KR20020059295A - Bobbin for voice-coil containing magnetic coating layer and voice-coil containing the same - Google Patents

Abstract

PURPOSE: A bobbin for a voice coil having a magnetic coating layer and a voice coil including the bobbin is provided to improve a workability and increase productivity in installation of a voice coil by rendering the center of width of a coil constituting the voice coil to accurately agree with the center of a thickness of a front plate of a speaker thanks to a Maglev magnetic levitation effect, and reduce an additional expense according to a design and fabrication of a jig. CONSTITUTION: A rectangular bobbin paper is folded in a cylindrical form for use as a bobbin, and when it is used for a voice coil, a Maglev magnetic levitation effect and center agreement effect can be obtained. A coil protecting blank portion(11) has a blank face in the range of 0.2-0,8mm in order to protect a voice coil, and preferably, 0.5mm. A winding width portion(12), on which the voice coil is substantially wound, is preferably formed to be in the range of 8-12mm. The voice coil is preferably wound with a width identical to a thickness of a front plate of a speaker. A reinforcing taping portion(13) is applied a reinforcing tape, of which size varies according to a size of the speaker.

Description

Bobbin for voice coil including magnetic coating layer and voice coil including same {BOBBIN FOR VOICE-COIL CONTAINING MAGNETIC COATING LAYER AND VOICE-COIL CONTAINING THE SAME}

The present invention relates to a bobbin for a voice coil including a magnetic coating layer, and more particularly, due to the excellent magnetic levitation effect, the width center of the coil constituting the voice coil during manufacture of the speaker is automatically exactly matched to the center thickness of the front plate of the speaker. It relates to a voice coil bobbin capable of manufacturing a voice coil having excellent speaker manufacturing workability and a voice coil including the same.

Speakers are devices that convert electrical vibrations into sound vibrations, which are cone type and horn type. Among them, the cone type vibrates a cone shaped cone and radiates sound directly into the air. It is usually used in a cabinet to improve efficiency and frequency characteristics. In addition, the horn is a trumpet-shaped horn attached to the front of the small diaphragm to efficiently radiate sound into the air.

In the conventional hybrid speaker as described above, the voice coil includes two or four layers of bobbins wound around a cylindrical body, and the voice coil is connected to the lead wire and receives a signal from the outside.

The voice coil of a speaker is generally manufactured as follows. First, the bobbin is inserted into the outer circumference of the ordinary jig, and then the coil is aligned and wound around the outside of the bobbin to form a coil, and the coil is wound onto the bobbin with a tape (or adhesive) to be bonded to the normal jig. The coil is made.

In general, when the user operates the acoustic system as shown in FIG. 1, the voice signal current of the amplifier constituting the acoustic system is input to the terminal 11 attached to the frame 7. Current is continuously input to the voice coil 8 through the signal supply line 10.

When the voice signal current is input to the voice coil 8 as described above, the voice coil is installed in the hole 4 formed in the rear plate 5 so as to be movable in the axial direction. Accordingly, the rear plate 5 forms the N-pole magnetic path and the front plate 6 forms the S-pole magnetic path in accordance with the magnetic flux generated by the front magnet 2. The magnet 3, the front plate 6, and the rear plate 5 constitute a magnetic circuit. At this time, the voice signal current 1 input to the voice coil 8 flows into the magnetic circuit and the current flowed therein. Since the force (F) is generated by the left-hand law of framing, the voice coil (8) is continuous by the damper (9), while the upper and lower vibrations in the radial direction are prevented while only the left and right vibrations in the axial direction are continuous. Do it.

When the speaker having the above structure is operated, the left and right vibration widths of the voice coils are equal to each other based on the front plate, thereby generating a clean sound.

However, it is difficult not only to accurately match the conventional voice coil to the thickness center of the front plate, but even if the voice coil is installed using a jig, the thickness of the front plate where the center of the width of the copper wire constitutes the magnetic circuit is not considered by the operator. Since it does not come to the center exactly, there was a problem that productivity is reduced due to deterioration of workability. In addition, when installing the voice coil, the width center of the copper wire is exactly matched to the thickness center of the front plate at first, but the width center of the copper wire and the thickness center of the front plate are often slightly distorted in the subsequent process. If the wrong voice coil is installed in the speaker, there is a problem that the sound quality of the speaker is degraded.

Accordingly, Korean Laid-Open Patent Publication No. 2000-0033283 winds a coil on a support tube, and wraps and winds the wound coil with an adhesive tape, wherein a magnetic material layer of iron oxide powder is further provided on a speaker voice coil. Korean Patent Laid-Open Publication No. 2000-0033282 discloses forming an insulating film and a fusion film on the outside of a core wire, forming a magnetic film of iron oxide on the outside of the fusion film, or forming a magnetic material of iron oxide in the fusion film. The added speaker voice coil is disclosed. These speaker voice coils are formed by the iron oxide magnetic material added to the outside of the coil or the outside of the wire, and the front of the voice coil may be used even if the speaker is not specially installed when the speaker is inserted into the shaft of the rear plate of the speaker using a separate jig. It has the effect of exactly matching the center of thickness of the plate.

However, when the magnetic coating of iron oxide is formed on the coil in order to precisely match the voice coil to the center of the thickness of the front plate, the iron oxide magnetic material should be coated with a fine powder of 0.3 to 0.5 μm, so that the manufacturing cost is high and the coil is coated on the coil. There is a problem in that it is difficult to obtain a desired degree of effect because there is a limitation in the magnetic film thickness. In addition, the magnetic material layer of iron oxide powder is formed on the coil wound on the outer surface of the bobbin, which requires an adhesive material to form the magnetic material layer of the iron oxide powder, and as a result, additional production cost and production cost There is a problem that increases. In the case of using a tape or a film containing a magnetic material in place of the adhesive material, there is a concern that the adhesive force of the tape or film is lowered, and thus there is a problem that the reliability is lowered. In addition, the formation of the self-fusion layer containing the insulating layer and the iron oxide in the coil has to pass through the coating machine because of the deposition, there is a problem that a high temperature (energy) of 400 ℃ or more is required.

Therefore, due to the excellent magnetic levitation effect, the center of the width of the coil constituting the voice coil when the speaker is manufactured is automatically matched to the center of the thickness of the front plate of the speaker automatically. There is a need for further research on excellent voice coil bobbins.

In order to solve the problems of the prior art as described above, the present invention is to produce a voice coil having excellent speaker manufacturing workability by automatically matching the center of the width of the coil constituting the voice coil automatically at the center of the thickness of the front plate of the speaker. An object of the present invention is to provide a bobbin for a voice coil.

Another object of the present invention is to include a magnetic coating layer in the bobbin has an excellent magnetic levitation effect so that the center of the width of the coil constituting the voice coil when the speaker is automatically matched exactly to the center of the thickness of the front plate of the speaker excellent speaker manufacturing workability To provide a voice coil.

It is another object of the present invention to provide excellent magnetic levitation effect, so that the center of the width of the coil constituting the voice coil when the speaker is manufactured is automatically matched exactly to the center of the thickness of the front plate of the speaker, thereby providing excellent speaker manufacturing workability and at the same time manufacturing cost. It is to provide a manufacturing method of the bobbin for voice coil having excellent productivity by lowering.

Still another object of the present invention is to provide a voice coil including a bobbin manufactured by the above method.

1 is a cross-sectional view of a typical speaker.

2 is a view showing a bobbin paper according to an embodiment of the present invention.

Figure 3 is a view showing a bobbin coated with a magnetic material on the outer surface of the winding width portion of the bobbin according to an embodiment of the present invention.

Figure 4 is a view showing a bobbin coated with a magnetic material on the inner surface of the winding width portion of the bobbin according to an embodiment of the present invention.

5 is a view showing a bobbin coated with a magnetic material on the outer surface of the winding width portion and the coil protection margin portion of the bobbin according to an embodiment of the present invention.

6 is a view showing a bobbin coated with a magnetic material on the inner surface of the winding width portion and the coil protection margin portion of the bobbin according to an embodiment of the present invention.

7 is a view showing a bobbin coated with a magnetic material on the inner and outer surfaces of the winding width portion of the bobbin according to an embodiment of the present invention.

In order to achieve the above object, the present invention provides a bobbin paper comprising a magnetic coating layer.

In another aspect, the present invention provides a bobbin for a voice coil comprising a magnetic coating layer.

In another aspect, the present invention provides a voice coil wound on a bobbin including the magnetic coating layer.

In addition, the present invention is a method of manufacturing a bobbin for voice coil,

a) providing bobbin paper;

b) forming a magnetic coating layer on the bobbin paper of step a); And

c) alcohol-soluble adhesive on the bobbin paper formed of the magnetic coating layer of step b)

Step of applying

It provides a method of manufacturing a voice coil bobbin comprising a.

In another aspect, the present invention provides a voice coil comprising a bobbin manufactured by the above production method.

Hereinafter, the present invention will be described in detail.

The inventor of the present invention, while studying the manufacturing method of the voice coil to reduce the production cost, and at the same time obtain excellent magnetic levitation effect, coating a magnetic material on the bobbin surface to form a magnetic coating layer, the magnetic material As a result of manufacturing the voice coil by winding the coil on the outer surface of the coating layer, the width center of the coil is automatically matched with the center of the thickness of the front plate of the speaker automatically, and the speaker manufacturing workability is remarkably improved. It was confirmed that the center of thickness of the front plate is not twisted, and based on this, the present invention was completed.

The present invention provides a bobbin paper by coating a magnetic layer on the surface of the bobbin paper. The magnetic coating layer may be formed by coating the surface of the bobbin paper by dispersing the magnetic material in an alcohol-soluble adhesive material, and applying a magnetic paint containing the magnetic material to a tape or film and then attaching the magnetic material to the surface of the bobbin paper. It can also be formed.

The bobbin including the magnetic coating layer of the present invention exhibits a magnetic levitation effect of maintaining a constant distance from the permanent magnet at the rear even when a voice signal is not input. Due to this effect, the coil or the voice coil constituting the voice coil Even if the magnet is not always magnetized, the width center of the coil constituting the voice coil is automatically and exactly matched to the center thickness of the front plate of the speaker when manufacturing the speaker, which improves workability due to the installation of the voice coil and increases productivity. And it is economical as the incidental cost is reduced according to the production. In addition, the magnetic coating layer formed on the outside of the bobbin has the effect of ensuring reliability because it is pressed by the coil, and even in the subsequent process, the center of the width of the coil and the center of thickness of the front plate are not misaligned, thereby greatly improving the sound quality of the speaker. Can be.

The bobbin paper used in the present invention can be used as conventional bobbin materials such as paper, aluminum foil, duralumin, various flame retardant films. The bobbin paper is divided into a coil protection margin part 11, a winding width part 12, and a reinforcing tape part 13 in the form shown in FIG. 2, and the magnetic coating layer of the present invention has a winding width or coil protection. It may be selectively formed on the inside and outside of the margin portion.

The bobbin of the rectangular shape shown in FIG. 2 is rolled into a cylinder and used as a bobbin, and when used for a voice coil, a kind of self-injury effect and a central matching effect can be obtained. The coil protection margin portion 11 has a margin in the range of 0.2 to 0.8 mm, preferably 0.5 mm, in order to protect the voice coil. The winding width portion 12 is a portion in which the voice coil is actually wound, and is preferably formed in the range of 8 to 12 mm. Preferably, the winding width portion 12 is preferably wound in a width that matches the thickness of the front plate of the speaker. In addition, the reinforcing tape portion 13 is a portion to which the reinforcing tape is attached, its size varies depending on the size of each speaker.

Compounds usable as the magnetic material used in the present invention are largely divided into three types, and most permanent magnet materials can be used.

That is, iii) at least one ferromagnetic alloy based on rare earth metals or transition metals;

Ii) at least one ferromagnetic composite oxide of said rare earth metal or transition metal;

Iii) at least one ferromagnetic composite nitride of the rare earth metal or transition metal.

Moreover, these can also be used in mixture with each other.

The metals are rare earth metals and transition metals, but most of them can be used. However, since the residual magnetic flux density (BR) and the maximum energy product (BH) max are relatively low, they may be formed in the form of ferromagnetic alloys, ferromagnetic oxides, ferromagnetic nitrides, or mixtures thereof. It is preferable to use.

The ferromagnetic alloy is also selected from the group consisting of nickel, iron, and iron and other metals (nickel, molybdenum, silicon, aluminum, cobalt, neodymium, platinum, samarium, zinc, boron, copper, bismuth, chromium, titanium, etc.). Alloys selected from more than one species, or Mn-Al based, Co-Pt based, Cu-Ni-Co based alloys containing no iron can be used.

As the ferromagnetic alloy, it is preferable to use a permanent magnet alloy mainly based on rare earth or transition metal. Examples include RCo ₅ , where R is one or more rare earth metals, R ₂ (Co, Cu, Fe, M) ₁₇ , where R is one or more rare earth metals and M is one Transition metals), or R-Fe-B, wherein R is at least one rare earth metal. In addition, B of the R-Fe-B may be substituted with C, N, Si, P, Ge, etc., which may improve sintering and increase the residual magnetic flux density (BR) and the maximum energy product (BH) max. Because. In addition to such a permanent magnet alloy in addition to the increase in the Curie temperature of the alloy Cobalt (Co); Chromium (Cr) or aluminum (Al) to improve the corrosion resistance of the alloy; And titanium, zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), vanadium (V), manganese (Mn), molybdenum (Mo), or tungsten for increased coercive force. An additional metal selected from the group consisting of the metal of (W) may be further added and used as an alloy. In addition, aluminum-nickel-cobalt alloys and samarium-cobalt alloys may be used.

In addition, the ferromagnetic composite oxide, manganese-iron-based composite oxide, cobalt-iron-based composite oxide, nickel-iron-based composite oxide, lithium-iron-based composite oxide, magnesium-iron-based composite oxide, copper-iron-based composite oxide, zinc-iron-based composite oxide, yttrium Iron-based composite oxide, Barium-iron based composite oxide, Strontium-iron based composite oxide, Neodymium-samarium-strontium-manganese composite oxide, Lithium-iron-manganese composite oxide, Manganese-zinc composite oxide, Nickel-Zinc composite Oxides, manganese-magnesium-zinc based composite oxides, nickel-copper-zinc based composite oxides, copper-zinc based composite oxides, manganese composite oxides, lithium composite oxides, magnesium composite oxides, nickel composite oxides and the like can be used. In addition, as the ferromagnetic composite nitride, molybdenum-iron-based composite nitride, samarium-iron-based composite nitride, and the like can be used.

The magnetic material may generally be used as it is a magnetic powder that is circulated, preferably has a particle size of 0.3 to 10 ㎛, more preferably has a particle size of 0.3 to 6 ㎛. Conventionally, iron oxide coated on the enameled wire should use fine powder of about 0.3 to 0.5 μm, but the magnetic material used in the present invention has no advantage in particle size, and thus, the purchase price of the magnetic material can be reduced.

The magnetic material preferably selects a material having a coercive force of at least 600 Oe, a magnetization saturation of at least 80 emu / g, and a residual magnetization of at least 30 emu / g. When the coercive force of the magnetic material is less than 600 Oe, the magnetic levitation effect is low so that the width center of the coil constituting the voice coil may not automatically match the center of thickness of the front plate of the speaker automatically. Accordingly, the magnetic coating layer of the present invention preferably exhibits at least 600 Oe of coercive force.

The magnetic material is mixed with 10 to 97% by weight of the alcohol-soluble adhesive 3 to 90% by weight of the magnetic material and coated on the bobbin surface to form a magnetic coating layer, or 3 to 90% by weight of the magnetic material, and the adhesive 10 to A magnetic body coating layer comprising 97 wt% of a magnetic body coating material may be bonded to a surface of a bobbin paper by applying a magnetic tape applied to one side or the whole surface thereof to form a magnetic body coating layer.

When the magnetic material is included in less than 3% by weight, it is difficult to obtain sufficient magnetic levitation effect after winding the coil for voice coil, and when the magnetic material exceeds 90% by weight, the magnetic material is difficult to disperse in the alcohol-soluble adhesive, even if dispersed in the bobbin paper. There is a problem in that the surface of the bobbin paper becomes rough during application and the bobbin paper and the magnetic coating layer are peeled off when the bobbin paper is bent or bent.

The magnetic material mixed with the alcohol soluble adhesive may be selectively applied to the inside or the outside of the winding width portion 12 and the coil protective margin portion 11 of the bobbin paper as needed. Then, the bobbin paper coated with the magnetic material is dried, and the magnetic material is mixed on the entire surface of the dried bobbin paper (the winding width portion 12, the coil protection margin portion 11, and the reinforcing tape portion 13). Non-alcoholic soluble adhesive is applied.

3 to 7, the magnetic material may be disposed outside, inside, or inside and outside of the winding width portion 12 of the bobbin paper, outside, inside, or inside and outside of the coil protection margin portion 11. The outer side, the inner side, or the inner side and the outer side of the width portion 12 and the coil protection margin portion 11 may be selected and coated as necessary.

At this time, the magnetic coating layer is preferably coated with a thickness of 0.1 ㎛ to 2 mm on the surface of the bobbin paper, preferably is coated with a thickness of 0.1 ㎛ to 1 mm. If the coating thickness is less than 0.1 ㎛ the magnetic material is not applied enough to withstand the weight of the bobbin paper and enameled wire does not obtain a sufficient magnetic levitation effect, if the thickness exceeds 2 mm the thickness of the bobbin at installation There is a problem that crushing or winding coils may cause friction on the skin.

In addition, the present invention, in addition to the method of mixing and applying the magnetic material to the alcohol-soluble adhesive, the magnetic powder is applied to the tape or film and the inside or outside of the winding width portion 12 and the coil protective margin portion 11 of the bobbin paper. It is possible to produce a bobbin paper including a magnetic coating layer by a method of selectively attaching as needed.

In another aspect, the present invention provides a method for manufacturing a bobbin that is manufactured by rolling a bobbin paper containing a magnetic coating layer as described above. The bobbin including the magnetic coating layer is firmly pressed to the magnetic material between the coil and the bobbin, rather than to form a voice coil by attaching a film or tape containing a magnetic material to the outer surface of the coil coil for the conventional coil coil to form a voice coil. Since the magnetic coating layer is not separated even in the severe impact because it is adsorbed quickly, it has an excellent effect of robustness and reliability.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

A portion of the fabric of kraft paper (Acease Paper Co., Ltd.) was removed in a rectangle to prepare a bobbin material. Then, 30% by weight of the barium composite magnetic material (BaO ₆ FeO ₃ ) was mixed with the alcohol of a CHCH alcohol soluble adhesive (union cabaide, USA) at a ratio of 1: 1, and then It was applied to the winding width portion 11 and dried for a certain time. Here, an alcohol soluble adhesive containing no magnetic material was applied to the entire surface of the kraft bobbin and dried, and then passed through an alcohol solvent to prepare a cylindrical bobbin. A voice coil was manufactured by winding an enameled wire of 0.16 mm having a polyester insulating layer formed on the bobbin prepared above.

Example 2

A magnetic tape coated with a magnetic material on the kraft bobbin prepared in Example 1 was bonded to the winding width portion 12 and the coil protective margin portion 11 of the kraft bobbin. At this time, the magnetic tape is at least three times a mixture of 40% by weight of the barium composite magnetic material (BaO ₆ FeO ₃ ) in a state in which the dilution of the alcohol and VMCH alcohol soluble adhesive used in Example 1 in the ratio of 1.2: 0.8 It was prepared by painting repeatedly. Then, an alcohol soluble adhesive containing no magnetic material was applied to the entire surface of the kraft bobbin, dried, and passed through an alcohol solvent to prepare a cylindrical bobbin. A voice coil was manufactured by winding an enameled wire of 0.16 mm having a polyester insulating layer formed on the bobbin prepared above.

Comparative example

After the alcohol soluble adhesive was coated and dried on the kraft bobbin prepared in Example 1, a cylindrical bobbin was prepared by passing the alcohol solvent. A voice coil was manufactured by winding an enameled wire of 0.16 mm in which a polyester insulating layer was formed on the bobbin prepared above.

The physical properties of the bobbins and voice coils prepared in Examples 1 or 2 and Comparative Examples were measured, respectively, and the results are shown in Table 1 below.

division Example 1 Example 2 Comparative example Maglev effect before energization Good Good - Magnetic levitation effect when energized Good Good Good Surface Adhesion (g) 50 45 45 Bobbin Thickness (mm) 53 57 51 Whether winding width matched (㎜) 0.00 0.25 0.00

Through Table 1, it was confirmed that the bobbin and the voice coil of Example 1 or Example 2 prepared by coating a magnetic coating layer on the surface of the bobbin according to the present invention exhibits a magnetic levitation effect even without flowing a current. The width center of the coil constituting the voice coil coincides with the center of the thickness of the front plate of the speaker so that the sound quality of the speaker can be remarkably improved when mounted on the speaker.

The bobbin including the magnetic coating layer according to the present invention exhibits a magnetic levitation effect of maintaining a constant distance from the permanent magnet at the rear even when a voice signal is not input, and due to this effect, the coil or the voice coil itself constituting the voice coil Even if the magnet is not always magnetized, the center of the width of the coil constituting the voice coil automatically matches exactly the center of the thickness of the front plate of the speaker when manufacturing the speaker, which improves workability due to the installation of the voice coil and increases productivity. It is economical due to the side cost of design and manufacturing. In addition, since the width center of the coil and the center of thickness of the front plate are not misaligned in the subsequent process, the left and right shaking of the voice coil is prevented, thereby improving the sound quality of the speaker.

Claims (19)

Bobbin paper comprising a magnetic coating layer. The method of claim 1, The magnetic coating layer is Iii) 3 to 90 weight percent of magnetic material; And Ii) 10-97 wt% alcohol soluble adhesive Bobbin paper containing. The method of claim 1, The magnetic coating layer is Iii) 3 to 90 weight percent of magnetic material; And Ii) 10 to 97% by weight of adhesive Bobbin paper magnetic material coating comprising a magnetic tape coating layer applied to one side or the entire surface. The method of claim 1, Bobbin paper formed on the portion of the magnetic coating layer is selected from the group consisting of the inner side, the outer side, and the inner and outer side of the winding width portion or the coil protection margin portion. The method of claim 1, The magnetic coating layer is Iii) a ferromagnetic alloy containing said rare earth metal or transition metal; Ii) ferromagnetic composite oxides of the rare earth metals or transition metals; And Iii) ferromagnetic composite nitrides of the rare earth metals or transition metals Bobbin paper containing a magnetic material selected from the group consisting of one or more. The method of claim 5, The ferromagnetic alloy of i) is a metal selected from the group consisting of nickel, iron, and iron and nickel, molybdenum, silicon, aluminum, cobalt, neodymium, platinum, samarium, zinc, boron, copper, bismuth, chromium, and titanium The bobbin paper which is an alloy selected from the group which consists of 1 or more types, or an alloy chosen from the group which consists of Mn-Al system, Co-Pt system, and Cu-Ni-Co system. The method of claim 1, The magnetic coating layer is RCo ₅ , wherein R is one or more rare earth metals, R ₂ (Co, Cu, Fe, M) ₁₇ , where R is one or more rare earth metals and M is one or more transition metals A ferromagnetic alloy selected from the group consisting of R-Fe-A, wherein R is at least one rare earth metal, and A is B, C, N, Si, P, or Ge; Cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), vanadium (V), Ferromagnetic alloys further comprising at least one additional metal selected from the group consisting of manganese (Mn), molybdenum (Mo), and tungsten (W); Aluminum-nickel-cobalt alloys, or samarium-cobalt ferromagnetic alloys; Manganese-iron composite oxide, cobalt-iron composite oxide, nickel-iron composite oxide, lithium-iron composite oxide, magnesium-iron composite oxide, copper-iron composite oxide, zinc-iron composite oxide, yttrium-iron composite oxide, barium- Iron-based composite oxide, strontium-iron composite oxide, neodymium-samarium-strontium-manganese composite oxide, lithium-iron-manganese composite oxide, manganese-zinc composite oxide, nickel-zinc composite oxide, manganese-magnesium-a Ferromagnetic composite oxides selected from the group consisting of linked composite oxides, nickel-copper-zinc composite oxides, copper-zinc-based composite oxides, manganese composite oxides, lithium composite oxides, magnesium composite oxides, and nickel composite oxides; And Ferromagnetic composite nitrides of molybdenum-iron based composite nitrides or samarium-iron based composite nitrides Bobbin paper containing a magnetic material selected from the group consisting of one or more. The method of claim 1, Bobbin paper comprising a magnetic material having a particle size of 0.3 to 10 ㎛ the magnetic coating layer. The method of claim 1, The magnetic coating layer is bobbin paper coated with a thickness of 0.1 ㎛ to 2 mm on the surface of the bobbin paper. The method of claim 1, And wherein the magnetic coating layer comprises a magnetic body having a coercive force of at least 600 Oe, a magnetization saturation of at least 80 emu / g, and a residual magnetization of at least 30 emu / g. Bobbin for voice coil comprising a magnetic coating layer. A voice coil comprising a bobbin coated with a magnetic material. In the manufacturing method of the bobbin for voice coil, a) providing bobbin paper; b) forming a magnetic coating layer on the bobbin paper of step a); And c) alcohol-soluble adhesive on the bobbin paper formed of the magnetic coating layer of step b) Step of applying Method of manufacturing a bobbin for voice coil comprising a. The method of claim 13, Wherein the magnetic coating layer is formed by mixing a magnetic material with an alcohol soluble adhesive and applying the coating on the surface of the bobbin paper. The method of claim 13, Wherein the magnetic coating layer is formed by mixing 3 to 90% by weight of a magnetic material with 10 to 97% by weight of an alcohol soluble adhesive and coating the surface of the bobbin paper. The method of claim 13, And the magnetic coating layer is formed by applying a magnetic paint containing a magnetic substance to a tape or a film, and then attaching the magnetic coating to the surface of the bobbin paper. The method of claim 13, wherein the magnetic coating layer is formed by applying a magnetic paint containing 3 to 90% by weight of the magnetic material, and 10 to 97% by weight of the adhesive, and then bonded to the bobbin surface of the bobbin for voice coil Way. A voice coil comprising a bobbin manufactured by the method according to claim 13. A voice coil comprising bobbins having a coercive force of at least 600 Oe.