. 45 to 48, Bi, As, Pb, and S are individually excessive. In No. 49, the total amount of Bi, As, Pb, and S was excessive, and all cracked during hot rolling.
No. Although No. 42 was castable, the amount of the deoxidizing agent Si was small and P was not added, so that the ingot casting surface became rough, that is, fragile porous due to insufficient deoxidation. For this reason, the subsequent steps were abandoned.
In contrast, No. of the present invention example and reference example . Nos. 1 to 23 (and Nos. 24 to 41 and 51 of Comparative Examples ) have good ingot quality and hot ductility, and can easily obtain a hot-rolled material. Extension is possible.

  Subsequently, no. Hot rolled sheets of copper alloys 1 to 41 and 51 were cold-rolled to a thickness of 2.5 to 0.50 mm, and intermediate annealing was performed in an electric furnace at a temperature of 370 to 600 ° C. for 1 to 20 hours. Subsequently, after removing the oxide scale of the plate, the recrystallization rate and the hardness distribution of the plate were measured (details will be described later). Further, this annealed material was cold-rolled to a thickness of 0.25 mm, and finish annealing was performed within a range of 250 ° C. to 490 ° C. for 5 seconds to 2 hours. Table 6 shows the production conditions of each copper alloy. Finally, the plate material was pickled to remove the oxide scale, and a final product plate was obtained. In addition, all alloys could be easily manufactured to the shape and thickness of the final product.

About the intermediate process material and final product after the intermediate annealing obtained by the said manufacturing process, the characteristic of following (1)-(9) was measured in the following way. The results are shown in Tables 7 and 8.
(1) Recrystallization rate after intermediate annealing Embedded in polishing resin so that the cross-section of the plate material can be observed, mirror-polished and then observed with an optical microscope with a magnification of 200 times or more. On the other hand, the percentage of the area where recrystallization was completed was evaluated. If the recrystallization rate is 90% or more, it does not affect the mechanical properties of the final product such as bending workability.

(2) Standard deviation of the measured hardness of the plate after intermediate annealing After buffing the surface of the plate, a micro Vickers hardness tester with a load of 10 to 100 grams was used, and the hardness of 30 points between 50 μm in the direction perpendicular to rolling. Evaluation was performed by measuring the thickness and calculating the standard deviation for the distribution of the 30 measured values. If the standard deviation is less than 5, recrystallization is uniformly completed and does not affect the mechanical properties of the final product such as bending workability.
(3) Yield strength of the final product Yield strength, which is a mechanical property that is especially important as an automobile terminal material, is made by machining a JIS No. 5 tensile test piece and tensile tested with a universal testing machine UH-10B manufactured by Shimadzu Corporation. And measured. Here, the proof stress is a tensile strength corresponding to a permanent elongation of 0.2% defined by JISZ2241. If the proof stress is 450 N / mm ² or more, the contact fitting force required for a small power supply connector for automobiles is maintained, and it can withstand galling when a male terminal is inserted.

(4) Conductivity conductivity measurement of the final product was performed by a four-terminal method using a double bridge 5752 manufactured by Yokogawa Electric in accordance with the nonferrous metal material conductivity measurement method defined in JISH0505. If the electrical conductivity is 50% IACS or more, self-heating can be suppressed with a small connector for power supply for automobiles.
(5) Spring limit value of final product The spring limit measurement value was measured in accordance with the moment type test of the spring limit value defined in JISH3130. When the spring limit value is 300 N / mm ² or more, it is possible to maintain the contact fitting force required for a small power supply connector for automobiles.

(6) Stress relaxation resistance upper limit temperature stress relaxation characteristics of the final product were measured using a cantilever method. Specifically, a strip-shaped test piece having a width of 10 mm is cut out from a direction perpendicular to the rolling direction of the material, one end thereof is fixed to a rigid test table, and the test piece is deflected by 10 mm at the start of the test, so that the material yield strength is 80%. A corresponding surface stress is applied to the material. Each material is held in each oven set at 120 ° C to 160 ° C in increments of 5 ° C for 1000 hours, and how much the warped L after unloading approaches a 10 mm sled within the initial elastic range. The ratio R was evaluated by measuring. That is, R = (10−L) / 10 × 100 (%) was calculated and compared. If the maximum temperature that can maintain R: 70% or higher in this evaluation is 150 ° C. or higher, the contact fitting force required for a small connector for power supply for automobiles can be maintained.

(7) Limit bending radius of 180 ° C. bending in the rolling longitudinal direction of the final product 180 ° bending test is a V block bending jig provided with each bending radius in the V block method bending test defined in JISZ2248 The test material was processed with a width of 10 mm and a length of 35 mm, and pre-bending was performed with a load of 1 ton using a universal testing machine RH-30 manufactured by Shimadzu Corporation, and further pre-bending on a flat metal table A piece was placed and brought into close contact with a universal tester RH-30 manufactured by Shimadzu Corporation under a load of 1 ton. Bending workability was determined by examining with a loupe whether or not the bent portion of the specimen had cracks or the like with respect to each bending radius of the bending jig. If the minimum bending radius is 0 mm with respect to the material plate thickness of 0.25 mm in this evaluation, a small connector for power supply for automobiles can be formed.

(8) Limit bending radius of the W-bending in the direction perpendicular to the rolling of the final product The bending workability of the W-shape is defined in the CESM0002 metal material W bending test method, with a B-type bending jig having each bending radius, a width of 10 mm, The sample material processed to a length of 35 mm was sandwiched and measured using a universal testing machine RH-30 manufactured by Shimadzu Corporation with a load of 1 ton. Bending workability was determined by examining with a loupe whether or not the bent portion of the specimen had cracks or the like with respect to each bending radius of the bending jig. If the minimum bending radius is 0.125 mm or less with respect to the material plate thickness of 0.25 mm in this evaluation, an automobile power supply small connector can be formed.

(9) Presence / absence of Sn plating peeling of final product Sn plating adhesion is: stannous sulfate 40 g / lit, sulfuric acid 100 g / lit, cresol sulfonic acid 30 g / lit, formalin 5 mlit / lit, dispersant 20 g / lit, brightener After Sn plating with a plating thickness of 1.5 μm was applied at a current density of 2.5 A / dm ^{2 in} an Sn plating bath (20 ° C.) consisting of 10 ml / lit, it was heated in an oven at 105 ° C. for 500 hours, and then 2 mmR After bending at 180 ° C., the plate was bent back and the presence or absence of peeling of the Sn plating from the material at that time was visually evaluated. If peeling of Sn plating does not occur in this evaluation, it can be used for a small power supply connector for automobiles.

In addition, about the final product board, the presence or absence of the foreign material which causes the quality fall of board | plate materials, such as an oxide, a coarse precipitate, a coarse crystallization thing, and a grain boundary reaction type precipitation, was determined by cross-sectional observation. Specifically, it was embedded in a polishing resin so that a cross section of the product plate material could be observed, followed by mirror polishing, and then observed with an optical microscope having a magnification of 200 times or more to confirm the presence or absence of the foreign matter.
In addition to observation with an optical microscope, after cutting a 10 mm × 10 mm × 0.25 mm plate from the center and both ends as a representative part of the product plate cross section, embedding in a polishing resin so that the cross section can be observed, and mirror polishing Then, cross-sectional observation was performed with EDX-SEM, and foreign object detection / dimension measurement and composition identification were performed. When there was one or more oxides or crystallized substances having a diameter of 1 μm or more in a range of 30 μm × 50 μm, it was judged that there was an oxide or crystallized substance.

As shown in Table 7, No. Nos. 1 to 23 are copper alloys for electric / electronic parts, which have good characteristics and are suitable for automobile connector materials.
On the other hand, as shown in Table 8, no. 24 (CDA19400) has a high yield strength and high conductivity, but can only provide a spring limit value of 231 N / mm ² which is insufficient for applications requiring a high spring limit value such as a connector or a relay. Also, the stress relaxation resistance upper limit temperature is only 120 ° C., similar to phosphor bronze.
No. 25 (Cu-Mg-P alloy disclosed in Japanese Examined Patent Publication No. 1-54420) has high yield strength, high conductivity, high spring limit value, and high stress relaxation characteristics, but has bending workability and Sn plating. Inferior.

No. 26, 27 (P-deoxidized Cu-Fe alloy similar to CDA19400 alloy with addition of Mg, Sn, Zn) has high strength, high conductivity, high spring limit, and high stress relaxation properties Since Si is not added, recrystallization is not easy by intermediate annealing within a practical range. Therefore, the hardness after intermediate annealing is not uniform, and bending workability deteriorates.
No. No. 28 has a small Fe addition amount and can secure an electrical conductivity of 60% IACS or more, but is inferior in mechanical properties such as proof stress, spring limit value, stress relaxation resistance and bending workability.
No. No. 29 has an excessive amount of Si added, and high yield strength, high spring limit value, and high stress relaxation characteristics can be obtained, but the electrical conductivity is less than 50% IACS and the bending workability is also inferior.
No. In No. 30, the amount of Si added is appropriate, but the amount of P added is excessive, and recrystallization is not easy by intermediate annealing within a practical range, and the product quality is not uniform. Therefore, the hardness after the intermediate annealing is not uniform, and the bending workability is deteriorated.

No. No. 31 has an excessive amount of added Mg, and the rolling structure introduced in the cold rolling step after hot rolling does not disappear by intermediate annealing, and a uniform fine recrystallized structure cannot be obtained, resulting in poor bending workability. No. 32, 33, and 35 do not contain both Mg and Sn in appropriate amounts, and include spring limit values (No. 32, 33, 35), bending workability (No. 32, 33, 35), and stress relaxation resistance ( No. 35) is inferior. No. No. 34 contains an appropriate amount of Sn, but Mg is not co-added, and the stress relaxation resistance is inferior. No. No. 36 contains an appropriate amount of Mg, but Sn is not co-added, and the stress relaxation resistance and bending workability are poor.
No. No. 37 has a small amount of Zn added and has poor Sn plating properties.
No. No. 38 has an excessive amount of added Zn, and in addition to Sn and Mg, one more element having a solid solution strengthening action is added, and hence the bending workability is deteriorated.
No. In No. 39, the amount of Ni added is excessive, and Si that improves the stress relaxation resistance is deprived of the formation of the Ni-Si intermetallic compound. Therefore, the stress relaxation resistance is deteriorated, and the bending workability is deteriorated due to the generation of the intermetallic compound. To do.
No. No. 40 has an excessive amount of Mn added, and Si that improves the stress relaxation resistance is deprived of the formation of the Mn-Si intermetallic compound. Therefore, the stress relaxation resistance deteriorates, and further, bending workability deteriorates due to the generation of the intermetallic compound. To do.

No. No. 41 had an excessive amount of Fe added, and the generation of coarse Fe particles was confirmed by observation of the cross-sectional structure with the optical microscope and EDX-SEM. Therefore, bending workability has been extremely deteriorated.
No. No. 51 contained an excessive amount of elements such as Ti, and the generation of coarse particles of Ti, Cr, and Zr was confirmed by observation of the cross-sectional structure with the optical microscope and EDX-SEM. Therefore, bending workability has been extremely deteriorated.

Next, in order to confirm that Pb does not affect each characteristic of the final product plate, copper alloys having compositions shown in Tables 9 (a) and 9 (b) with the Pb content suppressed to 0.0001% (reference) A final product plate was prepared from Example) . In this case, when removing the oxide scale generated by hot rolling, welding and seizure occurs on the milling blade, and thus a hot rolling process is applied to avoid this. Specifically, casting is performed with a mold assembled so that the thickness of the ingot plate is 36 mm, and it is maintained for 30 minutes at a heating temperature of 800 ° C. at which almost no oxide scale is generated. A 18 mm thick hot-rolled sheet was used, and face milling with a milling blade was performed in the same manner as in the previous example. At this time, the slightly generated primary scale is completely pulverized, and the oxide scale is not pushed in. Therefore, even when Pb is not contained in an amount of 0.0005% or more, no welding or seizure occurs on the milling blade.
In addition, since large ingots are used in actual operations where importance is placed on efficiency, an increase in the number of hot rolling passes and the accompanying generation and pushing of secondary scales cannot be avoided. These oxide scales become adhesion nuclei of the milling blade, which may cause welding and seizing on the milling blade. Previous No. In 1 to 51, in order to reproduce this situation, hot rolling of 5 to 8 passes was performed.

  Thereafter, cold rolling, intermediate annealing and finish annealing were performed under the conditions shown in Table 9 (c) to obtain a plate material of the final product. About the intermediate process material and final product after the intermediate annealing obtained by this manufacturing process, each characteristic was measured in the same way as the previous Example. As shown in Tables 9 (d) and (e), No. 1 with Pb suppressed to 0.0001%. In 52, a finished product plate having excellent characteristics is obtained.

Claims (3)

Fe: 1.0 to 2.1% (mass%, the same applies hereinafter), Si: 0.02 to 0.07% , Mg: 0.01 to 0.2%, Sn: 0.05 to 0.15 % Zn: 0.01-0.2%, P: more than 0.005% and less than 0.03%, Ni: 0.03% or less, Mn: 0.03% or less, and the balance Ri Do Cu and inevitable impurities, Bi of the unavoidable impurities, as, Sb and S is 0.003% or less individually, and it is the sum of these is less 0.005%, O content of 10ppm or less, and A copper alloy for electrical and electronic parts having an H content of 20 ppm or less . Furthermore, Pb: 0.0005 to 0.015% is contained, The copper alloy for electrical / electronic components described in Claim 1 characterized by the above-mentioned. The total content of one or more of Be, Al, Ti, V, Cr, Co, Zr, Nb, Mo, Ag, In, Hf, Ta, and B is 1% or less. Or a copper alloy for electrical and electronic parts described in 2.