TWI521073B - Copper alloy plate, and with its high current with electronic components and thermal electronic components - Google Patents

Description

Copper alloy plate, electronic component with high current and electronic component for heat dissipation

The present invention relates to a copper alloy sheet excellent in heat dissipation, electrical conductivity, bending workability and drawing processability, and more particularly to a terminal, a connector, a relay, a switch, a socket, a bus bar, a lead frame, etc. A copper alloy plate for use in electronic components, especially for heat-dissipating components used in smart phones or personal computers, and for high-current components used in electric vehicles or hybrid vehicles.

For electrical/electronic equipment such as smart phones, tablets, and personal computers, components for obtaining electrical connections for terminals, connectors, switches, sockets, relays, bus bars, lead frames, etc., and for making machines The heat-dissipating parts produced.

In recent years, with the miniaturization of smart phones, tablet computers, and personal computers, there is a tendency for heat storage during power-on of liquid crystal components or IC chips in an electric/electronic device. Since the state of heat storage is large, thermal damage to the IC chip or the substrate is large, and heat dissipation of the heat dissipating component becomes a problem.

Previously, heat-dissipating parts in electric/electronic machines such as smart phones, tablets, and personal computers have been mainly used in Worthite iron-based stainless steel (SUS304) and pure aluminum. For a heat dissipating component (liquid crystal frame) attached to a liquid crystal such as a smart phone or a tablet computer, in addition to requiring high heat dissipation, it is required as the strength of the structure and the bending workability required for fixing to the liquid crystal or Drawing processability. Further, there is a case where only the bending workability or the drawing workability is required depending on the heat dissipating component to be used.

In the Worstian Iron-based Stainless Steel (SUS304), although the flexibility and the drawability are good, the thermal conductivity is low, and an expensive heat conductive sheet or the like is used in order to compensate for this disadvantage. Therefore, the unit price of the heat dissipating component is increased. On the other hand, although pure aluminum and aluminum alloy are excellent in bending property and drawing workability, thermal conductivity and strength as a structure are insufficient.

Further, in an energized component such as a terminal or a connector, the cross-sectional area of the copper alloy in the current-carrying portion tends to be small. When the cross-sectional area is small, the heat generated by the copper alloy at the time of energization becomes large. In particular, among the electronic components used in the electric vehicle or the hybrid electric vehicle that has been significantly grown, there is a component that flows a significant high current such as a connector of the battery unit, and the heat generation of the copper alloy at the time of energization becomes a problem. Therefore, in order to reduce the amount of heat generation, electrical conductivity is required to be excellent, and further, in order to cope with the miniaturization or high functionality of the components, excellent bending workability or drawing workability is required.

It is known that thermal conductivity is proportional to electrical conductivity, and as an alloy having a relatively high electrical conductivity and strength, a material in which Zr or Ti is added to Cu is known. As a material having high conductivity and relatively high strength, for example, CDA (Copper Development Association) is registered with C15100 (0.1% by mass Zr-remaining Cu), C15150 (0.02% by mass Zr-remaining Cu). , C18140 (0.1% by mass Zr-0.3% by mass Cr-0.02% by mass Si-remaining Cu), C18145 (0.1% by mass Zr-0.2% by mass Cr-0.2% by mass Zn-remaining Cu), C18070 (0.1% by mass Ti-) An alloy such as 0.3 mass% Cr-0.02 mass% Si-remaining Cu), C18080 (0.06 mass% Ti-0.5 mass% Cr-0.1 mass% Ag-0.08 mass% Fe-0.06 mass% Si-remaining Cu).

However, in the past, a copper alloy (referred to as a Cu-Zr-Ti alloy) in which Zr or Ti is added to Cu has high strength and heat conduction characteristics, but does not satisfy the required bending workability or drawing processability, and sometimes two None of them are satisfied.

Therefore, it is industrially significant to improve the bending workability and the drawability while maintaining the high strength and electrical conductivity required for the Cu-Zr-Ti alloy.

Accordingly, an object of the present invention is to provide a copper alloy sheet which has high strength, electrical conductivity, excellent bending workability and drawing processability, and electronic components for high current and electronic components for heat dissipation, specifically In view of the above, an object of the present invention is to improve the drawability of a Cu-Zr-Ti alloy which is inexpensive and excellent in electrical conductivity and strength.

The present inventors have found that in the Cu-Zr-Ti alloy, the metal structure is adjusted by the elongation index, and the orientation of the crystal grains oriented on the rolling surface is controlled to improve the bending workability and the drawing workability. Then, with the above findings in mind, the following invention was completed.

The copper alloy sheet of the present invention contains a total of 0.01 to 0.50% by mass of one or both of Zr and Ti, more preferably 0.015 to 0.3% by mass, and the balance is composed of copper and unavoidable impurities, and has 70% IACS. The above conductivity and the 0.2% guaranteed stress of 350 MPa or more, and the relationship between the 0.2% proof stress σ (MPa) and the elongation L (%) satisfy σ/L ≦ 150.

In the copper alloy sheet of the present invention, the X-ray diffraction integral intensity of the {220} plane obtained by the X-ray diffraction method in the thickness direction in the rolling plane is set to I{220}, and the pure copper powder standard sample is used. The X-ray diffraction integral intensity from the {220} plane is set to I ⁰ {220}, and at this time, I{220}/I ⁰ {220}≧4.0 is preferable.

Further, preferably, in the copper alloy sheet of the present invention, the calendering in the W bending test is flat. The ratio of the minimum bending radius (MBR) to the sheet thickness (t) in the row direction (GW direction) and the rolling vertical direction (BW direction) can be expressed as MBR/t ≦ 2.0.

Further, in the copper alloy sheet of the present invention, it is preferable that the Echsen value/plate thickness in the Erichsen test can be expressed as 0.5 or more.

The high-current electronic component of the present invention includes any of the above-described copper alloy sheets. Moreover, the electronic component for heat dissipation of the present invention includes any one of the above copper alloy sheets.

According to the present invention, it is possible to provide a copper alloy sheet having high strength, high electrical conductivity, excellent bending workability, and drawing workability. The copper alloy plate is a raw material suitable for use as an electronic component such as a terminal, a connector, a switch, a socket, a relay, a bus bar, a lead frame, a heat sink, etc., and is suitable for a heat dissipating component used in a smart phone or a personal computer. Copper alloy sheets for use in high-current parts used in electric vehicles or hybrid vehicles.

Hereinafter, embodiments of the present invention will be described in detail.

(characteristic)

A copper alloy sheet according to an embodiment of the present invention has a conductivity of 70% IACS or more, a 0.2% proof stress of 350 MPa or more, and a 0.2% proof stress/elongation ratio (σ/L). Set to 150 or less. A copper alloy plate having such characteristics is suitable for heat dissipation electrons The purpose of the part.

(alloy concentration)

The Cu-Zr-Ti alloy plate according to the embodiment of the present invention contains one or two of Zr and Ti in a total amount of 0.01 to 0.50% by mass, and the total content of Zr and Ti is preferably set to 0.015 to 0.3% by mass. More preferably, it is 0.02 to 0.20% by mass. When the total of one or both of Zr and Ti is less than 0.01% by mass, it becomes difficult to obtain a tensile strength of 350 MPa or more. When the total of one or both of Zr and Ti exceeds 0.5% by mass, it becomes difficult to produce an alloy due to hot rolling cracking or the like. When Zr is added, it is preferable to adjust the addition amount to 0.01 to 0.45 mass%, and when Ti is added, it is preferable to adjust the addition amount to 0.01 to 0.20 mass%. When the amount added is less than the lower limit, the 0.2% proof stress may not reach 350 MPa, and if the amount exceeds the upper limit, the conductivity or the manufacturability may be deteriorated.

In order to improve the strength or the heat resistance, the Cu-Zr-Ti alloy plate may contain a total of 2.0% by mass or less of Ag, Co, Ni, Cr, Mn, Zn, Mg, Si, Fe, Sn, and B. the above. However, if the amount of addition is too large, the electrical conductivity may be lowered to less than 70% IACS, or the manufacturability of the alloy may be deteriorated. Therefore, the addition amount is preferably 1.0% by mass or less based on the total amount, more preferably 0.5% by mass or less. Moreover, in order to obtain the effect by addition, it is preferable to set the addition amount to 0.001 mass % or more in total amount.

(thickness)

The thickness of the product (i.e., the sheet thickness (t)) is preferably from 0.05 to 2.0 mm. If the thickness is too small, sufficient heat dissipation cannot be obtained, and thus it is not suitable as a raw material for electronic components for heat dissipation. On the other hand, if the thickness is too large, bending and drawing processing become difficult. In this regard, the preferred thickness is 0.08 to 1.5 mm. By making the thickness into the above range, it is possible to suppress heat storage and Good bending workability and drawing processability.

(Conductivity)

In the present invention, the conductivity measured according to JIS H0505 is set to 70% IACS or more. When the electrical conductivity is 70% IACS or more, the thermal conductivity is good, and good heat dissipation can be ensured. More preferably, it is set to 75% IACS or more.

(0.2% guaranteed stress)

In the present invention, the 0.2% proof stress of the copper alloy sheet is set to 350 MPa or more, whereby the copper alloy sheet can be said to have the necessary strength as a raw material of the structural material.

(elongation)

When the elongation (El) of the product is L (%) and the guaranteed stress (YS) of 0.2% is σ (MPa), it is adjusted to satisfy the relationship of σ/L ≦ 150, and more preferably σ/L. ≦100 relationship, drawing processability and flexibility are improved. If the 0.2% proof stress/elongation ratio is 150 or less, it is necessary to have the necessary drawability. When σ/L>150, the drawability and the bendability deteriorate. On the other hand, the lower limit of σ/L is preferably set to 30. If σ/L is small, there is a 0.2% guaranteed stress less than 350 MPa. The upper limit of the elongation L is not particularly limited, and if it is more than 15%, the strength is lowered, and as the case may be 0.2%, the stress is lower than 350 MPa. Therefore, in a preferred embodiment, the elongation L is 15% or less.

The term "elongation" as used herein refers to the "elongation at break" defined in JIS Z2241, and the "elongation" and "0.2% guaranteed stress" are determined by calendering the test piece according to JIS Z2241. The direction is set to a tensile test in parallel with the stretching direction to perform measurement.

(bending workability)

The bending workability of the present invention is evaluated by using a width of 10 mm × a length of 30 mm. The W test of the strip test piece (JIS H3130) was carried out. The direction in which the test piece was taken was set in the rolling parallel direction (GW) and the rolling vertical direction (BW), and the ratio of the minimum bending radius MBR (Minimum Bend Radius) and the sheet thickness t MBR/t without generating cracks was evaluated. From the viewpoint of ensuring good bendability, the ratio (MBR/t) of the minimum bending radius (MBR) is preferably 2.0 or less. A more suitable range of MBR/t is 1.8 or less.

(drawing processability)

The copper alloy sheet of the present invention preferably has a ratio of the Ichison value to the sheet thickness measured by the Icheson test according to JIS Z2247 of 0.5 or more. If the Icixon value/plate thickness is 0.5 or more, the drawing processability is practically no problem. On the other hand, the Icixon value/plate thickness is preferably set to 1.5 or less. The reason is that if it exceeds 1.5, the 0.2% proof stress may not reach 350 MPa. More preferably, the Ichison value/plate thickness is set in the range of 0.5 to 1.2.

(crystal orientation)

The X-ray diffraction method is used, and the integrated intensity of the X-ray diffraction of the {220} plane obtained in the thickness direction in the rolling plane is set to I{220}, and the standard sample of the pure copper powder is obtained from the {220} plane. The X-ray diffraction integral intensity is set to I ⁰ {220}, and in the case where I{220}/I ⁰ {220} is 4.0 or more, the drawability is improved. In the case where I{220}/I ⁰ {220} is less than 4.0, since the texture is small in expansion, the drawing processability is deteriorated. The upper limit is not particularly set, and it is more preferable to set it to I{220}/I ⁰ {220} to 4.0 to 7.0. Further, the pure copper powder standard sample was defined by a copper powder having a purity of 99.5% of 325 mesh (JIS Z8801).

Hereinafter, an example of a suitable method for producing a copper alloy sheet of the present invention will be described.

Melting electrolytic copper or the like as a pure copper material, adding Zr, Ti, and optionally Other alloying elements are cast into ingots having a thickness of about 30 to 300 mm. The ingot is formed into a plate having a thickness of about 3 to 30 mm by hot rolling at, for example, 800 to 1000 ° C, and then subjected to cold rolling and recrystallization annealing, and finally processed into a predetermined product thickness by final cold rolling. Finally, the relaxation annealing is performed. Although the elongation after the final cold rolling is as low as 2%, it is improved by the subsequent relaxation annealing.

In the recrystallization annealing, part or all of the rolled structure is recrystallized. Further, by annealing under appropriate conditions, Zr, Ti, and the like are precipitated, and the electrical conductivity of the alloy is increased. In the recrystallization annealing before the final cold rolling, the average crystal grain size of the copper alloy sheet was adjusted to 50 μm or less. When the average crystal grain size is too large, it becomes difficult to adjust the 0.2% proof stress to 350 MPa or more.

The conditions of the recrystallization annealing before the final cold rolling are determined based on the target crystal grain size after annealing and the target product conductivity. Specifically, the batch furnace or the continuous annealing furnace may be used, and the furnace temperature may be 350 to 800 ° C for annealing. For the batch furnace, it is advisable to adjust the heating time in the range of 30 minutes to 30 hours at a furnace temperature of 350 to 600 °C. For the continuous annealing furnace, the heating time can be appropriately adjusted in the range of 5 seconds to 10 minutes at an oven temperature of 450 to 800 °C. In general, if annealing is performed at a lower temperature for a longer period of time, a higher conductivity can be obtained with the same crystal grain size.

In the final cold rolling, the material is passed through a pair of calender rolls and gradually processed into a target thickness. Here, the total degree of processing of the final cold rolling and the degree of processing of each pass are controlled.

The total degree of work R (%) can be obtained from R = (t _{0 -} t) / t ₀ × 100 (t ₀ : plate thickness before final cold rolling, t: plate thickness after final cold rolling). Further, the degree of processing r (%) per pass refers to the plate thickness reduction rate when passing through the calender roll once, which can be obtained by r = (T _{0 -} T) / T ₀ × 100 (T ₀ : before passing through the calender roll The thickness, T: the thickness after rolling the roll) was determined.

The total processing degree R is set to 40 to 99%, preferably 45 to 98.5%, more preferably 50 to 98%. If R is too small, it is difficult to adjust the 0.2% proof stress to 350 MPa or more, and it becomes difficult to adjust I{220}/I ⁰ {220} to 4.0 or more. If the total workability R is too large, cracks may occur at the edges of the rolled material.

The degree of processing r per pass is set to 15% or more. If the processing degree r is too small, I{220}/I ⁰ {220} is reduced, and it is difficult to set I{220}/I ⁰ { as long as the processing degree r is less than 15% in all passes. 220} Adjusted to 4.0 or above. The upper limit of the degree of processing r is not particularly limited, but it is preferably less than 40% in consideration of the control of the sheet thickness accuracy by calendering.

The relaxation annealing of the present invention is carried out using a continuous annealing furnace in which a copper alloy sheet is held in a flat shape in a furnace. In the case of using a batch furnace, since the material is heated in a state in which it is wound in a coil shape, the material is plastically deformed during heating to cause warpage of the material. Therefore, the batch furnace is not suitable for the relaxation annealing of the present invention.

In the continuous annealing furnace, the temperature in the furnace is set to 300 to 700 ° C, preferably 350 to 650 ° C, and the heating time is appropriately adjusted in the range of 5 seconds to 10 minutes, and 0.2 after annealing is relaxed. The % guaranteed stress (σ) is adjusted to be 10 to 50 MPa lower than the 0.2% proof stress (σ ₀ ) before the relaxation force annealing, and more preferably adjusted to a value lower by 15 to 45 MPa. Thereby, at the end of the final cold rolling, the elongation of the decrease is improved and the bending workability is improved.

Further, in the continuous annealing furnace, the tension is applied to the material in a direction parallel to the rolling direction, and the tension added thereto is adjusted to 5 MPa or less, preferably 1 to 5 MPa, more preferably 2 to 4 MPa. If the tension is too large, it is difficult to adjust σ/L to 150 or less. Again, there is delay The rise in the rate of elongation has become insufficient. On the other hand, if the tension is too small, the material in the through sheet will come into contact with the furnace wall of the annealing furnace, which will damage the surface or edge of the material.

An embodiment of the present invention improves the drawing process by imparting the technical characteristics of σ/L ≦ 150 to the Cu-Zr-Ti alloy and the characteristics of I{220}/I ⁰ {220} ≧ 4.0. Sexuality and bending workability" This is a technical feature; if it is used to achieve the manufacturing conditions, it is as follows: (1) In order to make σ / L ≦ 150, a. in the relaxation annealing, adjust to (σ _{0 -} σ) = 10~50MPa.

b. Adjust the internal tension of the furnace during relaxation annealing to 5 MPa or less.

(2) In order to make I{220}/I ⁰ {220}≧4.0, a. in the final cold rolling, the processing degree of each pass is adjusted to 15% or more.

b. Set the total processing degree of the final cold rolling to 40~99%.

The copper alloy sheet obtained in the above manner can be processed into various kinds of copper-thickness products, for example, for use as electronic components for heat dissipation in electric/electronic machines such as smart phones, tablet computers, and personal computers. .

[Examples]

The embodiments of the present invention are shown below, but are provided to provide a better understanding of the present invention and its advantages, and are not intended to limit the present invention.

After adding an alloying element to the molten copper, it was cast into an ingot having a thickness of 200 mm. The ingot was heated at 950 ° C for 3 hours, and hot rolled at 950 ° C to form a plate having a thickness of 15 mm. After grinding and removing the scale on the surface of the hot rolled plate by a grinder, annealing and cold rolling are repeatedly performed, and finished into a predetermined product thickness in the final cold rolling. Finally, use a continuous annealing furnace Relaxation annealing is performed.

For the final cold rolling pre-anneal (final recrystallization annealing), use a batch furnace, The heating time was set to 5 hours, and the furnace temperature was adjusted in the range of 300 to 700 ° C to change the crystal grain size and electrical conductivity after annealing. For the measurement of the crystal grain size after annealing, the cross section perpendicular to the rolling direction was subjected to mirror polishing, chemical etching, and the average crystal grain size was determined by a cutting method (JIS H0501 (1999)).

Control the total processing degree and the processing degree of each pass in the final cold rolling system. Further, the 0.2% proof stress of the final cold rolled material was determined.

In the relaxation annealing using a continuous annealing furnace, the furnace temperature was set to 500 ° C, and the heating time was adjusted between 1 second and 15 minutes, and the 0.2% proof stress after annealing was varied. Moreover, various changes in the tension applied to the material in the furnace are caused. Furthermore, for some materials, the relaxation annealing is omitted.

The manufacturing conditions of the examples are shown in Tables 1 and 2, together with the invention examples and comparative examples. Here, Although a plurality of passes were performed in the final cold rolling, the minimum of the processing degrees of the respective passes was shown. Further, the expression "<5 μm" in the crystal grain size after the final recrystallization annealing shown in Table 1 indicates that only one portion of the rolled structure was recrystallized.

The following measurements were made for the materials in the manufacturing process and the materials after the relaxation annealing.

(ingredient)

The alloying element concentration of the material after relaxation annealing was analyzed by ICP-mass spectrometry.

(0.2% guaranteed stress)

For the material after the final cold rolling and the relaxation annealing, the test piece No. 13B specified in JIS Z2241 is used in parallel with the rolling direction in the direction of stretching, according to JIS Z2241, and the rolling direction. The tensile test was carried out in parallel to obtain a 0.2% proof stress.

(elongation)

The material after the relaxation annealing was subjected to the test piece No. 13B prescribed in JIS Z2241 in such a manner that the stretching direction was parallel to the rolling direction, and the gauge length was set to 50 mm to measure the elongation.

(Conductivity)

The material after the self-relaxation annealing was subjected to a test piece in such a manner that the longitudinal direction of the test piece was parallel to the rolling direction, and the electrical conductivity at 20 ° C was measured by a four-terminal method in accordance with JIS H0505.

(crystal orientation)

The X-ray diffraction integral intensity of the {220} plane is measured in the thickness direction for the surface of the material after the relaxation annealing. Similarly, the integral intensity of the X-ray diffraction of the {220} plane was also measured for the pure copper powder standard sample. The X-ray diffraction apparatus was measured using a RINT 2500 manufactured by Rigaku Co., Ltd. using a Cu bulb, with a tube voltage of 25 kV and a tube current of 20 mA.

(Ichsen value)

For the material after the relaxation annealing, a test machine manufactured by Erichsen was used to test the sample shape of Φ90 mm, lubricant: grease, and press speed of 5 mm/min. value. The evaluation results are shown in Table 2.

(MBR/t)

According to JIS H3130, the W bending test in the direction of the bending axis perpendicular to the rolling direction, that is, the GW (Goodway) direction, and the W bending test in the BW (Badway) direction in which the bending axis and the rolling direction are the same direction are respectively used, and the W-shaped metal is used. The mold, changing the bending radius, finds the ratio of the minimum bending radius (MBR) to the thickness (t) without generating cracks (MBR/t).

As can be seen from the contents shown in Tables 1 and 2, in Examples 1 to 11, a total of 0.01 to 0.50% by mass of one or both of Zr and Ti is contained, and crystallizing is performed in the recrystallization annealing before the final cold rolling. The particle size is adjusted to 50μm or less. In the final cold pressing delay, the total processing degree is adjusted to 40~99%. In the relaxation annealing, the material is passed through the continuous annealing furnace with a tension of 1~5MPa to make the 0.2% guaranteed stress. Reduce 10~50MPa. Thereby, the copper alloy sheets of Inventive Examples 1 to 11 can obtain a relationship of σ/L ≦ 150, and can achieve a conductivity of 70% IACS or more, a 0.2% proof stress of 350 MPa or more, and a W bendability of MBR/t ≦ 2.0. Furthermore, in Inventive Examples 5 and 7, since the processing degree of each pass in the final cold rolling is less than 15%, I{220}/I ⁰ {220} is less than 4.0, and again, these Ixon The value/plate thickness is less than 0.5, and the invention examples 1 to 4, 6, and 8 to 11 each having a degree of processing of 15% or more satisfy the relationship of I{220}/I ⁰ {220}≧4.0 and The relationship between the value of Ichison/plate thickness ≧0.5.

On the other hand, Comparative Examples 1 and 2 did not perform relaxation annealing, and σ/L exceeded 200. Bending and drawing workability are poor.

In Comparative Examples 3 to 6, although the relaxation annealing was performed, since the material tension in the furnace exceeded 5 MPa, σ/L was 150 or more, and particularly in Comparative Example 5 in which the tension was high, σ/L became a ratio. 200 is even larger, and the bending properties and drawing workability of Comparative Examples 3 to 6 are poor.

In Comparative Examples 7 and 8, 0.2% of the relaxation annealing was used to ensure that the amount of decrease in stress was too small, and (σ _{0 -} σ) was not in the range of 10 to 50 MPa. Therefore, σ/L exceeds 150, and the drawability and the bendability are inferior.

In Comparative Example 9, since the strength of the relaxation annealing was largely lowered, the 0.2% proof stress after the relaxation annealing did not satisfy 350 MPa.

In Comparative Example 10, since the total of one or both of Zr and Ti was less than 0.01% by mass, the 0.2% proof stress after the relaxation annealing did not satisfy 350 MPa.

In Comparative Example 11, since one or both of Zr and Ti totaled more than 0.5% by mass, the electrical conductivity did not satisfy 70% IACS.

In Comparative Example 12, since the crystal grain size at the end of the recrystallization annealing before the final cold rolling exceeded 50 μm, the total processing degree due to the final cold pressing delay did not satisfy 40% in Comparative Example 13, and therefore 0.2 after the relaxation annealing. % guaranteed stress does not meet 350 MPa.

As a result of the above, it is possible to provide a copper alloy sheet having both high strength and electrical conductivity, excellent drawability and bending workability, and electronic components for high current and electronic components for heat dissipation. .

Claims (6)

A copper alloy plate containing a total of 0.01 to 0.50% by mass of one or two of Zr and Ti, the remainder being composed of copper and unavoidable impurities, having a conductivity of 70% IACS or more, and a 0.2% guaranteed stress of 350 MPa or more And the 0.2% guaranteed stress σ (MPa) and the elongation L (%) satisfy the relationship of σ/L ≦ 150; the X-ray diffraction method is used to determine the X-ray of the {220} plane in the thickness direction in the rolling surface. The diffraction integral intensity is set to I{220}, and the X-ray diffraction integral intensity from the {220} plane of the pure copper powder standard sample is set to I ⁰ {220}, at this time, I{220}/I ⁰ {220 }≧4.0. A copper alloy sheet according to claim 1 which contains one or both of Zr and Ti in a total amount of 0.015 to 0.3% by mass. The copper alloy sheet according to claim 1 or 2, wherein the minimum bending radius/plate thickness (MBR/t) of the rolling parallel direction (GW direction) and the rolling vertical direction (BW direction) in the W bending test is expressed as MBR/t≦2.0. For example, the copper alloy sheet of claim 1 or 2, wherein the Erichsen test has an Echsen value/plate thickness of 0.5 or more. A high-current electronic component having a copper alloy plate of the first or second patent application scope. A heat-dissipating electronic component having a copper alloy plate of the first or second patent application scope.