TWI772446B - Wires and electronic parts for high frequency coils - Google Patents

Abstract

The present invention is directed to an electric wire for a high frequency coil and an electronic component, and its object is to provide an electric wire for a high frequency coil which ensures the reliability of solder joints and seeks to reduce the AC impedance at a high frequency, and an electric wire for a high frequency coil using the electric wire for a high frequency coil. electronic parts. The solution is to use at least a core wire (10) having a copper conductor (1) and a ferromagnetic layer (4) provided on the outer periphery of the copper conductor (1), and an insulating coating (10) provided on the core wire (10). 4) The ferromagnetic layer (4) has a gap (G) in the radial direction (X), or the wetting stress during welding is 3.4 mN or more, and the zero-crossing time is 0.4 seconds or less High-frequency coil wire (20) to solve the above problem.

Description

Wires and electronic parts for high-frequency coils

The present invention relates to electric wires and electronic components for high-frequency coils. More specifically, the present invention relates to a high-frequency coil wire used for various high-frequency coils and the like, and an electric wire for a high-frequency coil that can reduce AC impedance at high frequencies, and an electronic component using the high-frequency coil wire.

Patent Document 1 proposes an enamel insulated wire in which a copper wire is plated with a ferromagnetic material such as pure iron as a core wire, and describes that the high-frequency gain Q is increased by several 10%. This characteristic improvement is considered to be based on the reduction of AC impedance at high frequencies, and it is considered that when a ferromagnetic layer is applied to the outer periphery of the conductor, while shielding the external magnetic field, it is considered to be based on the reduction of the external magnetic field that penetrates into the interior through incomplete shielding. Eddy current, which suppresses the increase of AC impedance when the loss through the proximity effect is suppressed. In addition, Patent Document 1 also describes that a nickel plating layer is preferable to a copper plating layer as the plating layer provided on the ferromagnetic layer for the purpose of improving the soldering characteristics.

In addition, for the purpose of improving the solderability, Patent Document 2 proposes to provide an iron plating layer on the outer periphery of the conductor, and to provide a nickel plating layer with a thickness of 0.03 to 0.1 μm in order to ensure the solderability. A method of coating an enamel insulating resin layer made of a sintered polyurethane insulating coating before oxidation. Prior Art Documents Patent Documents

Patent Document 1: Japanese Patent Publication No. 42-1339 Patent Document 2: Japanese Patent Laid-Open No. 62-151594

The problem to be solved by the invention

In an insulating-coated electric wire used for coil parts, a urethane coating is generally applied as an enamel insulating layer. However, the operating environment of electronic equipment parts such as coil parts has shifted to a higher temperature side, and the requirements for heat resistance of the enamel insulating layer constituting the insulated-coated electric wire have also increased. The heat resistance of the insulating resin constituting the insulating coating layer is represented by the heat resistance class of type A, type E, type B, type F, type H, etc. and the maximum allowable temperature, and the polyurethane forming the above-mentioned polyurethane coating layer is equivalent to the temperature index E species 120 ℃. In recent times, there is a requirement to use high heat-resistant resins such as modified polyurethane or polyester with a temperature index F of 155°C, and moreover, a temperature index of H of 180°C such as polyurethane, and the temperature index is below 360°C. The soldering temperature of the operation is increased to 420°C in the F class and 460°C in the H class.

As the soldering temperature increases, the cross-section of the solder eroded through the wire (copper conductor, etc.) is likely to decrease, and the reliability of the connection strength becomes a problem. Therefore, it is preferable to solder the wire in a very short time. That is, the higher the wetting stress, and the shorter the zero-crossing time, the more reliable the solder connection can be.

In addition, along with the miniaturization and high frequency of the coil components, the insulated-coated electric wires are twisted in large numbers, and the wires are thinned. In particular, the thinner the wire system, the easier it is to cause problems such as solder erosion.

In the soldering of the enamel wire described in Patent Document 2, in an environment where the soldering temperature is high, the nickel plating layer reacts with the tin in the solder instantaneously and diffuses, and the iron plating layer that actually becomes the base and the solder joining of materials. However, when the intermetallic compound between iron and tin is not easily formed, the wetting stress (that is, the bonding strength) is low, and the reliability for bonding is poor. In the case where nickel is thickened more than necessary, the effect of iron, which is a ferromagnetic material, is gradually weakened, and the high frequency loss through the proximity effect is not suppressed.

An object of the present invention is to provide an electric wire for a high-frequency coil which secures reliability of solder joints and seeks to reduce the AC impedance at a high frequency, and an electronic component using the electric wire for a high-frequency coil. means of solving problems

(1) An electric wire for a high-frequency coil comprising at least a core wire having a copper conductor, a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating coating layer provided on the core wire. , which is characterized in that the aforementioned ferromagnetic layer has gaps in the radial direction. According to this invention, since the ferromagnetic layer has the gap in the radial direction, the tin in the solder at the time of soldering can easily reach the copper conductor. As a result, when an intermetallic bond occurs via copper and tin in the solder, the wetting stress becomes high, and a strong solder bond can be obtained.

In the high-frequency coil wire according to the present invention, it is preferable that the ferromagnetic layer has an iron layer and a nickel layer provided on the outer periphery of the iron layer.

In the high-frequency coil electric wire according to the present invention, the number coefficient of the gap is the number that can be seen on the surface of the core wire, and can be determined by a virtual line in the axial direction and a virtual line in the radial direction having the same length as the diameter D of the core wire. The number seen in the formed square is preferably within the range of 2 or more and 30 or less. According to this invention, since the number of gaps that can be seen in the square is within the above-mentioned range, the solder at the time of soldering can easily reach the copper conductor.

In the electric wire for a high-frequency coil according to the present invention, it is preferable that the gap has a coil within a range of a width of 0.3 μm or more and 5 μm or less.

In the high-frequency coil wire of the present invention, the copper conductor is preferably selected from refined copper, oxygen-free copper, copper-tin alloy, copper-silver alloy, copper-nickel alloy, copper-clad aluminum, and copper-clad magnesium. . According to the present invention, the above-mentioned copper conductor system has low impedance and good conductivity with a conductivity of 60% IACS or more. Even if the conductor diameter is reduced, the metal containing copper as the main body is located in the outermost layer. Oxidation, which can improve the reliability of solder joints.

(2) The electronic component according to the present invention is characterized by using the wire for the high-frequency coil according to the present invention described above. Examples of electronic components include wire winding components such as high frequency coils, circuit boards including wire winding components such as high frequency coils, and the like.

(3) The high-frequency coil wire according to the present invention is a high-frequency coil comprising at least a core wire having a copper conductor, a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating coating layer provided on the core wire. The wire for coils is characterized in that the wetting stress during soldering is 3.4 mN or more, and the zero-crossing time is 0.4 seconds or less. According to the present invention, the wetting stress becomes high and a strong welded joint can be obtained.

In the high-frequency coil wire according to the present invention, the diameter of the copper conductor is preferably within the range of 0.02 to 0.40 mm.

In the electric wire for a high frequency coil according to the present invention, the wetting stress is preferably 3.7 mN or more, and the zero-crossing time is preferably 0.2 seconds or less.

In the high frequency coil wire according to the present invention, the ferromagnetic layer has an iron layer and a nickel layer provided on the outer periphery of the iron layer, and the Vickers hardness of the iron layer is preferably 200HV.

In the high-frequency coil wire according to the present invention, the ferromagnetic layer has an iron layer and a nickel layer provided on the outer periphery of the iron layer, and the thickness of the iron layer is preferably 0.2 μm or more and 3.0 μm or less.

(4) The electronic component according to the present invention is characterized in that the high-frequency coil wire according to the present invention is connected by welding. Examples of electronic components include wire winding components such as high frequency coils, circuit boards including wire winding components such as high frequency coils, and the like. Invention effect

According to the present invention, it is possible to provide an electric wire for a high-frequency coil that can ensure the reliability of solder joints and can achieve a reduction in AC impedance at high frequencies.

Embodiments of the high-frequency coil wire and electronic component of the present invention will be described with reference to the drawings. However, the present invention includes the inventors who have the same technical idea as the embodiments described below and the forms described in the drawings, and the technical scope of the present invention is not limited only to the descriptions of the embodiments or the drawings. .

As shown in FIGS. 1 and 2 , a high-frequency coil wire 20 according to the present invention comprises at least a core wire 10 having a copper conductor 1 and a ferromagnetic layer 4 provided on the outer periphery of the copper conductor 1 , and a core wire 10 provided on the core wire 10 . The insulating coating layer 5 on it is formed. In addition, as shown in FIG. 3(A)(B), it is characterized in that the ferromagnetic layer 4 has a gap G in the radial direction X. As shown in FIG. The ferromagnetic layer 4 is preferably composed of the iron layer 2 and the nickel layer 3 disposed on the outer periphery of the iron layer 2 .

In this high-frequency coil wire 20 , the ferromagnetic layer 4 constituting the core wire 10 has a gap G in the radial direction X, so that the solder during soldering can easily reach the copper conductor 1 . As a result, when an intermetallic bond occurs via copper and tin in the solder, the wetting stress becomes high, and a strong solder bond can be obtained. However, the gap G is in the form of penetrating the ferromagnetic layer 4 (eg, the nickel layer 3 and the iron layer 2 ). When there is no gap G, the tin in the solder is bonded to nickel, but when the thickness of the nickel layer is extremely thin, nickel diffuses in the solder instantaneously. As a result, since it is actually bonded with iron, the wetting stress becomes low, and it becomes difficult to obtain good bonding strength.

Hereinafter, the constituent elements of the high-frequency coil wire will be described.

<core wire>

The core wire 10 has a copper conductor 1 and a ferromagnetic layer 4 provided on the outer periphery of the copper conductor 1 . The high-frequency coil electric wire 20 is constituted by at least the core wire 10 and the insulating coating layer 5 provided on the core wire 10 .

(copper conductor)

The copper conductor 1 contains copper or copper alloy as the main constituent metal, and in this application, is selected from the group consisting of refined copper, oxygen-free copper, copper-tin alloy, copper-silver alloy, copper-nickel alloy, copper-clad aluminum, Copper clad magnesium, etc. These conductor systems have low impedance and good conductivity with a conductivity of 60% IACS or more. Even if the conductor diameter is reduced, the metal containing copper as the main body is located in the outermost layer, so it is not easy to be oxidized. The reliability of welding joints. However, in copper-tin alloys, copper-silver alloys, copper-nickel alloys, copper-clad aluminum, copper-clad magnesium, etc., As the high-frequency coil wire 20, in order to achieve the desired electrical conductivity (60% IACS or more), it is preferable for the copper alloy to adjust its alloy composition, and for the cladding, to adjust the material of the core material or The ratio of cladding material to core material is preferred.

The diameter of the copper conductor 1 is not particularly limited, but in an environment where the soldering temperature is high, the reliability of the connection strength becomes a problem, and the fineness is preferably in the range of about 0.02 to 0.40 mm, for example.

(ferromagnetic layer)

The ferromagnetic layer 4 is provided on the copper conductor 1, and the obtained core wire 10 is used as the high-frequency coil wire 20, which reduces the AC impedance and improves the high-frequency characteristic when used in a high-frequency coil. The constituent material of the ferromagnetic layer 4 is not particularly limited, for example, iron, cobalt, nickel, high magnetic permeability alloy (Ni78-Fe22), high magnetic permeability alloy (Ni45-Fe55), superconducting magnetic alloy ( Ni75-Cu5-Fe20), Co-Ni-Fe (Co20-Ni40-Fe40) etc. The method for forming the ferromagnetic layer 4 is not particularly limited, but as a method for forming the ferromagnetic layer 4 on the copper conductor 1, the electroplating method is preferable. use. In the high-frequency coil wire 20 according to the present invention, the ferromagnetic layer 4 is characterized in that a gap G, which will be described later, is formed.

In the following, a configuration of the iron layer 2 and the nickel layer 3 as the ferromagnetic layer 4 will be described by way of example. The ferromagnetic layer 4 constituted by other than the iron layer 2 and the nickel layer 3 has slightly different high-frequency characteristics due to its composition, but the effect of the gap G, thickness, welding, etc. are the same.

(Iron Layer) The iron layer 2 is provided on the copper conductor 1, and forms the ferromagnetic layer 4 together with the nickel layer 3. The thickness of the iron layer 2 is preferably set within the range of 0.2 μm or more and 3.0 μm or less, and when used in high-frequency coils, the AC impedance is reduced and the high-frequency characteristics are improved. In particular, pure iron plating is ideal because of its strong magnetic properties. However, other elements (for example, nickel, cobalt, phosphorus, boron, etc.) may be contained in the iron layer 2 as long as the effect of reducing the AC impedance and the like is not inhibited.

The iron layer 2 can improve the high-frequency characteristics, and also has the effect of preventing solder erosion during soldering. However, in the iron layer 2 formed on the copper conductor 1, preventing the solder from being corroded means that it is difficult to form an intermetallic compound between tin and iron in the solder. It is difficult to achieve such an intermetallic compound formation, which hinders the combination of copper and tin in solder, and has low wetting stress (ie, bonding strength), poor connection reliability, and cannot meet the requirements of short-term solderability. situation.

In the present invention, the feature is that the ferromagnetic layer 4 formed by the iron layer 2 and the nickel layer 3 has a gap G in the radial direction X. With such a gap G, the tin in the solder during soldering can easily reach the copper conductor 1 . As a result, when an intermetallic bond occurs via copper and tin in the solder, the wetting stress becomes high, and a strong solder bond can be obtained. The gap G is in the form of penetrating from the nickel layer 3 to the iron layer 2 as a whole.

The number of the gap G is the number that can be seen on the surface of the core wire 10, and can be in the square (Y1×X1) formed by the imaginary line Y1 in the axial direction and the imaginary line X1 in the radial direction having the same length as the diameter D of the core wire 10. number seen. The number coefficient of the gap G is preferably within the range of 2 or more and 30 or less. When it is within such a range, the solder at the time of soldering can easily reach the copper conductor, and as a result, when the intermetallic bonding occurs between the copper and the tin in the solder, a good wetting stress is obtained, and a strong solder joint is obtained. When the number of the gaps G is less than 2, the bonding of tin and iron in the solder is the main reason, the wetting stress is low, and it is difficult to obtain good bonding strength. On the other hand, when the number of gaps G exceeds 30, the tin and copper in the solder are joined instantaneously, the solder is eroded, and the cross-sectional area of the conductor is easily reduced, and the joining strength may decrease. The width of the gap G is preferably within a range of 0.3 μm or more and 5 μm or less, and more preferably within a range of 0.5 μm or more and 2.0 μm or less. Through this gap G, the solder at the time of soldering can easily reach the copper conductor, and as a result, when the intermetallic bonding occurs between the copper and the tin in the solder, good wetting stress is obtained, and a strong solder joint is obtained. However, when the width of the gap G exceeds 5 μm, there is a possibility of pinholes.

The gap G is formed by controlling the mechanical properties (tensile strength, elongation) of the copper conductor 1 or the size and angle of the pulley as shown in the embodiments described later. In addition, when adding additives to the iron plating solution and controlling the plating conditions, the gap G can be formed by increasing the hardness of the iron layer 2 to 200 HV or more in Vickers hardness.

Examples of the additive system include thiourea, saccharin, benzothiazole, JGB (Guinea green B), benzylidene acetone, gelatin, polyethylene glycol, butynediol, coumarin, etc. In the case of several 10 ppm or the like, molecules or ions can be adsorbed at the precipitation site alone and precipitated. In addition, iron complexes are formed by these additives, and the complexes can be adsorbed and deposited at the precipitation sites. Through the effect of additives, fine and hard crystal grains can be obtained, and the iron layer 2 with a Vickers hardness of about 250HV can be formed. When the thickness of the iron layer 2 is set to be 0.5 μm or more, preferably 1 μm or more, the electrical stress increases, and a gap G exists in the iron layer 2 .

As the plating conditions, for example, when the temperature of the plating solution is lowered from 30°C to 20°C and the pH is lowered from 3 to 2, fine and hard crystal grains can be obtained, and a Vickers hardness of 300HV can be obtained. Degree of iron layer 2. When the thickness of the iron layer 2 is set to be 0.5 μm or more, preferably 1 μm or more, the electrical stress increases, and a gap G exists in the iron layer 2 .

The iron layer 2 is preferably formed by electroplating, and can be formed by supplying electricity to the copper conductor 1 in an iron electrolyte. The plating solution is usually a plating solution having at least an inorganic salt of iron and a supporting electrolyte, and is not particularly limited, but for example, a ferric sulfate plating solution, a ferric chloride plating solution, or the like can be applied. The plating solution may contain various additives such as a surfactant and a glossing agent, as necessary, within a range that does not inhibit the effects of the present invention.

(Nickel layer) The nickel layer 3 is provided on the iron layer 2, and forms the ferromagnetic layer 4 together with the iron layer 2. The thickness of the nickel layer 3 is preferably set within the range of 0.01 μm or more and 1.0 μm or less, and at the same time the weldability is improved, and the AC impedance can be reduced when the iron layer 2 is used in high frequency coils at the same time. , so that the high frequency characteristics are improved. When the nickel layer 3 is too thick, the effect of the iron of the ferromagnetic material is gradually weakened, and the high frequency loss through the proximity effect cannot be suppressed. On the other hand, when the nickel layer 3 is too thin, in an environment where the soldering temperature is high, the nickel layer 3 reacts with the tin in the solder instantaneously and diffuses, which is actually the joint between the iron layer 2 and the solder material that becomes the base. Therefore, the wetting stress is low, and it is difficult to obtain good bonding strength.

The nickel layer 3 and the iron layer 2 form the ferromagnetic layer 4 at the same time. The ferromagnetic layer 4 has the gap G in the radial direction X as described above. However, since the gap G has already been explained, the explanation is omitted here.

The nickel layer 3 is preferably formed by electroplating, and can be formed by supplying electricity to the copper conductor 1 provided with the iron layer 2 in a nickel electrolyte. The plating solution is usually a plating solution containing at least an inorganic salt of nickel and a supporting electrolyte, and is not particularly limited, but for example, a nickel sulfate plating solution, a nickel chloride plating solution, or the like can be applied. The plating solution may contain various additives such as a surfactant and a glossing agent, as necessary, within a range that does not inhibit the effects of the present invention.

<Insulating coating layer> The insulating coating layer 5 is provided on the ferromagnetic layer 4 as shown in FIG. 2 . When the insulating coating layer 5 is provided, the high-frequency coil wire 20 can be used as a variety of high-frequency coils, high-frequency coil wires (integrated stranded wires through the insulating coating, and insulation of the outer periphery of the assembled bare wires). wires, etc.) to be used effectively. The insulating coating 5 is formed on the outer periphery of the core wire 10 after the ferromagnetic layer 4 is formed, and is coated and baked to form a weldable insulating enamel film, or a weldable insulating enamel film and a fusion enamel film. Weldable insulating enamel coating is, for example, can be coated and fired to form general-purpose polyurethane, modified polyurethane, polyurethane, etc. welding possible enamel coatings. In addition, the fusion enamel coating film formed on the outer periphery can be, for example, a fusion enamel coating material such as nylon or epoxy, which can be formed by coating and firing. These coating films can be produced using a normal enamel wire production apparatus. However, in the case where the insulating coating layer 5 (polyimide imide, polyimide, polyester, etc.) that cannot be soldered is provided, the insulating coating layer 5 is mechanically and/or chemically peeled off, which can be favorable. welding.

The high-frequency coil wire 20 according to the present invention provided with the insulating coating layer 5 can be used as a constituent wire of a Litz wire, or a constituent wire of a triple-layer insulated wire, etc., even for a high-frequency coil. In addition, as for these others, as a structure using the core wire 10 before the insulating coating layer 5 is provided, or a structure provided with a protective film such as an imidazole complex on the surface of the core wire 10, these are twisted and used as a stranded wire or as a The assembled wire may be stranded wire or insulated wire for high frequency use on the outer periphery of the assembled wire by pressing, tape, sintering, etc. to integrate it.

<Electronic component> The electronic component according to the present invention is constructed using the high-frequency coil wire 20 according to the present invention described above. Examples of electronic components include wire winding components such as high frequency coils, circuit boards including wire winding components such as high frequency coils, and the like. Example

Hereinafter, an Example is given and this invention is demonstrated more concretely. However, the present invention is not limited to the following examples.

[Example 1] An annealed material (ACW, tensile strength: 240 MPa, elongation: 27%) with a diameter of 0.1 mm was annealed with a hard copper wire (HCW) with a diameter of 0.1 mm in an inert gas atmosphere at 360° C. as copper Conductor 1 was used, and after surface degreasing and acid activation treatment, an iron layer 2 with a thickness of 1 μm was formed by electroplating, and then a nickel layer 3 with a thickness of 0.03 μm was formed by electroplating to obtain a ferromagnetic layer 4 (iron layer 4). 2 and the core wire 10 of the nickel layer 3). The iron plating system uses an iron sulfate plating solution (ferrous sulfate 250 g/L, ferric chloride 50 g/L, ammonium chloride 30 g/L), and the nickel plating system uses a nickel sulfate plating solution (nickel sulfate 250 g/L , nickel chloride 30g/L, boric acid 15g/L). The obtained core wire 10 is wound while being brought into contact with a pulley having a diameter of 350 times the diameter at an angle of 120°, and a gap G is provided in the radial direction X of the ferromagnetic layer 4 . In this way, the core wire 10 having the gap G is obtained.

[Example 2] The thickness of the iron layer 2 was 2 μm. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 3] The thickness of the iron layer 2 was 3 μm. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 4] As the copper conductor 1, an annealed material with a diameter of 0.1 mm (ACAW, tensile strength: 330 MPa) was used which was annealed with a hard copper-silver alloy wire (HCAW) having a diameter of 0.1 mm in an inert gas atmosphere at 650°C. , extension: 24%). Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 5] As the copper conductor 1, an annealed material (ACSW, tensile strength: 300 MPa) with a diameter of 0.1 mm, which was annealed with a hard copper-tin alloy wire (HCSW) with a diameter of 0.1 mm, was annealed in an inert gas atmosphere at 600°C. , extension: 25%). Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 6] A pulley 300 times the diameter was used. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 7] A pulley 200 times the diameter was used. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 8] A pulley 100 times the diameter was used. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 9] Annealing was performed in an inert gas atmosphere at 300°C. Except for this, the core wire 10 was obtained in the same manner as in Example 1. Annealed material (ACW) tensile strength: 280 MPa, elongation: 15%.

[Example 10] Annealing was performed in an inert gas atmosphere at 280°C. Except for this, the core wire 10 was obtained in the same manner as in Example 1. Annealed material (ACW) tensile strength: 300 MPa, elongation: 5%.

[Example 11] Winding was performed while contacting the pulley at an angle of 90°. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 12] A pulley with a diameter of 100 times the diameter was used, and the winding was performed while contacting the pulley at an angle of 90°. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 13] A hard copper wire (HCW) with a diameter of 0.05 mm and an annealed material with a diameter of 0.05 mm (ACW, tensile strength: 280 MPa, elongation: 18%) annealed in an inert gas atmosphere at 360°C were used as copper conductor 1. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 14] A hard copper wire (HCW) with a diameter of 0.08 mm and an annealed material with a diameter of 0.08 mm (ACW, tensile strength: 260 MPa, elongation: 22%) annealed in an inert gas environment at 360°C were used as copper conductor 1. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Example 15] A hard copper wire (HCW) with a diameter of 0.12 mm and an annealed material with a diameter of 0.12 mm (ACW, tensile strength: 240 MPa, elongation: 28%) annealed in an inert gas environment at 360° C. were used as copper conductor 1. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Comparative Example 1] Annealing was not performed in an inert gas atmosphere. Except for this, the core wire 10 was obtained in the same manner as in Example 1. Unannealed hard copper wire (HCW) has tensile strength: 400 MPa, elongation: 2%.

[Comparative Example 2] The thickness of the iron layer 2 was 2 μm. Except for this, the core wire 10 was obtained in the same manner as in Comparative Example 1.

[Comparative Example 3] The thickness of the iron layer 2 was 3 μm. Except for this, the core wire 10 was obtained in the same manner as in Comparative Example 1.

[Comparative Example 4] Annealing was performed in an inert gas atmosphere at 280°C, and a pulley having a diameter of 400 times was used. Other than that, it was performed in the same manner as in Example 1, and an electric wire for a high-frequency coil was obtained. Annealed material (ACW) tensile strength: 300 MPa, elongation: 5%.

[Comparative Example 5] Annealing was performed in an inert gas atmosphere at 280°C, and a pulley having a diameter of 400 times the diameter was brought into contact at an angle of 90° while being wound. Except for this, the core wire 10 was obtained in the same manner as in Example 1. Annealed material (ACW) tensile strength: 300 MPa, elongation: 5%.

[Comparative Example 6] As the copper conductor 1, an annealed material (ACSW, tensile strength: 300 MPa) with a diameter of 0.1 mm, which was annealed with a hard copper-tin alloy wire (HCSW) with a diameter of 0.1 mm, was annealed in an inert gas atmosphere at 600°C. , extension: 25%). Furthermore, while the pulley 400 times the diameter is brought into contact with the pulley at an angle of 120°, the winding is performed. Except for this, the core wire 10 was obtained in the same manner as in Example 1.

[Comparative Example 7] Annealing was performed in an inert gas atmosphere at 300°C, and a pulley 350 times the diameter was brought into contact at an angle of 160° while being wound. Except for this, the core wire 10 was obtained in the same manner as in Example 1. Annealed material (ACW) tensile strength: 240 MPa, elongation: 15%.

[Measurement and Results] (Gap and Welding Properties) Table 1 shows the elements of the core wires 10 obtained in Examples and Comparative Examples. The gap G of each core wire 10 was measured with a microscope (manufactured by Keyence Co., Ltd., VX600 type, 500 times). The measurement system measures the average width of the gap G while measuring the number of gaps G that can be seen in a square (0.1 mm angle) formed by the imaginary line Y1 in the axial direction and the imaginary line X1 in the radial direction. The number of gaps G is measured by counting the length of 1/4 or more of the imaginary line X1 (= diameter of the core wire) in the radial direction. The case where the gap G is branched can be continuous or discontinuous, and it is regarded as the same (one) gap G that is connected. The results are shown in Table 2.

Wetting stress (mN) and zero-crossing time (seconds) at the time of welding were measured with an active wettability tester (manufactured by RHESCA Co., Ltd., model WET-6100). As the solder, Sn-3Ag-0.5Cu (manufactured by Senju Metal Industry Co., Ltd.) was used, and the test was carried out at a temperature of 380°C. The results are shown in Table 2.

From the results of Tables 1 and 2, when the wetting stress is 3.4 mN or more and the zero-crossing time is 0.4 seconds or less, the number of gaps G is 6 or more, and the product of the number of gaps G and the width is 6 or more. A particularly desirable configuration is when the wetting stress is 3.7 mN or more, the zero-crossing time is 0.2 seconds or less, the number of gaps G is 12 or more, and the product of the number and width of gaps G is 12 or more. Such a result can be realized mainly when the product of the number and the width of the gap G is 12 or more. Such a gap G can be formed under the manufacturing conditions shown in Table 1.

For the core wires 10 of Examples 13 to 15 in which the diameter of the copper conductor 1 was different, the same measurements as in Example 1 were performed (wetting stress, zero crossing time, number of gaps). In Example 13 (conductor diameter: 0.05 mm), wetting stress: 1.8 mN, zero crossing time: 0.2 seconds, number of gaps G: 25, width of gap G: 1.5 mm, and product of number and width: 37.5. In Example 14 (conductor diameter: 0.08 mm), wetting stress: 2.9 mN, zero crossing time: 0.2 seconds, number of gaps G: 19, width of gap G: 1.0 mm, product of number and width: 19. In Example 15 (conductor diameter: 0.12 mm), wetting stress: 4.3 mN, zero crossing time: 0.2 seconds, number of gaps G: 12, width of gap G: 1.0 mm, product of number and width: 12. From these results, the wetting stress (mN) was divided and compared per unit surface area, Example 1 (conductor diameter: 0.10 mm), Example 13 (conductor diameter: 0.05 mm), and Example 14 ( Conductor diameter: 0.08 mm) and Example 15 (conductor diameter: 0.12 mm) were all around 5.7 mN/mm ² .

(High-frequency characteristics) The high-frequency characteristics were measured with an LCR measuring instrument (Precision LCR measuring instrument, 4284A, 20 Hz to 1 MHz, manufactured by Agilent). Measurement system: Sample length: 1.50 m, special spool: inner diameter φ67 mm, number of revolutions: 5 revolutions, and the terminal is measured by attaching solder to both ends and connecting it to the fabric. Using the samples 1 to 3 (wires 20 for high-frequency coils) described below provided with two types of urethanes as the insulating coating layer 5, the frequency was changed to 1 kHz to 1 MHz, and the measurement was performed.

Sample 1: Two kinds of urethane-coated enamel-coated copper-plated strands (21 wires/φ0.10mm) Sample 2: Two kinds of urethane-coated enamel-coated iron-plated strands (21 wires/φ0.10mm), gap G: None, iron plating solution (same iron plating solution as in Example, without additives), nickel plating solution (same nickel plating solution as in Example 1), thickness of Fe layer: 0.8 μm, Ni Thickness of layer: 0.05 μm Sample 3: Two kinds of urethane-coated enamel iron plating strands (21 wires/φ0.10 mm), Gap G: Yes, iron plating solution (same iron plating as in Example 1) solution, additive: saccharin 2m/L), nickel plating solution (same nickel plating solution as in Example 1), thickness of Fe layer: 0.8 μm, thickness of Ni layer: 0.05 μm.

FIG. 3(A) is a photograph of the surface of the urethane-coated enamel magnetically plated strand of sample 3. FIG. FIG. 3(B) is a surface photograph of two types of urethane-coated enamel magnetically plated strands of sample 2. FIG. Fig. 3(C) is a photograph of the surface of two kinds of urethane-coated enamel copper strands of sample 1.

Table 3 shows the impedance results, and Table 4 shows the impedance loss results. As can be seen from Tables 3 and 4, in the case where the ferromagnetic layer 4 is provided, regardless of the presence or absence of the gap G, the same high-frequency characteristics are exhibited, and it is confirmed that the presence of the gap G does not degrade the high-frequency characteristics situation.

1: Copper conductor

2: Iron layer

3: Nickel layer

4: ferromagnetic layer

5: Insulation coating

10: Core wire

20: Wires for high frequency coils

D: diameter

G: Gap

X: radial direction

FIG. 1 is a cross-sectional view showing an example of a core wire constituting an electric wire for a high-frequency coil according to the present invention. Fig. 2 is a cross-sectional view showing an example of the electric wire for the high-frequency coil of the present invention. Fig. 3 is an electron microscope photograph of the surface of the ferromagnetic layer of the core wire obtained in the Example. (A) is the case with a gap. (B) is the case where the clearance is small. (C) is the case where there is almost no gap.

1‧‧‧Copper conductor

2‧‧‧Iron Layer

3‧‧‧Ni layer

4‧‧‧Ferrous magnetic layer

10‧‧‧Core wire

Claims (12)

An electric wire for a high-frequency coil comprising at least a core wire having a copper conductor, a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating coating layer provided on the core wire, and characterized in that: The aforementioned ferromagnetic layer has a radial gap. The electric wire for a high frequency coil according to claim 1, wherein the ferromagnetic layer has an iron layer and a nickel layer provided on the outer periphery of the iron layer. The electric wire for a high-frequency coil according to claim 1 or claim 2, wherein the number of the gap is the number visible on the surface of the core wire, and can be determined by the same length as the diameter D of the core wire The number seen in the square formed by the imaginary line in the axial direction and the imaginary line in the radial direction is within the range of 2 or more and 30 or less. The high-frequency coil wire according to claim 1 or claim 2, wherein the width of the gap is within a range of 0.5 μm or more and 5 μm or less. The high-frequency coil wire according to claim 1 or claim 2, wherein the copper conductor is selected from pure copper, oxygen-free copper, copper-tin alloy, copper-silver alloy, copper-nickel alloy, copper Aluminum-clad, copper-clad magnesium. An electronic component characterized by being constructed using the high-frequency coil wire according to any one of claims 1 to 5 of the scope of application. An electric wire for a high-frequency coil, which is composed of at least a core wire having a copper conductor, a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating coating layer provided on the core wire, characterized in that: The wetting stress during welding is 3.4 mN or more, and the zero-crossing time is 0.4 seconds or less. According to the high-frequency coil wire according to claim 7, the diameter of the copper conductor is within the range of 0.02 to 0.40 mm. The electric wire for a high-frequency coil according to claim 7 or claim 8, wherein the wetting stress is 3.7 mN or more, and the zero-crossing time is 0.2 seconds or less. The high-frequency coil wire according to claim 7 or claim 8, wherein the ferromagnetic layer has an iron layer, and a nickel layer provided on the outer periphery of the iron layer, and the Vickers hardness of the iron layer is 200HV. The high-frequency coil wire according to claim 7 or claim 8, wherein the ferromagnetic layer has an iron layer, and a nickel layer provided on the outer periphery of the iron layer, and the thickness of the iron layer is 0.2 μm More than 3.0 μm or less. An electronic component characterized in that the electric wire for a high-frequency coil according to any one of claims 7 to 11 of the scope of application is connected by welding.

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