JP4877152B2 - Wire wound electronic components - Google Patents

Description

  The present invention relates to a wound electronic component in which a winding wound around a core portion of a core is sealed with a magnetic resin portion containing magnetic powder, and more particularly to a wound electronic component with improved DC superposition characteristics. It is.

  Examples of conventional wire wound electronic components include those described in Patent Documents 1 to 3. In Patent Document 1, a ferrite-containing resin is applied to a conductor wound around a core portion of a core, a normal resin not containing ferrite is further applied to a ferrite-containing resin, and a conductor is formed with a resin having a two-layer structure. A sealed wound electronic component is described. Patent Document 2 describes a chip coil in which the outer surface of a coil element in which a coil is wound around a core is covered with a resin mold material mixed with calcined and pulverized magnetic powder. In Patent Document 3, a core having ridges at both ends of a coil winding portion around which a coil is wound is molded with an exterior resin, and a lead terminal joined to the ridge of the core and exposed to the outer surface is provided on the outer surface of the exterior resin. A chip type coil formed by applying a magnetic powdered resin is described.

  For example, as shown in FIG. 3, the techniques of Patent Documents 1 and 2 basically each include a core 1 having a core 1 </ b> A and flanges 1 </ b> B formed at both upper and lower ends thereof, Winding between winding 2 wound around 1A, a plurality of terminal electrodes 3 provided at lower flange 1B and electrically connected at both ends of winding 2, and upper and lower flanges 1B 2 and a magnetic resin part 4 for sealing 2 to improve the magnetic shielding property. Moreover, the technique of patent document 3 improves magnetic shielding property by the magnetic powdered resin applied to the outer surface of the exterior resin that seals the winding part, and magnetic flux is eliminated by partially removing the magnetic powdered resin. The cross-sectional area through which the coil passes is reduced to make the inductance value of the coil variable.

JP 11-067520 JP 02-251105 A Japanese Utility Model Open 04-04-521

  However, the conventional wire-wound electronic component shown in FIG. 3 improves the effective magnetic permeability by sealing the winding 2 of the core 1 with a magnetic powdered resin, thereby improving the effective magnetic permeability. Since the linear electronic component has a closed magnetic circuit structure, it is likely to be magnetically saturated, the rate of change in inductance value when a direct current is applied to the wound electronic component is increased, and the DC superposition characteristics are deteriorated. .

  The present invention has been made to solve the above-described problems, and improves DC superimposition characteristics by suppressing the concentration of magnetic flux at the corners of the winding wound around the rectangular core. It is another object of the present invention to provide a wire wound electronic component that can increase the mechanical strength.

  As a result of various investigations on the cause of the deterioration of the DC superposition characteristics in the wound electronic component having the core 1 formed in a rectangular shape (see FIG. 3), the inventor has particularly formed the core portion 1A in a rectangular shape. 3, it was found that the magnetic flux tends to concentrate on the portion surrounded by ○ in FIG. 3, that is, the portion where the corner portion of the core portion 1 </ b> A and the flange portion 1 </ b> B intersect.

  The present invention has been made on the basis of the above knowledge, and the wound electronic component according to claim 1 has a winding core portion having a rectangular cross section and a pair of flange portions formed in a rectangular shape at both ends thereof. In a wound electronic component including a core, a winding wound around the winding core, and an exterior resin portion that seals the winding between the pair of flange portions, the exterior resin portion includes: A non-magnetic resin part that does not contain magnetic powder and covers at least the corners of the winding located on the extension line drawn from the axis of the core to the intersection of the four corners of the core and the flange. And a magnetic resin portion containing magnetic powder that covers the windings located at portions other than the corners of the winding covered with the non-magnetic resin portion.

  Further, in the wound electronic component according to claim 2 of the present invention, in the invention according to claim 1, the nonmagnetic resin portion is covered over the four corners of the winding. It is characterized by.

  According to the present invention, it is possible to provide a wound electronic component that can improve the DC superimposition characteristics by reducing the concentration of magnetic flux at the corners of the winding and can increase the mechanical strength. .

  Hereinafter, the present invention will be described based on one embodiment shown in FIGS. In each figure, FIGS. 1A and 1B are views showing one embodiment of the wound electronic component of the present invention, FIG. 1A is a perspective view, and FIG. 2A and 2B are cross-sectional views showing the wire wound electronic component shown in FIG. 1, respectively, and FIG. 2A is a cross-sectional view taken along line AA in FIG. b) is a cross-sectional view taken along line BB in FIG. 1.

  For example, as shown in FIGS. 1A and 1B, the wound electronic component 10 of the present embodiment includes a winding core portion 11 formed in a rectangular shape and a flange portion formed in a rectangular shape at both upper and lower ends thereof. A core 13 having a core 12, a winding 14 with an insulating film wound around the core 11 of the core 13, an exterior resin portion 15 for sealing the winding 14 between the upper and lower flanges 12, and a lower portion Terminal electrode 16 (see FIG. 2A) provided on the lower surface of the flange portion 12 and connected to the end portion of the winding 14, and the cross-sectional shape of the core 13 is formed in an H shape. .

  In this embodiment, the exterior resin portion 15 is a non-magnetic resin portion made of a thermosetting resin that does not contain magnetic powder, as shown in FIGS. 1 (a) and 1 (b) and FIGS. 2 (a) and 2 (b). 15A and a magnetic resin portion 15B made of a thermosetting resin containing magnetic powder. The nonmagnetic resin portion 15A covers the corner portion 14A of the winding 14 positioned on the four extension lines drawn horizontally from the axis of the core 11 to the corner portion 11A of the core portion 11, and the magnetic resin portion 15B The planar portion other than the corner portion 14A of the winding 14 covered with the nonmagnetic resin portion 15A is covered. The nonmagnetic resin portion 15A of the corner portion 14A of the winding 14 and the magnetic resin portion 15B of the flat portion of the winding 14 are integrated to cover all sides of the winding 14 and seal the entire winding 14.

  In the case of the core part 11 formed in a rectangular shape, the magnetic flux tends to concentrate on the intersecting portion of the corner part of the core part 11 and the flange part 12 as described above. Therefore, in the present embodiment, as shown in FIGS. 1A, 1B, and 2B, the corner portion 14A of the winding 14 where the magnetic flux is concentrated is covered with the nonmagnetic resin portion 15A. The concentration of the magnetic flux in this portion is alleviated, and the deterioration of the DC superposition characteristic can be suppressed or prevented. As a result, a stable inductance value can be obtained as the wound electronic component 10.

  In addition, the exterior resin portion 15 composed of the nonmagnetic resin portion 15A and the magnetic resin portion 15B completely covers the winding 14 between the pair of flange portions 12 and 12 as shown in FIG. Since the flange portion 12 is mechanically reinforced, the mechanical strength of the wound electronic component 10 itself can be enhanced.

  Thus, the material of the core 13 is not particularly limited as long as it is a magnetic material having a high magnetic permeability. As such a magnetic material, a magnetic material having a high magnetic permeability such as ferrite is preferable. The material of the magnetic powder contained in the thermosetting resin is not particularly limited as long as it is a magnetic material, but for example, a Mn—Zn-based or Ni—Zn-based ferrite material is preferable. As the thermosetting resin, for example, epoxy resin, silicone resin, phenol resin, and polyester resin are preferable. The liquid thermosetting resin contains a thermosetting resin as a main component and an additive such as a dispersant as a subcomponent.

  The particle diameter of the magnetic powder used for the magnetic resin portion 15B is not particularly limited because it varies depending on the viscosity of the thermosetting resin containing magnetic powder (hereinafter referred to as “magnetic powder resin liquid”). For example, the average particle diameter is 5 μm or more. Are preferred. The viscosity of the magnetic powder resin liquid is preferably in the range of 0.2 to 2.0 Pa · s. If the viscosity of the magnetic powder resin liquid is out of this range, the fluidity is too high or the fluidity is too low, making it difficult to obtain the desired form of the magnetic resin portion 15B. Content of magnetic powder can be adjusted according to the viscosity of the resin liquid at the time of magnetic powder, for example, it is preferable that it is 50 to 63 volume% of a magnetic powder resin liquid. If the content of magnetic powder is less than 50% by volume, the magnetic permeability as the magnetic resin portion 15B is small and insufficient to form a closed magnetic path, and if it exceeds 63% by volume, it is difficult to form the magnetic resin portion 15B.

  The material of the terminal electrode 16 is not particularly limited as long as it is a metal used as an electrode, but is formed of, for example, an alloy of silver, nickel, copper, and tin.

  When forming the exterior resin part 15 of the wound electronic component 10 of the present embodiment, the wound resin part 15 is wound around the core part 11 between the pair of flange parts 12 and 12 using, for example, a dispenser (not shown). A liquid thermosetting resin is dropped and applied to each of the four corners 14A of the winding 14 to form a nonmagnetic resin portion 15A, and the four corners 14A of the winding 14 are connected to the nonmagnetic resin portion 15A. Cover with. Next, using a dispenser, a liquid thermosetting resin containing magnetic powder is dropped and applied to each of the remaining plane portions of the winding 14 wound around the core portion 11 to form the magnetic resin portion 15B. The remaining flat portion of the winding 14 is covered with the magnetic resin portion 15B. Thereby, the nonmagnetic resin portion 15A and the magnetic resin portion 15B are integrated as the exterior resin portion 15.

  As described above, according to the present embodiment, the core 13 having the core part 11 having a rectangular cross section and the pair of flange parts 12 formed in a rectangular shape at both ends thereof is wound around the core part 11. A winding 14 and an exterior resin portion 15 that seals the winding between the pair of flange portions 12 and 12, and the exterior resin portion 15 has four corners of the core portion 11 from the axis of the core 13. A nonmagnetic resin portion 15A that does not contain magnetic powder and covers the corner portion 14A of the winding 14 located on the extension line drawn to the intersection of the portion 11A and the flange portion 12, and a winding that is covered with the nonmagnetic resin portion 15A Since the wire 14 is composed of a magnetic resin portion 15B containing magnetic powder that covers the winding 14 other than the corner portion 14A of the wire 14, the flange portion 12 and the winding portion on which the magnetic flux tends to concentrate even when a direct current is applied to the wound electronic component 10 At the intersection of the wire 14 with the corner portion 14A, the concentration of magnetic flux is relaxed by the non-magnetic powder resin portion 15A. Has been able to improve the DC superposition characteristics of the wire wound electronic part 10, it is possible to increase the rated current of the wire wound electronic part 10, it is possible to obtain a stable inductance value.

  The present invention is not limited to the above embodiments. Each element of the wire wound electronic component of the present invention can be appropriately modified as necessary. For example, in the above-described embodiment, the case where the nonmagnetic resin portion 15A is covered over the entire length of the corner portion 14A of the winding 14 has been described, but the nonmagnetic resin portion 15A is formed between the corner portion 14A and the flange portion 12 of the winding 14 You may apply | coat only to the cross | intersection part.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for wire wound electronic components used for electronic devices and communication devices.

(A), (b) is a figure which shows one Embodiment of the winding type | mold electronic component of this invention, respectively, (a) is a perspective view, (b) is sectional drawing of the direction orthogonal to the axial center of a core. (A), (b) is sectional drawing which respectively shows the winding type electronic component shown in FIG. 1, (a) is sectional drawing which follows the AA line of FIG. 1, (b) is the BB line of FIG. FIG. It is sectional drawing of the axial direction which shows an example of the conventional winding type electronic component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Winding type | mold electronic component 11 Winding core part 11A Corner | angular part 12 Collar part 13 Core 14 Winding 14A Corner | angular part 15 Exterior resin part 15A Nonmagnetic resin part 15B Magnetic resin part

Claims (2)

  A core having a rectangular core section and a pair of flanges formed in a rectangular shape at both ends thereof, a winding wound around the core part, and the winding between the pair of flange parts And the exterior resin part is pulled from at least the axis of the core to the intersection of the four corners of the core and the flange part. Covering the corners of the windings located on the extended line, covering the non-magnetic resin part not containing magnetic powder, and windings located other than the corners of the windings covered with the non-magnetic resin part, A wire-wound electronic component comprising a magnetic resin portion containing magnetic powder. 2. The wound electronic component according to claim 1, wherein the non-magnetic resin portion is covered over the entire length of the four corners of the winding.

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