JP2010123993A - Method of manufacturing thin magnetic core and method of manufacturing magnetic part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a manufacturing yield after resin coating by maintaining the shape of a wound body (in particular, the end part on the inner diameter side) with excellent reproducibility in a method of manufacturing a magnetic core using a thin wound body. <P>SOLUTION: The method of manufacturing a thin magnetic core comprising a wound body formed by winding a thin band of soft magnetic alloy with a width of 5 mm or less into a toroidal shape, and a resin coating layer coated on the outer circumferential surface of the wound body, has: an inner diameter side end part fixing step of winding a thin band of soft magnetic alloy and fixing the thin band of soft magnetic alloy by welding after winding several turns until the number of windings becomes two to five; a winding step of further winding the thin band of soft magnetic alloy until a desired number of turns is reached; an outer diameter side end part fixing step of fixing the terminal end part of the thin band of soft magnetic alloy to form the wound body; and a coating step of coating the outer circumferential surface of the wound body with resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a small and thin magnetic core used in a pulse transformer and the like, and a method for manufacturing a magnetic component using the same.

  In recent years, as a constituent material for transformer cores and choke coil cores used in various electric and electronic parts such as power supply circuits and communication circuits, it has high magnetic permeability, low loss in the high frequency range, and saturation flux. Amorphous magnetic alloys are increasingly used because of their high density and other characteristics.

  When a magnetic part is composed of an amorphous magnetic alloy as described above, it is common to first form a magnetic core by winding a thin amorphous magnetic alloy and then winding the magnetic core to produce a magnetic part. Is. In this case, since the amorphous magnetic alloy ribbon has conductivity, the winding is applied after the surface (outer peripheral surface) of the core is covered with insulation.

  The insulation coating of the magnetic core is performed by applying a resin coating on the surface of the core or by storing the core in a resin case. For the resin coating of the magnetic core, for example, the resin powder for coating is applied to the surface of the wound body of the amorphous magnetic alloy ribbon by spraying, or it is immersed in a resin impregnating solution and then thermally cured. It is carried out by letting.

  Incidentally, the magnetic core and magnetic components using the magnetic core are required to be further reduced in size and thickness in order to enable high-density mounting and the like. For example, there is a strong demand to reduce the thickness of magnetic components used in PC cards for personal computers, personal digital assistants (PDAs), mobile communication devices, and the like. Thin magnetic cores (winding bodies) having a width of the band) of 5 mm or less and a ratio of the outer diameter to the height exceeding 2 are used as pulse transformers.

  In the thin magnetic core (winding body) as described above, since the shape is easily broken from the end portion on the inner diameter side, when winding a soft magnetic alloy ribbon such as an amorphous magnetic alloy ribbon, first, the inner diameter side After end-welding the end portions of 0 to 1 layer (welding between two ribbons), a soft magnetic alloy ribbon is wound so as to have a desired core shape. The outer diameter side end of the soft magnetic alloy ribbon is also usually welded.

  By the way, in the conventional thin magnetic core as described above, the outer end of the wound body is peeled off from the inner end when the outer surface of the wound body is resin-coated, although the inner end is welded. Cheap. This is considered to be based on the stress generated at the time of resin coating, and in the thin magnetic core as described above, the stress at the time of coating works in a direction to peel off the inner diameter side end.

  Due to the peeling from the inner diameter side end as described above, the conventional thin magnetic core has a problem that the production yield is low. For this reason, it is strongly desired to improve the production yield of thin magnetic cores by preventing peeling from the inner diameter side end.

  The present invention has been made in response to such a problem, and even when a thin wound body is used, the wound body shape can be maintained with good reproducibility, and the production yield after resin coating can be maintained. The purpose is to provide an improved magnetic core, and furthermore, by using such a magnetic core, we provide magnetic components that are improved in reliability and characteristics in response to miniaturization and thinning. The purpose is to do.

The thin magnetic core manufacturing method of the present invention comprises a wound body obtained by winding a soft magnetic alloy ribbon having a width of 5 mm or less in a toroidal shape, and a resin coating layer formed on the outer peripheral surface of the wound body. An inner diameter side end fixing step of winding the soft magnetic alloy ribbon and fixing the soft magnetic alloy ribbon by welding when the number of turns becomes 2 to 5 layers. When,
A winding step of winding the soft magnetic alloy ribbon until a desired number of turns, and an outer diameter side end fixing step of fixing the terminal portion of the soft magnetic alloy ribbon by welding to form the wound body And a coating step of coating the outer peripheral surface of the wound body with a resin.

  In the method for manufacturing a thin magnetic core of the present invention, it is preferable to perform welding in the inner diameter side end fixing step at a plurality of locations. In the thin magnetic core manufacturing method of the present invention, when the width of the soft magnetic alloy ribbon is 2 mm or less, the ratio of the outer diameter D of the wound body to the width t of the soft magnetic alloy ribbon (D / t) Is 3 or more, it is particularly suitable when the number of turns of the wound body is 50 or more. In the thin magnetic core manufacturing method of the present invention, the soft magnetic alloy ribbon is preferably a Co-based amorphous magnetic alloy ribbon.

  In the manufacturing method of the thin magnetic core of the present invention, the end on the inner diameter side of the wound body is terminal-welded across 2 to 5 layers of soft magnetic alloy ribbon. In other words, the end on the inner diameter side of the wound body is subjected to terminal welding over three or more soft magnetic alloy ribbons (for example, 3 to 6 soft magnetic alloy ribbons). Thus, by performing terminal welding over the soft magnetic alloy ribbons of a plurality of layers, the fixed state of the inner diameter side end of the wound body becomes strong and stable. Therefore, even if stress occurs when the outer surface of the wound body is coated with resin, it is possible to prevent peeling from the end on the inner diameter side, and it is possible to greatly increase the manufacturing yield of the thin magnetic core. .

  The method for manufacturing a magnetic component according to the present invention includes a step of winding a thin magnetic core obtained by the above-described method for manufacturing a thin magnetic core according to the present invention. Specific examples of the magnetic component include a transformer such as a power transformer or an oscillation transformer, or a pulse transformer for a communication circuit. It can also be used for choke coils and inductance coils.

  According to the present invention, even when a thin wound body is used, the shape of the wound body can be maintained with good reproducibility, which makes it possible to greatly improve the manufacturing yield and reliability. Furthermore, by using such a thin magnetic core, it is possible to provide a magnetic component that is improved in reliability and characteristics while being made smaller and thinner.

It is a perspective view which shows the principal part (winding body) of the thin magnetic core by one Embodiment of this invention. It is sectional drawing which shows the whole structure of the thin magnetic core shown in FIG. It is a figure which shows typically the welding state of the inner diameter side edge part of the wound body shown in FIG.

  Hereinafter, modes for carrying out the present invention will be described.

  FIG. 1 is a perspective view showing a main part (rolled body) of a thin magnetic core according to an embodiment of the present invention. 2 is a cross-sectional view showing the entire structure of the thin magnetic core, and FIG. 3 is a view schematically showing a welded state of the inner diameter side end of the wound body shown in FIG.

  In these drawings, reference numeral 1 denotes a core body made of a wound body of soft magnetic alloy ribbon 2. As the soft magnetic alloy ribbon 2 constituting the core body (rolled body) 1, for example, a Co-based or Fe-based amorphous magnetic alloy ribbon, an Fe-based soft magnetic alloy having fine crystal grains (hereinafter referred to as Fe-based micromagnetic alloy). A ribbon or the like (referred to as a crystalline alloy) is used.

Examples of the amorphous magnetic alloy ribbon include, for example, a general formula: (M _1-a M ′ _a ) _100-b X _b (wherein M is at least one element selected from Fe and Co, and M ′ is At least one element selected from Ti, V, Cr, Mn, Ni, Cu, Zr, Nb, Mo, Ta, W, etc., X is at least one element selected from B, Si, C, P, etc. And a and b are numbers satisfying 0 ≦ a ≦ 0.15 and 10 ≦ b ≦ 35 atomic%), respectively, and the composition is substantially represented.

As the Fe-based fine crystalline alloy thin strip, the general _{formula: Fe 100-c-d-} e-f-g-h A c D d E e Si f B g Z h ( wherein, A is Cu and Au D is at least one element selected from Group 4A elements, Group 5A elements, Group 6A elements and rare earth elements, E is Mn, Al, Ga, Ge, In, Sn and At least one element selected from platinum group elements, Z represents at least one element selected from C, N and P, and c, d, e, f, g and h are 0 ≦ c ≦ 8, 0.1 ≦ d ≦ 15, 0 ≦ e ≦ 10, 0 ≦ f ≦ 25, 1 ≦ g ≦ 12, 0 ≦ h ≦ 10, 1 ≦ f + g + h ≦ 30. All the numbers in the formula indicate atomic%) and the composition is substantially represented by an average particle size of eg 50 m can be mentioned those having the fine crystal grains.

  The composition of the amorphous magnetic alloy ribbon and the Fe-based fine crystal alloy ribbon as described above is appropriately selected according to the intended use of the magnetic component formed using the thin magnetic core of the present invention. For example, when used as a component such as a transformer, it is preferable to use a Co-based amorphous magnetic alloy or an Fe-based fine crystal alloy. In addition, when applied to an inductance coil (saturable inductor) such as a filter, a resonance, or a mag amplifier, it is preferable to use a high squareness ratio Co-based amorphous magnetic alloy, and when applied to a choke coil, It is preferable to use an Fe-based amorphous magnetic alloy having excellent direct current superposition characteristics.

  In the present invention, the soft magnetic alloy ribbon 2 is not necessarily excluded from the use of a crystalline magnetic alloy ribbon such as permalloy or sendust. It is preferable to use such an amorphous magnetic alloy ribbon or an Fe-based microcrystalline alloy ribbon (particularly an amorphous magnetic alloy ribbon).

  As shown in FIG. 2, the outer peripheral surface of the core body made of the wound body 1 of the soft magnetic alloy ribbon 2 is a resin coating layer (exterior) 3 made of a thermosetting insulating resin such as a fluorine resin or an epoxy resin. The thin magnetic core 4 is comprised by these. For the resin coating layer 3, it is particularly preferable to use a fluorine-based resin typified by polytetrafluoroethylene (PTFE). According to the fluororesin, even when the thickness of the coating layer 3 is reduced, the entire outer peripheral surface of the core body (rolled body) 1 can be uniformly coated.

  In the thin magnetic core 4 as described above, the inner diameter side end of the wound body 1 constituting the core body is fixed by terminal welding (welding fixing portion 5). As shown in FIG. 3, the end welding of the inner diameter side end portion is performed so that the weld fixing portion 5 extends over a plurality of layers of the soft magnetic alloy ribbon 2. That is, assuming that the innermost soft magnetic alloy ribbon 2a is zero, at least the first soft magnetic alloy ribbon 2b and the second soft magnetic alloy ribbon 2c wound thereon are reached. The welding fixing | fixed part 5 is provided so that it may.

  Thus, terminal welding is performed over a plurality of layers of soft magnetic alloy ribbons, in other words, terminal welding is performed over three or more soft magnetic alloy ribbons (2a to 2c), whereby the inner diameter side end of the wound body 1 is obtained. The fixing state of the part can be made strong and stable. Therefore, even if stress is generated when the resin coating layer 3 is formed on the outer surface of the wound body 1, it is possible to prevent the peeling from the end on the inner diameter side, and the production yield of the thin magnetic core 4 is greatly increased. It becomes possible to raise.

  The end welding of the inner diameter side end of the wound body 1 described above is performed by excluding the 0th layer of the soft magnetic alloy ribbon, that is, 2-5 layers of the soft magnetic alloy ribbon, in other words, 3-6 soft magnetic alloy ribbons. It is preferable to apply over the belt. If terminal welding is performed only on the 0th and 1st soft magnetic alloy ribbons, it is the same as the conventional magnetic core, and peeling is likely to occur from the inner diameter side end.

  On the other hand, even if terminal welding is performed beyond the fifth layer of the soft magnetic alloy ribbon, not only a further effect can be obtained, but conversely, the adhesion force of the innermost soft magnetic alloy ribbon 2a may be reduced. There is. Further, since welding is a process involving heat, the soft magnetic alloy ribbon 2 is likely to be adversely affected. For example, with regard to the amorphous alloy ribbon, the welded portion may be crystallized due to the heat of welding, and if the number of welds is increased too much, the characteristics and the like may be adversely affected. Furthermore, when welding 6 or more layers (for example, 20 sheets or more) of soft magnetic alloy ribbon 2, it is necessary to increase the welding power (for example, the amount of energization of spot welding), thereby causing a problem that the magnetic core is destroyed. There is a fear. Accordingly, the number of layers of the soft magnetic alloy ribbon 2 to be welded is preferably 2 to 5 layers (3 to 6 soft magnetic alloy ribbons).

  The terminal welding as described above is performed by spot welding (electric current welding), for example. If a similar fixing structure can be obtained, other welding methods such as laser welding may be applied. Moreover, it is preferable to implement the terminal welding 5 with respect to multiple places (for example, 3-8 places). Thereby, the adhering state of the inner diameter side end of the wound body 1 can be further stabilized. In this case, the welding locations may be concentrated in the vicinity of the end portion, or may be dispersed over the entire circumference.

  The stabilizing effect of the inner diameter side end portion according to the present invention is remarkable for a thin magnetic core using the soft magnetic alloy ribbon 2 having a width of 5 mm or less. The present invention is more effective when the width of the soft magnetic alloy ribbon 2 is further 2 mm or less. Further, the present invention is particularly effective for a thin magnetic core in which the ratio (D / t) of the outer diameter D of the wound body 1 to the width t of the soft magnetic alloy ribbon 2 is 3 or more. In addition, the present invention is particularly effective when the wound body 1 is used in which the number of windings of the soft magnetic alloy ribbon 2 is 50 or more, and further 100 or more.

  Such a thin magnetic core having a large outer diameter ratio with respect to a ribbon width having a D / t ratio of 3 or more, or a thin magnetic core having a wound body 1 having 50 or more turns is subjected to resin coating. Since the wound body 1 is easily separated from the inside due to the stress of the above, the effect of the present invention can be obtained more effectively.

  Further, the present invention exhibits a further effect when the soft magnetic alloy ribbon 2 having a high surface property is used. That is, when the soft magnetic alloy ribbon 2 having a high surface property is used, peeling is particularly likely to occur from the inner diameter side end. When terminal welding over the multiple layers of the soft magnetic alloy ribbon 2 is performed on such a wound body 1, the shape maintaining ability of the wound body 1 can be enhanced. The soft magnetic alloy ribbon 2 having a high surface property mentioned here indicates a ribbon having a Ks value (= micro plate thickness / weight plate thickness) of 1.2 or less, for example.

  The thin magnetic core 4 as described above is produced, for example, as follows.

  That is, the soft magnetic alloy ribbon 2 is started to be wound on the surface of the winding core. When the number of windings becomes 2 to 5 (3 to 6 in the number of laminated soft magnetic alloy ribbons 2), for example, spot welding is performed. The inner diameter side end is end welded. The specific conditions for terminal welding are as described above.

  Next, the end of the soft magnetic alloy ribbon 2 is taped to the end of the soft magnetic alloy ribbon 2 after winding the soft magnetic alloy ribbon 2 with a normal method starting from the end welding of the inner diameter side end. Secure with a weld stop. The winding amount of the soft magnetic alloy ribbon 2, that is, the cross-sectional area of the wound body 1 of the soft magnetic alloy ribbon 2 is set according to the required characteristics for the target magnetic component.

  Thereafter, the outer surface of the wound body 1 is resin-coated to form an exterior, whereby the intended thin magnetic core 4 is obtained. The resin coating is performed by applying a powder resin, thermosetting, impregnation with a resin liquid, thermosetting, or the like. The resin used for the resin coating is as described above.

  The thin magnetic core 4 having the toroidal shape as described above is substantially orthogonal to the magnetic path by the core body (winding body) 1 by winding the resin coating layer (exterior insulating coating layer) 3 or the like. By providing a current path in this way, it is used as a magnetic component such as a transformer or a choke coil. Such a magnetic component of the present invention is used as, for example, a power supply or oscillation transformer, a communication circuit pulse transformer, or the like. In some cases, it is used as a choke coil or an inductance coil. And according to the magnetic component of this invention, it becomes possible to achieve size reduction and thickness reduction of a pulse transformer etc. based on the thin magnetic core 4 mentioned above.

  Examples of the present invention will be described below.

Example 1
First, a Co-based amorphous magnetic alloy ribbon (composition: Co ₆₉ Fe ₄ Nb ₁ Cr ₁ Si ₁₄ B ₁₁ ) having a Ks value of 1.1, a plate thickness of 16 μm, and a width of 1 mm is prepared, and this is a core having a diameter of 4 mm. It was wound around (circular section). At this time, when the number of turns of the Co-based amorphous magnetic alloy ribbon becomes two layers (three by the number of laminated soft magnetic alloy ribbons 2), spot welding is performed at three locations, and the Co-based amorphous magnetic alloy ribbon is The inner diameter side end was fixed.

  Next, starting from the end welding of the inner diameter side end, the Co-based amorphous magnetic alloy ribbon was wound until the number of turns reached 130 (outer diameter about 10 mm). After fixing the outer diameter side end portion (terminal portion) of the Co-based amorphous magnetic alloy ribbon, resin coating was applied to form an exterior. Resin coating was performed by a liquid spraying method. 100 such thin magnetic cores were produced, and the yield after resin coating was evaluated. The results are shown in Table 1.

Examples 2-4
In Example 1 described above, the end welding of the inner diameter side end portion was performed by three layers of soft magnetic alloy ribbons (4 in the number of layers: Example 2), and four layers of soft magnetic alloy ribbons (5 in the number of layers: Example 3 A thin magnetic core was produced in the same manner except that it was a five-layer soft magnetic alloy ribbon (six in number of layers: Example 4). Also about these, 100 thin magnetic cores were produced and the yield after resin coating was evaluated. The results are shown in Table 1.

Comparative Examples 1-2
In Example 1 described above, end welding at the inner diameter side end portion is made of 0 layers of soft magnetic alloy ribbons (Comparative Example 1), 1 layer of soft magnetic alloy ribbons (2 in number of layers: Comparative Example 2). A thin magnetic core was produced in the same manner except for the above. Also about these, 100 thin magnetic cores were produced and the yield after resin coating was evaluated. The results are also shown in Table 1. The terminal welding to the 0-layer soft magnetic alloy ribbon referred to here is a core manufactured without welding the terminal.

表１から明らかなように、各実施例による薄型磁性コアは巻回体形状の維持性に優れており、これによって樹脂コーティング後においても優れた歩留りが得られることが分かる。

As is clear from Table 1, it can be seen that the thin magnetic cores according to the respective examples are excellent in the maintainability of the wound body shape, and an excellent yield can be obtained even after resin coating.

1 …… Core body (winding body)
2 …… Soft magnetic alloy ribbon 3 …… Resin coating layer 4 …… Thin magnetic core 5 …… Welding fixing part

Claims (8)

A method for producing a thin magnetic core comprising: a wound body obtained by winding a soft magnetic alloy ribbon having a width of 5 mm or less in a toroidal shape; and a resin coating layer coated on the outer peripheral surface of the wound body. ,
An inner diameter side end fixing step of winding the soft magnetic alloy ribbon and fixing the soft magnetic alloy ribbon by welding when the number of turns becomes 2 to 5 layers;
A winding step of winding the soft magnetic alloy ribbon further to a desired number of turns;
An outer diameter side end fixing step in which the end of the soft magnetic alloy ribbon is fixed by welding to form the wound body;
And a coating step of coating the outer peripheral surface of the wound body with a resin. In the manufacturing method of the thin magnetic core of Claim 1,
A method of manufacturing a thin magnetic core, wherein welding is performed at a plurality of locations in the inner diameter side end fixing step. In the manufacturing method of the thin magnetic core of Claim 1 or Claim 2,
The method of manufacturing a thin magnetic core, wherein the soft magnetic alloy ribbon has a width of 2 mm or less. In the manufacturing method of the thin magnetic core of any one of Claims 1 thru | or 3,
The method of manufacturing a thin magnetic core, wherein the wound body has a ratio (D / t) of an outer diameter D of the wound body to a width t of the soft magnetic alloy ribbon is 3 or more. In the manufacturing method of the thin magnetic core of any one of Claims 1 thru | or 4,
A method of manufacturing a thin magnetic core, wherein the number of turns of the wound body is 50 or more. In the manufacturing method of the thin magnetic core of any one of Claims 1 thru | or 5,
A thin magnetic core manufacturing method, wherein the soft magnetic alloy ribbon is a Co-based amorphous magnetic alloy ribbon. In the manufacturing method of the thin magnetic core of any one of Claims 1 thru | or 6,
A method of manufacturing a mold magnetic core, wherein the welding is spot welding.   A method of manufacturing a magnetic component, comprising the step of winding a thin magnetic core obtained by the method of manufacturing a thin magnetic core according to any one of claims 1 to 7.

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