WO2019004110A1 - Electric wire for high-frequency coil, and electronic component - Google Patents

Abstract

An electric wire for a high frequency coil and an electronic component using the electric wire for a high frequency coil, capable of securing reliability of solder joint and reducing AC resistance at a high frequency. 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 covering layer 4 provided on the core wire 10 The above problem is solved by the high frequency coil electric wire 20 having a gap G in the radial direction X of the layer 4 or having a wetting stress of 3.4 mN or more at the time of soldering and a zero cross time of 0.4 seconds or less.

Description

Electric wire and electronic component for high frequency coil

The present invention relates to a wire for high frequency coil and an electronic component. More particularly, the present invention relates to a wire for a high frequency coil which can be used for electronic components such as various high frequency coils and can reduce AC resistance at high frequency, and an electronic component using the wire for the high frequency coil.

Patent Document 1 proposes an enameled insulated wire having a core wire made of a conductor plated with a ferromagnetic substance such as pure iron on a copper wire, and describes that the high frequency gain Q is improved by several tens of percent. This characteristic improvement is considered to be based on the reduction of alternating current resistance at high frequency, and by applying a ferromagnetic layer to the outer periphery of the conductor, the external magnetic field is shielded and the outside penetrates the inside without being able to be shielded. It is believed that the increase in AC resistance is suppressed by reducing the eddy current due to the magnetic field and suppressing the loss due to the proximity effect. Further, Patent Document 1 also describes that a nickel plating layer is preferable to a copper plating layer as a plating layer provided on a ferromagnetic layer in order to improve soldering characteristics.

Further, in Patent Document 2, in order to improve solderability, an iron-plated layer is provided on the outer periphery of a conductor, and a nickel-plated layer having a thickness of 0.03 to 0.1 μm to ensure solderability. And a method of coating and baking an enamel insulating resin layer made of a polyurethane insulating paint before the iron plating layer is oxidized has been proposed.

Japanese Utility Model Publication No. 42-1339 Japanese Patent Application Laid-Open No. 62-151594

In the insulation coated electric wire used for coil parts, a polyurethane coating layer is generally applied as an enamel insulation layer. However, the operating environment of electronic device parts such as coil parts has shifted to a higher temperature side, and the demand for heat resistance of the enamel insulating layer constituting the insulation coated wire has also increased. The heat resistance of the insulating resin constituting the insulating covering layer is indicated by a heat resistance class such as type A, E, B, F, or H and the maximum allowable temperature, and the polyurethane forming the above-mentioned polyurethane covering layer is The temperature index corresponds to E class 120 ° C. Recently, there has been a demand for using a high temperature resistant resin such as a modified polyurethane or polyester having a temperature index F of 155 ° C., or a polyesterimide having a temperature index H of 180 ° C. The soldering temperature is as high as 420 ° C. in Class F class and 460 ° C. in Class H class.

As the soldering temperature rises, cross-section reduction due to solder corrosion of the lead (copper conductor etc.) is likely to occur, and the reliability of the connection strength becomes a problem, so the lead is soldered in a very short time Is desirable. That is, the higher the wetting stress and the shorter the zero crossing time, the more reliable the solder connection can be.

Further, with the miniaturization of the coil parts and the increase in frequency, etc., a large number of insulation coated electric wires are twisted and thinned. In particular, as the wire becomes thinner, problems such as solder corrosion tend to occur.

In the soldering of the enameled wire described in Patent Document 2, in an environment where the soldering temperature is high, the nickel plating layer and tin in the solder react instantaneously and diffuse, and in fact, the iron plating layer of the base and the solder material It is a joint of However, since it is difficult to form an intermetallic compound of iron and tin, the wetting stress (i.e., the bonding strength) is low and the connection reliability is deteriorated. If the thickness of nickel is made thicker than necessary, the effect of iron, which is a ferromagnetic substance, is weakened, and the reduction of high frequency loss due to the proximity effect can not be achieved.

An object of the present invention is to provide a wire for a high frequency coil and an electronic component using the wire for a high frequency coil, in which reliability of solder bonding can be ensured and reduction of alternating current resistance at high frequency can be achieved.

(1) The electric wire for high frequency coil according to the present invention comprises at least a core wire having a copper conductor and a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating covering layer provided on the core wire. A wire for a high frequency coil, wherein the ferromagnetic layer has a gap in the radial direction. According to the present invention, since the ferromagnetic layer has a gap in the radial direction, tin in the solder at the time of soldering can easily reach the copper conductor. As a result, due to metal-to-metal bonding between copper and tin in the solder, the wetting stress becomes high, and a strong solder joint can be obtained.

In the wire for a high frequency coil 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 of the gaps is a number visible on the surface of the core and is formed by an axial imaginary line and a radial imaginary line having the same length as the diameter D of the core. The number of squares visible in the square is preferably in the range of 2 or more and 30 or less. According to the present invention, since the number of gaps visible in the square is within the above range, the solder at the time of soldering can easily reach the copper conductor.

In the wire for a high frequency coil according to the present invention, the gap preferably has a coil width within a range of 0.3 μm to 5 μm.

In the wire for a high frequency coil according to the present invention, the copper conductor is preferably selected from tough pitch copper, oxygen free copper, copper-tin alloy, copper-silver alloy, copper-nickel alloy, copper clad aluminum, copper clad magnesium . According to the present invention, since the copper conductor has a low resistance and good conductivity of 60% IACS or more, the copper-based metal is in the outermost layer even when the diameter of the conductor is reduced. It is not easily oxidized and the reliability of the soldered joint can be enhanced.

(2) The electronic component according to the present invention is characterized by being configured using the electric wire for a high frequency coil according to the present invention. Examples of the electronic component include a winding component such as a high frequency coil, and a circuit board provided with a winding component such as a high frequency coil.

(3) The electric wire for high frequency coil according to the present invention comprises at least a core wire having a copper conductor and a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating covering layer provided on the core wire. A wire for a high frequency coil, characterized in that a wetting stress at the time of soldering is 3.4 mN or more and a zero cross time is 0.4 seconds or less. According to this invention, the wetting stress is high, and a strong solder joint can be obtained.

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

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

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

In the wire for a high frequency coil 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 0.2 μm or more and 3.0 μm. It is preferable that it is the following.

(4) The electronic component according to the present invention is characterized in that the electric wire for high frequency coil according to the present invention is connected by soldering. Examples of the electronic component include a winding component such as a high frequency coil, and a circuit board provided with a winding component such as a high frequency coil.

According to the present invention, it is possible to provide a wire for a high frequency coil capable of securing the reliability of the soldered joint and reducing the AC resistance at a high frequency.

It is sectional drawing which shows an example of the core wire which comprises the electric wire for high frequency coils which concerns on this invention. It is sectional drawing which shows an example of the electric wire for high frequency coils which concerns on this invention. It is an electron micrograph of the surface of the ferromagnetic layer of the core wire obtained in the Example. (A) is a case where there is a gap. (B) is the case where the gap is small. (C) is a case where there is almost no gap.

Embodiments of a high frequency coil wire and an electronic component according to the present invention will be described with reference to the drawings. The present invention includes inventions of the same technical concept as the embodiments described below and the embodiments described in the drawings, and the technical scope of the present invention is limited only to the description of the embodiments and the drawings. It is not a thing.

An electric wire 20 for a high frequency coil according to the present invention, as shown in FIGS. 1 and 2, includes a core 10 having a copper conductor 1 and a ferromagnetic layer 4 provided on the outer periphery of the copper conductor 1, and the core 10 And at least the insulating covering layer 5 provided on the And as shown to FIG. 3 (A) (B), the ferromagnetic layer 4 has the characteristics in having the clearance gap G of radial direction X. As shown in FIG. The ferromagnetic layer 4 preferably comprises an iron layer 2 and a nickel layer 3 provided on the outer periphery of the iron layer 2.

In the high frequency coil wire 20, since the ferromagnetic layer 4 constituting the core wire 10 has the gap G in the radial direction X, the solder at the time of soldering easily reaches the copper conductor 1. As a result, due to metal-to-metal bonding between copper and tin in the solder, the wetting stress becomes high, and a strong solder joint can be obtained. The gap G is in a form in which the ferromagnetic layer 4 (for example, the nickel layer 3 and the iron layer 2) is pierced. If there is no gap G, tin in the solder will bond with nickel, but if the thickness of the nickel layer is very thin, nickel will diffuse into the solder instantaneously. As a result, since it will actually be bonded to iron, the wetting stress is low and it is difficult to obtain good bonding strength.

The components of the high frequency coil wire will be described below.

<Core wire>
Core wire 10 includes copper conductor 1 and ferromagnetic layer 4 provided on the outer periphery of copper conductor 1. The high frequency coil wire 20 is at least constituted by a core 10 and an insulating covering layer 5 provided on the core 10.

(Copper conductor)
The copper conductor 1 contains copper or a copper alloy as a main constituent metal, and in the present application, tough pitch copper, oxygen free copper, copper-tin alloy, copper-silver alloy, copper-nickel alloy, copper clad aluminum, copper It is selected from clad magnesium and the like. Since these conductors have low resistance and good conductivity of 60% IACS or higher, even when the diameter of the conductor is reduced, a metal mainly composed of copper is in the outermost layer, so it is difficult to be oxidized, and solder is It is possible to improve the reliability of the post-joining. In addition, in the case of copper-tin alloy, copper-silver alloy, copper-nickel alloy, copper clad aluminum, copper clad magnesium, etc., copper is used so that the above-mentioned conductivity (60% IACS or more) preferable as the high frequency coil wire 20 can be obtained. In the case of an alloy, its alloy composition is preferably adjusted, and in the case of a clad, it is preferable that the material of the core material and the ratio of the clad material to the core material be adjusted.

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

(Ferromagnetic layer)
The ferromagnetic layer 4 is provided on the copper conductor 1, and when the core wire 10 obtained is used as a high frequency coil wire 20 for a high frequency coil, it acts to reduce AC resistance and improve high frequency characteristics. . The constituent material of the ferromagnetic layer 4 is not particularly limited. For example, iron, cobalt, nickel, permalloy (Ni78-Fe22), permalloy (Ni45-Fe55), supermalloy (Ni75-Cu5-Fe20), Co-Ni-Fe (Co20-Ni40-Fe40) etc. can be mentioned. Although the method of forming the ferromagnetic layer 4 is not particularly limited, electroplating is preferred as a method of forming on the copper conductor 1, but any of the above-described compositions can be deposited by electroplating, and thus preferably used. it can. The high frequency coil wire 20 according to the present invention is characterized in that a gap G described later is formed in the ferromagnetic layer 4.

Hereinafter, the ferromagnetic layer 4 will be described by way of an example comprising an iron layer 2 and a nickel layer 3. The ferromagnetic layer 4 composed of other than the iron layer 2 and the nickel layer 3 has the high frequency characteristics slightly different depending on its composition, but the same applies to the action, thickness, soldering and the like of the gap G.

(Iron layer)
The iron layer 2 is provided on the copper conductor 1 and constitutes the ferromagnetic layer 4 together with the nickel layer 3. The thickness of the iron layer 2 is preferably in the range of 0.2 μm to 3.0 μm. When the iron layer 2 is used for a high frequency coil or the like, the AC resistance is reduced to improve the high frequency characteristics. In particular, pure iron plating is preferably employed because it is ferromagnetic. The iron layer 2 may contain other elements (for example, nickel, cobalt, phosphorus, boron, etc.) as long as the effect of reducing the AC resistance is not impaired.

The iron layer 2 can improve high frequency characteristics, and also has an effect of preventing solder corrosion at the time of soldering. However, the fact that solder corrosion is prevented by the iron layer 2 formed on the copper conductor 1 means that it is difficult to form an intermetallic compound of tin and iron in the solder. The difficulty in forming such intermetallic compounds inhibits the combination of copper and tin in the solder, which results in low wetting stress (ie, bonding strength) and poor connection reliability, and in a short time. It may not be possible to meet the demand for solderability.

The present invention is characterized in that the ferromagnetic layer 4 composed of the iron layer 2 and the nickel layer 3 has a gap G in the radial direction X. By having such a gap G, tin in the solder at the time of soldering can easily reach the copper conductor 1. As a result, due to metal-to-metal bonding between copper and tin in the solder, the wetting stress becomes high, and a strong solder joint can be obtained. The gap G has an integral form which is penetrated from the nickel layer 3 to the iron layer 2

The number of gaps G is a number visible on the surface of the core wire 10, and in a square (Y1 × X1) formed by an axial imaginary line Y1 having the same length as the diameter D of the core wire 10 and a radial imaginary line X1. It is a number that looks like The number of gaps G is preferably in the range of 2 or more and 30 or less. Within this range, the solder during soldering can easily reach the copper conductor, and as a result, good wetting stress can be obtained by the metal-to-metal bonding between copper and tin in the solder, and a strong solder can be obtained. Bonding is obtained. When the number of the gaps G is less than 2, the bonding between tin in the solder and iron is mainly performed, so the wetting stress may be low and it may be difficult to obtain a good bonding strength. On the other hand, if the number of gaps G exceeds 30, tin and copper in the solder will instantaneously bond, and solder corrosion proceeds and the cross-sectional area of the conductor tends to decrease, so the bonding strength may decrease. is there. The width of the gap G is preferably in the range of 0.3 μm to 5 μm, and more preferably in the range of 0.5 μm to 2.0 μm. By this gap G, the solder at the time of soldering can easily reach the copper conductor, and as a result, good wetting stress can be obtained by the metal-to-metal bonding between copper and tin in the solder, and a strong solder joint can be obtained. Be In addition, when the width | variety of the clearance gap G exceeds 5 micrometers, it may become a pinhole easily.

The gap G can be formed by controlling the mechanical characteristics (tensile strength, elongation) of the copper conductor 1 and the size and angle of the pulley as shown in the later-described embodiment. In addition, the gap G can be formed by adding an additive to the iron plating solution or controlling the plating conditions to increase the hardness of the iron layer 2 to 200 HV or more in Vickers hardness.

Examples of the additive include thiourea, saccharin, benzothiazole, JGB (Janas green B), bensalacetone, gelatin, polyethylene glycol, butynediol, coumarin and the like, and several tens of ppm of these may be added. As a result, molecules or ions can be adsorbed on the precipitation site alone and precipitated. In addition, an iron complex is formed by these additives, and the complex can be adsorbed to the precipitation site to be precipitated. Fine and hard crystal grains can be obtained by the effect of the additive, and the iron layer 2 having a Vickers hardness of about 250 HV can be formed. By setting the thickness of the iron layer 2 to 0.5 μm or more, preferably 1 μm or more, the electrodeposition stress is increased, and a gap G is present in the iron layer 2.

As the plating conditions, fine and hard crystal grains can be obtained, for example, by lowering the temperature of the plating solution from 30 ° C. to 20 ° C., or lowering the pH to 3 to 2, and iron with a Vickers hardness of about 300 HV. Layer 2 can be formed. By setting the thickness of the iron layer 2 to 0.5 μm or more, preferably 1 μm or more, the electrodeposition stress is increased, and a gap G is present in the iron layer 2.

The iron layer 2 is preferably formed by electroplating, and can be formed by supplying power to the copper conductor 1 in an iron electrolytic solution. The plating solution is not particularly limited as long as it is a plating solution having at least an inorganic salt of iron and a supporting electrolyte. For example, an iron sulfate plating solution or an iron chloride plating solution can be used. The plating solution may contain various additives such as a surfactant and a brightening agent, as needed, as long as the effects of the present invention are not impaired.

(Nickel layer)
The nickel layer 3 is provided on the iron layer 2 and constitutes the ferromagnetic layer 4 together with the iron layer 2. The thickness of the nickel layer 3 is preferably in the range of 0.01 μm or more and 1.0 μm or less, and when the solderability is improved, the nickel layer 3 is used together with the iron layer 2 for a high frequency coil or the like. AC resistance can be reduced to improve high frequency characteristics. If the nickel layer 3 is too thick, the effect of iron, which is a ferromagnetic material, is reduced, and the suppression of high frequency loss due to the proximity effect can not be achieved. On the other hand, if the nickel layer 3 is too thin, in an environment where the soldering temperature is high, the nickel layer 3 and tin in the solder react instantaneously and diffuse, and in fact, for bonding the underlying iron layer 2 to the solder material Therefore, the wetting stress is low and it is difficult to obtain a good bonding strength.

The nickel layer 3 and the iron layer 2 constitute the ferromagnetic layer 4, and the ferromagnetic layer 4 has the gap G in the radial direction X as described above. In addition, since the gap G has already been described, the description thereof is omitted here.

The nickel layer 3 is preferably formed by electroplating, and can be formed by supplying power to the copper conductor 1 provided with the iron layer 2 in a nickel electrolytic solution. The plating solution is not particularly limited as long as it is a plating solution having at least an inorganic salt of nickel and a supporting electrolyte. For example, a nickel sulfate plating solution or a nickel chloride plating solution can be used. The plating solution may contain various additives such as a surfactant and a brightening agent, as needed, as long as the effects of the present invention are not impaired.

<Insulating coating layer>
The insulating covering layer 5 is provided on the ferromagnetic layer 4 as shown in FIG. By providing the insulating covering layer 5, the high frequency coil wire 20 is useful as various high frequency coils and wires for high frequency coils (a stranded wire, an insulated wire etc. in which the outer periphery of the gathered strands is integrated with the insulating coating) Available to The insulating covering layer 5 is formed by applying and baking a solderable insulating enamel film, or a solderable insulating enamel film and a fusion enamel film on the outer periphery of the core wire 10 after the ferromagnetic layer 4 is formed. Be done. The solderable insulating enamel coating can be formed, for example, by applying and baking a solderable enamel paint such as general purpose polyurethane, modified polyurethane, or polyester imide. Further, the fused enamel film formed on the outer periphery can be formed by coating and baking a fused enamel paint such as nylon or epoxy. These coatings can be manufactured using a conventional enameled wire manufacturing apparatus. In the case where the insulating coating layer 5 (polyamide imide, polyimide, polyester or the like) which can not be soldered is provided, the insulating coating layer 5 can be satisfactorily soldered by peeling it mechanically and / or chemically.

The high frequency coil electric wire 20 according to the present invention provided with the insulating covering layer 5 can be used as a component wire of a litz wire, a component wire of a three-layer insulated wire, or the like, except for the high frequency coil. In addition to these, using a core wire 10 before providing the insulating covering layer 5 or a surface of the core wire 10 provided with a protective film such as an imidazole complex film, it is twisted to form a stranded wire or assembly. It is good also as an insulated wire etc. for high frequency which set it as the assembly line, and the perimeter of the strand or the assembly line was united by extrusion, tape winding, baking etc.

<Electronic parts>
The electronic component according to the present invention is configured using the high frequency coil wire 20 according to the present invention described above. Examples of the electronic component include a winding component such as a high frequency coil, and a circuit board provided with a winding component such as a high frequency coil.

Hereinafter, the present invention will be more specifically described by way of examples. The present invention is not limited to the following examples.

Example 1
A 0.1 mm diameter annealed material (ACW, tensile strength: 240 MPa, elongation: 27%) obtained by annealing a 0.1 mm diameter hard copper wire (HCW) in an inert gas atmosphere at 360 ° C. as a copper conductor 1 After degreasing and acid activation treatment, an iron layer 2 with a thickness of 1 μm is formed by electroplating, and subsequently, a nickel layer 3 with a thickness of 0.03 μm is formed by electroplating, and a ferromagnetic layer 4 (iron layer A core wire 10 provided with 2 and a nickel layer 3) was obtained. Iron plating uses iron sulfate plating solution (250 g / L of ferrous sulfate, 50 g / L of iron chloride, 30 g / L of ammonium chloride), and nickel plating uses nickel sulfate (250 g / L of nickel sulfate, 30 g of nickel chloride) / L and boric acid 15 g / L) were used. The obtained core wire 10 was wound while being in contact with a 350 times diameter pulley at an angle of 120 °, and a gap G was provided in the radial direction X of the ferromagnetic layer 4. Thus, a core wire 10 provided with a gap G was obtained.

Example 2
The thickness of the iron layer 2 was 2 μm. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

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

Example 4
As the copper conductor 1, an annealed material (ACAW, tensile strength: 330 MPa, elongation: 24%) of 0.1 mm in diameter obtained by annealing hard copper-silver alloy wire (HCAW) of 0.1 mm in diameter in an inert gas atmosphere at 650 ° C. Using. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 5]
As the copper conductor 1, an annealed material (ACSW, tensile strength: 300 MPa, elongation: 25%) of 0.1 mm in diameter obtained by annealing hard copper-tin alloy wire (HCSW) of 0.1 mm in diameter in an inert gas atmosphere at 600 ° C. Using. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 6]
A 300 times diameter pulley was used. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 7]
A 200 times diameter pulley was used. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 8]
A pulley 100 times the diameter was used. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 9]
Annealing was performed in an inert gas atmosphere at 300.degree. The core wire 10 was obtained in the same manner as in Example 1 except for the above. The annealed material (ACW) had a tensile strength of 280 MPa and an elongation of 15%.

[Example 10]
Annealing was performed at 280 ° C. in an inert gas atmosphere. The core wire 10 was obtained in the same manner as in Example 1 except for the above. The annealed material (ACW) had a tensile strength of 300 MPa and an elongation of 5%.

[Example 11]
It was wound while contacting the pulley at an angle of 90 °. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 12]
It was wound using a 100 times diameter pulley and contacting the pulley at a 90 ° angle. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 13]
An annealed material (ACW, tensile strength: 280 MPa, elongation: 18%) having a diameter of 0.05 mm obtained by annealing a hard copper wire (HCW) having a diameter of 0.05 mm in an inert gas atmosphere at 360 ° C. was used as a copper conductor 1. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

Example 14
An annealed material (ACW, tensile strength: 260 MPa, elongation: 22%) having a diameter of 0.08 mm obtained by annealing a hard copper wire (HCW) having a diameter of 0.08 mm in an inert gas atmosphere at 360 ° C. was used as a copper conductor 1. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

[Example 15]
An annealed material (ACW, tensile strength: 240 MPa, elongation: 28%) having a diameter of 0.12 mm obtained by annealing a hard copper wire (HCW) having a diameter of 0.12 mm in an inert gas atmosphere at 360 ° C. was used as a copper conductor 1. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

Comparative Example 1
It did not anneal in inert gas atmosphere. The core wire 10 was obtained in the same manner as in Example 1 except for the above. The non-annealed hard copper wire (HCW) had a tensile strength of 400 MPa and an elongation of 2%.

Comparative Example 2
The thickness of the iron layer 2 was 2 μm. The core wire 10 was obtained in the same manner as in Comparative Example 1 except for the above.

Comparative Example 3
The thickness of the iron layer 2 was 3 μm. The core wire 10 was obtained in the same manner as in Comparative Example 1 except for the above.

Comparative Example 4
Annealed in an inert gas atmosphere at 280 ° C. and used a 400 times diameter pulley. The others were the same as in Example 1 to obtain a high frequency coil wire. The annealed material (ACW) had a tensile strength of 300 MPa and an elongation of 5%.

Comparative Example 5
Annealed in an inert gas atmosphere at 280 ° C. and wound while contacting a 400 times diameter pulley at a 90 ° angle. The core wire 10 was obtained in the same manner as in Example 1 except for the above. The annealed material (ACW) had a tensile strength of 300 MPa and an elongation of 5%.

Comparative Example 6
As the copper conductor 1, an annealed material (ACSW, tensile strength: 300 MPa, elongation: 25%) of 0.1 mm in diameter obtained by annealing hard copper-tin alloy wire (HCSW) of 0.1 mm in diameter in an inert gas atmosphere at 600 ° C. Using. Further, it was wound while contacting a pulley having a diameter of 400 times at an angle of 120 °. The core wire 10 was obtained in the same manner as in Example 1 except for the above.

Comparative Example 7
Annealed in an inert gas atmosphere at 300 ° C. and wound while contacting a 350 times diameter pulley at a 160 ° angle. The core wire 10 was obtained in the same manner as in Example 1 except for the above. The annealed material (ACW) had a tensile strength of 240 MPa and an elongation of 15%.

[Measurement and result]
(Near gap and soldering characteristics)
Table 1 shows the elements of the core wire 10 obtained in the example and the comparative example. The gap G of each core wire 10 was measured with a microscope (VX600, manufactured by Keyence Corporation, 500 ×). In the measurement, the number of gaps G visible in a square (0.1 mm square) formed by the axial imaginary line Y1 and the radial imaginary line X1 was measured, and the average width of the gaps G was measured. In the measurement of the number of gaps G, one having a length of 1⁄4 or more of the radial imaginary line X1 (= diameter of core wire) was counted. When it can be recognized that the gap G is continuous or discontinuous and branched, it is regarded as the same (one) gap G related. The results are shown in Table 2.

The wetting stress (mN) and the zero cross time (seconds) at the time of soldering were measured with a dynamic wettability tester (WET-6100, manufactured by Lesca Co., Ltd.). The solder was tested at a temperature of 380 ° C. using Sn-3Ag-0.5Cu (manufactured by Senju Metal Industry Co., Ltd.). The results are shown in Table 2.

According to the results in 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 Was the case. Particularly preferable is the case where the number of gaps G is 12 or more and the product of the number of gaps and the width is 12 or more when the wetting stress is 3.7 mN or more and the zero cross time is 0.2 seconds or less. These results were mainly realized when the product of the number of gaps G and the width was 12 or more. Such a gap G could be formed under the manufacturing conditions shown in Table 1.

The same measurement (wet stress, zero cross time, number of gaps) as in Example 1 was performed on core wires 10 of Examples 13 to 15 having different diameters of copper conductor 1. In Example 13 (conductor diameter: 0.05 mm), wetting stress: 1.8 mN, zero cross time: 0.2 seconds, number of gaps G: 25, width of gaps G: 1.5 mm, product of number and width : 37.5. In Example 14 (conductor diameter: 0.08 mm), wetting stress: 2.9 mN, zero cross time: 0.2 seconds, number of gaps G: 19, width of gaps G: 1.0 mm, product of number and width : 19. In Example 15 (conductor diameter: 0.12 mm), wetting stress: 4.3 mN, zero cross time: 0.2 seconds, number of gaps G: 12, width of gaps G: 1.0 mm, product of number and width : 12. From these results, the wetting stress (mN) was divided by a unit surface area, and as a result, Example 1 (conductor diameter: 0.10 mm), Example 13 (conductor diameter: 0.05 mm), 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 by an LCR meter (a precision LCR meter, 4284 A, 20 Hz to 1 MHz, manufactured by Agilent). The measurement was made with a sample length of 1.50 m, a dedicated bobbin: inner diameter φ67 mm, and a number of turns of 5 turns, and the terminal was soldered at both ends and connected to the texture for measurement. Using the following samples 1 to 3 (electric wire 20 for high frequency coil) provided with two types of urethane as the insulating coating layer 5, the frequency was changed from 1 kHz to 1 MHz and measurement was performed.

Sample 1: 2 kinds urethane coated enameled copper wire (21 pieces / φ 0.10 mm)
Sample 2: Two types of urethane coated enameled iron plated stranded wire (21 pieces / φ 0.10 mm), gap G: none, iron plating solution (the same iron plating solution as in Example 1, no additive), nickel plating solution (Example The same nickel plating solution as 1), Fe layer thickness: 0.8 μm, Ni layer thickness: 0.05 μm
Sample 3: Two kinds of urethane coated enameled iron plated stranded wire (21 pieces / φ 0.10 mm), gap G: Yes, iron plating solution (the same iron plating solution as in Example 1, additive: saccharin 2 m / L), nickel plating Solution (the 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 surface photograph of a seed urethane coated enameled magnetic plated strand of sample 3. FIG. FIG. 3 (B) is a surface photograph of the two types of urethane coated enameled magnetic plated strands of sample 2. FIG. 3 (C) is a surface photograph of the two types of urethane-coated enameled copper stranded wire of sample 1.

Table 3 is an impedance result, and Table 4 is a result of resistance loss. As can be seen from Tables 3 and 4, when the ferromagnetic layer 4 is provided, the same high frequency characteristics are shown regardless of the presence or absence of the gap G, and the presence of the gap G lowers the high frequency characteristics. It was not confirmed.

DESCRIPTION OF SYMBOLS 1 copper conductor 2 iron layer 3 nickel layer 4 ferromagnetic layer 5 insulation coating layer 10 core wire 20 electric wire for high frequency coil 11 square 12 circle G gap W gap width X radial direction X1 radial direction imaginary line Y axis direction Y1 axis direction imaginary line

Claims (12)

A wire for a high frequency coil comprising at least a core wire having a copper conductor and a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating covering layer provided on the core wire, wherein the ferromagnetic layer is And a radial gap, characterized in that the wire for a high frequency coil. 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 an outer periphery of the iron layer. The number of the gaps is a number visible on the surface of the core, and the number of visible in a square formed by an axial imaginary line and a radial imaginary line having the same length as the diameter D of the core is two or more The electric wire for high frequency coils according to claim 1 or 2, which is within the range of 30 or less. The electric wire for a high frequency coil according to any one of claims 1 to 3, wherein the gap has a width in a range of 0.5 μm to 5 μm. The copper conductor according to any one of claims 1 to 4, wherein the copper conductor is selected from tough pitch copper, oxygen free copper, copper-tin alloy, copper-silver alloy, copper-nickel alloy, copper clad aluminum, copper clad magnesium. High frequency coil wire. An electronic component comprising the high frequency coil wire according to any one of claims 1 to 5. A wire for a high frequency coil comprising at least a core wire having a copper conductor and a ferromagnetic layer provided on the outer periphery of the copper conductor, and an insulating covering layer provided on the core wire, which is wet when soldered A wire for a high frequency coil characterized by having a stress of 3.4 mN or more and a zero cross time of 0.4 seconds or less. The electric wire for high frequency coil according to claim 7, wherein a diameter of the copper conductor is in a range of 0.02 to 0.40 mm. The electric wire for a high frequency coil according to claim 7 or 8, wherein the wetting stress is 3.7 mN or more and the zero crossing time is 0.2 seconds or less. The said ferromagnetic layer has an iron layer and the nickel layer provided in the outer periphery of this iron layer, The Vickers hardness of the said iron layer is 200 HV, Any one of Claims 7-9 High frequency coil wire. 10. The method according to claim 7, wherein the ferromagnetic layer comprises an iron layer and a nickel layer provided on an outer periphery of the iron layer, and the thickness of the iron layer is 0.2 μm or more and 3.0 μm or less. The electric wire for high frequency coils according to any one of the items. An electronic component characterized in that the high frequency coil wire according to any one of claims 7 to 11 is connected by soldering.

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