JP2016139634A - Inductor component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a resin having small stress occurring in a hardened state as a mold part and expose a give portion of a magnetic core from the mold part to easily improve heat radiation characteristics of an inductor component.SOLUTION: An inductor component includes: a coil part 9 having an end part 6 and a wound part 8 sealed by a mold part 7; and a magnetic core 10 fixed to the mold part 7 on a surface facing at least the wound part 8 by a fastening force of the mold part 7. Silicon rubber is used as a resin forming the mold part 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inductor component used in various electronic devices.

  Hereinafter, conventional inductor components will be described with reference to the drawings. FIG. 5 is a cross-sectional view showing the configuration of a conventional inductor component. In a conventional inductor component, for example, a bobbinless structure is used in order to reduce the size of the inductor component, reduce the floor area, or reduce the weight. At this time, the inductor component includes the winding part 1, the magnetic core 2, and the exterior resin 3, and the winding part 1 is wound around the magnetic core 2, and the entire periphery of the winding part 1 and the outer periphery of the magnetic core 2 are substantially exterior. It was covered with resin 3.

  Measures have been taken so that the stress generated in the magnetic core 2 by the exterior resin 3 sealing the winding portion 1 and the magnetic core 2 does not cause deterioration of the magnetic characteristics in the magnetic core 2. As countermeasures, for example, the thickness of the exterior resin 3 is provided uniformly over the entire periphery of the magnetic core 2, or an exterior opening (not shown) is provided at a portion where the stress in the magnetic core 2 is particularly likely to occur due to the exterior resin 3. Was provided.

  For example, Patent Documents 1 and 2 are known as prior art document information related to the invention of this application.

JP 2003-173917 A JP-A-8-241820

  However, in the conventional inductor component, when the exterior resin 3 is formed, a plurality of holding portions 4 are accurately placed at appropriate positions in a molding die (not shown) in order to provide a uniform thickness of the exterior resin 3. It is required that they are arranged and that they are projected in an appropriate amount. Alternatively, since the opening forming portion 5 of the molding die (not shown) forms an exterior opening portion (not shown), a plurality of holding portions 4 are accurately and appropriately provided in the molding die (not shown). It is required to be placed in position. Accordingly, even when an exterior opening (not shown) is provided in the exterior resin 3, the region where the exterior opening (not shown) is provided is limited to a specific portion.

  As a result, heat transfer or heat dissipation from an arbitrary region of the magnetic core 2 to the outside is not easy, and it is difficult to improve the heat dissipation characteristics of the inductor component.

  Accordingly, an object of the present invention is to easily improve the heat dissipation characteristics of inductor components.

  And in order to achieve this object, the present invention opposes at least the winding part by a winding part having an end part, a winding part sealed by the mold part, and the fixing force of the mold part. And a magnetic core fixed to the mold part on the surface, and a silicone rubber is used as a resin forming the mold part.

  According to the present invention, a resin having a small stress generated after curing is used for the mold part for sealing the winding part and fixing the winding part and the magnetic core. For this reason, the site | part which fixes a magnetic core and a coil | winding part with a mold part, or the site | part which covers a magnetic core with a mold part can be selected arbitrarily. Accordingly, an arbitrary part of the magnetic core can be exposed from the mold part.

  Thereby, the heat dissipation characteristics of the inductor component can be easily improved.

1 is an external perspective view showing a configuration in which a winding portion of an inductor component is molded according to an embodiment of the present invention. FIG. 3 is an external perspective view showing a configuration before sealing of the inductor component in the embodiment of the present invention. FIG. 3 is an external perspective view showing a configuration in which the entire surface of the inductor component in the embodiment of the present invention is molded. 1 is an external perspective view showing a configuration in which a part of a magnetic core of an inductor component is exposed in an embodiment of the present invention. Sectional view showing the configuration of a conventional inductor component

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is an external perspective view showing a configuration in which a winding portion of an inductor component is molded according to an embodiment of the present invention. The inductor component includes a winding portion 9 having an end portion 6 and a winding portion 8 sealed by the mold portion 7, and at least a surface facing the winding portion 8 due to the fixing force of the mold portion 7. And a fixed magnetic core 10. Here, silicone rubber is used for the resin forming the mold part 7.

  With the above configuration, in the inductor component, a silicone rubber is used as a resin having a small stress generated after curing in the mold portion 7 for sealing the winding portion 8 and fixing the winding portion 9 and the magnetic core 10. Is used. For this reason, the site | part which fixes the magnetic core 10 and the coil | winding part 9 with the mold part 7, or the site | part which covers the magnetic core 10 with the mold part 7 can be selected arbitrarily. Accordingly, an arbitrary part of the magnetic core 10 can be exposed from the mold part 7.

  The silicone rubber may be liquid silicone rubber at the time of molding, and in the finished product, the silicone rubber after the liquid silicone rubber is cured may be used. Thereby, the site | part which fixes the magnetic core 10 and the coil | winding part 9 with the mold part 7, or the site | part which covers the magnetic core 10 with the mold part 7 can be selected in the state which increased the degree of freedom further. Accordingly, any part of the magnetic core 10 can be exposed from the mold part 7 in various forms.

  That is, since the exposed state of the surface of the magnetic core 10 can be arbitrarily changed as necessary, the exposed portion of the magnetic core 10 is brought into close contact with a mounting substrate (not shown) to generate heat or heat generated in the magnetic core 10. The heat transmitted from the wound portion 8 to the magnetic core 10 is transmitted to the mounting substrate and can be dissipated. Alternatively, by disposing a heat radiating fin or the like on the exposed portion of the magnetic core 10, heat generated in the magnetic core 10 can be easily released to the outside of the inductor component. Thereby, the heat dissipation characteristics of the inductor component can be easily improved.

  Hereinafter, the configuration of the inductor component will be described in detail. FIG. 2 is an external perspective view showing the configuration of the inductor component before sealing in the embodiment of the present invention. That is, here, the state before the inductor component is completed is shown.

  The magnetic core 10 is formed by combining an upper divided magnetic core 11A in the drawing and a lower divided magnetic core 11B in the drawing. The split magnetic core 11A includes a middle magnetic leg 13A provided at the center, outer magnetic legs 12A provided on both sides of the middle magnetic leg 13A so as to sandwich the outer magnetic leg 12A, and the middle magnetic leg 13A. 14A. Similarly, the split magnetic core 11B has an outer magnetic leg 12B, a middle magnetic leg 13B, and a connecting leg 14B. The outer magnetic leg 12A and the outer magnetic leg 12B, and the middle magnetic leg 13A and the middle magnetic leg 13B are: The magnetic core 10 is formed by abutting each other.

  Thereafter, the magnetic core 10 and the winding portion 9 or the winding portion 8 in a state of being incorporated therein are put into a molding die (not shown). Therefore, the mold part 7 is formed of a resin using liquid silicone rubber by injection molding. Here, a resin mainly composed of silicone rubber having high fluidity before injection molding and at the time of injection molding and having low elasticity after curing, which is a state in which injection molding is completed, is used for the mold part 7. . As a result, the molded part 7 having a silicone rubber as a main component can be arbitrarily molded by the molding die without considering the stress applied to the magnetic core 10. Further, in addition to the silicone rubber, a filler for improving heat conductivity may be added to the above resin.

  In other words, regardless of the shape of the magnetic core 10, the shape of the mold part 7 and the thickness of each part can be set or changed without restriction depending on the application. Therefore, in order to maintain the state in which the winding portion 9 is firmly fixed to the magnetic core 10, the mold portion 7 includes and seals the winding portion 8, and at least in the mold portion 7 and the magnetic core 10. The part facing the winding part 8 should just contact. Here, since liquid silicone rubber has adhesiveness at the time of hardening and after hardening, mold part 7 and magnetic core 10 are maintained in a fixed state. Further, the positional relationship and combination state of the upper divided magnetic core 11A in the drawing and the lower divided magnetic core 11B in the drawing may be determined by the adhesive force of the cured silicone rubber. That is, since silicone rubber has an adhesive effect, no new adhesive is required. For this reason, thermal distortion and stress resulting from the adhesive are suppressed, and the characteristics of the inductor component are stabilized.

  Strictly speaking, the mold part 7 and the magnetic core 10 may be fixed in contact with each other on the inner peripheral surface of the magnetic core 10. Here, the inner peripheral surface of the magnetic core 10 refers to the peripheral surfaces of the middle magnetic legs 13A and 13B, the surfaces facing the middle magnetic legs 13A and 13B in the outer magnetic legs 12A and 12B, and the outer magnets in the connecting legs 14A and 14B. It is good also as a protrusion direction surface of leg 12A, 12B and middle magnetic leg 13A, 13B. In particular, it is desirable that the mold part 7 and the magnetic core 10 are in contact with the entire inner peripheral surface of the magnetic core 10.

  From the above, when the winding part 9 and the magnetic core 10 are fixed by the mold part 7 or when a part of the winding part 9 and the magnetic core 10 are covered, It becomes hard to receive restrictions about thickness. As a result, since the exposed state of the surface of the magnetic core 10 can be arbitrarily changed as necessary, the exposed portion of the magnetic core 10 is brought into close contact with a mounting substrate (not shown) to mount the heat generated in the magnetic core 10. It can be transferred to the board to dissipate heat. Alternatively, disposing heat radiating fins (not shown) or the like on the exposed portion of the magnetic core 10 makes it easy to release the heat generated in the magnetic core 10 to the outside of the inductor component. Thereby, the heat dissipation characteristics of the inductor component can be easily improved. Further, when the mold part 7 is provided, it is not necessary to cover the inductor component with an exterior structure such as a case (not shown) in order to define the shape and thickness of the mold part 7. For this reason, since the mold part 7 and the magnetic core 10 can be directly brought into contact with the outside air or the heat radiating means, the inductor component can obtain highly efficient heat dissipation.

  Moreover, it is difficult to generate restrictions on the molding position, thickness, and the like of the mold portion 7 because the mold size, the mold structure, the arrangement of the molded structure, etc. when the mold portion 7 is formed in the molding die. For, no strict or complicated setting is required. Therefore, workability and efficiency during production of inductor parts are improved.

  In the above description, the mold part 7 and the magnetic core 10 are fixed to each other by contacting with the inner peripheral surface of the magnetic core 10. In addition to this, although not shown here, the outer magnetic legs 12A corresponding to the joints of the magnetic core 10 and the combination of the divided magnetic core 11A and the divided magnetic core 11B are not shown here in order to make the positional relationship and combination state more accurate. A band-shaped outer peripheral mold part may be formed so as to cover the periphery of the abutting surface with the outer magnetic leg 12B. Naturally, even if the outer peripheral mold portion is formed, new stress is hardly generated in the magnetic core 10. Therefore, deterioration of the magnetic characteristics of the inductor component due to the stress generated in the magnetic core 10 does not occur.

  FIG. 3 is an external perspective view showing a configuration in which the entire surface of the inductor component in the embodiment of the present invention is molded. Here, everything except the end portion 6 of the winding portion 9 is covered with the mold portion 7. Since the mold part 7 is formed of a resin mainly composed of silicone rubber, no stress due to the mold part 7 is generated inside the magnetic core 10 even if the entire outer periphery of the magnetic core 10 is covered with the resin. Accordingly, when priority is given to prevention of mechanical shock and buffering from the outside to the magnetic core 10 over heat radiation from the magnetic core 10 to the outside, everything except the end portion 6 of the winding portion 9 is covered by the mold portion 7. It is good to be told. And since the change of the elasticity accompanying a temperature is also small, silicone rubber can also reduce the mechanical distortion which arises in the magnetic core 10 with a temperature change. Further, for example, the thickness of the mold part 7 on the bottom surface corresponding to the lower side in the figure, where the magnetic core 10 is easily subjected to an impact during mounting, may be larger than the thickness of the mold part 7 in other parts. Thereby, the reliability with respect to the external force of an inductor component improves, without the mold part 7 producing stress in the magnetic core 10. FIG.

  FIG. 4 is an external perspective view showing a configuration in which a part of the magnetic core of the inductor component in the embodiment of the present invention is exposed. Here, a part of the split magnetic core 11A is exposed, and heat is easily radiated from the exposed portion 15 to the outside of the inductor component. Here, the exposed portion 15 is provided so that a part of the connecting leg 14A is exposed, but the exposed portion 15 may be provided so that a part of the outer magnetic leg 12A is exposed. Alternatively, a part or the whole of the bottom surface of the split magnetic core 11 </ b> B may be formed as the exposed portion 15. The exposed portion 15 may be provided in either one or both of the divided magnetic core 11A and the divided magnetic core 11B. Further, a heat radiating fin (not shown) or a heat radiating plate (not shown) may be attached to the exposed portion 15 to improve the heat radiating efficiency.

  The magnetic core 10 used for the description here may be a ferrite magnetic core or a dust core using a dust metal molded body. In particular, when a ferrite core that is likely to be cracked or chipped is used as the magnetic core 10, stress caused by the mold portion 7 does not occur inside the magnetic core 10. In addition, the reliability of the inductor component against vibration and shock is improved.

  In FIGS. 1 to 4, only a single winding portion 9 is described as the winding portion 9, but a plurality of winding portions 9 may be provided. In other words, the inductor component may be a choke coil or a reactor having a single winding portion 9, or the inductor component may be a transformer having a plurality of winding portions 9.

  Furthermore, especially the winding part 8 of the winding part 9 may be provided with a coating or may have copper exposed. Even if the winding part 8 has exposed copper, the insulation of the surface of the winding part 8 is maintained by the mold part 7.

  The inductor component of the present invention has an effect that heat dissipation characteristics can be improved, and is useful in various electronic devices.

6 End part 7 Mold part 8 Winding part 9 Winding part 10 Magnetic core 11A, 11B Split magnetic core 12A, 12B Outer magnetic leg 13A, 13B Middle magnetic leg 14A, 14B Connecting leg 15 Exposed part

Claims (6)

A winding part having an end part and a winding part sealed by a mold part;
A magnetic core fixed to the mold part at least on the surface facing the winding part by the fixing force of the mold part,
An inductor component in which silicone rubber is used for the resin forming the mold part. The magnetic core is formed by abutment of a first divided magnetic core and a second divided magnetic core,
The inductor component according to claim 1, wherein the fixed state between the first divided magnetic core and the second divided magnetic core is maintained by the mold portion. The entire surface of the winding part and the magnetic core is sealed by the mold part,
3. The inductor component according to claim 2, wherein a sealing thickness of the mold portion on the top and bottom surfaces of the magnetic core is formed to be thinner than a sealing thickness at a butt portion of the magnetic core. 2. The inductor component according to claim 1, wherein the winding portion is sealed by the mold portion, and the magnetic core is sealed by the mold portion while exposing an upper surface and a bottom surface thereof. 2. The inductor component according to claim 1, wherein the wound portion is sealed by the mold portion, and the magnetic core is sealed by the mold portion while exposing an upper surface or a bottom surface thereof. The inductor component according to claim 1, wherein a silicone rubber after the liquid silicone rubber is cured is used as the resin forming the mold part.

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